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2018 SkS Weekly Climate Change & Global Warming News Roundup #33

August 18, 2018 - 10:52am
A chronological listing of news articles posted on the Skeptical Science Facebook Page during the past week. Editor's Pick Research Highlight: Climate Model Predicts Faster Warming for the North Atlantic Ocean

As aerosol emissions decline, heat uptake in the North Atlantic could increase dramatically


The Gulf Stream, part of the larger Atlantic Meridional Overturning Circulation system. Photo: NASA

Researchers at Scripps Institution of Oceanography at UC San Diego have predicted faster rates of warming than previously predicted for the North Atlantic Ocean in a recent paper published in the Journal of Climate. This warming could disrupt major oceanic cycles and have worldwide impacts on climate systems.

The researchers modeled scenarios based on possible future greenhouse gas and aerosol emission rates. One likely scenario focuses on future decline in aerosols and continued increase of greenhouse gases in the atmosphere. Aerosols are minute particles suspended in the atmosphere. Some scatter sunlight, thereby actually acting as cooling agents.

The aerosol cooling effect is about 50 percent of the warming effect of anthropogenic carbon dioxide at present. Aerosols released from human activities are pollutants, however, and their health concerns have triggered worldwide efforts to curb emissions. An aerosol decline could spark an interesting catch-22: Because of their cooling effect, this decline would accelerate ocean warming that is already being caused by increasing carbon dioxide emissions–most notably initiating major warming in the North Atlantic.

Historically, the Southern Ocean has been the predominant heat absorber, accounting for roughly 72 percent of uptake of anthropogenic greenhouse heat in the oceans, due in part to the area’s low levels of cooling aerosols. The opposite is true of the North Atlantic: under strong aerosol cooling, the North Atlantic has not taken up much heat, meaning that most of the warming in the Northern Hemisphere is happening in the atmosphere and not in the ocean.

“The ocean heat uptake moderates atmospheric warming by storing much of the greenhouse heat below the surface,” said Shang-Ping Xie, a climate researcher at Scripps and co-author of the study. “We now show that the ocean uptake is not only uneven, but its distribution also evolves with time."

Research Highlight: Climate Model Predicts Faster Warming for the North Atlantic Ocean by Chase Martin, Scripps Institution of Oceanography, Aug 14, 2018

Links posted on Facebook

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Fri Aug 17, 2018

Sat Aug 18, 2018

New research, August 5-12, 2018

August 17, 2018 - 3:59am

A selection of new climate related research articles is shown below.

Climate change impacts

Climate change and future wildfire in the western USA: an ecological approach to non‐stationarity (open access)

Influence of uncertainties in burned area estimates on modeled wildland fire PM2.5 and ozone pollution in the contiguous U.S.


Coastal homeowners in a changing climate

Indigenous impacts on North American Great Plains fire regimes of the past millennium

Measuring temperature-related mortality using endogenously determined thresholds

Assessing thermal comfort in tourist attractions through objective and subjective procedures based on ISO 7730 standard: A field study

Global Freshwater availability below normal conditions and population impact under 1.5°C and 2°C stabilization scenarios

Climate change impacts on the energy system: a review of trends and gaps

Effects of climate change and agronomic practice on changes in wheat phenology

Climatic, topographic, and anthropogenic factors determine connectivity between current and future climate analogs in North America (open access)

An institutional analysis to address climate change adaptation in Tenerife (Canary Islands) (open access)

Economic sector loss from influential tropical cyclones and relationship to associated rainfall and wind speed in China

Re-imagining the potential of effective drought responses in South Africa

Understanding the current state of collaboration in the production and dissemination of adaptation knowledge in Namibia

Dynamic adaptive pathways in downscaled climate change scenarios (open access)

On the evaluation of adaptation practices: a transdisciplinary exploration of drought measures in Chile


Dramatic loss of seagrass habitat under projected climate change in the Mediterranean Sea

Differential sensitivity of larvae to ocean acidification in two interacting mollusc species

Ocean warming and acidification affect the nutritional quality of the commercially-harvested turbinid snail Turbo militaris

Microbes follow Humboldt: temperature drives plant and soil microbial diversity patterns from the Amazon to the Andes

The strength of flowering–temperature relationship and preseason length affect temperature sensitivity of first flowering date across space

A combined tree‐ring and vegetation model assessment of European forest growth sensitivity to inter‐annual climate variability

Climatic drivers of tree growth at tree line in Southwest Yukon change over time and vary between landscapes

Landscape variability of vegetation change across the forest to tundra transition of central Canada

Sensitivity of Leaf Area to Interannual Climate Variation as a Diagnostic of Ecosystem Function in CMIP5 Carbon Cycle Models

Experimental shifts in phenology affect fitness, foraging, and parasitism in a native solitary bee

Drought negates growth stimulation due to root herbivory in pasture grasses

Climate change mitigation

Climate change communication

Public perception of climatological tornado risk in Tennessee, USA

Assessing the relative importance of psychological and demographic factors for predicting climate and environmental attitudes

Climate Policy

Incorporating uncertainty in national-level climate change-mitigation policy: possible elements for a research agenda

Energy production

Effects of wholesale electricity markets on wind generation in the midwestern United States 

Do subsidies improve the financial performance of renewable energy companies? Evidence from China

Capturing complexity: Forests, decision-making and climate change mitigation action (open access)

Emission savings

The environmental impact of packaging in food supply chains—does life cycle assessment of food provide the full picture? (open access)

Dynamics of net ecosystem methane exchanges on temporal scale in tropical lowland rice

Climate change

Temperature, precipitation, wind

How will the onset and retreat of rainy season over East Asia change in future? (open access)

Evaluating the long-term changes in temperature over the low-latitude plateau in China using a statistical downscaling method

On the emergence of anthropogenic signal in extreme precipitation change over China

Intensification of the daily wet day rainfall distribution across Australia

Seasonal Prediction from Arctic Sea Surface Temperatures: Opportunities and Pitfalls

Observed and projected climate change in the European region during the twentieth and twenty-first centuries according to Feddema

Long-range dependence, nonlinear trend, and breaks in historical sea surface and land air surface global and regional temperature anomalies

Extreme events

The continuum of drought in Southwestern North America (open access)

Drought and Fire in the Western USA: Is Climate Attribution Enough?

Prolonged seasonal drought events over northern China and their possible causes

Impact of Dynamical Downscaling Two CMIP5 Models on the Historical and Future Changes in Winter Extratropical Cyclones Along the East Coast of North America

Contribution of Interdecadal Pacific Oscillation to the recent abrupt decrease in tropical cyclone genesis frequency over the western North Pacific since 1998

Forcings and feedbacks

Volcanic impact on the climate – the stratospheric aerosol load in the period 2006–2015 (open access)

Reduced wet season length detected by satellite retrievals of cloudiness over Brazilian Amazonia: a new methodology

Larger Sensitivity of Precipitation Extremes to Aerosol than Greenhouse Gas Forcing in CMIP5 Models

Estimated long-term variability of direct and diffuse solar radiation in North China during 1959–2016


Evidence for predictive skill of high‐latitude climate due to midsummer sea‐ice extent anomalies

Recent Acceleration of a Rock Glacier Complex, Ádjet, Norway, Documented by 62 Years of Remote Sensing Observations

Response of the Intertropical Convergence Zone to Antarctic Ice Sheet melt1

Changes in surface icing duration over north China during 1961–2015


Impacts of 1.5 and 2.0 °C Warming on Pan‐Arctic River Discharge Into the Hudson Bay Complex Through 2070

Is the Last Glacial Maximum a reverse analog for future hydroclimate changes in the Americas?

Atmospheric and oceanic circulation

Resolving Future Arctic/Midlatitude Weather Connections (open access)

Weakening of nonlinear ENSO under global warming

Response of the Intertropical Convergence Zone to Climate Change: Location, Width, and Strength (open access)

Carbon and nitrogen cycles

Potential roles of CO2 fertilization, nitrogen deposition, climate change, and land use and land cover change on the global terrestrial carbon uptake in the twenty-first century

A global synthesis inversion analysis of recent variability in CO2 fluxes using GOSAT and in situ observations (open access)

Seasonal trends in surface pCO2 and air‐sea CO2 fluxes in Apalachicola Bay, Florida from VIIRS ocean color

Estimates of methane emissions from the Southern Ocean from quasi-continuous underway measurements of the partial pressure of methane in surface seawater during the 2012/13 austral summer (open access)

The Ephemeral Signature of Permafrost Carbon in an Arctic Fluvial Network

Global Warming Potential of CH4 uptake and N2O emissions in saline–alkaline soils

Other papers


Testing the consistency between changes in simulated climate and Alpine glacier length over the past millennium (open access)

Temperature and cyclone frequency in Kimmeridgian Greenhouse period (late Jurassic)

The reconstruction of past forest dynamics over the last 13,500 years in SW Sweden

Climate change and wildfires – how do we know if there is a link?

August 16, 2018 - 1:48am

Kevin Trenberth, Distinguished Senior Scientist, National Center for Atmospheric Research

This article was originally published on The Conversation. Read the original article.

A firefighter runs after trying to save a home in Lakeport, California, suffering its biggest fires ever. AP Photo/Noah Berger Kevin Trenberth, National Center for Atmospheric Research

Once again, the summer of 2018 in the Northern Hemisphere has brought us an epidemic of major wildfires.

These burn forests, houses and other structures, displace thousands of people and animals, and cause major disruptions in people’s lives. The huge burden of simply firefighting has become a year-round task costing billions of dollars, let alone the cost of the destruction. The smoke veil can extend hundreds or even thousands of miles, affecting air quality and visibility. To many people, it has become very clear that human-induced climate change plays a major role by greatly increasing the risk of wildfire.

Yet it seems the role of climate change is seldom mentioned in many or even most news stories about the multitude of fires and heat waves. In part this is because the issue of attribution is not usually clear. The argument is that there have always been wildfires, and how can we attribute any particular wildfire to climate change?

As a climate scientist, I can say this is the wrong framing of the problem. Global warming does not cause wildfires. The proximate cause is often human carelessness (cigarette butts, camp fires not extinguished properly, etc.), or natural, from “dry lightning” whereby a thunderstorm produces lightning but little rain. Rather, global warming exacerbates the conditions and raises the risk of wildfire.

Even so, there is huge complexity and variability from one fire to the next, and hence the attribution can become complex. Instead, the way to think about this is from the standpoint of basic science – in this case, physics.

