TWELVE
For climate scientists, the first decade of the new millennium was marked by two radically divergent trends. There were many scientific breakthroughs and advances, but in terms of the public face of science, the decade was marked by backpedaling and bogus controversies. Some of the worst-case scenarios from the 1990s became the scientific consensus, but then two IPCC Summaries for Policymakers dialed back some of the extrapolations of earlier assessments. The mixed messages further added to public confusion about the imminence and seriousness of the threat of climate change, even as the scientific consensus solidified.
In 2004, Naomi Oreskes, a historian of science at Harvard, along with colleagues, published a sample review in Science of 928 peer-reviewed studies on climate change from a ten-year period between 1993 and 2003 to see whether any challenged the scientific consensus that human activities were causing climate to change. None did.
This was a stake in the heart of the denier community’s biggest arguments for delay: that the science was unsettled and that there was active disagreement in the scientific community about the role of humans in changing climate. The deniers were not going to take this lying down.
First, a British scientist named Benny Peiser, a social anthropologist, repeated Oreskes’s survey and claimed to have found thirty-four peer-reviewed studies challenging the consensus. Further inspection showed that the papers Peiser listed either didn’t challenge the consensus after all or were letters or editorials that were not peer reviewed. Peiser retracted his criticism.
Not to be outdone, another energetic denier with the ten-dollar name of Viscount Monckton of Brenchley presented five articles challenging the consensus. These fizzled as well; some were reviews and not peer reviewed, while others either supported the consensus or had been amended to reflect the consensus.
This should have been the end of it, of course, but deniers have always had a prominent and friendly outlet in the editorial pages of The Wall Street Journal, and they were still giving space to Monckton’s casuistry more than a decade after Science magazine put its weight behind the consensus. The sleight of hand is worth noting. As reported by the fact-checking organization Skeptical Science, Monckton compared papers that explicitly quantified the human contribution to climate change with all papers that used the words “global warming” or “global climate change.”
This is a meaningless comparison because it implies that those papers on global warming that don’t note the human contribution disagree with the consensus. As Dana Nuccitelli, an environmental scientist, pointed out in The Guardian, by this standard less than 1 percent of papers on astronomy accept the consensus that the earth rotates around the sun because they don’t explicitly mention that fact. This kind of analysis would also provide supporting evidence for those who believe the earth is flat. Such examples utterly contradict any imputation that the editors of The Wall Street Journal or others who give space to such ludicrous analyses are acting in good faith.
There are, of course, real climate scientists who dispute the consensus. Roy Spencer of the University of Alabama is one. He teamed up with Joseph Bast, president of the Heartland Institute, a Koch brothers–financed astroturf outfit that serves as Grendel’s Den of denialism. They published an op-ed in The Wall Street Journal attacking the notion of consensus. They didn’t help their case when, as noted by Nuccitelli, they referenced a petition that could be signed by anyone with any sort of science degree, and whose signatories included one of the Spice Girls.
In any event, several subsequent studies all supported the consensus. One, conducted by Nuccitelli and colleagues, surveyed more than ten thousand scientists whose published papers referenced human-caused climate change. In this case, 98.4 percent supported the consensus. It’s important to note that the consensus can be wrong—the earth rotates around the sun and not the other way around as was thought for thousands of years—but some arduously obtained scientific results are factual and enduring. Few, except for a couple of well-known climate deniers, would argue that smoking is not bad for the lungs. The scientific consensus on the human role in climate change is even more robust. Tragically, even today, most of the public doesn’t know that.
Another noteworthy event in the jelling of that consensus was a publication in 2002 by the National Research Council of the National Academy of Sciences, entitled Abrupt Climate Change: Inevitable Surprises. This came nine years after publication of the dramatic findings taken from the Greenland ice core projects that confirmed that climate had changed with extraordinary rapidity in the past. The span provides a data point about how long it takes for an emerging theory to become the consensus, even after it has been blessed by the most respected scientific journals. The National Academy report described the acknowledgment of rapid climate change as a “paradigm shift,” lending its imprimatur to what almost all actively engaged scientists had accepted for years.
