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2017 SkS Weekly Climate Change & Global Warming News Roundup #29

July 22, 2017 - 12:57pm
A chronological listing of news articles posted on the Skeptical Science Facebook page during the past week.  Editor's Pick

The Planet Is Warming. And It's Okay to Be Afraid

Why being fearful can be part of a healthy, heroic response to the climate crisis


Climate warriors from around the world, like those facing rising seas in the Pacific islands, have turned the fear of lost homes and future devastation into the courage to confront the most powerful industries on the planet. (Image: via

Last Week, David Wallace-Wells wrote a cover story for of New York Magazine, "The Uninhabitable Earth," on some of the worst-case scenarios that the climate crisis could cause by the end of this century. It describes killer heat waves, crippling agricultural failures, devastated economies, plagues, resource wars, and more. It has been read more than two million times.

The article has caused a major controversy in the climate community, in part because of some factual errors in the piece—though by and large the piece is an accurate portrayal of worst-case climate catastrophe scenarios. But by far the most significant criticism the piece received was that it was too frightening.

"Importantly, fear does not motivate, and appealing to it is often counter-productive as it tends to distance people from the problem, leading them to disengage, doubt and even dismiss it," wrote  Michael Mann, Susan Joy Hassol and Tom Toles at the Washington Post.

Erich Holthaus tweeted about the consequences of the piece:

"A widely-read piece like this that is not suitably grounded in fact may provoke unnecessary panic and anxiety among readers."

"And that has real-world consequences. My twitter feed has been filled w people who, after reading DWW's piece, have felt deep anxiety." 

"There are people who say they are now considering not having kids, partly because of this. People are losing sleep, reevaluating their lives."

While I think both Mann and Holthaus are brilliant scientists who identified some factual problems in the article, I strongly disagree with their statements about the role of emotions—namely, fear—in climate communications and politics. I am also skeptical of whether climate scientists should be treated as national arbiters of psychological or political questions, in general. I would like to offer my thoughts as a clinical psychologist, and as the founder and director of The Climate Mobilization.

Affect tolerance—the ability to tolerate a wide range of feelings in oneself and others—is a critical psychological skill. On the other hand, affect phobia—the fear of certain feelings in oneself or others—is a major psychological problem, as it causes people to rely heavily on psychological defenses.

Much of the climate movement seems to suffer from affect phobia, which is probably not surprising given that scientific culture aspires to be purely rational, free of emotional influence. Further, the feelings involved in processing the climate crisis—fear, grief, anger, guilt, and helplessness—can be overwhelming. But that doesn’t mean we should try to avoid "making" people feel such things. Experiencing them is a normal, healthy, necessary part of coming to terms with the climate crisis. I agree with David Roberts that it is OK, indeed imperative, to tell the whole, frightening story. As I argued in a 2015 essay, The Transformative Power of Climate Truth, it's the job of those of us trying to protect humanity and restore a safe climate to tell the truth about the climate crisis and help people process and channel their own feelings—not to preemptively try to manage and constrain those feelings.

Holthaus writes of people feeling deep anxiety, losing sleep, re-considering their lives due to the article… but this is actually a good thing. Those people are coming out of the trance of denial and starting to confront the reality of our existential emergency. I hope that every single American, every single human experiences such a crisis of conscience. It is the first step to taking substantial action. Our job is not to protect people from the truth or the feelings that accompany it—it’s to protect them from the climate crisis.

I know many of you have been losing sleep and reconsidering your lives in light of the climate crisis for years. We at The Climate Mobilization sure have. TCM exists to make it possible for people to turn that fear into intense dedication and focused action towards a restoring a safe climate.

In my paper, Leading the Public into Emergency Mode—a New Strategy for the Climate Movement, I argue that intense, but not paralyzing, fear combined with maximum hope can actually lead people and groups into a state of peak performance. We can rise to the challenge of our time and dedicate ourselves to become heroic messengers and change-makers.

I do agree with the critique, made by Alex Steffen among others, that dire discussions of the climate crisis should be accompanied with a discussion of solutions. But these solutions have to be up to the task of saving civilization and the natural world.  As we know, the only solution that offers effective protection is a maximal intensity effort, grounded in justice, that brings the United States to carbon negative in 10 years or less and begins to remove all the excess carbon from the atmosphere. That's the magic combination for motivating people: telling the truth about the scale of the crisis and the solution.

In Los Angeles, our ally City Councilmember Paul Koretz is advocating a WWII-scale mobilization of Los Angeles to make it carbon neutral by 2025. He understands and talks about the horrific dangers of the climate crisis and is calling for heroic action to counter them. Local activists and community groups are inspired by his challenge.

Columnist Joe Romm noted, we aren't doomed—we are choosing to be doomed by failing to respond adequately to the emergency, which would of course entail initiating a WWII-scale response to the climate emergency. Our Victory Plan lays out what policies would look like that, if implemented, would actually protect billions of people and millions of species from decimation. They include: 1) An immediate ban on new fossil fuel infrastructure and a scheduled shut down of all fossil fuels in 10 years; 2) massive government investment in renewables; 3) overhauling our agricultural system to make it a huge carbon sink; 4) fair-shares rationing to reduce demand; 5) A federally-financed job guarantee to eliminate unemployment 6) a 100% marginal tax on income above $500,000.

Gradualist half measures, such as a gradually phased-in carbon tax or cap-and-trade system, that seem "politically realistic" but have no hope of actually restoring a safe climate, are not adequate to channel people's fear into productive action.

We know what is physically and morally necessary. It's our job—as members of the climate emergency movement—to make that politically possible. This will not be easy, emotionally or otherwise. It will take heroic levels of dedication from ordinary people. We hope you join us.

The Planet Is Warming. And It's Okay to Be Afraid by Margaret Klein Salamon, Common Dreams, July 17, 2017

This work is licensed under a Creative Commons Attribution-Share Alike 3.0 License

Margaret Klein Salamon, Phd is co-founder and director of Climate Mobilization. Klein earned her doctorate in clinical psychology from Adelphi University and also holds a BA in Social Anthropology from Harvard. Though she loved being a therapist, Margaret felt called to apply her psychological and anthropological knowledge to solving climate change. Follow her and Climate Mobilization on Twitter: @ClimatePsych /@MobilizeClimate

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Is energy 'dominance' the right goal for US policy?

July 18, 2017 - 1:53am

Daniel Raimi, Senior research associate (Resources for the Future), Lecturer (University of Michigan Ford School of Public Policy), University of Michigan

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

In recent weeks, a new energy buzzword has taken flight from Washington, D.C., making stops in Alaska, North Dakota, Texas, Utah and more: “American energy dominance.” Taking a cue from a 2016 speech by then-candidate Donald Trump, top federal officials including Energy Secretary Rick Perry and Interior Secretary Ryan Zinke have begun to trumpet the notion of energy “dominance.”