This year is proving to be another active wildfire season. Climate Central, CC BY-NC

Global warming is happening

To understand the interplay between global warming and wildfires, consider what’s happening to our planet.

The composition of the atmosphere is changing from human activities: There has been over a 40 percent increase in carbon dioxide, mainly from fossil fuel burning since the 1800s, and over half of the increase is since 1985. Other heat-trapping gases (methane, nitrous oxide, etc.) are also increasing in concentration in the atmosphere from human activities. The rates are accelerating, not declining (as hoped for with the Paris agreement).

This leads to an energy imbalance for the planet.

The flows of energy through the climate system are schematically illustrated with numbers on the top-of-atmosphere values and net energy imbalance at the surface. Trenberth et al 2009

Heat-trapping gases in the atmosphere act as a blanket and inhibit the infrared radiation – that is, heat from the Earth – from escaping back into space to offset the continual radiation coming from the sun. As these gases build up, more of this energy, mostly in the form of heat, remains in our atmosphere. The energy raises the temperature of the land, oceans and atmosphere, melts ice, thaws permafrost, and fuels the water cycle through evaporation.

Moreover, we can estimate Earth’s energy imbalance quite well: It amounts to about 1 watt per square meter, or about 500 terawatts globally.

While this factor is small compared with the natural flow of energy through the system, which is 240 watts per square meter, it is large compared with all other direct effects of human activities. For instance, the electrical power generation in the U.S. last year averaged 0.46 terawatts.

The extra heat is always the same sign and it is spread across the globe. Accordingly, where this energy accumulates matters.

Tracking the Earth’s energy imbalance

The heat mostly accumulates ultimately in the ocean – over 90 percent. This added heat means the ocean expands and sea level rises.

Heat also accumulates in melting ice, causing melting Arctic sea ice and glacier losses in Greenland and Antarctica. This adds water to the ocean, and so the sea level rises from this as well, rising at a rate of over 3 milimeters year, or over a foot per century.

Global ocean heat content for the top 2000 meters of the ocean, with uncertainty estimates by the pink region. ScienceAdvances, CC BY-NC

On land, the effects of the energy imbalance are complicated by water. If water is present, the heat mainly goes into evaporation and drying, and that feeds moisture into storms, which produce heavier rain. But the effects do not accumulate provided that it rains on and off.

However, in a dry spell or drought, the heat accumulates. Firstly, it dries things out, and then secondly it raises temperatures. Of course, “it never rains in southern California” according to the 1970s pop song, at least in the summer half year.

So water acts as the air conditioner of the planet. In the absence of water, the excess heat effects accumulate on land both by drying everything out and wilting plants, and by raising temperatures. In turn, this leads to heat waves and increased risk of wildfire. These factors apply in regions in the western U.S. and in regions with Mediterranean climates. Indeed many of the recent wildfires have occurred not only in the West in the United States, but also in Portugal, Spain, Greece, and other parts of the Mediterranean.

A satellite image of the Carr Fire in California. Drought conditions, in addition to a lot of dead trees and vegetation, are contributing to another year of severe wildfires. NASA

The conditions can also develop in other parts of the world when strong high pressure weather domes (anticyclones) stagnate, as can happen in part by chance, or with increased odds in some weather patterns such as those established by either La Niña or El Niño events (in different places). It is expected that these dry spots move around from year to year, but that their abundance increases over time, as is clearly happening.

How big is the energy imbalance effect over land? Well, 1 Watt per square meter over a month, if accumulated, is equivalent to 720 Watts per square meter over one hour. 720 Watts is equivalent to full power in a small microwave oven. One square meter is about 10 square feet. Hence, after one month this is equivalent to: one microwave oven at full power every square foot for six minutes. No wonder things catch on fire!

Attribution science

Coming back to the original question of wildfires and global warming, this explains the argument: there is extra heat available from climate change and the above indicates just how large it is.

In reality there is moisture in the soil, and plants have root systems that tap soil moisture and delay the effects before they begin to wilt, so that it typically takes over two months for the effects to be large enough to fully set the stage for wildfires. On a day to day basis, the effect is small enough to be lost in the normal weather variability. But after a dry spell of over a month, the risk is noticeably higher. And of course the global mean surface temperature is also going up.

“We can’t attribute a single event to climate change” has been a mantra of climate scientists for a long time. It has recently changed, however.

As in the wildfires example, there has been a realization that climate scientists may be able to make useful statements by assuming that the weather events themselves are relatively unaffected by climate change. This is a good assumption.

Also, climate scientists cannot say that extreme events are due to global warming, because that is a poorly posed question. However, we can say it is highly likely that they would not have had such extreme impacts without global warming. Indeed, all weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be.

In particular, by focusing on Earth’s Energy Imbalance, new research is expected to advance the understanding of what is happening, and why, and what it implies for the future.

Humans are pushing the Earth closer to a climate cliff

August 15, 2018 - 1:29am

A new paper, just published in the Proceedings of the National Academy of Sciences has received a lot of media attention. The attention is justified because the paper paints a very grim picture of the climate and what humans may be doing to it. In particular, the authors of this study tried to determine the trajectory that the Earth is on so we can predict what the future climate will be.

There are many really important insights from this paper. The authors wanted to know how feedbacks in the Earth’s climate will play a role in shaping the climate in the future. By feedbacks, we mean a change in one part of the climate that then causes another change, which in turn may cause another change, and so on, potentially setting up chain reactions.

Feedbacks are really important because they are changes that the natural system makes without being caused directly by humans.

For example, melting ice is one feedback, particularly in the Arctic. Humans have emitted greenhouse gases that have caused the Earth to warm. As the Earth warms, ice melts; as ice melts, it means there is less white reflective cover on the Earth surface. In fact, a lot of this ice melting is happening in the Arctic. Instead of having a white surface that reflects sunlight, we have open ocean water that absorbs sunlight. Consequently, melting of ice leads to more absorbed sunlight which then leads to more melting of ice – a reinforcing cycle, as illustrated below.

 Melting ice positive feedback cycle diagram. Illustration: John Abraham

Activating one of these cycles is bad news for a few reasons. First, it takes away a lot of control of the Earth’s climate from us. Right now, humans control the climate through our emissions of greenhouse gases. But once these cycles get activated, the Earth’s climate will partially control itself. That means it will be harder to stop the warming process.

The second reason this is bad news is that many of the cycles are linked together. For instance, the feedback cycle shown above might be strong enough to activate another cycle (for example, melting of permafrost and release of trapped methane). So, you can’t look at these feedbacks in isolation. You have to consider how they behave as a group.

The image below is taken from the paper. It shows 15 different feedback cycles. They are colored by the temperature at which they will be triggered. For instance, the authors believe the Greenland ice sheet will be activated when temperatures rise 1–3°C. The East Antarctic ice sheet however, shown at the bottom, will be activated once temperatures rise by 5°C or more. 

The various feedbacks also have connecting arrows to show how they are interrelated. For instance, there is an arrow connecting the Greenland Ice Sheet and Arctic summer sea ice. This means the two feedbacks affect each other.

 Map of potential tipping cascades. Illustration: Steffen et al. 2018, Proceedings of the National Academy of Sciences

This image is really important for understanding why scientists are so worried. Consider the summer Arctic sea ice. We know that it has decreased by about 70% in volume and perhaps 50% or so in area. Loss of Arctic sea ice will affect the Greenland Ice Sheet. That in turn will affect the West Antarctic Ice Sheet.

It doesn’t stop there;

Click here to read the rest

2018 SkS Weekly Climate Change & Global Warming News Roundup #32

August 11, 2018 - 1:36pm
A chronological listing of news articles posted on the Skeptical Science Facebook Page during the past week. Editor's Pick Scientists mock Trump’s tweet on wildfires as ‘comedically ill-informed’ and ‘unmitigated crap’ 

Trump's climate denial is "a crime against the planet" warns climatologist.


Embers Smolder from Wildfires Near Clearlake Oaks, California, On August 5, 2018. Credit: Noah Berger/AFP/Getty Images

Two years ago, an actual headline from CBS in Sacramento was, “Donald Trump Tells California ‘There Is No Drought’ As Drought Continues.

And now, on Sunday evening, Trump’s denial of reality in California continued, as he attempted to blame the ever-worsening wildfires in the state on everything but climate change.

“California wildfires are being magnified & made so much worse by the bad environmental laws which aren’t allowing massive amount of readily available water to be properly utilized,” the President tweeted. “It is being diverted into the Pacific Ocean. Must also tree clear to stop fire spreading!”

The tweet came just hours after the Trump administration declared the California wildfires a major disaster

Scientists mock Trump’s tweet on wildfires as ‘comedically ill-informed’ and ‘unmitigated crap’ by Joe Romm, Think Progress, Aug 6, 2018

Links posted on Facebook

Sun Aug 5, 2018

Mon Aug 6, 2018

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Wed Aug 8, 2018

Thu Aug 9, 2018

Fri Aug 10, 2018

Sat Aug 11, 2018

Welcome to the Pliocene

August 10, 2018 - 10:14pm
The whole story in a table....

The graphic below (click on it for a large version) is adapted from a table in the supporting information from a newly published paper in Proceedings of the National Academy of Sciences (PNAS). Trajectories of the Earth System in the Anthropocene, as the paper is entitled, looks at several climate states - the present day, the mid-Holocene, the relatively warm Eemian interglacial and, heading back a bit further into geological time, the mid-Pliocene and mid-Miocene. Data are from palaeoclimate studies. The right-hand column assesses our chances of stabilising our climate at these states in the coming decades. In some cases, it is already too late - we have gone beyond the physical parameters that support such climates:

Data details: atmospheric CO2, temperature anomaly relative to the pre-industrial era and sea-levels relative to now measured and from palaeoclimate records. The graphic, created by "JG", is adapted from Table S1 from the paper's supporting information section, available here. Data sources are fully referenced.

Why is this paper important?

Trajectories of the Earth System in the Anthropocene, written by Will Steffen together with a large interdisciplinary team of colleagues, was published on 6th August in PNAS and has made quite an impact. Certain sections of the media used terms like "runaway global warming" in their headlines, which could be taken by some to imply that the paper says we are going to take Earth to a Venus-like state (it doesn't and we aren't). In fact, the term "runaway" does not appear, either in the main paper or the supporting information, as a quick word-search will demonstrate. However, the possibility that we may nevertheless end up on an unstoppable path to a Hothouse climate-state is something that cannot be ignored. The authors describe examples of how such trajectories could occur, in the main body of the paper.