The simple logic chain following from this new paradigm should have been alarming to both policymakers and the public. If the past pattern of climate change had been characterized by rapid jumps, and if climate is already changing because of human inputs into the atmosphere, then it is likely that these changes will continue and come about rapidly.
The relatively ponderous path that the acceptance of rapid climate change took to go from the fringes to the conventional wisdom offered a cautionary tale for how long it might take for several other alarming discoveries about climate change to become consensus, much less have an impact on policymakers and the public. It took a couple of decades from the time Wallace Broecker and others first offered evidence that climate had changed rapidly in the past until the dramatic data from the dome of the Greenland Ice Sheet confirmed these past changes, and then another eight years before the majority of the scientific community accepted that this was the way climate shifts.
If rapid climate change posed a problem for scientists because of difficulties finding reliable proxies with sufficient resolution to reveal the rapid changes, another climate issue became even more controversial because of difficulties of measuring and interpreting how the various components of the phenomenon might interact. This was sea level rise, an issue with immediate pertinence to the roughly 300 million people who might be impacted in the coming decades.
Reasonably reliable measurements of global sea level only became possible in 1993 with the advent of satellite data. Previously, most measurements came from tidal gauges and buoys, which at best provided an incomplete picture. The likely contributions of glaciers and ice sheets were shrouded in even more uncertainty. When the first IPCC assessment came out in 1990, researchers were cautious about forecasts, asserting that they could only talk about possibilities, not predictions.
By the new millennium, however, many of these fuzzy areas had come into sharper focus. The melting of midlatitude and tropical glaciers was well underway and well documented. In 1991, retreating Swiss glaciers uncovered the preserved mummy of a Copper Age European hunter who died 5,300 years previously. Andean glacial melting uncovered plants that had been frozen for several thousand years, and tropical glaciers were well on their way to disappearing. Those atop Mount Kilimanjaro in Kenya shrank by 26 percent in the years between 2000 and 2007.
By 2000, the signal of sea level rise was unambiguous. For one thing, land-based glacial melting had accelerated sixfold between 1993 and the early 2010s according to a study out of the University of Bristol in the United Kingdom. The melting was having a discernible impact on sea levels.
After 2000, scientists quickly caught up to reality on several fronts, though the IPCC still lagged behind. If in the 1990s it was unclear whether the ice sheets would be a plus or a minus for sea level rise, by the middle of the decade it was clear that they would be contributing significantly to increases. If in 1990 there wasn’t enough data to predict how much the permafrost might melt and how soon, by 2000, throughout the Arctic, buildings were tilting and roads buckling as the top layer of permafrost began to melt.
During that first decade of the new millennium, researchers concerned with the antipodes made significant progress in understanding the reaction of the ice sheets to climate change, and, in turn, the interconnections between ice sheets, glaciers, sea ice, and climate change. In 2001, Science published a satellite survey of two thousand glaciers that showed that most of them were shrinking. Surveys of sea ice showed clear evidence that the so-called ice minimums at the end of the Arctic summer in September were getting progressively smaller. As the summer extent of sea ice shrank, many scientists realized that the increased area of open water would have immediate impacts on Northern Hemisphere weather.
That’s because whether a surface is reflective or absorbent—its albedo—can have a profound impact on the weather. While the white surface of sea ice reflects between 50 and 70 percent of incoming solar energy, the dark ocean reflects only about 6 percent of such energy and absorbs the rest. Thus, as sea ice retreats, the lower albedo of the open water amplifies the warming.