Although no Cabinet official has offered a precise definition, it’s a recurring theme in a set of administration events organized around energy policy, including a planned speech by Trump emphasizing exports of coal, natural gas and oil.

So what does this new energy catchphrase mean, and how should we think about it?

Domestic boom

For decades, U.S. politicians have trumpeted the notion of energy “independence,” focused primarily on the need to eliminate oil imports from OPEC nations and other countries that may not share U.S. interests. But as other energy policy experts have observed, “independence” was never a smart energy goal. Isolating the U.S. from global energy markets is neither in the interest of domestic consumers nor newly resurgent oil and gas producers in the U.S.

For consumers, access to international markets ensures energy supplies at more stable prices. For instance, consider what would happen if a hurricane shut down production and refining along the Gulf Coast, the hub of the U.S. oil and gas industry. Without access to global markets, prices for motor fuels, home heating fuels and other products would be far more volatile.

As for producers, they have argued strongly for opening up, rather than sealing off, access to international energy markets. They’ve lobbied to lift restrictions on crude oil exports and encouraged exports of natural gas via new pipelines and liquefied natural gas (LNG) terminals.

Spurred by increased oil and gas production as a result of the shale revolution, these policy changes have resulted in dramatic growth in U.S. energy exports. In fact, net energy exports (energy exports minus energy imports) have risen to their highest level in decades. The United States could even be a net energy exporter by 2020 under one optimistic scenario.

The surge in oil and natural gas production in the U.S. means the country could become a net exporter of oil and natural gas. Energy Information Administration

This is a historic change, and administration officials are right to point out that the boom in energy production has benefited local economies, boosted tax revenues and increased U.S. leverage in diplomatic matters with countries like Russia and Iran. It has also raised important environmental and social concerns in impacted communities, such as soil and water contamination from oil and gas wastewater spills, increased traffic accidents and more.

But does does a strengthened oil and gas industry put the United States on track to energy dominance? In a word, no.

Pull of global markets

When people use the word “dominant,” they might think of the 2017 NBA Golden State Warriors, or Roger Federer in his heyday at Wimbledon.

“Dominance” suggests the United States could bend geopolitical adversaries to its will by wielding energy as some type of bargaining chip or weapon. But the buying and selling of oil, gas and other forms of U.S.-produced energy are directed by market forces, not government policy. For example, a large share of recently increased crude oil exports from the U.S. has effectively gone to Venezuela, hardly a close ally. (To be precise, these exports go to the island of Curacao, where a Venezuelan-owned refinery blends U.S. light oil with heavier Venezuelan crudes.)

Indeed, U.S. policymakers routinely object when other nations (such as Iran, Russia or Saudi Arabia) make decisions about buying or selling energy with geopolitical goals in mind. What’s more, manipulating energy exports to punish or reward other nations would almost certainly lead to retaliation, erecting new trade barriers that would ultimately harm the domestic and global economy.

And even if it were desirable, “dominance” of global energy markets in today’s world is simply unrealistic. There is no Roger Federer of energy.

Consider the Organization of Petroleum Exporting Countries (OPEC), maybe the closest thing to the Golden State Warriors of the energy world, which has struggled mightily in recent years to exert some control over consistently low oil prices. U.S. oil and natural gas producers, while reemergent as major players, do not have OPEC’s market power, let alone that of John D. Rockefeller in the late 1800s and early 1900s or the Texas Railroad Commission from the 1930s through the 1960s (see the excellent new book “Crude Volatility” for more on this).

And why is it unrealistic to expect U.S. producers to exert this type of power? The answer lies in the enormous scale of the global energy system, which is many times larger than in the heyday of Rockefeller or other effective market managers.

A better objective

When viewed on this global scale, the resurgence of U.S. energy production looks more far more modest. The scale of current and projected global energy demand is so vast, changes in trends of U.S. energy production hardly make a dent. As a share of global energy demand, U.S. production has actually declined from 24 percent in 1980 to about 15 percent today, and is projected to decline further – even under a scenario where domestic oil and gas production grows more rapidly than expected – to 13 percent by 2040.

Even with surging oil and gas production, the U.S. still only supplies a small portion of global demand, which limits its geopolitical influence. Energy Information Administration

To craft smart energy policies, decision-makers need to clearly identify their objectives, then work toward meeting them. These objectives should focus on enabling widespread access to reliable, affordable and sustainable energy sources.

Like its forerunner, energy “independence,” the notion of American energy “dominance” is unrealistic, given the outsize role global markets play compared to U.S. policy, and it unwisely distracts from the goals that should be shaping U.S. energy policy.


Surrendering to fear brought us climate change denial and President Trump

July 17, 2017 - 1:46am

This story picks up where an earlier post left off a few weeks ago. Then, I discussed some of the political realities associated with inaction on climate change. In that post, I said I would revisit the question of why so many people deny the evidence of a changing climate. Now is the time for that discussion.

What continually befuddles people who work on climate change is the vehement and indefensible denial of evidence by a small segment of the population. I give many public talks on climate change, including radio and television interviews and public lectures. Nearly every event has a few people who, no matter what the evidence, stay in a state of denial. By listening to denialist arguments, I find they fall into a few broad categories. Some of them are just plain false. Examples in this category are ones like:

There was a halt to global warming starting 1998.

Humans are only responsible for a tiny fraction of the greenhouse gases in the atmosphere.

Scientists are colluding to create this fraud.

Others are not false but are completely irrelevant. For example:

Climate is always changing.

We didn’t have thermometers a million years ago to measure global temperatures.

Cities are hotter than their surroundings.

Why would people think things or repeat statements that are known to be false or irrelevant? I am convinced that for the vast majority of people, they are not intentionally being incorrect. Something must be forcing them to be wrong. What could that be? Why are people so willing to believe and repeat lies?

That brings me to the connection with President Trump. His sheer number of falsehoods and flip-flops is so great, you lose track of them all. For instance, let us take the so-called wall to stop illegal immigration. First he said Mexico will pay for it and it will be “so tall;” now, he wants it to be paid by the US taxpayer. He falsely exaggerated the number of jobs that have been created since he came into office. He made false statements about the size of his electoral win. He made false statements about President Obama’s birthplace. He has made false and unsupported claims about voter fraud. He has made false claims about climate scientists. 

Finally, there is the current investigation into his and his administration’s potential collusion with Russia and obstruction of justice. I could go on and on and likely will get complaints from readers that I forgot this or that falsehood, but I have to limit the length of this post.

In a sane world, everyone would understand the threat of climate change and our ability to take meaningful action to handle it. In a sane world, no one would believe a president who has misled them time and time again.

So that raises the question - what is the reason people still discount the incontrovertible climate change evidence? What is the reason a persistent minority still support this dishonest president? I think I have figured it out, and if I’m right, it makes it much easier to reconcile the generally logical people I know with their seeming indefensible belief systems.

