Steven Koonin was the undersecretary for science at the Department of Energy in the Obama administration, but recently considered an advisory role to Scott Pruitt when he was head of the Environmental Protection Agency. A new book has been published. Posted on May 4, titled Unsettled: What climate science tells us, what it doesn’t, and why it matters, Its main theme is that the science about Earth’s climate is still inconclusive. He argues that pundits and politicians, and most who disagree, are victims of what he publicly calls “consensus science.”
Kooning was wrong on both counts. The science surrounding the discovery of the possibilities and consequences of climate impacts is stronger than ever, and has been getting stronger for decades. In the early days of research, uncertainty is high; but with each subsequent step, uncertainty has narrowed or become better understood. That’s how science works, and in the case of climate, the early signs of discovery and attribution in the 1980s and 1990s have come true time and time again, and earlier than expected.
This is not to say that uncertainty is being eliminated, but that policymakers are becoming more comfortable dealing with the inevitable residuals. They are using the best and most honest science to inform potential investments in mitigation (reducing greenhouse gas emissions to reduce the estimated likelihood of the impacts of dangerous climate change) and adaptation (reducing vulnerability to reduce their current and projected consequences).
Koonin’s intervention in the debate on how to address climate risk appears to be aimed at subverting this on all fronts by making distracting, irrelevant, misleading, misleading and unconditional statements about the supposed uncertainty he believes scientists are hiding under the rug. a progress. Here I consider some early statements in his own words. They were taken verbatim from his introductory pages, so he must want readers to see them as relevant take-home discoveries throughout the book. They are briefly assessed in the proper context, supported by the findings documented in the latest report of the Intergovernmental Panel on Climate Change. Notably, Koonin acknowledges this source in his discussion of the assessment, even covering the basis for the confidence and likelihood language embedded in his findings (specific references in the IPCC report are given in parentheses).
Two such statements by Koonin follow a simple preamble “For example, the literature and government reports summarizing and assessing the state of climate science clearly indicate…”:
- “The heat wave in America right now no longer common Compared with 1900, the hottest temperature in the United States has not risen in the past 50 years. (Original in italics.) This is a questionable statement by the definition of “heat waves,” so it’s really not informative. Heat waves are a poor indicator of heat stress. Whether or not they’ve become more frequent, in the past Over the decades, they have apparently gotten hotter and longer, and the population has become largely more vulnerable because they are on average older [Section 184.108.40.206]. In addition, during these longer periods of extreme heat events, nighttime temperatures rose the most. As a result, people are never freed from the unbearable heat and many more are at risk of dying.
- “The hottest temperature in the U.S. hasn’t risen in the past five decades.” By what measure? Global annual highest average? Absolutely not.The planet has warmed since the Industrial Revolution, it’s clear that more than 30% of that warming has occurred in the past 25 years, followed by the hottest annual temperatures in history [Section SPM.1].
Here are some statements from Koonin’s introduction on the first two pages, “Here are three more that may surprise you, from recently published research or the latest climate science assessments published by the U.S. government and the United Nations”:
- “Greenland’s ice sheet is not shrinking any faster today than it was eighty years ago.” Such claims are irrelevant for a risk-based approach to climate discussions about what we “should do.” What worries us is the future. Observations from 11 satellite missions monitoring the North and South Pole show that the ice sheet is losing mass six times faster than it was in the 1990s. Is this the start of a new trend? Maybe. For those taking a risk management approach, the steady state of science is that this is a high-risk possibility (with huge consequences) that should be taken seriously and examined more thoroughly.This is even more important because even without these contributions to accelerating historical trends, sea level rise will continue to exaggerate coastal exposure by drastically shortening the return times of various storms [Section 220.127.116.11]; that is, a once-in-100-year storm became a once-in-50-year event, a once-in-50-year storm became a once-in-10-year event, and ultimately an almost annual fact of life.
- “At least until the end of the century, the net economic impact of human-induced climate change will be minimal.” It would be unconscionable to make such a statement, not least because the adjective “minimal” is not at all informative.No qualifications are unsupportable as overall estimates are very incomplete [Section 18.104.22.168]Nonetheless, Swiss Re recently released a major report on climate change, saying that insurers are underinsured by rising climate risks, which are currently on the rise and are expected to continue to do so in the near term. Despite the uncertainty, they see a looming source of risk and won’t wait until the end-of-the-century forecast is clear to respond.
The first of these misleading statements about Greenland is more troubling because global mean sea level rise has accelerated. Although Chapter 8 says to the contrary, this is widely known, described in the introduction as “a sober view of sea levels that have been rising for thousands of years”. Koonin continued: “We’ll unravel what we really know about the impact of humans on the current rate of ascent, which is about a foot per century, and explain why it’s so hard to believe that rough waters will flood the coast any time soon.”
The problem is that while sea levels have risen by 8 to 9 inches since 1880, more than 30% of the increase has occurred in the past 20 years: 30% of the historical record has occurred in the past 14% of the time series.This is why sea level rise is expected to exaggerate coastal risks and economic consequences with great confidence [Section 22.214.171.124].
His trailer for Chapter 7 is an equally disturbing misdirection. He promises to highlight “some points that may surprise anyone who follows the news — for example, the annual global area burned by fires has decreased by 25 percent since observations began in 1998.” In this case, global statistics Meaningless. Wildfires (if that’s what he’s talking about) are localized events, and regional patterns in their intensity and frequency lend themselves well to risk-based calibration because they’re increasing in many places. Take the 2020 experience, for example. Record-setting wildfires have occurred in several major locations including the western United States, Siberia, Indonesia and Australia (starting in 2019).
Take a more concrete example. From August to October 2020, California suffered the largest wildfire in California history. With the third, fourth, fifth and sixth largest fires in state history; and all five were still burning on October 3. Their incredible strength and coincidence can only be explained by the confluence of four climate change consequences so far attributed to climate change: record droughts, record heatwaves lasting from July to August, Years of bark beetle infestation killed 85 percent of trees in large swathes of forest, and prolonged warming extended the fire season by 75 days.
So, what is the takeaway message? Regardless of what Kooning writes in his new book, the science is clear and the consensus is very broad. Scientists have been generating and reporting increasingly specific data on climate impacts and surrounding uncertainties. This is especially true for exaggerated natural, social and economic risks associated with climate extremes – low-probability, high-consequence events are an essential part of effective risk management. This is not an unstable state. It lives in a dynamic picture of what’s going on, with each new peer-reviewed paper being painted in a clearer and more detailed way.
In preparing this article, the author benefited from conversations with Henry Jacoby, Richard Richel, and Benjamin Santer.
This is an opinion and analysis article.