The shift in the oceans from the white surface of sea ice reflecting heat back into space to the dark surface of open water absorbing and releasing heat has a dramatic impact on climate. As open water expands, the oceans warm large expanses of Arctic air. With the warmer Arctic air, there is less contrast between the temperatures of the Far North and the midlatitudes. The sharper the contrast, the more vigorous the jet stream, but as temperatures in the Arctic warm and the contrast becomes less defined, the jet stream slows when, for instance, it moves over North America. In turn, this leads to exaggerated kinks in the high-altitude winds, which allow warm air to intrude northward and polar air to plunge south. The slowing of the jet stream means that weather patterns become extreme in other ways, notably in their persistence. Cold spells become longer and more intense, as do heat waves and droughts, and storms linger.
What happens in the Arctic doesn’t stay in the Arctic. At the point in the 2000s when the retreat of sea ice became incontrovertible, the incredibly complex interactions between ice, the oceans, and the atmosphere in the Arctic were still on the frontiers of science. Indeed, this was perhaps the most extreme case of science being forced to develop explanations for the implications of global warming even as those implications were unfolding in real time.
In ecological terms a disaster was already underway as polar bears found themselves with shorter hunting seasons out on the ice, walruses were forced to use haulouts (places where they could rest and reproduce) on land rather than ice, which left them vulnerable to predators as the ice retreated farther and farther from shore, and countless other delicate balances, developed over millennia, suddenly were thrown out of kilter. In subsequent years the ecological toll has accelerated, marked by massive bird die-offs and tales of starving polar bears.
In the 2000s, the Arctic was already changing. I saw these changes for myself while reporting various articles for Time. In Yakutia I saw a baby mammoth that had been preserved for tens of thousands of years in the permafrost and was now in danger of decomposing as the warmth penetrated deeper into the ground above it. I also saw tilting buildings in Yakutsk, the capital, which became destabilized as the ground liquefied beneath them (in this case global warming might have been performing a public service, as many of these buildings were soulless legacies of the Stalin era). I visited a polar bear “jail” in Churchill on Hudson Bay, a facility where rangers put bears that strayed into town looking for food because they couldn’t get enough sustenance from their normal hunting grounds as the warming Arctic melted the sea ice.
I concluded an article on climate changes in the Arctic by noting the irony that far northern defense installations on the front lines of the Cold War have been repurposed to study climate change:
At the entrance to the Churchill Northern Studies Centre, a base for investigations of regional climate change, a rusting rocket is a mute reminder of the complex’s earlier life as part of defenses against Soviet nuclear attack. That threat never materialized, and now, belatedly, scientists venture from the base to study a threat that has materialized but against which no adequate defense has been mounted. Despite the danger that climate change poses, the resources currently devoted to studying this problem—and combatting it—are inconsequential compared with the trillions spent during the cold war. Twenty years from now, we may wonder how we could have miscalculated which threat represented the greater peril.
Now it is twenty years later, and a good question for a public opinion expert might be how many people now see climate change as a bigger danger than the Soviets posed during the Cold War.
In that first decade of the 2000s, the Arctic saw the most dramatic changes in climate. Scientists, prominently Jennifer Francis, then at Rutgers and now at the Woodwell Climate Research Center, explored how these changes in circulatory patterns might impact the lower latitudes. She didn’t have to wait long to find confirmation for most of her predictions as persistent cold spells (misleadingly dubbed “polar vortexes”), heat waves, and droughts became hallmarks of midlatitude life in North America during the very next decade, as did their connection to the extreme changes in the northern cryosphere.
Nor did scientists who were worried about the stability of the ice sheets have to wait long to see whether their shrinkage would contribute to sea level rise. A study done by NASA’s Jet Propulsion Laboratory and the University of Kansas in 2006 found that the Greenland Ice Sheet was melting twice as fast as previously estimated based on satellite data going back to 1996. Later that year another study out of the University of Texas confirmed the acceleration, and subsequent studies out of the University of Bristol documented a further acceleration of the melting of the ice sheet in the years following 2006. The message of these studies was that Greenland was melting and the melting was accelerating.