Hothouse in fact describes Earth's climate state throughout much of geological time, especially in the Phanerozoic (541 million years ago-present day). Icehouse climates, during which glacials and interglacials alternate, are relatively uncommon along the time-line and were often short-lived (in geological terms, that means a few million years). The big problem we have is that we happened to develop as a species during an icehouse climate, and especially during a relatively stable interglacial - the Holocene - during which we have created a widespread high-tech and interdependent infrastructure (i.e. civilisation as we know it), much of which is rooted to the ground. A transition, over the coming centuries, towards Hothouse essentially means an ongoing battle with us on the one side and changing weather-patterns and rising seas on the other, until there is no more Polar or mountain ice left to melt. Chaos, in other words.

Through our activities, especially our intensive burning of the various fossil fuels, CO2 levels in Earth's atmosphere have changed from the 180-300ppm range of the glacial-interglacial cycles, to more than 400ppm, a concentration last seen in the Pliocene. The Pliocene was the period of geological time immediately prior to the onset of the glacial-interglacial cycles of the Pleistocene. Beginning 5.33 million years ago, after the Miocene, and ending 2.58 million years ago, the Pliocene featured a notable period of warmth around the middle of the period, during which boreal forests flourished in the Arctic (see this post from 2013 to learn how that was discovered).

Mid-Pliocene Earth and its climate are of particular interest, because global continental configurations were remarkably similar to those of today. We therefore know that a 400ppm CO2 world, with a near-identical geographical layout, is eventually a much warmer one than the Earth which we are familiar today: it takes time for the planet to catch up - head towards equilibrium with - such atmospheric changes. As the table shows, though, we have taken the atmosphere well beyond anything closely resembling the interglacial-glacial cycles, so that it is towards the mid-Pliocene climate we are, decade by decade, heading. It is the past, not climate models, that is speaking out here. Geological evidence should never be ignored, because it tells us what actually happened.

If we drastically cut emissions right now, Earth will gradually come towards equilibrium with that 400ppm atmosphere (or with whatever CO2 level we end up with). There will of course be consequences in the long term as the table shows, with respect to changing weather-patterns and sea-level rise. However, fail to accomplish such cuts and we risk setting in motion various chains of events that will lead us towards that Hothouse state: some of these chains, referred to in the paper as "tipping cascades", may not be stoppable. Although it's been a hot few months in the Northern Hemisphere, the mid-Pliocene was a bit similar: this is something we may have to get used to. But, "let's not make things any worse", sounds like an extremely good idea to me, right now, bearing in mind that our species has never had to deal with the Hothouse climate state.

New research, July 30 - August 4, 2018

August 10, 2018 - 11:26am

A selection of new climate related research articles is shown below.

Climate change

Temperature, precipitation, wind

Optimal Ranking Regime Analysis of U.S. Summer Temperature and Degree-Days: 1895-2015

Detectable Impacts of the Past Half‐Degree Global Warming on Summertime Hot Extremes in China

Time series analysis of quarterly rainfall and temperature (1900–2012) in sub-Saharan African countries

Trends of the observed temperature and its variations in the Tamil Nadu State of India

Roles of SST versus internal atmospheric variability in winter extreme precipitation variability along the U.S. West Coast

Extreme events

Factors influencing (mal)adaptive responses to natural disasters: The case of Hurricane Matthew

Changes in characteristics of rapidly intensifying western North Pacific tropical cyclones related to climate regime shifts

The effect of providing probabilistic information about a tornado threat on people’s protective actions

Future Projections of the Large Scale Meteorology Associated with California Heat Waves in CMIP5 Models

Extreme precipitation in the Netherlands: An event attribution case study

Impacts of climate and land use changes on flood risk management for the Schijn River, Belgium

Forcings and feedbacks

Accounting for changing temperature patterns increases historical estimates of climate sensitivity

Estimated spatiotemporal variability of total, direct and diffuse solar radiation across China during 1958–2016

Solar radiation measurements in the United States between 1916 and 1949 document widespread brightening in the mid‐20th century


Atmospheric river impacts on Greenland Ice Sheet surface mass balance

Current and future glacier and lake assessment in the deglaciating Vilcanota-Urubamba basin, Peruvian Andes

Recent evolution of glaciers in Western Asia in response to global warming: the case study of Mount Ararat, Turkey

Estimation of surface flow speed and ice surface temperature from optical satellite imagery at Viedma glacier, Argentina

Large discrepancy between measured and remotely sensed snow water equivalent in the northern Europe and western Siberia during boreal winter


Conversion features of evapotranspiration responding to climate warming in transitional climate regions in northern China

Changing groundwater discharge dynamics in permafrost regions (open access)

Atmospheric and oceanic circulation

Impacts of Atmospheric Reanalysis Uncertainty on Atlantic Overturning Estimates at 25°N

Distinct mechanisms of ocean heat transport into the Arctic under internal variability and climate change

Impact of arctic oscillation on Indian winter monsoon

Polar Climate Change as Manifest in Atmospheric Circulation (open access)

Carbon cycle

Transport and storage of anthropogenic C in the North Atlantic Subpolar Ocean (open access)

A billion tons of unaccounted for carbon in the Southeastern United States

Forests dominate the interannual variability of the North American carbon sink

Study on carbon dioxide atmospheric distribution over the Southwest Indian Ocean islands using satellite data: Part 1 – Climatology and seasonal results

Climate change impacts


Cooling Effect of Urban Trees on the Built Environment of Contiguous United States (open access)

An examination of midwestern US cities’ preparedness for climate change and extreme hazards

Intergovernmental relations for public health adaptation to climate change in the federalist states of Canada and Germany


Rapid warming is associated with population decline among terrestrial birds and mammals globally

Self‐Amplifying Feedbacks Accelerate Greening and Warming of the Arctic

Potential medium-term impacts of climate change on tuna and billfish in the Gulf of Mexico: A qualitative framework for management and conservation

Climate limits on European forest structure across space and time

Generality in multispecies responses to ocean acidification revealed through multiple hypothesis testing

Reproductive performance and diving behaviour share a common sea‐ice concentration optimum in Adélie penguins (Pygoscelis adeliae)

A reality check for climate change experiments: do they reflect the real world? (open access)

Influence of winter precipitation on spring phenology in boreal forests

Range expansion and redefinition of a crop-raiding rodent associated with global warming and temperature increase

Climate change mitigation

Climate change communication

Effectiveness of gaming for communicating and teaching climate change

Emission savings

Personal mobility and climate change

Electric vehicle adoption in Sweden and the impact of local policy instruments

What drives energy efficiency? New evidence from financial crises

Energy production

Japan’s mega solar boom: quantifying social equity expectations and realities at the local scale

Climate Policy

Carbon tax or emissions trading? An analysis of economic and political feasibility of policy mechanisms for greenhouse gas emissions reduction in the Mexican power sector

Other papers


Abrupt climate change at ~2800 yr BP evidenced by a stalagmite record from peninsular India

The collapse of the North Song dynasty and the AD 1048–1128 Yellow River floods: Geoarchaeological evidence from northern Henan Province, China

Climate change science comeback strategies

August 8, 2018 - 1:46am

This is a re-post from Yale Climate Connections by Karin Kirk

Credit: Image by Karin Kirk.

Staircase wit. L’esprit de l’escalier. It’s the way the perfect response in an uncomfortable conversation comes cruelly late, occurring only after the crux moment has long since passed, and you’re descending the stairs on your way home.

Why didn’t I think of that? you ask, kicking yourself for temporarily forgetting how carbon isotopes show that fossil fuels are indeed the source of the CO2 buildup in the atmosphere.

As the American culture war flares up like a SoCal heat wave, many feel understandably helpless watching misinformation accelerate throughout society. But even as you hit “enter” on a witty post correcting the spelling and grammar of someone who suggests scientists are incompetent, at some level you probably know this doesn’t improve the situation. Lobbing talking points back and forth typically only entrenches deeply held positions, a process known as belief polarization.

Want to see some expert comeback strategies for discussing #climatechange with a doubter?CLICK TO TWEET

So how then, to respond? Do you nod, smile, and walk away with clenched teeth? Do you whip out your smartphone and wave around graphs of ice core data?

Here are four strategies, each from a distinctly different point of view, each penned by an expert, each useful in either a face-to-face conversation on an online chat. The first lesson is this: have a conscious strategy, rather than a knee-jerk response. Think about where you want to go and what your goals are. And if your aim is to simply make the other person feel bad or look bad, then maybe reconsider if that’s helpful to either of you.

Let’s start with one of the most common climate contrarian remarks of all. One we’ve all heard many times: but the climate has changed before!

This is a modified version from a commenter on a government science agency Facebook page.

Strategy #1 – Correct the science

At its core, climate change is a scientific topic, although the controversy around it is largely pinned to ideology, rather than to scientific acumen. Nonetheless, a healthy dose of science is rarely a bad idea, as long as it’s delivered in a constructive manner. Remember, climate contrarians who have changed their minds have credited science more than any other factor.

Richard Alley, a widely respected climate scientist and communicator, host and author of the PBS documentary and companion book, Earth – The Operators’ Manual, and presenter of countless standing-room-only scientific talks, offers his scientific debrief of this common contrarian talking point.

Alley continues with his explanation, noting, “In certain settings, experts have some expectation that they will be allowed to make a long enough statement to summarize the knowledge on which they are expert.”

The savvy communicator, Alley knows that even the best science can fall flat without a personal connection. “Responses must be tailored to the person or persons in the discussion, their demeanor, and much more.” And even fabulous lecturers know that a conversation is more effective than a lecture. Alley looks for a fruitful avenue, “Is there a hint of a question … that could be used to open the discussion?”

Strategy #2 – Expose the myth, misinformation, or fallacy

Few may be surprised that most attempts to undermine climate science hinge on some type of misinformation. Cherry-picked data, fake experts, and conspiracy theories are well-worn hallmarks of contrarian rhetoric.

John Cook, founder of Skeptical Science and now a research assistant professor at the Center for Climate Change Communication at George Mason University, has extensive experience unraveling climate denial. Cook’s work has found that a sort of “inoculation” can help with climate misinformation. In other words, if people are exposed to the techniques commonly used in misinformation, they become more resistant to being misled when in the future they encounter bogus information.

So Cook’s response to the example comment is simple. He points directly to the logical fallacy at the heart of the myth, and uses an easy example to illustrate that the statement can’t be correct.

Credit: John Cook.

Cognitive science suggests that lengthy, complex information is not as memorable as short, sweet takeaways. Cook uses cartoons and analogies to help message resonate.

Cook explains, “The beauty of this type of response is that by addressing faulty logic, you can demonstrate that an argument is false without having to get bogged down in complicated scientific explanations.” He adds, “Although as a science communicator, I’m always keen to explain the science whenever I get the chance.”

Although it’s tempting to be smug when you feel facts are on your side, that’s unlikely to buy you traction. “Discuss the topic with respect, try to understand their thinking and how they came to their position,” advises Cook. And even more importantly, “Recognize that most people who use this argument are also victims of misinformation.”

Strategy #3 – Engage in dialogue

One of the hardest tasks when faced with someone whose opinions clash with yours is to take a deep breath and do the unthinkable: listen.

Credit: Image by Karin Kirk.

Karin Tamerius, M.D., founder and managing director at Smart Politics, is trained in both psychiatry and political psychology. (Could there be a better preparation to understand today’s politics?)

Tamerius innovated an approach termed Radical Civility, which starts off by asking questions and actually listening to the answers. Radical, indeed.

Note how she starts off by agreeing with the commenter, and then asks a probing question.

“This seems to be a person who cares about and believes in science,” observes Tamerius. “For that reason, they are likely to be responsive to an inquiry about how climate science works.”

The Radical Civility Cycle is not a one-and-done approach. It takes several rounds of questions to establish rapport and nudge the conversation toward a productive outcome. Tamerius illuminates her long-game strategy, “I would hope to learn everything this person knows about the history of non-man-made climate change. Then, once they feel fully heard, I would gently explore the ways in which climate change is different in the human era and how we know.”

In an era where arguing dominates much of our public discourse, this technique offers a refreshing alternative. “I’m trying to move the other person from an argumentative to a learning mindset,” Tamerius notes. “I want them to be motivated by curiosity rather than a desire to show they are ‘right.'”

Strategy #4 – Be persuasive

Scott Gruhn doesn’t have formal training in climate science or communications, but he demonstrates admirable skill in both arenas. Gruhn is a tireless, effective defender and explainer of climate science on Facebook. His persuasive posts routinely get people to soften their stance and consider evidence, and he’s even been able to usher a half dozen people to do a complete turnabout in their views.

Like Tamerius, Gruhn settles in for a protected exchange, and kicks things off by praising and respecting the point of view of the commenter.

Gruhn continues, often in a series of shorter posts rather than one encyclopedic and unnavigable post.

Base image used with permission.

Gruhn often peppers his responses with graphics, and steps readers through the science in a friendly manner. Here, he annotates a graph for easy comprehension.

Taking a cue from John Cook’s strategy, Gruhn makes a point to shine light on tactics used to spread misinformation. He offers these insights as advice to commenters, rather than beating them over the head with it.

Gruhn’s closing advice is something we can all take to heart, and ring ever more true as we unfriend, ignore, and turn our backs on people with different ideologies.

“Know the science. Know your values. Be caring. Don’t expect dramatic, visible changes of heart. Write for the undecided readers. Turn off the computer before your words get too sharp.”

The author is grateful to John Cook of George Mason University for his advice and recommendations on this project.

Pollution is slowing the melting of Arctic sea ice, for now

August 7, 2018 - 1:40am

The Arctic is one of the “canaries in the coal mine” for climate change. Long ago, scientists predicted it would warm quicker than other parts of the planet, and they were right. Currently, the Arctic is among the fastest-warming places on the planet. Part of the reason is that as the Arctic warms, ice melts and ocean water is uncovered. The ocean is darker than ice so it in turn absorbs more sunlight and increases its warming. This is a feedback loop.

Another reason is that the Arctic doesn’t get that much sunlight so increased energy from the atmosphere has a bigger influence there than it would have elsewhere.

Scientists have looked to the Arctic for clues and hints of human climate change over the past decades. The fact that the Arctic is warming has led to a 70% reduction in the volume of summer sea ice – an enormous loss of ice.

 Decline in September Arctic ice extent (not volume). Illustration: Nasa

A recent paper just published in the Journal of Climate by the American Meteorological Society takes an in-depth look at how fast the Arctic ice is melting and why. According to the paper, the authors completed a detection and attribution study of Arctic sea ice decline from 1953 to 2012. That is 60 years of data that tell the picture of climate change. The “detection” part of this study was about detecting what long-term trends are apparent over these six decades. The “attribution” part of the study is figuring out what is the cause of the trends.

Why six decades? Well the authors wanted to go back as far as they could while still accessing high-quality records of the ice extent. They used three different sets of data that record the extent of ice in the region.

In terms of attribution, the authors looked for “fingerprints” of human activity. Humans emit greenhouse gases that trap heat. We know that and we have known that for a long time. Greenhouse gases make the Arctic warmer. But, other things are happening too. There are natural changes to the Arctic. There are also other human pollutants that affect the ice. For instance, humans emit small particles called “aerosols” that can get into the atmosphere and block sunlight. So, these human aerosol emissions can actually cause cooling. 

The authors concluded that the combined cooling effect from human aerosols was detected in all three datasets of ice. That means, it didn’t matter whose measurements you used – the effect of aerosol cooling was present. 

So how much of an effect do aerosols have? It turns out 23% of the warming caused by greenhouse gases was offset by the cooling from aerosols. Unfortunately, this isn’t good news. It means that if/when humans reduce our aerosol pollution, the warming in the Arctic and the ice loss there will be worse.

This puts us into a Faustian bargain. We want to reduce airborne pollution, like sulfur aerosols. But, if we do that, it makes the effects of greenhouse gas pollution worse. 

Click here to read the rest

2018 SkS Weekly Climate Change & Global Warming Digest #31

August 5, 2018 - 12:55pm

Stories of the Week... Toon of the Week... Quote of the Week... Graphic of the Week... SkS in the News... Photo of the Week... SkS Spotlights... Coming Soon on SkS... Climate Feedback Reviews... SkS Week in Review... Poster of the Week...

Stories of the Week... Scorching Summer in Europe Signals Long-Term Climate Changes


People trying to cool down in the Trocadero Fountain in front of the Eiffel Tower in Paris. Credit: Ludovic Marin/Agence France-Presse — Getty Images

In Northern Europe, this summer feels like a modern-day version of the biblical plagues. Cows are dying of thirst in Switzerland, fires are gobbling up timber in Sweden, the majestic Dachstein glacier is melting in Austria.

In London, stores are running out of fans and air-conditioners. In Greenland, an iceberg may break off a piece so large that it could trigger a tsunami that destroys settlements on shore. Last week, Sweden’s highest peak, Kebnekaise mountain, no longer was in first place after its glacier tip melted.

Southern Europe is even hotter. Temperatures in Spain and Portugal are expected to reach 105-110 degrees Fahrenheit this weekend. On Saturday, several places in Portugal experienced record highs, and over the past week, two people have died in Spain from the high temperatures, and a third in Portugal.

But in the northernmost latitudes, where the climate is warming faster than the global average, temperatures have been the most extreme, according to a study by researchers at Oxford University and the World Weather Attribution network. 

Scorching Summer in Europe Signals Long-Term Climate Changes by Alissa J. Rubin, World, New York Times, Aug 4. 2018

California vows to fight Trump EPA's move to freeze fuel economy rules


Vowing to defend California's authority to set its own greenhouse gas emissions rules, Gov. Jerry Brown said the state would fight the new EPA plan “in every conceivable way possible.” (Irfan Khan / Los Angeles Times)

The Trump administration Thursday pushed ahead with plans to unravel the federal government’s most effective action to fight climate change — aggressive fuel economy standards aimed at getting the nation’s cars and trucks to average more than 50 miles per gallon by 2025.

After months of discussion and drafts, the Environmental Protection Agency and the National Highway Traffic Safety Administration formally unveiled their plan to rewrite those rules and replace them with ones so lax that even automakers are wary.

The administration’s plan would freeze mileage targets in 2020 for six years. It would also move to end California’s power to set its own, tougher greenhouse gas emissions standards and nullify the state mandate that automakers sell a specified number of electric vehicles.

EPA officials sought to portray the proposal as the administration’s opening bid in a negotiation with California. State officials, however, loudly denounced the plan as too extreme and threatened to fight it in court. California and the 13 other states that follow its more stringent rules argue the Clean Air Act empowers them to keep the Obama-era standards in place in their markets.

California vows to fight Trump EPA's move to freeze fuel economy rules by Elvan Halper, Tony Barbosa & David Lauter, Los Angeles Times, Aug 2, 2018

Toon of the Week...

Hat tip to Moms Clean Air Force Facebook page.

Quote of the Week...

“In the past, we had this kind of heat wave once every 10 years, and now we have them every two years or something like that,” said François-Marie Bréon, a climatologist and deputy director of the Laboratory of Climate and Environmental Science, a research institute affiliated with France’s National Center for Scientific Research. “That’s really the sign of climate change: We have heat waves that aren’t necessarily more intense but that are more and more frequent.”

Scorching Summer in Europe Signals Long-Term Climate Changes by Alissa J. Rubin, World, New York Times, Aug 4. 2018

Graphic of the Week...


California vows to fight Trump EPA's move to freeze fuel economy rules by Elvan Halper, Tony Barbosa & David Lauter, Los Angeles Times, Aug 2, 2018

SkS in the News...

John Cook is extensively quoted by Shannon Osaka in her Grist article,A climate denial video has 6 million views. Facebook doesn’t care. posted on July 31, 2018. The lead quote:

John Cook, who focuses on climate misinformation as a professor of cognitive science at George Mason University, says he hasn’t heard of the social media giant flagging any climate denial content. “Facebook’s fact-checking algorithms are a bit of a black box,” he tells Grist via email. (The social media site did not respond to a request for comment.)

Photos of the Week...




Changes observed in vegetation, permafrost, and coastal erosion at the Yukon's Qikiqtaruk-Herschel Island Territorial Park between 1987 (top) and 2017 (bottom). Credit: Isla Myers-Smith/University of Edinburgh

Arctic carbon cycle is speeding up by Esprit Smith, Vital Signs of the Planet, NASA's Jet Propulsion Laboratory, Aug 3, 2018

SkS Spotlights...