In a certain respect, this reason is something we as humans are nearly powerless to counteract. Before I give the reason, I want to be clear that I am sure others have noticed this too. I am sure others have written learned papers articulating this much more clearly than I can. My discovery is just a personal observation; something I should have recognized long ago. I am also not a psychologist so this is just my observations as a physical scientist.

The reason isn’t religion, it isn’t political ideology, it isn’t lack of scientific knowledge, it isn’t politics, it isn’t tribal identification. It’s none of those things.

The reason is fear.

Whether people are reciting a litany of falsehoods about climate change or whether they are contorting themselves to justify support for this president, they are doing so because they have to. They have to, because they are afraid of what happens if they accept reality.

With climate change, people are afraid for two reasons. First, they are afraid there is nothing they can do about it. Humans hate to have threats that are beyond our control. We are more afraid of Ebola than heart disease. We are more afraid of flying than driving, we are more afraid of sharks than toasters. We afraid of things we feel we cannot directly control.

Secondly, we are also afraid of bad news. How often have you not checked your bank account because you don’t want the bad news? Have you ever known someone who didn’t go to a doctor because they just didn’t want to know what their ailment was? It is so much easier to pretend a problem doesn’t exist. In fact, I’ll go a step further and say that people like to be lied to when it quiets their fear.

So with respect to climate change, that puts the population into two groups. The first group (which I am part of) knows that there is a problem, wants to face it head on, and solve it together. The second group cannot bear to look the problem honestly in the face and finds it easier to deny its existence.

Click here to read the rest

2017 SkS Weekly Climate Change & Global Warming Digest #28

July 16, 2017 - 4:05pm

Story of the Week... El Niño/La Niña Update... Toon of the Week... SkS in the News... Coming Soon on SkS... Poster of the Week... Climate Feedback Reviews... SkS Week in Review... 97 Hours of Consensus...

Story of the Week...

Seven charts show why the IEA thinks coal investment has already peaked

Global investment in coal-fired power plants is set to decline “dramatically” after passing an all-time high during the past several years, says the International Energy Agency (IEA).

That’s one of the most striking messages from World Energy Investment 2017, published today. The report, now in its second year, offers a comprehensive picture of energy investment from fossil-fuel extraction through to transport, energy efficiency and power networks.

The IEA report is not only backwards looking, reporting money already invested. It also offers a glimpse of forthcoming trends, by reporting the value of decisions taken to invest in future.

Overall, investment fell again last year, as the oil-and-gas sector continued to cut back in response to low prices. Steady investment in renewables, along with falling costs, saw 50% more capacity being added in 2016 than in 2011. But gains for low-carbon wind and solar are being offset by declines in hydro and nuclear.

Carbon Brief has seven charts with the key messages from this year’s energy investment report. 

Seven charts show why the IEA thinks coal investment has already peaked by Robert McSweeney, Carbon Brief, July 11, 2017

El Niño/La Niña Update

The latest ENSO forecast by CPC/IRI is holding steady since last month and favoring ENSO-neutral conditions (50-55% chance) into the winter of 2017-18. Although not favored, El Niño development has an elevated chance of occurring (~35-45%) relative to the long-term average (~25-35%), so we still need to keep our eyes on this possibility.

July 2017 ENSO update: Holding steady by Nat Johnson, ENSO Blog, NOAA's, July 13, 2017

Toon of the Week...


SkS in the News...

[To be added.] 

Coming Soon on SkS...
  • 2017 SkS Weekly Climate Change & Global Waming Digest (John Hartz)
  • Reflections on the politics of climate change (How Trump informs us about climate denial) – part 2 (John Abraham)
  • As Trump pulls out of the Paris Agreement, remember: We've seen this before (Benjamin Franta)
  • Scott Pruitt wants to take climate science into The Matrix (Dana)
  • Is energy ‘dominance’ the right goal for US policy? (Daniel Raimi)
  • ClimateChats: Climate Pictures (Adam Levy)
  • 2017 SkS Weekly Climate Change & Global Warming News Roundup (John Hartz)
Poster of the Week...


Climate Feedback Reviews...

[To be added.] 

SkS Week in Review...  97 Hours of Consensus...


Penny Whetton's Wikipedia page and quote source.

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2017 SkS Weekly Climate Change & Global Warming News Roundup #28

July 15, 2017 - 2:11pm
A chronological listing of news articles posted on the Skeptical Science Facebook page during the past week.  Editor's Pick

Today’s Extreme Heat May Become Norm Within a Decade

When 2015 blew the record for hottest year out of the water, it made headlines around the world. But a heat record that was so remarkable only two years ago will be just another year by 2040 at the latest, and possibly as early as 2020, regardless of whether the greenhouse gas emissions warming the planet are curtailed.

That is the conclusion of a new study that uses climate models to project when today’s climate extremes will become commonplace — or the “new normal” as they are often called in both media reports and scientific analyses. 

Weather stations in the U.S. that are having a warmer than normal, colder than normal and record hot year.

Just how soon that record heat will become the norm surprised even its researchers, but the information could be useful to officials around the world trying to plan for the changes global warming will bring to their cities and countries. It will help show when notable heat waves, downpours, or other extremes may become run-of-the-mill, and would allow planners to develop the infrastructure and policies to withstand those extremes.

“At the moment, it doesn’t seem like such a big deal when we have record-hot summers or years,” study leader Sophie Lewis, a climate researcher at Australian National University, said in an email. “But this study really shows the nasty side of our current records becoming more frequent in the near future.”

While the phrase new normal has been used in different ways, it was rarely explicitly defined, so Lewis and her colleagues wanted to come up with a definition that could be used on all kinds of climate extremes.

The team used the climate models developed for the most recent report of the Intergovernmental Panel on Climate Change to see when a global temperature like that of 2015, or higher, becomes normal. When such temperatures happened at least half the time in a 20-year period, they defined that normal as having been reached in the first year of the period.

Today’s Extreme Heat May Become Norm Within a Decade by Andrea Thompson, Climate Central, July 14, 2017 

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Study: On climate change and elsewhere, politicians more conservative than citizens

July 14, 2017 - 2:57am

Academics have identified a skew in American politics, in which policies that are implemented are much more conservative than average Americans prefer. A new paper  by David Broockman at Stanford University and Christopher Skovron from the University of Michigan suggests a cause for this disparity: American politicians perceive their constituents’ positions as more conservative than they are in actuality on a wide range of issues; for example, Republican politicians tend to overestimate support for their conservative health care views by a whopping 20 percentage points. As Broockman and his colleague Christopher Warshaw of MIT put it in an article for the New York Times: “Research shows that politicians are surprisingly poor at estimating public opinion in their districts and state, Republicans in particular.” This in turn appears to be caused by greater political engagement among conservative constituents, who contact their members of Congress more frequently than liberal voters.