As for Antarctica, melting and iceberg calving from the West Antarctic Ice Sheet were already contributing to sea level rise, although the question of how much would, in 2007, become a cause célèbre. Subsequent analysis showed that melting from all the ice sheets (Greenland and Antarctica) contributed between about 1.3 and 1.5 millimeters of sea level rise in 2006. This doesn’t sound like much, but total sea level rise that year was roughly 3 millimeters, meaning that the ice sheets were contributing more than 40 percent of that increase.
This set the stage for some real drama over the next year as scientists and policymakers prepared to release the fourth IPCC assessment in 2007. By this point, most scientists agreed that sea level was rising about three times as fast as during most of the previous century, that the rate of sea level rise was accelerating, and that melting from the ice sheets was a significant factor in both the rate of sea level rise and the acceleration of the rate. On top of that, the consensus was that the rate of sea level rise would continue to accelerate; credible arguments that it would slow or level off were exceedingly difficult to find.
So how did the fourth assessment Summary for Policymakers treat sea level? It lowered its upper estimate of sea level rise from 88 centimeters in the previous assessment, published in 2001, to 59 centimeters. Both the 2001 and 2007 upper estimates for sea level were lower than the upper estimate of the first assessment in 1990. For the layman, the message of this consistent moderation of sea level rise estimates was that sea level was not going to be as severe a problem as initially thought and that, indeed, as scientists got better at estimating future sea level, the problem got less and less severe.
Needless to say, this was exactly the opposite of the message that the great preponderance of scientists wanted to convey, and so it’s worth digging into how the IPCC got to this point.
It’s no easy task to estimate future sea level rise given the wide variety of component inputs and uncertainties about future contributions from the ice sheets under various scenarios. To some degree the IPCC relied on what are called “process models.” As leading climate modeler Stefan Rahmstorf explains it, process models “aim to simulate individual processes like thermal expansion or glacier melt.” This seems like an entirely reasonable approach, but Rahmstorf and many other scientists felt that the models were not “mature.” For one thing, at the time, they couldn’t even reproduce the observed sea level rise since 1990, and the models underestimated actual sea level rise by 50 percent according to the German scientist.
To address this shortcoming, Rahmstorf developed a “semi-empirical” model for projections. Calibrating his model to past data, Rahmstorf’s projections linked future sea level rise to global temperature data. He published his findings in Science in 2006, and they were vastly different from the IPCC projections. His upper case showed roughly twice as much sea level rise as the IPCC consensus. Though the paper elicited tremendous interest among scientists—Rahmstorf noted in the climate blog RealClimate that it was the second-most-cited paper of the ten thousand sea-level-related papers published between 2007 and 2013—the IPCC did not take semi-empirical models into consideration in assembling the chapter on sea level rise.
Why not?
It could have been a case of inherent scientific conservatism, though Rahmstorf has openly wondered whether the semi-empirical models would have been included had they projected less sea level rise than the process models. Naomi Oreskes wonders whether it’s a case of torquing the results by omission. She and coauthors published a paper entitled “Climate Change Prediction: Erring on the Side of Least Drama?,” where they argued that “scientists are biased not toward alarmism but rather the reverse: toward cautious estimates, where we define caution as erring on the side of less rather than more alarming predictions.”
They go on to show that in case after case, the IPCC has been more willing to consider the outlier benign case over the outlier alarming case. Many others have pointed out that reality has been consistently worse than IPCC best estimates. A recent paper in Nature Climate Change shows that Greenland ice melt, for instance, has tracked or exceeded the IPCC’s upper case (the widespread tendency is to say “worst case,” but IPCC authors point out that they don’t give a worst case, but rather an upper case within the bounds of probability).
This tendency toward conservatism has provided ammunition for the “nothing to see here” crowd. Patrick Michaels, who has made a career downplaying the threat of climate change, used data cherry-picked from the fourth assessment to attack Al Gore’s book An Inconvenient Truth. Other climate deniers went over the report with a fine-tooth comb, looking for errors and feeding them to denier-friendly reporters such as Jonathan Leake. This led to a series of “gate” stories—“Amazongate,” “Africagate,” etc.—all of which turned out to be what I would call “vaporgates” upon examination.
