Almost from the start, arguments about mitigating climate change have included an element of cost-benefit analysis: Would it cost more to move the world off fossil fuels than it would to simply try to adapt to a changing world? A strong consensus has built that the answer to the question is a clear no, capped off by a Nobel in Economics given to one of the people whose work was key to building that consensus.
While most academics may have considered the argument put to rest, it has enjoyed an extended life in the political sphere. Large unknowns remain about both the costs and benefits, which depend in part on the remaining uncertainties in climate science and in part on the assumptions baked into economic models.
In Wednesday’s edition of Nature, a small team of researchers analyzed how local economies have responded to the last 40 years of warming and projected those effects forward to 2050. They find that we’re already committed to warming that will see the growth of the global economy undercut by 20 percent. That places the cost of even a limited period of climate change at roughly six times the estimated price of putting the world on a path to limit the warming to 2° C.
Linking economics and climate
Many economic studies of climate change involve assumptions about the value of spending today to avoid the costs of a warmer climate in the future, as well as the details of those costs. But the people behind the new work, Maximilian Kotz, Anders Levermann, and Leonie Wenz decided to take an empirical approach. They obtained data about the economic performance of over 1,600 individual regions around the globe, going back 40 years. They then attempted to look for connections between that performance and climate events.
Previous research already identified a number of climate measures—average temperatures, daily temperature variability, total annual precipitation, the annual number of wet days, and extreme daily rainfall—that have all been linked to economic impacts. Some of these effects, like extreme rainfall, are likely to have immediate effects. Others on this list, like temperature variability, are likely to have a gradual impact that is only felt over time.
The researchers tested each factor for lagging effects, meaning an economic impact sometime after their onset. These suggested that temperature factors could have a lagging impact up to eight years after they changed, while precipitation changes were typically felt within four years of climate-driven changes. While this relationship might be in error for some of the economic changes in some regions, the inclusion of so many regions and a long time period should help limit the impact of those spurious correlations.
With the climate/economic relationship worked out, the researchers obtained climate projections from the Coupled Model Intercomparison Project (CMIP) project. With that in hand, they could look at future climates and estimate their economic costs.
Obviously, there are limits to how far into the future this process will work. The uncertainties of the climate models grow with time; the future economy starts looking a lot less like the present, and things like temperature extremes start to reach levels where past economic behavior no longer applies.
To deal with that, Kotz, Levermann, and Wenz performed a random sampling to determine the uncertainty in the system they developed. They look for the point where the uncertainties from the two most extreme emissions scenarios overlap. That occurs in 2049; after that, we can’t expect the past economic impacts of climate to apply.
Kotz, Levermann, and Wenz suggest that this is an indication of warming we’re already committed to, in part because the effect of past emissions hasn’t been felt in its entirety and partly because the global economy is a boat that turns slowly, so it will take time to implement significant changes in emissions. “Such a focus on the near term limits the large uncertainties about diverging future emission trajectories, the resulting long-term climate response and the validity of applying historically observed climate–economic relations over long timescales during which socio-technical conditions may change considerably,” they argue.
Enlarge/ Members of Swiss association Senior Women for Climate Protection react after the announcement of decisions after a hearing of the European Court of Human Rights (ECHR) to decide in three separate cases if states are doing enough in the face of global warming in rulings that could force them to do more, in Strasbourg, eastern France, on April 9, 2024.
More than 2,000 older Swiss women have won a landmark European case proving that government climate inaction violates human rights.
The European Court of Human Rights (ECHR) ruled Tuesday that Switzerland had not acted urgently to achieve climate targets, leading victims, who are mostly in their 70s, to suffer physically and emotionally while potentially placed at risk of dying.
The women, part of a group called KlimaSeniorinnen (Senior Women for Climate Protection), filed the lawsuit nine years ago. They presented medical documents and scientific evidence that older women are more vulnerable to climate impacts, arguing that “their health and daily routines were affected” by Swiss heatwaves connected to climate change.
One woman who had to regularly measure her blood pressure and refrain from activities when temperatures were too high told the court that “the thermometer determined the way she led her life.” Another woman described how isolated she felt when “excessive heat” with “highly probable” links to climate change “exacerbated her asthma and chronic obstructive pulmonary disease.”
“Evidence showed that the life and health of older women were more severely impacted by periods of heatwaves than the rest of the population,” ECHR’s ruling said, noting that during recent warmest summers on record “nearly 90 percent of heat-related deaths had occurred in older women, almost all of whom were older than 75.”
The ECHR ruled that the Swiss government had violated these women’s rights to respect for private and family life under the European Convention on Human Rights by failing to comply with climate duties or to address “critical gaps” in climate policies. Throughout the proceedings, Swiss authorities acknowledged missing climate targets, including by not properly supervising greenhouse gas emissions in sectors like building and transport, and not regulating emissions in other sectors such as agricultural and financial.
“There was a long history of failed climate action,” ECHR’s ruling said.
“This included a failure to quantify, through a carbon budget or otherwise, national greenhouse gas emissions limitations,” ECHR President Siofra O’Leary said, noting in a Reuters report that Switzerland “had previously failed to meet its past greenhouse gas emission reduction targets by failing to act in good time and in an appropriate and consistent manner.”
As a result of the ECHR ruling, Switzerland may be forced to escalate efforts to reduce fossil fuel consumption, CNN reported.
Swiss President Viola Amherd told a news conference attended by Reuters that she would be reviewing the judgment, seemingly defending the country’s current climate actions by saying that “sustainability is very important to Switzerland, biodiversity is very important to Switzerland, the net zero target is very important to Switzerland.”
The court’s judgment is binding, cannot be appealed, and could “influence the law in 46 countries in Europe including the UK,” the BBC reported. Experts told CNN that the case could also influence other international courts, potentially opening the floodgates to more climate litigation globally.
Enlarge/ Cell-cultivated chicken is made in the pictured tanks at the Eat Just office on July 27, 2023, in Alameda, Calif.
Justin Sullivan/Getty Images
Months in jail and thousands of dollars in fines and legal fees—those are the consequences Alabamians and Arizonans could soon face for selling cell-cultured meat products that could cut into the profits of ranchers, farmers, and meatpackers in each state.
State legislators from Florida to Arizona are seeking to ban meat grown from animal cells in labs, citing a “war on our ranching” and a need to protect the agriculture industry from efforts to reduce the consumption of animal protein, thereby reducing the high volume of climate-warming methane emissions the sector emits.
Agriculture accounts for about 11 percent of the country’s greenhouse gas emissions, according to federal data, with livestock such as cattle making up a quarter of those emissions, predominantly from their burps, which release methane—a potent greenhouse gas that’s roughly 80 times more effective at warming the atmosphere than carbon dioxide over 20 years. Globally, agriculture accounts for about 37 percent of methane emissions.
For years, climate activists have been calling for more scrutiny and regulation of emissions from the agricultural sector and for nations to reduce their consumption of meat and dairy products due to their climate impacts. Last year, over 150 countries pledged to voluntarily cut emissions from food and agriculture at the United Nations’ annual climate summit.
But the industry has avoided increased regulation and pushed back against efforts to decrease the consumption of meat, with help from local and state governments across the US.
Bills in Alabama, Arizona, Florida, and Tennessee are just the latest legislation passed in statehouses across the US that have targeted cell-cultured meat, which is produced by taking a sample of an animal’s muscle cells and growing them into edible products in a lab. Sixteen states—Alabama, Arkansas, Georgia, Kansas, Kentucky, Louisiana, Maine, Mississippi, Missouri, Montana, North Dakota, Oklahoma, South Carolina, South Dakota, Texas, and Wyoming—have passed laws addressing the use of the word “meat” in such products’ packaging, according to the National Agricultural Law Center at the University of Arkansas, with some prohibiting cell-cultured, plant-based, or insect-based food products from being labeled as meat.
“Cell-cultured meat products are so new that there’s not really a framework for how state and federal labeling will work together,” said Rusty Rumley, a senior staff attorney with the National Agricultural Law Center, resulting in no standardized requirements for how to label the products, though legislation has been proposed that could change that.
At the federal level, Rep. Mark Alford (R-Mo.) introduced the Fair and Accurate Ingredient Representation on Labels Act of 2024, which would authorize the United States Department of Agriculture to regulate imitation meat products and restrict their sale if they are not properly labeled, and US Sens. Jon Tester (D-Mont.) and Mike Rounds (R-S.D.) introduced a bill to ban schools from serving cell-cultured meat.
But while plant-based meat substitutes are widespread, cell-cultivated meats are not widely available, with none currently being sold in stores. Just last summer, federal agencies gave their first-ever approvals to two companies making cell-cultivated poultry products, which are appearing on restaurant menus. The meat substitutes have garnered the support of some significant investors, including billionaire Bill Gates, who has been the subject of attacks from supporters of some of the state legislation proposed.
“Let me start off by explaining why I drafted this bill,” said Rep. David Marshall, an Arizona Republican who proposed legislation to ban cell-cultured meat from being sold or produced in the state, during a hearing on the bill. “It’s because of organizations like the FDA and the World Economic Forum, also Bill Gates and others, who have openly declared war on our ranching.”
In Alabama, fear of “franken-meat” competition spurs legislation
In Alabama, an effort to ban lab-grown meat is winding its way through the State House in Montgomery.
There, state senators have already passed a bill that would make it a misdemeanor, punishable by up to three months in jail and a $500 fine, to sell, manufacture, or distribute what the proposed legislation labels “cultivated food products.” An earlier version of the bill called lab-grown protein “meat,” but it was quickly revised by lawmakers. The bill passed out of committee and through the Senate without opposition from any of its members.
Now, the bill is headed toward a vote in the Alabama House of Representatives, where the body’s health committee recently held a public hearing on the issue. Rep. Danny Crawford, who is carrying the bill in the body, told fellow lawmakers during that hearing that he’s concerned about two issues: health risks and competition for Alabama farmers.
“Lab-grown meat or whatever you want to call it—we’re not sure of all of the long-term problems with that,” he said. “And it does compete with our farming industry.”
Crawford said that legislators had heard from NASA, which expressed concern about the bill’s impact on programs to develop alternative proteins for astronauts. An amendment to the bill will address that problem, Crawford said, allowing an exemption for research purposes.
Enlarge/ The Wamme river is seen at a low level during the European heatwave on Aug 10, 2022 in Rochefort, Belgium.
Thierry Monasse/Getty Images
The Arctic Ocean is mostly enclosed by the coldest parts of the Northern Hemisphere’s continents, ringed in by Siberia, Alaska and the Canadian Arctic, with only a small opening to the Pacific through the Bering Strait, and some narrow channels through the labyrinth of Canada’s Arctic archipelago.
But east of Greenland, there’s a stretch of open water about 1,300 miles across where the Arctic can pour its icy heart out to the North Atlantic. Those flows include increasing surges of cold and fresh water from melted ice, and a new study in the journal Weather and Climate Dynamics shows how those pulses can set off a chain reaction from the ocean to the atmosphere that ends up causing summer heatwaves and droughts in Europe.