The study's authors looked at data surveying thousands of American politicians’ perceptions of their constituents’ opinions, and compared those results to actual public opinion. They found that both Democratic and Republican politicians perceive that public opinion is more conservative than it is in actuality, but it’s especially true among Republican legislators. That matches patterns in grassroots mobilization—Republican voters are about 40 percent more likely to contact their member of Congress’ office than Democratic voters, especially when their member of Congress is a fellow Republican.

The conservative bias in Republican politicians’ perceptions of constituent opinion extended to every question in the survey, on issues such as firearms background checks, where GOP politicians perceive 36 percent more support for their conservative positions than there actually is among the general public—something that statisticians call “skew.” Similar overestimates occur regarding the depth of support for conservative positions on the banning of assault rifles (overestimated by about 18 percent), granting amnesty to illegal immigrants (9 percent), banning abortion (9 percent), and gay marriage (7 percent). This again matches statistics on grassroots mobilization—conservative constituents are especially well-organized and vocal on the issue of gun control.

The survey didn’t include any questions about climate change, but that’s another issue on which Republican politicians’ perceptions of constituent opinion appear extremely skewed. For example, 75 percent of Americans support regulating carbon as a pollutant, and 62 percent of Trump voters support a carbon tax or a cap-and-trade system. But despite the sentiments of an overwhelming number of their constituents, the vast majority of Republican Party politicians oppose all climate policies and the GOP stands alone as the only climate-denying major political party in the world. In fact, Republican politicians’ climate policy opposition is so strong that 22 of 52 Republican senators sent a letter to Donald Trump urging withdrawal from the non-binding Paris climate accord. This position was again out of step with Republican voters, a majority of whom supported participation in the Paris agreement, including a strong plurality of Trump voters.

The question then arises—how do Republicans keep winning elections if the policies they implement are more conservative than voters prefer?

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2017 SkS Weekly Climate Change & Global Warming Digest #27

July 9, 2017 - 5:15pm

Story of the Week... Toon of the Week... SkS Spotlights... Coming Soon on SkS... Poster of the Week... Climate Feedback Reviews... SkS Week in Review... 97 Hours of Consensus...

Story of the Week...

The World Is on the Brink of an Electric Car Revolution

The internal combustion engine had a good run. It has helped propel cars — and thus humanity — forward for more than 100 years.

But a sea change is afoot that is forecast to kick gas-powered vehicles to the curb, replacing them with cars that run on batteries. A flurry of news this week underscores just how rapidly that change could happen.

Robots at the Tesla factory in Fremont, Calif. put together electric cars. Credit: Tesla Motors 

A quick recap: On Monday, Tesla announced that the Model 3, its mass-market electric car, would start rolling off production lines this week with the first handful delivered to customers later this month. Then on Wednesday, Volvo announced that every car it produces will have a battery in it by 2019, putting it at the forefront of major car manufacturers. Then came France’s announcement on Thursday that it would ban the sale of gas-powered cars by 2040.

All this news dropped just in time for Bloomberg New Energy Finance’s latest electric car report, which lays out why electric cars are the way of the future and when they’re projected to take over the market. The authors said although electric vehicles are currently a tiny fraction of the car market, that market could reach an inflection point sometime between 2025-2030. After that, electric car sales are slated to increase rapidly.

Driven by the falling cost of batteries and the growing number of automakers producing a wider variety of electric cars, Bloomberg NEF expects that electric cars will account for 54 percent of all car sales globally by 2040. That’s a huge uptick from its forecast last year of electric vehicles accounting for 35 percent of all sales.

The shift to electric vehicles will disrupt the fossil fuel industry. The 530 million total electric cars forecast to be on the road by 2040 will require 8 million fewer barrels of oil a day to run.

A new forecast for electric cars shows explosive growth in new sales, particularly in China.
Credit: Bloomberg NEF 

One of the big pitches for electric cars is their positive benefit for the climate because they reduce the use of oil. But they will require a lot more power from the electric grid. Energy use from electric vehicles is expected to rise 300 times above current demand, putting more strain on power generation.

How that energy is produced will go a long ways toward determining how climate-friendly electric cars actually are. A recent Climate Central analysis looked at all 50 states and found that the energy mix was clean enough in 37 of them to ensure electric cars are more climate friendly than their most fuel-efficient combustion engine counterparts.

That’s a sharp uptick from a 2013 analysis, which found that there were just 13 states where electric cars were cleaner than gas-powered ones, and it’s driven in large part by a precipitous drop in coal use.

While the U.S. is projected to be one of the biggest drivers of the electric vehicle revolution, China and the European Union will also be major players. By 2025, Bloomberg NEF’s projections show that China will be the biggest buyer of electric vehicles in the world, a trend that continues through 2040.

That means how China’s energy mix develops will be one of the most important factors to determining how climate friendly all the new electric vehicles on the road will be.

The World Is on the Brink of an Electric Car Revolution by Brian Kahn, Climate Central, July 6, 2017 

Toon of the Week...


SkS Spotlights...

ReliefWeb is the leading humanitarian information source on global crises and disasters. It is a specialized digital service of the UN Office for the Coordination of Humanitarian Affairs (OCHA).

We provide reliable and timely information, enabling humanitarian workers to make informed decisions and to plan effective response. We collect and deliver key information, including the latest reportsmaps and infographics and videos from trusted sources.

ReliefWeb is also a valuable resource for job listings and training programs, helping humanitarians build new skills and discover exciting new career opportunities. 

Coming Soon on SkS...
  • 2017 SkS Weekly Climate Change & Global Waming Digest #27 (John Hartz)
  • Conservatives are again denying the existence of global warming (Dana)
  • Those 80 graphs that only show evidence of climate myths (Ari Jokimaki)
  • Explainer: Dealing with the ‘loss and damage’ caused by climate change (Carbon Brief)
  • Republicans want to use taxpayer dollars to fund climate science losers (John Abraham)
  • ClimateChats: Climate Pictures (Adam Levy)
  • 2017 SkS Weekly Climate Change & Global Warming News Roundup #28 (John Hartz) 
Poster of the Week...


Climate Feedback Reviews...

Climate Feedback asked its network of scientists to review The American South Will Bear the Worst of Climate Change’s Costs by Robinson Meyer, The Atlantic, June 29, 2017

Three scientists analyzed the article and estimated its overall scientific credibility to be ‘high’.  
A majority of reviewers tagged the article as: Accurate

Click here to acess the entire review.

SkS Week in Review... 97 Hours of Consensus...



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2017 SkS Weekly Climate Change & Global Warming News Roundup #27

July 8, 2017 - 3:37pm
A chronological listing of news articles posted on the Skeptical Science Facebook page during the past week.  Editor's Pick

G20 closes with rebuke to Trump's climate change stance


German Chancellor Angela Merkel closed the G20 summit in Hamburg with a rebuke to President Donald Trump's stance on climate change, but the group of the world's economic leaders appeared to make a concession on his protectionist trade policies.