At a time, then, when a clear message from scientists could have been “Climate changes are accelerating and are worse than we scientists anticipated,” the muddled message to the public mediated by the deniers was a self-contradictory but effective “IPCC sees climate change as less of a threat” and “Don’t trust the IPCC.” Consequently, at a point when the public should have been hearing that scientific alarm about the scale and proximity of the climate peril was mounting, the message received was that scientists were still trying to sort things out.
The dustup over sea level rise and the contribution of the ice sheets at least involved scientific arguments, even if those arguments might have been tainted by political considerations. For the public, the three other scientific kerfuffles of the decade were pure disingenuous inventions of denier spinmeisters. The first two involved repercussions from the publication in the late 1990s of what was dubbed the “hockey stick” by Michael Mann and colleagues. Based on proxies, they showed that recent temperatures indicated that the planet was warmer than it had been in more than a thousand years and that the recent rises were so extreme that a graph of temperatures looked like a hockey stick.
The attacks were swift in coming. A Canadian mining consultant named Stephen McIntyre went after Mann, first for the legitimacy of the data, then for willfully misrepresenting the data. It bears noting that none of the challengers came from the paleoclimatology community or had any expertise in using proxies for reconstructing past climates (proxies, ranging from tree rings to lake bed sediments and ice cores, supplied most of Mann’s data). McIntyre did find some small errors in proxy data that were not in the main body of Mann’s analysis, but none of them would have affected the outcome, and McIntyre and his colleagues were swiftly rebutted for errors in their own methodology. That did not stop the fossil fuel lobby and their minions in Congress from seizing on this made-up “scandal.”
McIntyre and a like-minded economist named Ross McKitrick were invited to meet with fossil fuel devotees such as Oklahoma senator James Inhofe, who once called climate change “the greatest hoax ever perpetrated on the American people.” Rush Limbaugh blasted news of the supposed outrage, as did the editorial page of The Wall Street Journal. McIntyre and others besieged Mann and his colleagues with requests for “raw data” even when it was readily available on databases. The requests were so persistent that the scientists on the receiving end came to believe the demands were intended more to distract and annoy the scientists than for any other purpose. As reported in Mother Jones, the University of East Anglia’s Climatic Research Unit (CRU), a major keeper of temperature data, received fifty-eight Freedom of Information Act requests in just one week in July 2009.
But there was no scandal. The hockey stick was featured in the third assessment of the IPCC published in 2001. The National Academy of Sciences weighed in, supporting Mann’s assertion of unprecedented warming. Subsequent analyses conducted by scores of scientists scattered over many institutions actually lengthened Mann’s initial time period from one thousand to fourteen hundred years, and then to eleven thousand years. There were so many confirmations that Mann joked that rather than a hockey stick, they had a “hockey team.” Projections of future temperatures make the hockey stick look even more frightening.
Step back and consider what the critics were arguing: they were saying that the entire paleoclimate community was mistaken and that the present warming was in accord with normal variations in climate over the past thousand years. In the early 2000s, there were countless other pieces of evidence that the warming was extraordinary—the melting of permafrost, the discovery of Ötzi the Iceman, a body entombed in ice 5,300 years ago but revealed as Swiss glaciers retreated, the march of insect-borne diseases into altitudes where they had never been before, the collapse of ice shelves that had been stable for thousands of years, the advancing date of spring and delayed autumns, the retreat and disappearance of glaciers that had been around for thousands of years, the opening of the Northwest Passage. Everywhere one looked there was evidence that climate changes were outside of normal bounds. And yet these critics were saying that if there was the tiniest error in one piece of data (and there wasn’t), that all the other evidence didn’t matter; we have to conclude that there was no warming. It was a classic case of “Who are you going to believe, us or your lying eyes?”