The large new inflows of fresh water from melting ice are a relatively new ingredient to the North Atlantic weather cauldron, and based on measurements from the new study, a currently emerging “freshwater anomaly” will likely trigger a drought and heatwave this summer in Southern Europe, said the study’s lead author, Marilena Oltmanns, an oceanographer with the United Kingdom’s National Oceanography Centre.
She said warmth over Greenland in the summer of 2023 melted a lot of ice, sending more freshwater toward the North Atlantic. Depending on the exact path of the influx, the findings suggest that, in addition to the immediate impacts this year, it will also trigger a heatwave and drought in Northern Europe in a more delayed reaction in the next five years, she said.
The coming extremes will probably be similar to the European heatwaves of 2018 and 2022, she added, when there were huge temperature spikes in the Scandinavian and Siberian Arctic, as well as unusual wildfires in far northern Sweden. That year, much of the Northern Hemisphere was scorched, with “22 percent of populated and agricultural areas simultaneously experiencing heat extremes between May and July,” according to a 2019 study in Nature.
In 2022, persistent heat waves across Europe from May to August killed more than 60,000 people, subsequent research showed. The United Kingdom reported its first-ever 40° Celsius (104° Fahrenheit) reading that summer, and the European Union’s second-worst wildfire season on record burned about 3,500 square miles of land.
Meanwhile, 2022 was also Europe’s driest year on record, with 63 percent of its rivers showing below-average discharge and low flows hampering important river shipping channels as well as power production.
Enlarge/ The Combined Drought Indicator—used to identify areas affected by agricultural drought, and areas with the potential to be affected—estimated for the first 10 days of each month from April to September 2022.
European Commission, Joint Research Centre
Oltmanns said the findings will help farmers, industries, and communities to plan ahead for specific weather conditions by developing more resilient agricultural methods, predicting fuel demand and preparing for wildfires.
Changing effects of freshwater flows into the North Atlantic had previously been observed over decadal timescales, associated with cyclical, linked shifts of ocean currents and winds, but that was “a very low frequency signal,” she said. “We have disentangled the signals.”
Now the fluctuations are more frequent and more intense, “switching between different states very rapidly,” she said, adding that the study shows how the ocean changes driven by freshwater inflows have “direct and immediate consequences on the atmospheric circulation,” and thus on subsequent weather patterns in Europe.
Enlarge/ Materials such as steel, cement, aluminum, electricity, fertilizer, hydrogen, and iron will soon be subject to greenhouse gas emissions fees when imported into Europe.
Monty Rakusen/Getty
The year 2023 was a big one for climate news, from record heat to world leaders finally calling for a transition away from fossil fuels. In a lesser-known milestone, it was also the year the European Union soft-launched an ambitious new initiative that could supercharge its climate policies.
Wrapped in arcane language studded with many a “thereof,” “whereas” and “having regard to” is a policy that could not only help fund the European Union’s pledge to become the world’s first carbon-neutral continent, but also push industries all over the world to cut their carbon emissions.
It’s the establishment of a carbon price that will force many heavy industries to pay for each ton of carbon dioxide, or equivalent emissions of other greenhouse gases, that they emit. But what makes this fee revolutionary is that it will apply to emissions that don’t happen on European soil. The EU already puts a price on many of the emissions created by European firms; now, through the new Carbon Border Adjustment Mechanism, or CBAM, the bloc will charge companies that import the targeted products—cement, aluminum, electricity, fertilizer, hydrogen, iron, and steel—into the EU, no matter where in the world those products are made.
These industries are often large and stubborn sources of greenhouse gas emissions, and addressing them is key in the fight against climate change, says Aaron Cosbey, an economist at the International Institute for Sustainable Development, an environmental think tank. If those companies want to continue doing business with European firms, they’ll have to clean up or pay a fee. That creates an incentive for companies worldwide to reduce emissions.
In CBAM’s first phase, which started in October 2023, companies importing those materials into the EU must report on the greenhouse gas emissions involved in making the products. Beginning in 2026, they’ll have to pay a tariff.
Even having to supply emissions data will be a big step for some producers and could provide valuable data for climate researchers and policymakers, says Cosbey.
“I don’t know how many times I’ve gone through this exercise of trying to identify, at a product level, the greenhouse gas intensity of exports from particular countries and had to go through the most amazing, torturous processes to try to do those estimates,” he says. “And now it’s going to be served to me on a plate.”
Enlarge/ CBAM will apply to a set of products that are linked to heavy greenhouse gas emissions.
Side benefits at home
While this new carbon price targets companies abroad, it will also help the EU to pursue its climate ambitions at home. For one thing, the extra revenues could go toward financing climate-friendly projects and promising new technologies.
But it also allows the EU to tighten up on domestic pollution. Since 2005, the EU has set a maximum, or cap, on the emissions created by a range of industrial “installations” such as oil and metal refineries. It makes companies within the bloc use credits, or allowances, for each ton of carbon dioxide—or equivalent discharges of other greenhouse gases—that they emit, up to that cap. Some allowances are currently granted for free, but others are bought at auction or traded with other companies in a system known as a carbon market.
But this idea—of making it expensive to harm the planet—creates a conundrum. If doing business in Europe becomes too expensive, European industry could flee the continent for countries that don’t have such high fees or strict regulations. That would damage the European economy and do nothing to solve the environmental crisis. The greenhouse gases would still be emitted—perhaps more than if the products had been made in Europe—and climate change would careen forward on its destructive path.
The Carbon Border Adjustment Mechanism aims to impose the same carbon price for products made abroad as domestic producers must pay under the EU’s system. In theory, that keeps European businesses competitive with imports from international rivals. It also addresses environmental concerns by nudging companies overseas toward reducing greenhouse gas emissions rather than carrying on as usual.
This means the EU can further tighten up its carbon market system at home. With international competition hopefully less of a concern, it plans to phase out some leniencies, such as some of the free emission allowances, that existed to help keep domestic industries competitive.
That’s a big deal, says Cosbey. Dozens of countries have carbon pricing systems, but they all create exceptions to keep heavy industry from getting obliterated by international competition. The carbon border tariff could allow the EU to truly force its industries—and consumers—to pay the price, he says.
“That is ambitious; nobody in the world is doing that.”
For nearly a year now, a bizarre heating event has been unfolding across the world’s oceans. In March 2023, global sea surface temperatures started shattering record daily highs and have stayed that way since.
You can see 2023 in the orange line below, the other gray lines being previous years. That solid black line is where we are so far in 2024—way, way above even 2023. While we’re nowhere near the Atlantic hurricane season yet—that runs from June 1 through the autumn—keep in mind that cyclones feed on warm ocean water, which could well stay anomalously hot in the coming months. Regardless, these surface temperature anomalies could be triggering major ecological problems already.
“In the tropical eastern Atlantic, it’s four months ahead of pace—it’s looking like it’s already June out there,” says Brian McNoldy, a hurricane researcher at the University of Miami. “It’s really getting to be strange that we’re just seeing the records break by this much, and for this long.”
You’ll notice from these graphs and maps that the temperature anomalies may be a degree or two Celsius warmer, which may not sound like much. But for the seas, it really is: Unlike land, which rapidly heats and cools as day turns to night and back again, it takes a lot to warm up an ocean that may be thousands of feet deep. So even an anomaly of mere fractions of a degree is significant. “To get into the two or three or four degrees, like it is in a few places, it’s pretty exceptional,” says McNoldy.
University of Maine
So what’s going on here? For one, the oceans have been steadily warming over the decades, absorbing something like 90 percent of the extra heat that humans have added to the atmosphere. “The oceans are our saviors, in a way,” says biological oceanographer Francisco Chavez of the Monterey Bay Aquarium Research Institute in California. “Things might be a lot worse in terms of climate impacts, because a lot of that heat is not only kept at the surface, it’s taken to depths.”
This is a story I had sporadically wondered whether I’d ever have the chance to write. Over a decade ago, I covered a lawsuit filed by climate scientist Michael Mann, who finally had enough of being dragged through the mud online. When two authors accused him of fraud and compared his academic position to that of a convicted child molester, he sued for defamation.
Mann was considered a public figure, which makes winning defamation cases extremely challenging. But his case was based on the fact that multiple institutions on two different continents had scrutinized his work and found no hint of scientific malpractice—thus, he argued, that anyone who accused him of fraud was acting with reckless disregard for the truth.
Over the ensuing decade, the case was narrowed, decisions were appealed, and long periods went by without any apparent movement. But recently, amazingly, the case finally went to trial, and a jury rendered a verdict yesterday: Mann is entitled to damages from the writers. Even if you don’t care about the case, it’s worth reflecting on how much has changed since it was first filed.
The suit
The piece that started the whole mess was posted on the blog of a free market think tank called the Competitive Enterprise Institute. In it, Rand Simberg accused Mann of manipulating data and compared the investigations at Penn State (where he was faculty at the time) to the university’s lack of interest in pursuing investigations of one of its football coaches who was convicted of molesting children. A few days later, a second author, Mark Steyn, echoed those accusations at the publication National Review.
Mann’s case was based on the accusations of fraud in those pieces. He had been a target for years after he published work showing that the recent warming was unprecedented in the last few thousand years. This graph, known as the “hockey stick” due to its sudden swerve upwards, later graced the cover of an IPCC climate report. The pieces were also published just a few years after a large trove of emails from climate scientists were obtained illicitly from the servers of a research institution, leading to widespread accusations of misconduct against climate scientists.
Out of the public eye were a large number of investigations, both by the schools involved and the governments that funded the researchers, all of which cleared those involved, including Mann. But Simberg and Steyn were part of a large collection of writers and bloggers who were convinced that Mann (and by extension, all of modern climate science) had to be wrong. So they assumed—and in Simberg and Steyn’s case, wrote—that the investigations were simply whitewashes.
Mann’s suit alleged the exact opposite: that, by accusing him of fraud despite these investigations, the two authors showed a reckless disregard for truth. That would be enough to hold them responsible for defamation despite the fact that Mann was a public figure. The authors’ defense was largely focused on the fact that they genuinely believed their own opinions and so should be free to express them under the First Amendment.
In essence, the case came down to whether people who appear to be incapable of incorporating evidence into their opinions should still be able to voice those opinions without consequences, even if doing so has consequences for others.
Victory at last-ish
In the end, the jury decided they did not. And their damage awards suggest that they understood the present circumstances quite well. For starters, the compensatory damages awarded to Mann for the defamation itself were minimal: one dollar each from Simberg and Steyn. While Mann alleged he lost grants and suffered public scorn due to the columns, he’s since become a successful book author and received a tenured chair at the University of Pennsylvania, where he now heads its Center for Science, Sustainability, and the Media.