Officials had been at an impasse over an increasingly isolationist United States and Trump's climate change and trade policies for most of the summit, and Merkel made it clear the United States had made talks difficult. "Unfortunately — and I deplore this — the United States of America left the climate agreement, or rather announced their intention of doing this," Merkel said as she closed the summit and presented a G20 declaration. 

G20 closes with rebuke to Trump's climate change stance by Angela Dewan & Stephanie Halasz, CNN, July 8, 2017

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2017 SkS Weekly Climate Change & Global Warming Digest #26

July 2, 2017 - 5:21pm

Story of the Week... Toon of the Week... Quote of the Week... Coming Soon on SkS... Poster of the Week... Climate Feedback Reviews... SkS Week in Review... 97 Hours of Consensus...

Story of the Week...

Carbon in Atmosphere Is Rising, Even as Emissions Stabilize

The Cape Grim Baseline Air Pollution Station in Tasmania. Credit: Commonwealth Scientific and Industrial Research Organization (CSIRO)

CAPE GRIM, Tasmania — On the best days, the wind howling across this rugged promontory has not touched land for thousands of miles, and the arriving air seems as if it should be the cleanest in the world.

But on a cliff above the sea, inside a low-slung government building, a bank of sophisticated machines sniffs that air day and night, revealing telltale indicators of the way human activity is altering the planet on a major scale.

For more than two years, the monitoring station here, along with its counterparts across the world, has been flashing a warning: The excess carbon dioxide scorching the planet rose at the highest rate on record in 2015 and 2016. A slightly slower but still unusual rate of increase has continued into 2017.

Scientists are concerned about the cause of the rapid rises because, in one of the most hopeful signs since the global climate crisis became widely understood in the 1980s, the amount of carbon dioxide that people are pumping into the air seems to have stabilized in recent years, at least judging from the data that countries compile on their own emissions.

That raises a conundrum: If the amount of the gas that people are putting out has stopped rising, how can the amount that stays in the air be going up faster than ever? Does it mean the natural sponges that have been absorbing carbon dioxide are now changing? 

Carbon in Atmosphere Is Rising, Even as Emissions Stabilize by Justin Gillis, New York Times, June 26, 2017

Toon of the Week...


Quote of the Week...

The basics of scientists’ understanding of climate change can be communicated in five key points: It’s real, it’s caused by humans, it’s bad, the experts agree, and there’s still hope for fixing it, according to John Cook, a research assistant professor at George Mason University’s Center for Climate Change Communication.

“When you look at all the climate denial arguments, they’re basically the flip of all that: It’s not real, it’s not us, it’s not bad, the experts disagree or the experts are unreliable, and there’s no hope, we can’t fix it,” Cook told HuffPost. “You expect them to be moving along that spectrum.”

Don’t Be Fooled By The Gentler Tone Of Charles Koch’s Climate-Change Denial by Alexander C Kaufman, HuffPost, June 26, 2017

SkS Spotlights...

Nature World News offers fascinating and comprehensive news about the scientific world. Whether it's about animals, health, space, or archaeological finds, the website brings out the science geek in every reader, fostering an improved appreciation of our environment.

Our writers and editors are dedicated to dissect and interpret complex information from the latest scientific studies to deliver articles that are easily digestible. We get our information from authoritative sources, world’s leading scientists, experts and researchers, encompassing a variety of topics — animals, biology, environment, health and medicine, technology, travel, and space.

We live in a world where we depend on science and technology for our everyday life; yet, almost no one understands it. At Nature World News, by using accessible journalism, we hope to make complicated science easier to understand. 

Coming Soon on SkS...
  • 2017 SkS Weekly Climate Change & Global Waming Digest #26 (John Hartz)
  • 'The best data we have' just got a lot hotter (John Abraham)
  • Mapped: Climate change laws around the world (Simon Evans)
  • Rick Perry's 'I don't believe that' – the slogan for climate denial (Dana)
  • Republicans want taxpayers to pay for a 'Red Team' of climate science losers (John Abraham)
  • ClimateChats: Climate Pictures (Adam Levy)
  • 2017 SkS Weekly Climate Change & Global Warming News Roundup #27 (John Hartz) 
Poster of the Week...


Climate Feedback Reviews...

Climate Feedback asked its network of scientists to review 95-Degree Days: How Extreme Heat Could Spread Across the World by Brad Pulmer & Nadja Popovich, New York Times, June 22, 2017

Four scientists analyzed the article and estimated its overall scientific credibility to be ‘high’.  
A majority of reviewers tagged the article as: .

Click here to acess the entire review.

SkS Week in Review...  97 Hours of Consensus...



James Hansen's bio page

Quote derived with author's permission from:

"We have known since the 1800s that carbon dioxide traps heat in the atmosphere. The right amount keeps the climate conducive to human life. But add too much, as we are doing now, and temperatures will inevitably rise too high. This is not the result of natural variability, as some argue. The earth is currently in the part of its long-term orbit cycle where temperatures would normally be cooling. But they are rising — and it’s because we are forcing them higher with fossil fuel emissions." 

High resolution JPEG (1024 pixels wide)

2017 SkS Weekly Climate Change & Global Warming News Roundup #26

July 1, 2017 - 12:30pm
A chronological listing of news articles posted on the Skeptical Science Facebook page during the past week.  Editor's Pick

Mission 2020: A new global strategy to ‘rapidly’ reduce carbon emissions

Figure from Figueres et al. (2017)

In April, a new global initiative called Mission 2020 was launched by Christiana Figueres, the former UN climate chief who oversaw the signing of the Paris Agreement on climate change in late 2015.

The aim of Mission 2020 is to bring “new urgency” to the “global climate conversation” with a call to begin “rapidly declining” global greenhouse gas emissions by 2020.

Today, in a co-authored commentary published in the journal Nature, Figueres sets out further details about Mission 2020’s six central calls to action. The commentary is endorsed by 61 signatories, which include climate scientists as well as a range of NGO, religious, political and business leaders. 

Mission 2020: A new global strategy to ‘rapidly’ reduce carbon emissions by Zeke Hausfather, Carbon Brief, June 28, 2017 

Links posted on Facebook

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Trump fact check: Climate policy benefits vastly exceed costs

June 30, 2017 - 1:45am

When people who benefit from maintaining the status quo argue against climate policies, they invariably use two misleading tactics: exaggerating the costs of climate policies, and ignoring their benefits—economic and otherwise. In justifying his historically irresponsible decision to withdraw America from the Paris Agreement on climate change, President Trump followed this same playbook, falsely claiming: “The cost to the economy at this time would be close to $3 trillion in lost GDP [gross domestic product].”