The purpose of CoalSwarm is to create shared information for the worldwide citizens’ movement seeking to address the impacts of fossil fuels and move to cleaner sources of energy. The Global Coal Plant Tracker has information on 13,000 existing and proposed coal plants worldwide. The CoalWire newsletter is a global weekly news digest. The CoalSwarm portal on SourceWatch contains over 9,000 wiki articles providing a constantly expanding reference. FrackSwarm provides a reference on oil and gas, including hundreds of major pipelines and  LNG (liquified natural gas) terminals. CoalSwarm’s reports can be found here.

Coming Soon on SkS...
  • The GOP and Big Oil can't escape blame for climate change (Dana)
  • Pollution is slowing the melting of Arctic sea ice, for now (John Abraham)
  • Climate change science comeback strategies (Karin Kirk)
  • State of the climate: 2018 set to be fourth warmest year despite cooler start (Zeke Hausfather)
  • New research this week (Ari)
  • 2018 SkS Weekly Climate Change & Global Warming News Roundup #32 (John Hartz)
  • 2018 SkS Weekly Climate Change & Global Warming Digest #32 (John Hartz)
Climate Feedback Reviews... Washington Post story puts recent weather extremes in accurate climate change context

Climate Feedback asked a team of scientists to review the article, Climate change is supercharging a hot and dangerous summer by Angela Fritz & Joel Achenbach, Health & Science, Washington Post, July 26, 2018

Three scientists analyzed the article and estimate its overall scientific credibility to be 'very high'.

A majority of reviewers tagged the article as: Accurate.

Review Summary 

This story in The Washington Post lists a variety of extreme weather events seen around the Northern Hemisphere recently. The article explains that some of these types of weather are known to be connected to human-caused climate trends.

Scientists who reviewed the article found that this scientific context was accurately provided. Heatwaves and intense rainstorms, for example, are increasing in severity and frequency. Some weather patterns—like slow-moving meanders in the jet stream—are indeed less clear and consequently subjects of active research. 

Washington Post story puts recent weather extremes in accurate climate change context, Edited by Scott Johnson, Climate Feedback, July 31, 2018

SkS Week in Review...  Poster of the Week...


2018 SkS Weekly Climate Change & Global Warming News Roundup #31

August 4, 2018 - 12:22pm
A chronological listing of news articles posted on the Skeptical Science Facebook Page during the past week. Editor's Pick 143-mph 'fire tornado' that cut a path of destruction is an ominous sign of the future


A high-tension power transmission line tipped over from a tornado-like vortex that reached speeds of possibly more than 143 mph. (Cal Fire / National Weather Service)/h5>

As authorities sifted the rubble from the fire that burned more than 1,000 residences in Shasta County, they were startled by what they encountered.

A soaring transmission tower was tipped over. Tiles were torn off the roofs of homes. Massive trees were uprooted. Vehicles were moved. In one spot, a fence post was bent around a tree, with the bark on one side sheared off.

This was not typical wildfire damage. Rather, it was strong evidence of a giant, powerful spinning vortex that accompanied the Carr fire on July 26. The tornado-like condition, lasting an hour and a half and fueled by extreme heat and intensely dry brush as California heats up to record levels, was captured in dramatic videos that have come to symbolize the destructive power of what is now California’s sixth-most destructive fire.

It may take years before scientists come to a consensus on what to exactly call this vortex — a fire whirl, as named by the National Weather Service, or a fire tornado. Whatever it’s called, it’s exceptionally rare to see a well-documented fire-fueled vortex leap out of a wildfire and enter a populated area with such size, power and duration. 

143-mph 'fire tornado' that cut a path of destruction is an ominous sign of the future by Rong-Gong Lin Ii , Joseph Serna & Louis Sahagun, Los Angeles Times, Aug 3, 2018

Links posted on Facebook

Sun July 29, 2018

Mon July 30, 2018

Tue July 31, 2018

Wed Aug 1, 2018

Thu Aug 2, 2018

Fri Aug 3, 2018

Sat Aug 4, 2018

New research, July 2-29, 2018

August 3, 2018 - 2:59am

A selection of new climate related research articles is shown below.

Climate change mitigation

Climate change communication

Place, proximity, and perceived harm: extreme weather events and views about climate change

Teaching climate change in middle schools and high schools: investigating STEM education’s deficit model

Cool dudes in Norway: climate change denial among conservative Norwegian men

Emission savings

How important are future marine and shipping aerosol emissions in a warming Arctic summer and autumn? (open access)

Work time reduction and economic democracy as climate change mitigation strategies: or why the climate needs a renewed labor movement

The remaining potential for energy savings in UK households

Energy production

The slow expansion of renewable energy in Russia: Competitiveness and regulation issues

Promises and limitations of nuclear fission energy in combating climate change

Russia's Nuclear Export Programme

Better late than never, but never late is better: Risk assessment of nuclear power construction projects

The changing risk perception towards nuclear power in China after the Fukushima nuclear accident in Japan

Analyzing the factors that influence U.S. public support for exporting natural gas

Climate Policy

US and international climate policy under President Trump

The withdrawal of the U.S. from the Paris Agreement and its impact on global climate change governance (open access)

U.S. withdrawal from the Paris Agreement: Reasons, impacts, and China's response (open access)

The impacts of U.S. withdrawal from the Paris Agreement on the carbon emission space and mitigation cost of China, EU, and Japan under the constraints of the global carbon emission space (open access)

The climate lobby: a sectoral analysis of lobbying spending on climate change in the USA, 2000 to 2016

Short term policies to keep the door open for Paris climate goals (open access)

Is India pulling its weight? India’s nationally determined contribution and future energy plans in global climate policy

Climate change

Temperature, precipitation, wind

Arctic amplification metrics

Can an ensemble climate simulation be used to separate climate change signals from internal unforced variability? (open access)

Changes in surface air temperature over China under the 1.5 and 2.0 °C global warming targets (open access)

Recent subsurface North Atlantic cooling trend in context of Atlantic decadal-to-multidecadal variability (open access)

Multidecadal Changes of the Upper Indian Ocean Heat Content during 1965-2016

Detectable impacts of the past half‐degree global warming on summertime hot extremes in China

Human contribution to the increasing summer precipitation in Central Asia from 1961 to 2013

Diminishing Arctic Sea Ice Promotes Stronger Surface Winds

Extreme events

Spatiotemporal variability of tornadoes in the Czech Lands, 1801–2017

Drivers of 2016 record Arctic warmth assessed using climate simulations subjected to Factual and Counterfactual forcing (open access)

Increase in extreme precipitation events under anthropogenic warming in India (open access)

Forcings and feedbacks

Self‐amplifying feedbacks accelerate greening and warming of the Arctic

Contributions of Internal Variability and External Forcing to the Recent Pacific Decadal Variations

Assessment of the Impact of Solar Spectral Irradiance on Near‐Infrared Clear‐Sky Atmospheric Absorption and Heating Rates


Ocean‐induced melt triggers glacier retreat in Northwest Greenland

Greenland Ice Mapping Project: ice flow velocity variation at sub-monthly to decadal timescales (open access)

Dynamic response of Antarctic Peninsula Ice Sheet to potential collapse of Larsen C and George VI ice shelves (open access)

Glacier change along West Antarctica's Marie Byrd Land Sector and links to inter-decadal atmosphere–ocean variability (open access)

Attribution of Arctic sea ice decline from 1953 to 2012 to influences from natural, greenhouse-gas and anthropogenic aerosol forcing

Evolution of the global coupled climate response to Arctic sea ice loss during 1990-2090 and its contribution to climate change

Responses and changes in the permafrost and snow water equivalent in the Northern Hemisphere under a scenario of 1.5 °C warming (open access)

Global snow zone maps and trends in snow persistence 2001–2016


Rising Oceans Guaranteed: Arctic Land Ice Loss and Sea Level Rise (open access)

Sensitivity of streamflow to climate change in California

Atmospheric and oceanic circulation

Blocking and its Response to Climate Change (open access)

Two AMOC states in response to decreasing greenhouse gas concentrations in the coupled climate model MPI-ESM

Carbon cycle

Long-term response of oceanic carbon uptake to global warming via physical and biological pumps (open access)

Grasslands may be more reliable carbon sinks than forests in California (open access)

Climate change impacts


Projected heat stress under 1.5oC and 2oC global warming scenarios creates unprecedented discomfort for humans in West Africa (open access)

Climatic variability and dengue risk in urban environment of Delhi (India)

Unprecedented risk of spring frost damage in Switzerland and Germany in 2017

Heat in the Heartland: Crop Yield and Coverage Response to Climate Change Along the Mississippi River

Economically robust protection against 21st century sea-level rise

Limits to growth redux: A system dynamics model for assessing energy and climate change constraints to global growth


Acceleration of global vegetation greenup from combined effects of climate change and human land management

Dramatic loss of seagrass habitat under projected climate change in the Mediterranean Sea

The Arctic picoeukaryote Micromonas pusilla benefits synergistically from warming and ocean acidification (open access)

Increasing temperature sensitivity caused by climate warming, evidence from Northeastern China

Increased growth of Qinghai spruce in northwestern China during the recent warming hiatus

Development and analysis of spring plant phenology products: 36 years of 1-km grids over the conterminous US

Impacts of recent climate extremes on spring phenology in arid-mountain ecosystems in China

Unchanged risk of frost exposure for subalpine and alpine plants after snowmelt in Switzerland despite climate warming

Effects of ocean acidification on algae growth and feeding rates of juvenile sea urchins

Transgenerational deleterious effects of ocean acidification on the reproductive success of a keystone crustacean (Gammarus locusta)

Climate change alterations to ecosystem dominance: how might sponge‐dominated reefs function?

Ecophysiological plasticity of Amazonian trees to long-term drought

Does sexual dimorphism predispose dioecious riparian trees to sex ratio imbalances under climate change?

Interactions between rising CO2 and temperature drive accelerated flowering in model plants under changing conditions of the last century

Elevated atmospheric concentrations of carbon dioxide reduce monarch tolerance and increase parasite virulence by altering the medicinal properties of milkweeds

Oysters and eelgrass: potential partners in a high pCO2 ocean

Other papers

General climate science

Understanding weather and climate of the last 300 years from ships' logbooks

Climate history of Russia and the Soviet Union


Large-scale, millennial-length temperature reconstructions from tree-rings

Tracing winter temperatures over the last two millennia using a north-east Atlantic coastal record (open access)

Permafrost and wetland emissions could cut 1.5C carbon budget ‘by five years’

August 2, 2018 - 1:38am

This is a re-post from Carbon Brief by Robert McSweeney

Emissions of CO2 and methane from wetlands and thawing permafrost as the climate warms could cut the “carbon budget” for the Paris Agreement temperature limits by around five years, a new study says.