But the suit also sought punitive damages to discourage future behavior of the sort. Here, there was a dramatic split. Simberg, who now tends to write about politics rather than science and presents himself as a space policy expert, was placed on the hook for just $1,000. Steyn, who is still actively fighting the climate wars and hosts a continued attack on Mann on his website, was told to pay Mann $1 million.
That said, the suit’s not over yet. Steyn has suggested that there are grounds to appeal the monetary award, while Mann has indicated that he will appeal the decision that had terminated his case against the Competitive Enterprise Institute and National Review. So, check back in another decade and we may have another decision.
Enlarge/ Aerial view of the Athabasca oil sands near Fort McMurray, Alberta, Canada.
Canada’s tar sands have gained infamy for being one of the world’s most polluting sources of oil, thanks to the large amounts of energy and water use required for their extraction. A new study says the operations are also emitting far higher levels of a range of air pollutants than previously known, with implications for communities living nearby and far downwind.
The research, published Thursday in Science, took direct measurements of organic carbon emissions from aircraft flying above the tar sands, also called oil sands, and found levels that were 20 to 64 times higher than what companies were reporting. Total organic carbon includes a wide range of compounds, some of which can contribute directly to hazardous air pollution locally and others that can react in the atmosphere to form small particulate matter, or PM 2.5, a dangerous pollutant that can travel long distances and lodge deep in the lungs.
The study found that tar sands operations were releasing as much of these pollutants as all other human-made sources in Canada combined. For certain classes of heavy organic compounds, which are more likely to form particulates downwind, the concentrations were higher than what’s generally found in large metropolises like Los Angeles.
“The absolute magnitude of those emissions were a lot higher than what we expected,” said John Liggio, a research scientist at Environment and Climate Change Canada, the nation’s environmental regulatory agency, and a co-author on the study. Researchers at Yale University also contributed.
Seth Shonkoff, executive director of PSE Healthy Energy, an independent scientific research institute in California, who was not involved in the study, said the findings suggest air pollution from tar sands operations is more damaging to people’s health than previously known.
“I actually could hardly believe what I was reading,” Shonkoff said of the new study.
Over the last decade, a growing body of research has examined emissions of different air pollutants from oil and gas operations across the United States and Canada, and much of that has shown that industry estimates tend to undercount what’s being released, he said. “But the scale of this discrepancy is very surprising.”
Mark Cameron, vice president of external relations at the Pathways Alliance, an oil sands industry group, said in an email that the findings warrant further review and that “the oil sands industry measures emissions using standards set by Environment and Climate Change Canada and we look forward to working together to explore opportunities to further enhance our measurement practices.”
Content creators have spent the past five years developing new tactics to evade YouTube’s policies blocking monetization of videos making false claims about climate change, a report from a nonprofit advocacy group, the Center for Countering Digital Hate (CCDH), warned Tuesday.
What the CCDH found is that content creators who could no longer monetize videos spreading “old” forms of climate denial—including claims that “global warming is not happening” or “human-generated greenhouse gasses are not causing global warming”—have moved on.
Now they’re increasingly pushing other claims that contradict climate science, which YouTube has not yet banned and may not ever ban. These include harmful claims that “impacts of global warming are beneficial or harmless,” “climate solutions won’t work,” and “climate science and the climate movement are unreliable.”
The CCDH uncovered these new climate-denial tactics by using artificial intelligence to scan transcripts of 12,058 videos posted on 96 YouTube channels that the CCDH found had previously posted climate-denial content. Verified by researchers, the AI model used was judged accurate in labeling climate-denial content approximately 78 percent of the time.
According to the CCDH’s analysis, the amount of content disputing climate solutions, climate science, and impacts of climate change today comprises 70 percent of climate-denial content—a percent that doubled from 2018 to 2023. At the same time, the amount of content pushing old climate-denial claims that are harder or impossible to monetize fell from 65 percent in 2018 to 30 percent in 2023.
These “new forms of climate denial,” the CCDH warned, are designed to delay climate action by spreading disinformation.
“A new front has opened up in this battle,” Imran Ahmed, the CCDH’s chief executive, said on a call with reporters, according to Reuters. “The people that we’ve been looking at, they’ve gone from saying climate change isn’t happening to now saying, ‘Hey, climate change is happening, but there is no hope. There are no solutions.'”
Since 2018—based on “estimates of typical ad pricing on YouTube” by social media analytics tool Social Blade—YouTube may have profited by as much as $13.4 million annually from videos flagged by the CCDH. And YouTube confirmed that some of these videos featured climate denialism that YouTube already explicitly bans.
In response to the CCDH’s report, YouTube de-monetized some videos found to be in violation of its climate change policy. But a spokesperson confirmed to Ars that the majority of videos that the CCDH found were considered compliant with YouTube’s ad policies.
The fact that most of these videos remain compliant is precisely why the CCDH is calling on YouTube to update its policies, though.
Currently, YouTube’s policy prohibits monetization of content “that contradicts well-established scientific consensus around the existence and causes of climate change.”
“Our climate change policy prohibits ads from running on content that contradicts well-established scientific consensus around the existence and causes of climate change,” YouTube’s spokesperson told Ars. “Debate or discussions of climate change topics, including around public policy or research, is allowed. However, when content crosses the line to climate change denial, we stop showing ads on those videos. We also display information panels under relevant videos to provide additional information on climate change and context from third parties.”
The CCDH worries that YouTube standing by its current policy is too short-sighted. The group recommended tweaking the policy to instead specify that YouTube prohibits content “that contradicts the authoritative scientific consensus on the causes, impacts, and solutions to climate change.”