That statistic originated from a report by National Economic Research Associates, Inc., which explicitly notes that it “does not take into account potential benefits from avoided emissions. The study results are not a benefit-cost analysis of climate change.” As Yale economistKenneth Gillingham noted, the report’s cost estimates are also based on one specific set of policy actions that the United States could implement to meet its Paris pledges. But there’s an infinite combination of possible climate policy responses, with some costing more than others.

For example, a revenue-neutral carbon tax is the proposed policy that currently has the most widespread support. One such proposal by the Climate Leadership Council has been endorsed by a broad coalition that includes Stephen Hawking, ExxonMobil, the Nature Conservancy, and George Shultz. And the Citizens’ Climate Lobby—a nonpartisan grassroots organization advocating for a similar policy—recently sent over 1,000 volunteers to lobby members of Congress in Washington, DC.

Regional Economic Modeling, Inc. (REMI) evaluated how the Citizens’ Climate Lobby’s proposed policy would impact the US economy. The REMI report concluded that implementing a rising price on carbon pollution and returning 100 percent of the revenue equally to American taxpayers would grow the economy and modestly increase personal disposable income, employment, and gross domestic product—the total of all goods and services produced within a nation’s borders. And the REMI report didn’t even include the financial benefits of slowing climate change and curbing its harmful economic impacts.

Those benefits are potentially massive. In terms of climate change, many of the benefits are realized in avoided costs. For example, the 2006 Stern Review on the Economics of Climate Change found that unabated climate change would cost the world 5 to 20 percent of GDP by 2100. The economic picture could be even bleaker yet—most economic modeling assumes that economic growth will continue steadily regardless of climate change, but in reality, climate impacts are likely to slow economic growth. That was the finding of two papers published in 2015 by researchers from Stanford and the University of California at Berkeley.

The second paper found that there’s a sweet spot average temperature of around 13 degrees Celsius (55 degrees Fahrenheit) at which economic productivity is highest. The United States and much of Europe currently have climates in that optimal range, but many countries near the equator—which happen to predominantly be poorer, developing countries—already have temperatures above the sweet spot. As global warming causes temperatures to rise, the climates of the United States and Europe will slip out of the economically optimal temperature range, and that same temperature rise will push those poorer countries even further into the realm of economy-crippling heat. As a result, global warming will hamper economic growth. The researchers estimated that this would amplify the costs of climate change by at least 2.5 times more than previous estimates.

Tackling global warming will certainly come with costs. Although a revenue-neutral carbon tax would benefit the economy, that one policy by itself won’t be enough to solve the problem. We would still need to invest in and deploy low-carbon technologies like renewable energy and electric vehicles. However, looking at those costs in isolation without considering their benefits, as President Trump did, paints a misleading and inaccurate picture.

For example, Citibank—America’s third-largest bank—published a report in 2015 looking at both the costs and benefits of climate action and inaction scenarios. The report found that inaction actually had higher investment costs than the action scenario—such as cost-saving investments in energy efficiency, for example. 

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SkS Analogy 9 - The greenhouse effect is a stack of blankets

June 29, 2017 - 3:53am
Tag Line

The greenhouse effect is like a stack of blankets on a winter night.

Elevator Statements
  1. More blankets = more warmth: The greenhouse effect is like blankets warming the Earth. If it is -18°C (0°F) in your bedroom, you need a few blankets to keep yourself warm. More blankets = more warming. Too many blankets and you sweat. So the point is that the greenhouse effect is a good thing, up to a point.
  2. More blankets means warmer inside, cooler outside: With an increasing number of blankets, the temperature above the blankets gets cooler, because more energy is trapped below the blankets. With increasing greenhouse gases (GHGs) in Earth’s atmosphere, the upper atmosphere gets progressively cooler, because more energy is trapped in the lower layers of the atmosphere. This is one way that scientists know that the recent warming is due to greenhouse gases and not due to increasing solar output. In the sleeping analogy, if you turned up the temperature in the room, it would get warmer both above and below the blankets. If the recent warming was due to a hotter sun, then both the upper and lower atmosphere would warm. But the upper atmosphere is getting colder, just as the top of the outer blanket covering you gets colder when you add more blankets but leave the room temperature the same. See the SkS article "Is the CO2 effect saturated?"
  3. It is not the rate at which you put blankets on, but the total number of blankets that determines your final warmth. CO2 emission rates don’t mean anything, except that if we slow the emission rates it buys us more time. It is the total CO2 emitted that matters, just like it is only the total number of blankets over you that matters, and not the rate at which you put them on. Carbon budgets refer to the total amount of CO2 we can emit before we exceed a dangerous level of warming, just as a blanket budget represents the total number of blankets we can tolerate before we start to sweat and overheat. Some skeptics refer to a time about 600 million years ago, during the late Ordovician when CO2 levels were higher, but earth was the same temperature as now, or cooler. They point to this time to imply that CO2 levels do not correlate to temperature. But 600 million years ago the sun was cooler (like a colder bedroom), so that the colder bedroom combined with more blankets = similar temperature as today. If you turn down the heat in your room, you need an extra blanket or two. Thus, with a colder room, your blanket budget is higher.
Climate Science

On the topic of the blanket budget, assuming that we warm 3°C for every doubling of CO2 (this is the average climate sensitivity used by the IPCC [Intergovernmental Panel on Climate Change]), this corresponds to the following temperature increase for given CO2 atmospheric concentrations. Each of these atmospheric concentrations roughly corresponds to a particular CO2 budget.
•    350 ppm CO2 = 1°C warming
•    445 ppm CO2 = 2°C warming (2°C is the target agreed to by the Paris Agreement)
•    560 ppm CO2 = 3°C warming
•    700 ppm CO2 = 4°C warming (considered by many Climate Scientists to be unbearable)
We are currently at about 406 ppm, increasing at about 2 ppm/year. This means that at the current emission rates we will have reached our budget for 2°C by the year 2035 and crossed into really dangerous territory. This is why Climate Scientists are saying that there is no time to waste for cutting our carbon emissions.

The budgets used by the IPCC  are based on scenarios more complex than the simple math above, but IPCC budget estimates also often assume that we will be able to suck CO2 out of the air and bury it in the ground … at some time in the future. My simple estimate uses a climate sensitivity of 3°C/doubling of CO2, and assumes that we will not be successful at sucking CO2 out of the atmosphere and storing it underground. After all, to bring CO2 concentrations down means that we have to suck all of the CO2 emitted in a given year + an extra amount. Is that feasible? Great if we succeed, but at current emission rates we will be at our budget limit by 2035, and the planet will be warming while we are trying to bring these massive negative emissions technologies online. A good read on the subject is Kevin Anderson, or if you can watch him as well.