These natural processes are “positive feedbacks” – so called because they release more greenhouse gases as global temperatures rise, thus reinforcing the warming. They have previously not been represented in carbon budget estimates as they are not included in most climate models, the researchers say.

The findings suggest that human-caused emissions will need to be cut by an additional 20% in order to meet the Paris Agreement’s 1.5C or 2C limits, the researchers estimate.

‘Engines for turning CO2 into methane’

Over the last year or so, there has been a flurry of new carbon budget studies – using slightly different approaches to estimate how much CO2 we can emit and still hold global temperature rise to no more than 1.5C or 2C above pre-industrial levels.

(Carbon Brief summarised all the 1.5C budgets in a recent analysis piece.)

Many of these studies use global climate models to make their estimates. However, there are some processes which affect the climate that are not yet incorporated into these models.

The new study, published in Nature Geoscience, aims to fill that gap. It focuses on two processes on the land surface: thawing permafrost and natural wetlands.

These are both positive feedbacks for the climate because, as they respond to rising temperatures, they cause the release of more greenhouse gases into the atmosphere.

Permafrost is the name given to soil that has been frozen for at least two years. It is predominantly found in the northern hemisphere – stretching across northern reaches of Russia, Canada and Alaska.

A massive permafrost thaw slump near the Arctic Ocean coastline, Canada. Credit: National Geographic Creative/Alamy Stock Photo.

These soils hold a huge amount of carbon, accumulated from dead plants and animals over thousands of years. Rising temperatures put this carbon at risk of being released, explains Dr Chris Jones, head of the earth system and mitigation science team at the Met Office Hadley Centre. Jones is not an author on the new study, but his team was involved closely in the work. He tells Carbon Brief:

“While [permafrost] is frozen, it is inert. As it thaws, this carbon is vulnerable to decomposition – like any other soil carbon. Depending on whether it is waterlogged or not this can be emitted to the atmosphere as CO2 or methane.”

How much is released as CO2 and how much as methane is still uncertain, and is an active area of research. Methane is a potent greenhouse gas – approximately 26 times more powerful than CO2 at trapping heat in the atmosphere, although it only lasts for around a decade in the atmosphere.

In natural wetlands, plants absorb CO2 from the atmosphere as they grow. But, because they are waterlogged, when the plants decompose they release methane, rather than CO2. This makes wetlands “effectively engines for turning CO2 into methane”, says Jones.

In the Amazon, for example, flooded forests actually release methane through the trees themselves.

Wetlands respond to a warming climate in three ways, Jones explains:

“As [the climate] warms, the local decomposition rate increases. Also, as rainfall changes, we may see increased or decreased areas of wetlands. This varies regionally and, again, is a large uncertainty across climate models. Finally, a direct effect of increased CO2 in the atmosphere is to increase the growth rate of the vegetation and, hence, increase the amount of CO2 being turned into methane.”

The study is the first to bring all these factors together, he notes.

Inverted model

The researchers used a “multi-layered soil carbon model” called JULES (Joint UK Land Environment Simulator), explains lead author Dr Edward Comyn-Platt, a land surface modeller at the Centre for Ecology & Hydrology. JULES has an improved representation of soil chemistry and the way that wetlands create methane.

With permafrost, for example, “this not only improves our estimates of the carbon stored in soils at high latitudes, but also allows us to estimate how much of this soil will be lost as the permafrost regions thaw”, Comyn-Platt tells Carbon Brief.

To estimate carbon budgets, the researchers use an “inverted” form of the model. This means, rather than plugging in pathways of future greenhouse gas emissions and seeing how global temperatures respond, the researchers input pathways of global temperature rise and use the model to estimate the corresponding levels of greenhouse gases in the atmosphere.

The study looks at three scenarios of future global warming: holding temperature rise at 1.5C and 2C, and one where warming “overshoots” 1.5C, reaches 1.75C, then returns to 1.5C.

In their “control” model runs with no permafrost or wetland feedbacks, the researchers estimate the 1.5C budget at 720bn-929bn tonnes of CO2 from the beginning of 2018 – equivalent to 20-25 years of emissions at current rates.

Wetlands with palms and flying blue and yellow macaws, Mato Grosso, Brazil, 2009. Credit: Juergen Ritterbach/Alamy Stock Photo.

This is slightly higher than some recent budgets because the JULES model tends to simulate a large amount of carbon uptake from the land surface, explains Comyn-Platt, freeing up space for more CO2 emissions in the budget.

The researchers then used the model to simulate the response of permafrost and natural wetlands to climate change. When the additional CO2 and methane emissions are incorporated, the available carbon budget shrinks substantially – falling to 533bn-753bn tonnes of CO2 for 1.5C, or 14-20 years of emissions.

That means accounting for the impacts of permafrost and wetlands takes around five years off the 1.5C budget. And, as the table below shows, the budgets for the 1.5C overshoot and 2C scenarios are similarly reduced.

 ControlFeedbacks included   Tonne of CO2 Years of emissions Tonne of CO2 Years of emissions 1.5C 720-929bn 20-25 533-753bn 14-20 1.5C overshoot 723-947bn 20-26 522-771bn 14-21 2C 1592-1974bn 43-54 1372-1776bn 37-48

Table shows remaining carbon budget (from 2018 to 2100) for three temperature pathways for the “control”  (left) and “feedbacks included” (right) scenarios. Carbon budgets are shown as tonnes of CO2 and as total years of emissions (based on 2017 global emissions). Table adapted from Comyn-Platt et al. (2018)


This “nice work” shows that even if we were to get net emissions to zero in the next few decades, emissions would need to fall further in order to stabilise temperatures at 1.5C or 2C, says Prof Piers Forster, professor of physical climate change at the University of Leeds and director of the Priestley International Centre for Climate. He tells Carbon Brief:

“The extra carbon released from thawing permafrost and warming wetlands would continue beyond the date of net-zero emissions and this would need to be countered for in order to consider carbon budgets applicable for 2100 and beyond.”

The study also highlights the constant evolution in the complexity of climate models, says Jones, with new model components being developed and run separately before being incorporated into global models.

The graphic below shows how new components have been added to global climate models over time.

In this case, the wetland model “scheme” will be shortly be brought into UKESM1 – the UK Earth System Model run by the Met Office Hadley Centre and partners, says Jones. And the permafrost scheme “will follow in due course”.


Comyn-Platt, E. et al. (2018) Carbon budgets for 1.5 and 2C targets lowered by natural wetland and permafrost feedbacks, Nature Geoscience, doi:10.1038/s41561-018-0174-9 


Climate change made 2018 European heatwave up to ‘five times’ more likely

July 31, 2018 - 1:51am

This is a re-post from Carbon Brief

rapid assessment by scientists of the ongoing heatwave across northern Europe this summer has found that human-caused climate change made it as much as five times more likely to have occurred.

The preliminary analysis, by a team of scientists at the World Weather Attribution network, uses data from seven weather stations in Ireland, the Netherlands, Denmark, Sweden, Norway and Finland. The team were not able to get sufficient data at short notice to include a UK station.

The findings suggest that rising global temperatures have increased the likelihood of such hot temperatures by five times in Denmark, three times in the Netherlands and two times in Ireland.

The sizeable year-to-year fluctuations in summer weather in Scandinavia makes it harder to pin down a specific change in likelihood for the heatwaves in Norway, Sweden and Finland, the researchers say. However, “we can state that, yes, heatwaves have increased – and are increasing – in Scandinavia as in the rest of Europe”, says one of the scientists involved.

Climate change link

From the UK to Canada through to Oman and Japan, the northern hemisphere has seen a pattern of prolonged heatwaves in recent weeks. The record-breaking temperatures have been linked to wildfires in Sweden, Greece and California and heatwave deaths in several countries.

Many news reports have speculated on the potential role that rising global temperatures could be having on the spate of extremes this summer. Carbon Brief has published a summary of all the media coverage from recent weeks.

Now, in a rapid analysis over the past few days, scientists have been able to quantify the impact that climate change is having.

The study uses data from individual weather stations, explained Dr Friederike Otto, the deputy director of the Environmental Change Institute at the University of Oxford, in a press conference this morning:

“What we have done in this study is look at locations – individual weather stations, so at the place where people live – to represent the heatwave that people are actually experiencing.”

These stations were selected because they had “data immediately available to us”, added Otto, and also because they had long records that could be analysed. Because the team needed data as close to real-time as possible – while they were carrying out their analysis – they used forecasts of temperature for the most recent few days.

The locations of each station were: Dublin, Ireland; De Bilt, Netherlands; Copenhagen, Denmark; Oslo, Norway; Linköping, Sweden; Sodankyla, northern Finland; and Jokioinen, southern Finland.

The researchers defined the heatwave at each location by taking the hottest three-day period in the year so far. Although this is a short period compared to the extended heatwave for much of Europe this summer, using longer period would have left fewer hot events to analyse, the researchers say.

The map below shows how the hottest three-day period across Europe this summer so far compares to the hottest three-days in an average summer. The orange and red shading show higher-than-average temperatures, while the blues show lower. It illustrates how unusually warm Northern Europe, in particular, has been.

The hottest 3-day consecutive period in 2018 (up to the end of July) compared to the average for the 1981-2010. Based on observed data up to 24 July, forecasts up to 31 July. Source: World Weather Attribution

The researchers used the long-term observed records of temperature to work out how rare this year’s heatwaves have been. They found that such warm three-day periods would occur once every five-to-eight years in Ireland, Denmark, Norway and the Netherlands, but just once every 30 years in Sweden and less than once every 90 years in Finland.

For the weather station in northern Finland, the recent heat is unlike anything on record, said Dr Geert Jan van Oldenborgh, from the Royal Netherlands Meteorological Institute:

“We found that for the weather station in the far north, in the Arctic Circle, the current heat wave is just extraordinary – unprecedented in the historical record.”

Using a collection of climate models, they then assessed the probability of such an event occurring in the current climate – which includes the influence of human-caused climate change – and in the past before the human impact on climate was detectable. Before using each model, they checked it could simulate heatwaves in each location accurately.

The findings suggest that climate change made the heatwave around twice as likely in Dublin (between a range of 1.2 and 3.3 times), five times as likely in Copenhagen (with a range of 2.4-12) and more than three times as likely in De Bild (with a range of 1.6-16).

The change in likelihood was “much harder to quantify” for the more northerly stations, the researchers say.