If YouTube and other social media platforms don’t acknowledge new forms of climate denial and “urgently” update their disinformation policies in response, these new attacks on climate change science “will only increase,” the CCDH warned.
“It is vital that those advocating for action to avert climate disaster take note of this substantial shift from denial of anthropogenic climate change to undermining trust in both solutions and science itself, and shift our focus, our resources and our counternarratives accordingly,” the CCDH’s report said, adding that “demonetizing climate-denial” content “removes the economic incentives underpinning its creation and protects advertisers from bankrolling harmful content.”
Earlier this week, the European Union’s Earth science team came out with its analysis of 2023’s global temperatures, finding it was the warmest year on record to date. In an era of global warming, that’s not especially surprising. What was unusual was how 2023 set its record—every month from June on coming in far above any equivalent month in the past—and the size of the gap between 2023 and any previous year on record.
The Copernicus dataset used for that analysis isn’t the only one of the sort, and on Friday, Berkeley Earth, NASA, and the National Oceanic and Atmospheric Administration all released equivalent reports. And all of them largely agree with the EU’s: 2023 was a record, and an unusual one at that. So unusual that NASA’s chief climate scientist, Gavin Schmidt, introduced his look at 2023 by saying, “We’re frankly astonished.”
Despite the overlaps with the earlier analysis, each of the three new ones adds some details that flesh out what made last year so unusual.
Each of the three analyses uses slightly different methods to do things like fill in areas of the globe where records are sparse, and uses a different baseline. Berkeley Earth was the only team to do a comparison with pre-industrial temperatures, using a baseline of the 1850–1900 temperatures. Its analysis suggests that this is the first year to finish over 1.5° C above preindustrial temperatures.
Most countries have committed to an attempt to keep temperatures from consistently coming in above that point. So, at one year, we’re far from consistently failing our goals. But there’s every reason to expect that we’re going to see several more years exceeding this point before the decade is out. And that clearly means we have a very short timeframe before we get carbon emissions to drop, or we’ll commit to facing a difficult struggle to get temperatures back under this threshold by the end of the century.
Berkeley Earth also noted that the warming was extremely widespread. It estimates that nearly a third of the Earth’s population lived in a region that set a local heat record. And 77 nations saw 2023 set a national record.
Enlarge/ Lots of factors converged on warming in 2023.
The Berkeley team also had a nice graph laying out the influences of different factors on recent warming. Greenhouse gases are obviously the strongest and most consistent factor, but there are weaker short-term influences as well, such as the El Niño/La Niña oscillation and the solar cycle. Berkeley Earth and EU’s Copernicus also noted that an international agreement caused sulfur emissions from shipping to drop by about 85 percent in 2020, which would reduce the amount of sunlight scattered back out into space. Finally, like the EU team, they note the Hunga Tonga eruption.
An El Niño unlike any other
A shift from La Niño to El Niño conditions in the late spring is highlighted by everyone looking at this year, as El Niños tend to drive global temperatures upward. While it has the potential to develop into a strong El Niño in 2024, at the moment, it’s pretty mild. So why are we seeing record temperatures?
We’re not entirely sure. “The El Niño we’ve seen is not an exceptional one,” said NASA’s Schmidt. So, he reasoned, “Either this El Niño is different from all of them… or there are other factors going on.” But he was at a bit of a loss to identify the factors. He said that typically, there are a limited number of stories that you keep choosing from in order to explain a given year’s behavior. But, for 2023, none of them really fit.
Enlarge/ Something very ominous happened to the North Atlantic last year.
Berkeley Earth had a great example of it in its graph of North Atlantic sea surface temperatures, which have been rising slowly for decades, until 2023 saw record temperatures with a freakishly large gap compared to anything previously on record. There’s nothing especially obvious to explain that.
Lurking in the background of all of this is climate scientist James Hansen’s argument that we’re about to enter a new regime of global warming, where temperatures increase at a much faster pace than they have until now. Most climate scientists don’t see compelling evidence for that yet. And, with El Niño conditions likely to prevail for much of 2024, we can expect a very hot year again, regardless of changing trends. So, it may take several more years to determine if 2023 was a one-off freak or a sign of new trends.
Enlarge/ Month by month, 2023 stood far above the rest.
The confused wiggles on the graph above have a simple message: Most years, even years with record-high temperatures, have some months that aren’t especially unusual. Month to month, temperatures dip and rise, with the record years mostly being a matter of having fewer, shallower dips.
As the graph shows, last year was not at all like that. The first few months of the year were unusually warm. And then, starting in June, temperatures rose to record heights and simply stayed there. Every month after June set a new record for high temperatures for that month. So it’s not surprising that 2023 will enter the record books as far and away the warmest year on record.
The EU makes it official
Several different organizations maintain global temperature records; while they use slightly different methods, they tend to produce very similar numbers. So, over the next few weeks, you can expect each of these organizations to announce record temperatures (NASA and the National Oceanic and Atmospheric Administration will do so on Friday). On Tuesday, it was the European Union’s turn, via its Copernicus Earth-observation program.
Copernicus rates 2023 as being nearly 1.5° C above pre-industrial temperatures and about 0.17° C above 2016, the previous holder of the warmest year on record. The difference between 2023 and 2022 was the largest single-year change in the record as well, confirming that the amount of warming this past year was exceptional.
The 1.5° C landmark is significant because many countries have committed to trying to limit global warming to that mark. This doesn’t mean we’ve failed; the average temperature for the last decade is still below that. But it does highlight how little time we have left to act before we potentially experience more radical consequences of climate change.