Climate scientists just debunked deniers' favorite argument

June 28, 2017 - 1:21am

Whenever they hold one of their frequent hearings to reject and deny established climate science, congressional Republicans invariably trot out contrarian scientist John Christy, who disputes the accuracy of climate models. In doing so, Christy uses a cherry-picked, error riddled chart, but there’s a nugget of truth in his argument. Although the discrepancy isn’t nearly as large as Christy’s misleading chart suggests, atmospheric temperatures seem not to have warmed quite as fast since the turn of the century as climate model simulations anticipated they would.

Remote Sensing Systems estimate of the temperature of the middle troposphere compared to the CMIP5 multi-model average (top frame), and the difference between the two over time (bottom frame). Illustration: Santer et al. (2017), Nature Geoscience

How you react to this information is a good test of whether you’re a skeptic or a denier. A denier will declare “aha, the models are wrong, therefore we don’t need any climate policies!” A skeptic will ask what’s causing the difference between the observational estimates and model simulations.

There are many possible explanations. Maybe the tricky and often-adjusted estimates of the atmospheric temperature made by instruments on orbiting satellites are biased. Maybe there’s something wrong with the models, or our understanding of Earth’s atmosphere. Maybe the inputs used in the model simulations are flawed. The answer is likely a combination of these possibilities, but in congressional testimony earlier this year, Christy tried to place the blame entirely on the models, with a denier-style framing:

the average of the models is considered to be untruthful in representing the recent decades of climate variation and change, and thus would be inappropriate for use in predicting future changes in the climate or for related policy decisions.

And in testimony to Congress in December 2015, Christy offered his unsupported speculation that the discrepancy was a result of climate models being too sensitive to rising greenhouse gases:

Indeed, the theoretical (model) view as expressed in the IPCC AR5 in every case overestimated the bulk tropical atmospheric temperature response of extra greenhouse gases … indicating the theoretical understanding of the climate response is too sensitive to greenhouse gases.

New study tests and falsifies Christy’s assertions In a new study, a team climate scientists led by Ben Santer sought to answer this question. They effectively disproved Christy’s assertion that the discrepancy was due to models being too sensitive to the increased greenhouse effect. Instead, the main culprit seems to be incorrect inputs used in the climate model simulations.

The issue is that climate model simulations are run using specific scenarios. These scenarios assume specific changes in factors that influence global temperature and climate changes (known as “forcings”), like rising levels of atmospheric greenhouse gases and changes in solar and volcanic activity. Climate models don’t make “predictions;” rather, they make “projections” of how temperatures and other climatological factors will change in response to those forcing input scenarios. There’s also a random component known as “internal variability” due to factors like unpredictable ocean cycles. 

An infamous example of deniers exploiting this wonky technical point to mislead policymaker happened in 1998. Congressional Republicans invited fossil fuel-funded Pat Michaels to testify ahead of the Kyoto international climate negotiations. In a shameless distortion of reality, Michaels evaluated a 1988 global temperature projection by James Hansen at NASA, but deleted all except the scenario that was the least like the actual forcing changes that had occurred over the prior decade. By only looking at Hansen’s model projection under a scenario where greenhouse gases rose much faster than they had in reality, Michaels deceptively made it appear as though Hansen’s climate model had vastly over-predicted global warming.

Santer’s team found a similar issue in comparing simulated and observed changes in atmospheric temperatures over the past few decades:

There are known systematic errors in these forcings in model simulations performed in support of the IPCC Fifth Assessment Report. These errors arise in part because the simulations were performed before more reliable estimates of early 21st century forcing became available. The net effect of the forcing errors is that the simulations underestimate some of the cooling influences contributing to the observed “slowdown”.

For example, were Christy right that models are too sensitive to rising greenhouse gases, they should be systematically wrong during the entire period for which we have observational data. On the contrary, aside from a small discrepancy in the late 20th century that can be explained by natural internal variability, Santer’s team showed that the difference between model simulations and observations only begins around 1998. A problem with model sensitivity would also show up in studies looking at global temperature changes in response to large volcanic eruptions, which create a big change in forcing and temperature. But those studies rule out the low climate sensitivities that Christy favors, and as Santer’s team notes:

there are no large systematic model errors in tropospheric cooling following the eruptions of El Chichon in 1982 and Pinatubo in 1991.

On the other hand, research has identified a number of real-world cooling influences in the early 21st century that weren’t accurately represented in the climate model simulation scenarios. The sun went into an unusually quiet cycle, there was a series of moderate volcanic eruptions, and the boom in Chinese coal power plants added sunlight-blocking pollution to the atmosphere. Using statistical tests, Santer’s team showed that those unexpected cooling effects combined with shifts in ocean cycles best explained the model-data discrepancy in atmospheric temperatures over the past 20 years.

Deniers respond by turning on the spin cycle

Unsurprisingly, in blogs and on Twitter, deniers tried to spin the results of this study in their favor. Some claimed that the paper admitted there was a “pause” or “hiatus” in global warming. In reality, the paper used neither term, but did use the phrase “slowdown” 15 times, including explicitly clarifying that it was a “temporary” slowdown. In other words, the study clearly rejected the myth that global warming “paused;” instead, the rise in atmospheric temperatures temporarily slowed due to the aforementioned decline in solar activity, increase in pollution from coal plants and volcanic eruptions, and shifts on ocean cycles.

Other contrarians have exhibited their confirmation bias by claiming the paper is an admission that climate models are wrong. As statistician George Box said, “all models are wrong, but some are useful.” Declaring that climate models are wrong and tossing them in the waste bin is a brain-dead denial move. What any skeptical scientific mind should want to know is why they’re imperfect – what’s causing the difference between simulations and reality, and what can we learn from that?

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We are heading for the warmest climate in half a billion years

June 27, 2017 - 1:59am

Gavin Foster, Professor of Isotope Geochemistry, University of Southampton; Dana Royer, Professor of Earth and Environmental Sciences, Wesleyan University, and Dan Lunt, Professor of Climate Science, University of Bristol

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

Carbon dioxide concentrations are heading towards values not seen in the past 200m years. The sun has also been gradually getting stronger over time. Put together, these facts mean the climate may be heading towards warmth not seen in the past half a billion years.

A lot has happened on Earth since 500,000,000BC – continents, oceans and mountain ranges have come and gone, and complex life has evolved and moved from the oceans onto the land and into the air. Most of these changes occur on very long timescales of millions of years or more. However, over the past 150 years global temperatures have increased by about 1℃, ice caps and glaciers have retreated, polar sea-ice has melted, and sea levels have risen.

Some will point out that Earth’s climate has undergone similar changes before. So what’s the big deal?

Scientists can seek to understand past climates by looking at the evidence locked away in rocks, sediments and fossils. What this tells us is that yes, the climate has changed in the past, but the current speed of change is highly unusual. For instance, carbon dioxide hasn’t been added to the atmosphere as rapidly as today for at least the past 66m years.