‘Heatwaves have increased’

The team also looked into how the frequency of heatwaves has changed over the long records of each station, explained van Oldenborgh in the press conference:

“For Ireland, Netherlands and Denmark, there is a clear trend in the observations towards more heatwaves. In the Netherlands, that trend is really large.”

For Norway, Sweden and Finland, there is not yet a statistically significant trend in heatwave changes in the observed data, noted van Oldenborgh:

“The reason for that is the variability of the weather from year to year is very large in this region and so it hides any trend.”

As a result, the team were “hesitant to put an actual number on the increase” in the region, said van Oldenborgh. Despite this, “we can state that, yes, heatwaves have increased – and are increasing – in Scandinavia as in the rest of Europe”, he added.

Single-event attribution

The new research is the latest in what are known as “single-event attribution” studies. The fast-moving area of research aims to identify the influence that human-caused climate change does – or does not – have on extreme weather events around the world. Carbon Brief has previously mapped all the peer-reviewed attribution studies in the scientific literature.

The research was conducted by World Weather Attribution – a network of scientists in six institutions established to provide near-real time analysis of possible links between climate change and extreme weather events.

It should be noted that the findings are still only preliminary, the researchers say:

“It is important to note that, compared to other attribution analyses of European summers, attributing a heatwave early in the season with the whole of August still to come will only give a preliminary result of the 2018 northern hemisphere heatwave season.”

The findings also have not yet been peer-reviewed. The researchers will be submitting the results to a journal once the summer is over. However, the methods underlying the findings are well established and have been published in previous attribution studies.

America spends over $20bn per year on fossil fuel subsidies. Abolish them

July 30, 2018 - 1:45am

Imagine that instead of taxing cigarettes, America subsidized the tobacco industry in order to make each pack of smokes cheaper.

report from Oil Change International (OCI) investigated American energy industry subsidies and found that in 2015–2016, the federal government provided $14.7bn per year to the oil, gas, and coal industries, on top of $5.8bn of state-level incentives (globally, the figure is around $500bn). And the report only accounted for production subsides, excluding consumption subsidies (support to consumers to lower the cost of fossil fuel use – another $14.5bn annually) as well as the costs of carbon and other fossil fuel pollutants.

At a time when we need to transition away from fossil fuels as quickly as possible, the federal and state governments are giving the industry tens of billions of dollars to make the production of their dirty, dangerous products more profitable.

We already have to leave tapped fossil fuels in the ground

Crucially, the OCI report noted that if we want to meet the Paris target of limiting global warming to less than 2°C (and we do!), not only does the fossil fuel industry have stop developing new reserves, but “some already-tapped reserves must be retired early.”

 Developed fossil fuel reserves vs. remaining carbon budget to meet 2°C and 1.5°C Paris climate targets. Illustration: Oil Change International

This reality is incompatible with continued US government subsidization of fossil fuel industry production, including $2.5bn per year for the exploration of new fossil fuel resources ­– new resources that simply cannot be developed if we’re to meet the Paris climate target.

To achieve that goal, we instead need to replace fossil fuels with clean energy as quickly as possible. And yet, OCI notes that permanent tax breaks to the US fossil fuel industry are more than seven times larger than those for renewable energy. Some of those fossil fuel subsidies have been around for over a century. And they’re making it profitable for the oil industry to extract resources that would otherwise be left in the ground:

at current prices, the production of nearly half of all U.S. oil is not economically viable, except with federal and state subsidies.

And as David Roberts notes, federal policy is also propping up the coal industry. Were they forced to meet modern pollution standards, 98% of currently operating coal power plants would be unprofitable compared to an equivalent natural gas plant. Coal power plants only stay open through regulations allowing pollution exemptions, and by forcing taxpayers to pick up the climate change bill.

Add another trillion dollars in climate subsidies

Without a price on carbon pollution, Americans are effectively subsidizing the fossil fuel industry for the costs incurred through its products’ climate change damages. For example, think about the added costs to taxpayers for worse wildfires, droughts, hurricanes, and flooding, all amplified by human-caused climate change. In the absence of a price on carbon pollution, the fossil fuel industry doesn’t pay a cent of those costs. Taxpayers pick up the whole tab.

These costs can be estimated via the ‘social cost of carbon.’ It’s a difficult number to pin down, but even at the extremely conservative US federal estimate of $37 per ton of carbon dioxide pollution (some recent research pegs the value at more than five times higher), that’s about $200bn per year for America and $1.3tn globally. While direct government subsidies to the fossil fuel industry are expensive, they’re dwarfed by the costs incurred by failing to tax carbon pollution.

The fossil fuel industry owns the GOP

The OCI report noted that the Obama administration actually proposed to eliminate 60% of federal fossil fuel industry subsidies, but that proposal went nowhere for one obvious reason:

In the 2015-2016 election cycle oil, gas, and coal companies spent $354 million in campaign contributions and lobbying and received $29.4 billion in federal subsidies in total over those same years - an 8,200% return on investment.

Of those fossil fuel industry contributions to political campaigns, 88% went to Republican politicians. As a result, 97% of House Republicans oppose taxing carbon pollution, and the Trump administration is looking into every possible scheme to further prop up the dying coal industry. The GOP might as well rebrand itself as the Grand Oil Party.

Click here to read the rest

2018 SkS Weekly Climate Change & Global Warming News Roundup #30

July 28, 2018 - 12:32pm
A chronological listing of news articles posted on the Skeptical Science Facebook Page during the past week. Editor's Pick How Did the End of the World Become Old News?


The fire this time (in Sweden). Photo: Mats Andersson/AFP/Getty Images

There has been a lot of burning lately. Last week, wildfires broke out in the Arctic Circle, where temperatures reached almost 90 degrees; they are still roiling northern Sweden, 21 of them. And this week, wildfires swept through the Greek seaside, outside Athens, killing at least 80 and hospitalizing almost 200. At one resort, dozens of guests tried to escape the flames by descending a narrow stone staircase into the Aegean, only to be engulfed along the way, dying literally in each other’s arms.

Last July, I wrote a much-talked-over magazine cover story considering the worst-case scenarios for climate change — much talked over, in part, because it was so terrifying, which made some of the scenarios a bit hard to believe. Those worst-case scenarios are still quite unlikely, since they require both that we do nothing to alter our emissions path, which is still arcing upward, and that those unabated emissions bring us to climate outcomes on the far end of what’s possible by 2100.

But, this July, we already seem much farther along on those paths than even the most alarmist climate observers — e.g., me — would have predicted a year ago. In a single week earlier this month, dozens of places around the world were hit with record temperatures in what was, effectively, an unprecedented, planet-encompassing heat wave: from Denver to Burlington to Ottawa; from Glasgow to Shannon to Belfast; from Tbilisi, in Georgia, and Yerevan, in Armenia, to whole swaths of southern Russia. The temperature of one city in Oman, where the daytime highs had reached 122 degrees Fahrenheit, did not drop below 108 all night; in Montreal, Canada, 50 died from the heat. That same week, 30 major wildfires burned in the American West, including one, in California, that grew at the rate of 10,000 football fields each hour, and another, in Colorado, that produced a volcano-like 300-foot eruption of flames, swallowing an entire subdivision and inventing a new term — “fire tsunami” — along the way. On the other side of the planet, biblical rains flooded Japan, where 1.2 million were evacuated from their homes. The following week, the heat struck there, killing dozens. The following week.

How Did the End of the World Become Old News? by David Wallace-Wells, The Daily Intelligencer, New York Magazine. July 26, 2018

Links posted on Facebook

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Fri July 27, 2018

Sat July 28, 2018

Upcoming webinars on turning misinformation into an educational opportunity

July 27, 2018 - 11:00am

Since starting Skeptical Science in 2007, I've been researching how to counter misinformation.  One answer is inoculation - you can neutralize misinformation by exposing people to a "weak form of misinformation" (e.g., explain the techniques used to mislead). But how do we put this into practice?

One of the most powerful ways to teach science and counter science denial is in the classroom through misconception-based learning. I've been lucky enough to collaborate with several organizations to provide educational resources using this approach. The Skeptical Science team worked with UQx to develop the online course Making Sense of Climate Science Denial.

Now I'm based in the U.S., I've been lucky enough to collaborate with the National Center for Science Education and the Alliance of Climate Educators to develop a set of lesson plans teaching key facts about climate change while addressing five of the most common climate myths. With Brad Hoge (Director of Teacher Support at NCSE) and teachers from around the country who field-tested the lessons, we'll be presenting a five-part webinar series on how to teach our five lessons.

Each webinar will focus on a single NGSS-aligned lesson plan. You can sign up for free to any or all five to get the full complement of lessons. All participants will receive a certificate that can be used for continuing education units. The webinars will be at 7:00-8:30 pm Eastern Time via Zoom.

Register at 

July 31: Scientific Consensus on Climate Change

In this lesson, students create their own scientific consensus on climate change through direct interpretation with climate data, as well as examining a popular climate myth.

August 7: Climate Models

Some of the most common climate skeptic arguments focus on climate models. In this lesson, students examine climate model data and learn how climate models are developed, as well as debunk common misconceptions about climate models and their capabilities.

August 15: Past vs Present Climate Change

"Climate has always changed. Why is today any different?" With Milankovitch cycles (what?!), ice cores and other paleoclimate data, students explore the logical fallacy behind this misconception. 

August 21: Local Climate Impacts

Let's take a gamble... In this lesson, students delve into local impacts of climate change and try their hand at beating the odds to see how climate change really is loading the dice and increasing the odds of more extreme weather. 

August 29: Climate Solutions

What do wedges have to do with solving climate change? Turns out, everything. Students play the "Wedges Game" to balance various greenhouse gas-reductions strategies to achieve net zero emissions. Students also explore local climate solutions that works in their community.

Register now!

CSLDF is fighting attacks on science. Here’s how you can help.

July 26, 2018 - 6:09am

This is a guest post from Lauren Kurtz of the Climate Science Legal Defense Fund (CSLDF).

We at the Climate Science Legal Defense Fund (CSLDF) wanted to share what we’ve been up to in 2018 and ask for your help raising $100K to protect science.

As you know, today’s political environment is extremely dangerous for science and scientists, which means we’re busier than ever. To help us meet the demand for our services and prepare for the challenges that lie ahead, Charles Zeller, one of our founding board members, is matching all donations, dollar for dollar, up to $50,000.

We’ve raised $35K so far and need your help to meet our summer fundraising goal. Please consider making a gift to CSLDF today. Your contribution will not only be doubled, we’ll put it to immediate use protecting science.