The Copernicus analysis notes a couple of additional daily landmarks within the yearly record. It defines pre-industrial temperatures as those experienced between 1850–1900. The records from this period are sparse enough that, rather than daily temperature data, it’s been handled as a monthly average. So, the best Copernicus could do is compare 2023’s daily temperatures to the equivalent month in the pre-industrial record.
Even given that limitation, some of the results of this comparison were striking. For the first time ever, individual days in 2023 were 2.0° C above the preindustrial monthly average. Nearly half the days in 2023 were 1.5° C warmer than preindustrial records, and it was the first time every day was at least 1.0° C warmer.
Why so extreme?
The simplest answer is El Niño. The past few years have been spent in a reasonably strong La Niña, the cooler phase of the Southern Oscillation. But that started fading throughout the spring, and by mid-year, a weak El Niño had arrived. Normally, a relatively feeble El Niño like this would have a limited effect on global temperatures, and in any case, it would normally take some time for its effect to be felt in global temperatures.
Red means hot: last year saw a strong La Niña come to a close, with conditions shifting to a slight El Niño.
But with temperatures poised near record levels to begin with, just a little push appeared to be all 2023 needed to soar to record heights.
Still, there are plenty of indications that the year wasn’t only the result of El Niño, which is a phenomenon that occurs in the tropical Pacific. For example, the North Atlantic, which is not directly connected to the Tropical Pacific, experienced exceptionally warm sea surface temperatures over the second half of the year.
Copernicus suggests that several additional, weak factors could have contributed to the year’s warmth. These include lower emissions of cooling aerosols from shipping, a peak in the solar cycle, and high levels of water vapor in the stratosphere due to the eruption of the Hunga Tonga volcano. On its own, the impact of any of these would likely be minimal. In combination with the weak El Niño and the continued emission of greenhouse gasses, however, they might have enhanced what was already an exceptionally warm year.
The announcement of 2023’s warmth comes only months after a set of UN climate negotiations that many have derided as lacking the sort of urgency the record might have provided. Instead, Copernicus notes that carbon dioxide and methane emissions increased last year.
Enlarge/ Where beavers set up home, the dams they build profoundly change the landscape.
For the first time in four centuries, it’s good to be a beaver. Long persecuted for their pelts and reviled as pests, the dam-building rodents are today hailed by scientists as ecological saviors. Their ponds and wetlands store water in the face of drought, filter out pollutants, furnish habitat for endangered species, and fight wildfires. In California, Castor canadensis is so prized that the state recently committed millions to its restoration.
While beavers’ benefits are indisputable, however, our knowledge remains riddled with gaps. We don’t know how many are out there, or which direction their populations are trending, or which watersheds most desperately need a beaver infusion. Few states have systematically surveyed them; moreover, many beaver ponds are tucked into remote streams far from human settlements, where they’re near-impossible to count. “There’s so much we don’t understand about beavers, in part because we don’t have a baseline of where they are,” says Emily Fairfax, a beaver researcher at the University of Minnesota.
But that’s starting to change. Over the past several years, a team of beaver scientists and Google engineers have been teaching an algorithm to spot the rodents’ infrastructure on satellite images. Their creation has the potential to transform our understanding of these paddle-tailed engineers—and help climate-stressed states like California aid their comeback. And while the model hasn’t yet gone public, researchers are already salivating over its potential. “All of our efforts in the state should be taking advantage of this powerful mapping tool,” says Kristen Wilson, the lead forest scientist at the conservation organization the Nature Conservancy. “It’s really exciting.”
The beaver-mapping model is the brainchild of Eddie Corwin, a former member of Google’s real-estate sustainability group. Around 2018, Corwin began to contemplate how his company might become a better steward of water, particularly the many coastal creeks that run past its Bay Area offices. In the course of his research, Corwin read Water: A Natural History, by an author aptly named Alice Outwater. One chapter dealt with beavers, whose bountiful wetlands, Outwater wrote, “can hold millions of gallons of water” and “reduce flooding and erosion downstream.” Corwin, captivated, devoured other beaver books and articles, and soon started proselytizing to his friend Dan Ackerstein, a sustainability consultant who works with Google. “We both fell in love with beavers,” Corwin says.
Corwin’s beaver obsession met a receptive corporate culture. Google’s employees are famously encouraged to devote time to passion projects, the policy that produced Gmail; Corwin decided his passion was beavers. But how best to assist the buck-toothed architects? Corwin knew that beaver infrastructure—their sinuous dams, sprawling ponds, and spidery canals—is often so epic it can be seen from space. In 2010, a Canadian researcher discovered the world’s longest beaver dam, a stick-and-mud bulwark that stretches more than a half-mile across an Alberta park, by perusing Google Earth. Corwin and Ackerstein began to wonder whether they could contribute to beaver research by training a machine-learning algorithm to automatically detect beaver dams and ponds on satellite imagery—not one by one, but thousands at a time, across the surface of an entire state.
After discussing the concept with Google’s engineers and programmers, Corwin and Ackerstein decided it was technically feasible. They reached out next to Fairfax, who’d gained renown for a landmark 2020 study showing that beaver ponds provide damp, fire-proof refuges in which other species can shelter during wildfires. In some cases, Fairfax found, beaver wetlands even stopped blazes in their tracks. The critters were such talented firefighters that she’d half-jokingly proposed that the US Forest Service change its mammal mascot—farewell, Smoky Bear, and hello, Smoky Beaver.