Nor was refutation of the accusations by every credible scientific body that looked at the issue sufficient to put the debate to rest. The argument trumpeted by the deniers was that there was a vast conspiracy of climate scientists to hype the threat because that’s how they got government money. Putting aside the hilarious idea that the George W. Bush administration was going to channel money to scientists seeking supporting evidence of a climate crisis—that administration was more likely to subsidize critics of global warming—the very argument represented a profound misunderstanding of what motivates scientists. Scientists are born contrarians, and they make their reputation by challenging the consensus, not supporting it. Moreover, even then, there was direct evidence that the ones getting paid for their opinions were the ones throwing the accusations.
As the saying goes, when the facts aren’t with you, challenge the messenger. First there were the vague allegations that all climate scientists were in it for the money. Then, when a hacker stole more than a thousand emails from CRU servers, there came accusations of outright fraud, that scientists were hiding data that contradicted the global warming thesis. Poring through the emails between various scientists trying to make sense of the proxy and instrumental data, critics jumped on words like “trick” and “decline” to show that scientists were conspiring the hide the awful truth that climate change was a big lie.
The usual crowd jumped on the “scandal.” The BBC quoted the Saudi Arabian climate negotiator, hardly a neutral source as a representative of the world’s most famous petro-state: “It appears from the details of the scandal that there is no relationship whatsoever between human activities and climate change.” Other conservative outlets used such phrases as “the greatest deception in history.”
I won’t devote much space to Climategate because it turned out to be a scandal based on nothing. The “trick” turned out to be a standard statistical method, and the “decline” referred to a curious cool signal from tree rings during relatively recent periods when the instrumental record showed warming. Several subsequent investigations concluded that nothing in the stolen emails contradicted the published work of the scientists in any way whatsoever.
The phony scandal achieved its likely goal of making life miserable for the scientists involved. Never in his most paranoid dreams when he was a graduate student did Michael Mann think that his work on paleoclimate would lead to death threats, or that a reconstruction of past temperatures would lead Attorney General Ken Cuccinelli of Mann’s home state, Virginia, to launch McCarthyesque investigations of his work (ultimately Mann left his position at the University of Virginia and moved to the friendlier state of Pennsylvania). Cuccinelli initiated a protracted legal battle ostensibly to see whether state money had been misspent on Mann’s work. In his court filings, he continued to cite the stolen emails long after investigations had determined that they contained nothing improper. Ultimately, Cuccinelli lost in the state supreme court, but not before Mann and his defenders spent hundreds of thousands of dollars and countless hours trying to fend off what amounted to state-sponsored harassment of a distinguished scientist.
In a just world, Cuccinelli would have been driven off the public stage in shame. Unfortunately, in Trump’s world, a despicable attack on a serious scientist made Cuccinelli their kind of guy. Trump would name him acting director of the United States Citizenship and Immigration Services, part of the Department of Homeland Security. And if someone is looking for a current “scandal,” it turns out that Cuccinelli was appointed in contravention of federal law, and the Trump administration ultimately dropped its appeal to defend his appointment.
Despite the fact that every Climategate turned out to do nothing more than debase the significance of appending “-gate” to some alleged scandal, and despite the fact that the courts rebuked various efforts to harass working scientists, these fake scandals and lawsuits were fabulous successes for the hucksters promoting them. Six months after news of the stolen emails hit the headlines, a Gallup poll showed that the number of people who believed that global warming was an exaggerated threat jumped to 48 percent from 41 percent a year earlier. Polling in the United Kingdom showed similar results. And, as we shall see, the deniers were not done sowing confusion and doubt.
The first decade of the millennium turned out to be the warmest yet recorded. Scientifically, it turned out to be something of a schizophrenic decade. There were solid advances in the understanding of the components of sea level rise, particularly with regard to the role of the great ice sheets, but the most critical elements did not make it into the Summary for Policymakers, which, rightly or wrongly, was regarded as the scientific consensus. Consequently, if we take the IPCC fourth assessment as the public face of the state of the science in the decade, it looks as though the scientific clock ran backward during this time.