In fact, if we continue on our current path and exploit all convention fossil fuels, then as well as the rate of CO₂ emissions, the absolute climate warming is also likely to be unprecedented in at least the past 420m years. That’s according to a new study we have published in Nature Communications.

Life in the planet’s last greenhouse period, the Eocene. Jay Matternes / Smithsonian Museum, CC BY

In terms of geological time, 1℃ of global warming isn’t particularly unusual. For much of its history the planet was significantly warmer than today, and in fact more often than not Earth was in what is termed a “greenhouse” climate state. During the last greenhouse state 50m years ago, global average temperatures were 10-15℃ warmer than today, the polar regions were ice-free, palm trees grew on the coast of Antarctica, and alligators and turtles wallowed in swamp-forests in what is now the frozen Canadian Arctic.

In contrast, despite our current warming, we are still technically in an “icehouse” climate state, which simply means there is ice on both poles. The Earth has naturally cycled between these two climate states every 300m years or so.

Just prior to the industrial revolution, for every million molecules in the atmosphere, about 280 of them were CO₂ molecules (280 parts-per-million, or ppm). Today, due primarily to the burning of fossil fuels, concentrations are about 400 ppm. In the absence of any efforts to curtail our emissions, burning of conventional fossil fuels will cause CO₂ concentrations to be around 2,000ppm by the year 2250.

This is of course a lot of CO₂, but the geological record tells us that the Earth has experienced similar concentrations several times in the past. For instance, our new compilation of data shows that during the Triassic, around 200m years ago, when dinosaurs first evolved, Earth had a greenhouse climate state with atmospheric CO₂ around 2,000-3,000ppm.

So high concentrations of carbon dioxide don’t necessarily make the world totally uninhabitable. The dinosaurs thrived, after all.

That doesn’t mean this is no big deal, however. For a start, there is no doubt that humanity will face major socio-economic challenges dealing with the dramatic and rapid climate change that will result from the rapid rise to 2,000 or more ppm.

If we burnt all fossil fuel reserves the vast Antarctic ice sheet may disappear. vladsilver / shutterstock

But our new study also shows that the same carbon concentrations will cause more warming in future than in previous periods of high carbon dioxide. This is because the Earth’s temperature does not just depend on the level of CO₂ (or other greenhouse gases) in the atmosphere. All our energy ultimately comes from the sun, and due to the way the sun generates energy through nuclear fusion of hydrogen into helium, its brightness has increased over time. Four and a half billion years ago when the Earth was young the sun was around 30% less bright.

So what really matters is the combined effect of the sun’s changing strength and the varying greenhouse effect. Looking through geological history we generally found that as the sun became stronger through time, atmospheric CO₂ gradually decreased, so both changes cancelled each other out on average.

But what about in the future? We found no past time period when the drivers of climate, or climate forcing, was as high as it will be in the future if we burn all the readily available fossil fuel. Nothing like it has been recorded in the rock record for at least 420m years.

A central pillar of geological science is the uniformitarian principle: that “the present is the key to the past”. If we carry on burning fossil fuels as we are at present, by 2250 this old adage is sadly no longer likely to be true. It is doubtful that this high-CO₂ future will have a counterpart, even in the vastness of the geological record.


New study confirms the oceans are warming rapidly

June 26, 2017 - 1:22am

As humans put ever more heat-trapping gases into the atmosphere, the Earth heats up. These are the basics of global warming. But where does the heat go? How much extra heat is there? And how accurate are our measurements? These are questions that climate scientists ask. If we can answer these questions, it will better help us prepare for a future with a very different climate. It will also better help us predict what that future climate will be.

The most important measurement of global warming is in the oceans. In fact, “global warming” is really “ocean warming.” If you are going to measure the changing climate of the oceans, you need to have many sensors spread out across the globe that take measurements from the ocean surface to the very depths of the waters. Importantly, you need to have measurements that span decades so a long-term trend can be established. 

These difficulties are tackled by oceanographers, and a significant advancement was presented in a paper just published in the journal Climate Dynamics. That paper, which I was fortunate to be involved with, looked at three different ocean temperature measurements made by three different groups. We found that regardless of whose data was used or where the data was gathered, the oceans are warming.

Ocean heat content increase globally (top frame) and in four ocean basins (bottom frames). Illustration: Wang et al. (2017), Climate Dynamics

In the paper, we describe perhaps the three most important factors that affect ocean-temperature accuracy. First, sensors can have biases (they can be “hot” or “cold”), and these biases can change over time. An example of biases was identified in the 1940s. Then, many ocean temperature measurements were made using buckets that gathered water from ships. Sensors put into the buckets would give the water temperature. Then, a new temperature sensing approach started to come online where temperatures were measured using ship hull-based sensors at engine intake ports. It turns out that bucket measurements are slightly cooler than measurements made using hull sensors, which are closer to the engine of the ship.

During World War II, the British Navy cut back on its measurements (using buckets) and the US Navy expanded its measurements (using hull sensors); consequently, a sharp warming in oceans was seen in the data. But this warming was an artifact of the change from buckets to hull sensors. After the war, when the British fleet re-expanded its bucket measurements, the ocean temperatures seemed to fall a bit. Again, this was an artifact from the data collection. Other such biases and artifacts arose throughout the years as oceanographers have updated measurement equipment. If you want the true rate of ocean temperature change, you have to remove these biases.

Another source of uncertainty is related to the fact that we just don’t have sensors at all ocean locations and at all times. Some sensors, which are dropped from cargo ships, are densely located along major shipping routes. Other sensors, dropped from research vessels, are also confined to specific locations across the globe. 

Currently, we are heavily using the ARGO fleet, which contains approximately 3800 autonomous devices spread out more or less uniformly across the ocean, but these only entered service in 2005. Prior to that, temperatures measurements were not uniform in the oceans. As a consequence, scientists have to use what is called a “mapping” procedure to interpolate temperatures between temperature measurements. Sort of like filling in the gaps where no data exist. The mapping strategy used by scientists can affect the ocean temperature measurements.

Finally, temperatures are usually referenced to a baseline “climatology.” So, when we say temperatures have increased by 1 degree, it is important to say what the baseline climatology is. Have temperatures increased by 1 degree since the year 1990? Since the year 1970? Since 1900? The choice of baseline climatology really matters.

In the study, we looked at the different ways that three groups make decisions about mapping, bias, and climatology. We not only asked how much the oceans are warming, but how the warming differs for various areas (ocean basins) and various depths. We found that each ocean basin has warmed significantly. Despite this fact, there are some differences amongst the three groups. For instance, in the 300-700 meter oceans depths in the Pacific and Southern oceans, significant differences are exhibited amongst the tree groups. That said, the central fact is that regardless of how you measure, who does the measurements, when or where the measurements are taken, we are warming.

The lead author, Dr. Gonjgie Wang described the importance of the study this way:

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