Fairfax was enthusiastic about the pond-mapping idea. She and her students already used Google Earth to find beaver dams to study within burned areas. But it was a laborious process, one that demanded endless hours of tracing alpine streams across screens in search of the bulbous signature of a beaver pond. An automated beaver-finding tool, she says, could “increase the number of fires I can analyze by an order of magnitude.”
With Fairfax’s blessing, Corwin, Ackerstein, and a team of programmers set about creating their model. The task, they decided, was best suited to a convolutional neural network, a type of algorithm that essentially tries to figure out whether a given chunk of geospatial data includes a particular object—whether a stretch of mountain stream contains a beaver dam, say. Fairfax and some obliging beaverologists from Utah State University submitted thousands of coordinates for confirmed dams, ponds, and canals, which the Googlers matched up with their own high-resolution images to teach the model to recognize the distinctive appearance of beaverworks. The team also fed the algorithm negative data—images of beaverless streams and wetlands—so that it would know what it wasn’t looking for. They dubbed their model the Earth Engine Automated Geospatial Elements Recognition, or EEAGER—yes, as in “eager beaver.”
Training EEAGER to pick out beaver ponds wasn’t easy. The American West was rife with human-built features that seemed practically designed to fool a beaver-seeking model. Curving roads reminded EEAGER of winding dams; the edges of man-made reservoirs registered as beaver-built ponds. Most confounding, weirdly, were neighborhood cul-de-sacs, whose asphalt circles, surrounded by gray strips of sidewalk, bore an uncanny resemblance to a beaver pond fringed by a dam. “I don’t think anybody anticipated that suburban America was full of what a computer would think were beaver dams,” Ackerstein says.
As the researchers pumped more data into EEAGER, it got better at distinguishing beaver ponds from impostors. In May 2023, the Google team, along with beaver researchers Fairfax, Joe Wheaton, and Wally Macfarlane, published a paper in the Journal of Geophysical Research Biogeosciencesdemonstrating the model’s efficacy. The group fed EEAGER more than 13,000 landscape images with beaver dams from seven western states, along with some 56,000 dam-less locations. The model categorized the landscape accurately—beaver dammed or not—98.5 percent of the time.
That statistic, granted, oversells EEAGER’s perfection. The Google team opted to make the model fairly liberal, meaning that, when it predicts whether or not a pixel of satellite imagery contains a beaver dam, it’s more likely to err on the side of spitting out a false positive. EEAGER still requires a human to check its answers, in other words—but it can dramatically expedite the work of scientists like Fairfax by pointing them to thousands of probable beaver sites.
“We’re not going to replace the expertise of biologists,” Ackerstein says. “But the model’s success is making human identification much more efficient.”
According to Fairfax, EEAGER’s use cases are many. The model could be used to estimate beaver numbers, monitor population trends, and calculate beaver-provided ecosystem services like water storage and fire prevention. It could help states figure out where to reintroduce beavers, where to target stream and wetland restoration, and where to create conservation areas. It could allow researchers to track beavers’ spread in the Arctic as the rodents move north with climate change; or their movements in South America, where beavers were introduced in the 1940s and have since proliferated. “We literally cannot handle all the requests we’re getting,” says Fairfax, who serves as EEAGER’s scientific adviser.
The algorithm’s most promising application might be in California. The Golden State has a tortured relationship with beavers: For decades, the state generally denied that the species was native, the byproduct of an industrial-scale fur trade that wiped beavers from the West Coast before biologists could properly survey them. Although recent historical research proved that beavers belong virtually everywhere in California, many water managers and farmers still perceive them as nuisances, and frequently have them killed for plugging up road culverts and meddling with irrigation infrastructure.
Yet those deeply entrenched attitudes are changing. After all, no state is in more dire need of beavers’ water-storage services than flammable, drought-stricken, flood-prone California. In recent years, thanks to tireless lobbying by a campaign called Bring Back the Beaver, the California Department of Fish and Wildlife has begun to overhaul its outdated beaver policies. In 2022, the state budgeted more than $1.5 million for beaver restoration, and announced it would hire five scientists to study and support the rodents. It also revised its official approach to beaver conflict to prioritize coexistence over lethal trapping. And, this fall, the wildlife department relocated a family of seven beavers onto the ancestral lands of the Mountain Maidu people—the state’s first beaver release in almost 75 years.
It’s only appropriate, then, that California is where EEAGER is going to get its first major test. The Nature Conservancy and Google plan to run the model across the state sometime in 2024, a comprehensive search for every last beaver dam and pond. That should give the state’s wildlife department a good sense of where its beavers are living, roughly how many it has, and where it could use more. The model will also provide California with solid baseline data against which it can compare future populations, to see whether its new policies are helping beavers recover. “When you have imagery that’s repeated frequently, that gives you the opportunity to understand change through time,” says the Conservancy’s Kristen Wilson.
What’s next for EEAGER after its California trial? The main thing, Ackerstein says, is to train it to identify beaverworks in new places. (Although beaver dams and ponds present as fairly similar in every state, the model also relies on context clues from the surrounding landscape, and a sagebrush plateau in Wyoming looks very different from a deciduous forest in Massachusetts.) The team also has to figure out EEAGER’s long-term fate: Will it remain a tool hosted by Google? Spin off into a stand-alone product? Become a service operated by a university or nonprofit?
“That’s the challenge for the future—how do we make this more universally accessible and usable?” Corwin says. The beaver revolution may not be televised, but it will definitely be documented by satellite.