We’re extremely grateful to the SkS community for contributing to our work since our founding over six years ago. With your continued support we’ve been able to provide vital free legal services to scientists, educate researchers about their legal rights and responsibilities, and call out attacks on science.

With that, here’s a quick roundup of what we’ve accomplished so far this year:

  • We’ve provided free legal advice and direct representation to 22 researchers on issues ranging from open records to scientific integrity complaints. We expect to exceed the number of scientists we helped in 2017.
  • We hosted a session at the American Association for the Advancement of Science (AAAS) Annual Meeting, where attorneys from CSLDF and the ACLU discussed steps scientists can take to avoid ending up in political crosshairs.
  • We hired a new attorney, Augusta Wilson, bringing our total staff to five. Augusta’s work is focused on defending scientists from threats and educating researchers on how to protect themselves.
  • We expanded our Campus Reps initiative and held a third program training in April. As a result, there are now 23 law professors across the United States providing education and assistance to scientists at their institutions.
  • We continue to publish Scientists’ Stories, which focus on how attacks and anti-science actions impact researchers, both personally and professionally.

And there will be no shortage of action in the coming months. Among our many activities: In July we held an event in New York City with our local 500 Women Scientists pod; in September, we’re co-hosting a panel on attacks on climate science at Columbia Law School as part of Climate Week NYC; in November we’re co-hosting a webinar with the American Geophysical Union (AGU) on anti-lobbying restrictions for scientists; and in December you’ll find us at the AGU Fall meeting with an expanded presence.

If you can’t support us financially, please help by spreading the word to others who might not be familiar with CSLDF. For more information, visit or SkS’ own “Getting involved with Climate Science via crowdfunding and crowdsourcing” page.

Many thanks to SkS readers for your support and interest in our work — and the public service you provide at SkS!

Scientists detect a human fingerprint in the atmosphere's seasonal cycles

July 23, 2018 - 1:08am

We know that humans are causing Earth’s climate to change. It used to be that “climate change” mostly referred to increasing temperatures near the Earth’s surface, but increasingly, climate change has come to mean so much more. It means warming oceans, melting ice, changing weather patterns, increased storms, and warming in other places.

A recent study has just been published that finds ‘fingerprints’ of human-caused warming someplace most of us don’t think about – in the higher atmosphere. Not only that, but these scientists have found changes to the seasonal climate – how much the temperature varies from winter to summer to winter – and the changes they found matched expectations. 

The paper was authored by a top group of scientists including Benjamin Santer, Stephen Po-Chedley, Mark Zelinka, Ivana Cvijanovic, Celine Bonfils and Paul Durack from Lawrence Livermore National Laboratory; Carl Mearsand Frank Wentz from Remote Sensing Systems; Qiang Fu from the University of Washington; Jeffrey Kiehl from the University of California, Santa Cruz; Susan Solomon from MIT; and Cheng-Zhi Zou from the University of Maryland. These are literally the best of the best climate scientists studying Earth’s atmosphere.

So, how did the scientists carry out their research? First of all, temperature measurements were made throughout the atmosphere using satellites. These satellites fly across the skies and take continuous measurements, so we get a picture of the whole planet. This is different from using a weather balloon that measures temperature only where the balloon flies. Satellites give a nearly continuous picture of what is happening everywhere.

While all that is great, satellites are prone to errors that have to be accounted for. For instance, their orbits change over time, which affects the accuracy of the measurements. They also have issues with a process called calibration. Finally, whenever a new satellite is launched, it may not behave the same as the satellite it replaced. While all of these issues can be dealt with, it’s a challenge to do so. But regardless, satellites are a very useful tool for understanding global changes in climate.

The authors compared these satellite temperature measurements with the “human influence” fingerprint patterns from computer models of the climate system. The fingerprints were based on computer calculations made with human-caused changes in greenhouse gas levels in the atmosphere. 

The “human influence” fingerprints were also compared with results from “no human influence” calculations, which did not have any year-to-year changes in human factors. Comparing these two sets of calculations allowed the researchers to determine whether the “human influence” fingerprint matched the satellite data, and whether such a fingerprint match could be due to natural climate variability alone.

In particular, the researchers wanted to know whether they could detect a human fingerprint in the seasonal cycle of temperature changes in the atmosphere (as the atmosphere heats and cools during different seasons of the year).

They discovered that in the lower part of the atmosphere (the troposphere), the fingerprint of global warming can be found in the satellite measurements of the changing seasonal cycles of temperature. The “human influence” fingerprint matched the satellite patterns of seasonal cycle change. The match was significant – it couldn’t be explained by natural climate variability.

Click here to read the rest

2018 SkS Weekly Climate Change & Global Warming Digest #29

July 22, 2018 - 12:37pm

Story of the Week... Analysis of the Week... SkS Highlights... El Niño/La Niña Update... Toon of the Week... Quote of the Week... Graphic of the Week... SkS in the News... Photo of the Week... SkS Spotlights... Video of the Week... Reports of Note... Coming Soon on SkS... Poster of the Week... SkS Week in Review...

Story of the Week... A Global Heat Wave Has Set the Arctic Circle on Fire

Fire burns in Karbole, Sweden. Photo: Mats Andersson/AFP/Getty Images

From Japan to Sweden, and Oman to Texas, a global heat wave is setting records, igniting wildfires, and killing dozens all across the world this week.

The south-central region is home to the highest temperatures in the U.S. this week, with nearly 35 million people living under excessive heat warnings issued by the National Weather Service. Temperatures are expected to be in the triple digits across Texas this weekend, marking the most severe heat wave in the state since 2011.

The Texas heat has already led to record-breaking days for the Texas power grid twice this week. Things aren’t any better elsewhere in the region, with heat indexes in Oklahoma, Arkansas, and Louisiana reaching up to 110 degrees.

A Global Heat Wave Has Set the Arctic Circle on Fire by Adam K Raymond, Daily Intelligencer, New York Magazine, July 20, 2018

Analysis of the Week... The 5 most important questions about carbon taxes, answered


Carbon taxes are in the news these days. In recent months, not one but two conservative national carbon tax proposals have emerged, disrupting the usual partisan dynamic on climate policy.

First there was the proposal from the Climate Leadership Council, a group of (mostly older, retired) Republicans and centrists, which was released last year but recently gained the backing of a new big-money conservative PAC. And next week, Rep. Carlos Curbelo (R-FL), co-chair of the House Climate Solutions Caucus, plans to release a carbon-tax proposal of his own.

Neither proposal has a snowflake’s chance in hell of passage any time soon. And on Thursday, the House passed a resolution trying to squash even the possibility of a carbon tax. But the existence of these proposals does indicate a heightened level of awareness of and interest in carbon taxes. So now seems like a good opportunity to review some of the basics.

The 5 most important questions about carbon taxes, answered by David Roberts, Energy & Environment, Vox, July 20, 2018

Toon of the Week...


Quote of the Week...

“The red alert is on,” Laurent Fabius, who was president of the 2015 international climate change negotiations in Paris, told an audience last week at the EuroScience Open Forum, Europe’s largest interdisciplinary science meeting. As of 2015, global temperatures had risen about 1 degree Celsius above pre-industrial levels. “It’s a race against time,” Fabius said, and the political challenge is to avoid acting too late.

What Climate Change Looks Like In 2018 by Christie Aschwanden, Climate, FiveThirtyEight, July 19, 2018

SkS in the News...

Carolyn Kormann interviewed John Cook for her New Yorker magazine article, In Andrew Wheeler, Trump Gets a Cannier E.P.A. Chief. Cook's observations are contained in this paragraph:

Wheeler has long been a climate denialist, fighting any policies that would establish mandatory carbon limits. In 2003, in a long speech on the Senate floor opposing a climate bill put forward by Senators John McCain and Joe Lieberman, Inhofe famously said that “man-made global warming is the greatest hoax ever perpetrated on the American people.” Wheeler defended his boss’s position for years, criticizing the work of the Intergovernmental Panel on Climate Change and casting doubt on the science. (In 2006, he said in an interview with E&E News, “The fact is that the climate changes regularly.”) On Friday, however, in an interview with the Washington Post, Wheeler changed his position—or, at least, chose his words carefully. He said that he believes climate change is real and that “people have an impact on the climate.” (During his Senate confirmation hearings for deputy administrator, last November, he expressed more uncertainty. “I believe man has an impact on the climate,” he said. “But what is not completely understood is what the impact is.”) John Cook, a climate-change communications researcher at George Mason University, categorizes this kind of statement as “doubt-mongering misinformation,” Republicans’ latest argument, he told me, to support climate inaction. (Previously, Wheeler and others used the “explicit misinformation” argument, Cook said. “It seems to be on its way out.”) Wheeler now claims, as he told the Post, that he has “always deferred to career scientists,” and will continue to do so. In his first e-mail to E.P.A. employees as acting administrator, last week, he wrote, “I look forward to working alongside all of you to continue our collective goal of protecting public health and the environment.” 

In his New York Times article, He Sues to Discredit Climate Scientists. Now He’s Being Sued by His Allies., John Schwartz wrote:

The efforts by Mr. Schnare and Mr. Horner to obtain climate scientists’ emails followed a trail blazed in 2009 in an episode known as Climategate, when hackers exposed a trove of private messages between scientists. Global warming denialists took the blunt discussions out of context to allege that researchers had tampered with data, but subsequent investigations found no evidence of fraud.

The first link in the above is to the Basic version of the SkS rebuttal article, Clearing up misconceptions regarding 'hide the decline' 

Reports of Note...

Bioenergy with Carbon Capture and Storage Approaches for Carbon Dioxide Removal and Reliable Sequestration: Proceedings of a Workshop in Brief

Coming Soon on SkS...
  • Scientists detect a human fingerprint in the warming of the atmosphere (John Abraham)
  • Wind Energy: What About Those Subsidies? And, the Key Advantage over Natural Gas (greenman)
  • Facebook video spreads climate denial misinformation to 5 million users (Dana)
  • CSLDF is fighting attacks on science. Here’s how you can help (Lauren Kurtz)
  • Permafrost and wetland emissions could cut 1.5C carbon budget ‘by five years’ (Robert McSweeney)
  • 2018 SkS Weekly Climate Change & Global Warming News Roundup #30 (John Hartz)
  • 2018 SkS Weekly Climate Change & Global Warming Digest #30 (John Hartz)
Poster of the Week...


SkS Week in Review...