BAMS Report Editors Named "Leading Thinkers" of 2013

The September issue of BAMS included a special supplement, “Explaining Extreme Events of 2012 from a Climate Perspective,” edited by Thomas Peterson, Martin Hoerling, and Stephanie Herring of NOAA and Peter Stott of the UK Met Office. This was the second edition of this annual investigation of the causes of recent extreme events. The supplement consists of short, concise studies by various author teams and thus serves as a demonstration of the latest methodologies for attributing specific events to longer term trends in climate. For their work on the report, Peterson, Hoerling, Herring, and Stott are lauded in this month’s issue of Foreign Policy magazine as “Leading Global Thinkers of 2013.”
Foreign Policy called the report “a breakthrough in climate science” for connecting extreme events like Hurricane Sandy to human-influenced climate change. The magazine praised the report’s four editors for “point[ing] problem-solvers in the right direction” on better understanding the causes of extreme weather and climate events. Upon learning about the honor, the four noted that the recognition highlights the value that studying extreme events can provide to global security and sustainability.
“It is clearly an acknowledgement that attribution of extreme events is an important scientific topic—that the results of event attribution research can help guide real-world, climate-smart actions,” Peterson told
The editors also noted that the tribute “honors the collective effort” of all climate scientists studying extreme events, and specifically the 18 different research groups that contributed to the BAMS report. Of course, extreme events will be a featured topic at the AMS Annual Meeting in Atlanta in February, as the theme of the meeting is “Extreme Weather–Climate and the Built Environment: New Perspectives, Opportunities, and Tools.”
Foreign Policy‘s 100 Leading Global Thinkers of 2013 are divided into 10 categories ranging from “the innovators” and “the healers” to “the artists” and “the decision-makers.” The coeditors of the BAMS report were cited in “the naturals” category. Others who made the list of 100 include Vladimir Putin, Pope Francis, the Mars Rover Team, Mark Zuckerberg, Shinzo Abe, and the IPCC. Foreign Policy will be honoring the 100 Global Thinkers at a special event this Wednesday in Washington, D.C.
Watch for the third extreme-events supplement to be released with BAMS next September.

Climate and Weather Extremes: Asking the Right Questions

The still-developing field of attribution science examines specific weather events and short-term atmospheric patterns in a broader, longer-term climate context. In such research, communication is key; it’s vital to understand exactly what questions are being asked. A case in point is an article in the July issue of BAMS. “Explaining Extreme Events of 2011 from a Climate Perspective” gives long-term context to some of the significant weather events of 2011 featured in the new State of the Climate, which is also part of the July BAMS.
The authors write:

One important aspect we hope to help promote …is a focus on the questions being asked in attribution studies. Often there is a perception that some scientists have concluded that a particular weather or climate event was due to climate change whereas other scientists disagree. This can, at times, be due to confusion over exactly what is being attributed. For example, whereas Dole et al. (2011) reported that the 2010 Russian heatwave was largely natural in origin, Rahmstorf and Coumou (2011) concluded it was largely anthropogenic. In fact, the different conclusions largely reflect the different questions being asked, the focus on the magnitude of the heatwave by Dole et al. (2011) and on its probability by Rahmstorf and Coumou (2011), as has been demonstrated by Otto et al. (2012). This can be particularly confusing when communicated to the public.

So the new attribution paper in BAMS strives to answer a very specific questions–a series of them, as it turns out, since the paper is actually a collection of a number of studies by different teams, representing several of the cutting-edge approaches to researching attribution in rapid response to the extreme weather. Most of the authors, but not all, seek to answer questions about how global climate change changes odds that extreme events might occur.
Last week, NOAA held a briefing to discuss both the State of the Climate and the new BAMS article. Two coauthors of the article, Tom Peterson of NOAA’s National Climatic Data Center and Peter Stott of the Met Office Hadley Centre, discussed the answers they found. They noted that in some cases, such as the rainfall that caused flooding in Thailand, there was no connection between human activities and the extreme weather. But other events exhibited a clear human influence that increased the possibility of that event occurring. One example is the prolonged heat wave in Mexico and the southwestern United States, which was the region’s hottest and driest growing season on record by a significant margin. The steamy temperatures were connected to the La Niña that was prominent last year, and the study found that such a heat wave is 20 times more likely in La Niña years today than it was in 1960. As the coauthors noted in the briefing, the answer might be completely different in years without a La Niña , pointing out the importance of context–and understanding the questions being asked–in this study.
The State of the Climate itself documents the weather extremes of the recent past and give them context in the historical record. The 282-page peer-reviewed report, compiled by 378 scientists from 48 countries around the world, also provides a detailed update on global climate indicators and other data collected by environmental monitoring stations and instruments on land and ice, at sea, and in the sky. It used 43 climate indicators to track and identify changes and overall trends to the global climate system. These indicators include greenhouse gas concentrations, temperature of the lower and upper atmosphere, cloud cover, sea surface temperature, sea level rise, ocean salinity, sea ice extent, and snow cover. Each indicator includes thousands of measurements from multiple independent datasets.
Among the highlights of this year’s SOC:

  • Warm temperature trends continue: Four independent datasets show 2011 among the 15 warmest since records began in the late nineteenth century, with annually-averaged temperatures above the 1981–2010 average, but coolest on record since 2008. The Arctic continued to warm at about twice the rate compared with lower latitudes. On the opposite end of the planet, the South Pole recorded its all-time highest temperature of 9.9°F on December 25, breaking the previous record by more than 2 degrees.
  • Greenhouse gases climb: Major greenhouse gas concentrations, including carbon dioxide, methane, and nitrous oxide, continued to rise. Carbon dioxide steadily increased in 2011 and the yearly global average exceeded 390 parts per million (ppm) for the first time since instrumental records began. This represents an increase of 2.10 ppm compared with the previous year. There is no evidence that natural emissions of methane in the Arctic have increased significantly during the last decade.
  • Arctic sea ice extent decreases: Arctic sea ice extent was below average for all of 2011 and has been since June 2001, a span of 127 consecutive months through December 2011. Both the maximum ice extent (5.65 million square miles on March 7, 2011) and minimum extent (1.67 million square miles, September 9, 2011) were the second smallest of the satellite era.
  • Ozone levels in Arctic drop: In the upper atmosphere, temperatures in the tropical stratosphere were higher than average while temperatures in the polar stratosphere were lower than average during the early 2011 winter months. This led to the lowest ozone concentrations in the lower Arctic stratosphere since records began in 1979 with more than 80 percent of the ozone between 11 and 12 miles altitude destroyed by late March, increasing UV radiation levels at the surface.
  • Sea surface temperature and ocean heat content rise: Even with La Niña conditions occurring during most of the year, the 2011 global sea surface temperature was among the 12 highest years on record. Ocean heat content, measured from the surface to 2,300 feet deep, continued to rise since records began in 1993 and was record high.
  • Ocean salinity trends continue: Continuing a trend that began in 2004, and similar to 2010, oceans were saltier than average in areas of high evaporation, including the western and central tropical Pacific, and fresher than average in areas of high precipitation, including the eastern tropical South Pacific, suggesting that precipitation is increasing in already rainy areas and evaporation is intensifying in drier locations.

The report also provides details on a number of extreme events experienced all over the globe, including the worst flooding in Thailand in almost 70 years, drought and deadly tornado outbreaks in the United States, devastating flooding in Brazil and the worst summer heat wave in central and southern Europe since 2003.

IPCC's New Special Report: Adapt to Extremes, but Prepare for the Presentation

For a first reaction to the new Intergovernmental Panel on Climate Change special report, Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation, read William Hooke’s full post here, but keep in mind his take away message for now:

The world need not just this and the other IPCC reports themselves but also the body of diverse analysis and reaction the reports trigger. IPCC reports should and do stimulate thought and action. They don’t prescribe it.
What should you and I keep in mind as we read?
1. We should remember that the Earth does its business through extreme events and always has. Extremes are not suspensions of the normal order; they are its fulfillment.
2. Extremes leave no sphere of the natural or social or technological world unaffected and the disruptions in all those normally distinct spheres intereact with each other, compounding the challenge.
3. Social change matters more to what extreme events and disasters portend for our future than does climate change. .
4. We’ve got to get past reacting to the crisis of the moment

This will be good preparation not only for reading the full report when it’s available online in February 2012 (the summary is now available here) but also for discussions with Roger Pulwarty and colleagues when the present the reports findings on the first day of the upcoming AMS Annual Meeting in New Orleans (23 January, 11:30 a.m., Room 243). If you’re interested in hearing from the report authors now, check out the video from Friday’s press conference: