Climate Risks: Lessons from 2010’s Extreme Weather


Update: Dr. Jay Gulledge is featured on National Journal's Energy & Environment Expert Blogs. Click here to read Dr. Gulledge's take on Climate Risks Here and Now

Last fall I posted a blog about the unusual number and severity of extreme weather events that have been striking around the globe for the past several years. That entry focused on the alternating severe drought and heavy flooding in Atlanta in 2007-2009 as an example of the roller coaster ride that climate change is likely to be. As every dutiful scientist does, I stopped short of blaming those individual weather events on global warming, but I am also careful to point out that it is scientifically unsound to claim that the confluence of extreme weather events in recent years is not associated with global warming; I’ll return to this question later.

Tempestuous 2010

The weather of 2010 continues the chaos of recent years. In the past six months, the American Red Cross says it “has responded to nearly 30 larger disasters in 21 [U.S.] states and territories. Floods, tornadoes and severe weather have destroyed homes and uprooted lives …” Severe flooding struck New England in March, Nashville in May, and Arkansas and Oklahoma in June.

"Facts are Stubborn Things ..."

In his defense of soldiers in the Boston Massacre trials, John Adams went on to say “… and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence.”

No matter what we may wish were happening, no matter what spin some may try to sell, the clear evidence of climate change continues to mount.

The U.S. National Oceanic and Atmospheric Administration (NOAA) has just released its annual report on the state of the climate, and the facts speak volumes about the pervasiveness and speed of actual climate change, not model projections. 

"Climategate" Scientists Exonerated

I posted previously on the controversy surrounding emails that were hacked from a computer server at the University of East Anglia’s (UEA) Climatic Research Unit (CRU) in the U.K. The emails revealed the private exchanges of several prominent climate scientists dealing with their science and their reactions to climate change deniers who requested access to their private computer files and intellectual property. The contents of the emails suggested to the untrained eye that the scientists had manipulated data and tried to undermine the scientific peer-review process. From my reading of the emails, I judged that nothing of the sort had happened. Since my last writing on the topic, five separate independent investigations (3 in the United Kingdom and 2 in the U.S.) of the matter have concluded that there was no mishandling of data or other wrongdoing beyond some foot-dragging in response to Freedom of Information requests by climate change deniers. The clear message from these investigations is that proper scientific methods were followed and the integrity of climate science remains solid as a rock. 

Comprehensive Climate Science Reports Released Today

Today the National Academy of Sciences (NAS) released three of its long-awaited “America’s Climate Choices” (ACC) reports. A fourth report will be released later this year, as will an overarching synthesis report. The three reports released today focused on advancing the science of climate change, adapting to unavoidable climate change, and limiting the ultimate extent of climate change. The reports and background information on the study are accessible from the ACC web site.

Collectively, the ACC reports are the most comprehensive study the NAS has conducted on climate change. The project was mandated by Congress and requested by the National Oceanographic and Atmospheric Administration in 2008. Unlike past NAS efforts, the ACC reports emphasize how the nation can move forward on solving the climate change problem.

NAS president Ralph J. Cicerone said, “These reports show that the state of climate change science is strong.” The study emphasizes that our current understanding of human-induced climate change is supported by many independent lines of evidence that have weathered intense debate and serious exploration of alternative explanations: “Climate change is occurring, is caused largely by human activities, and poses significant risks for – and in many cases is already affecting – a broad range of human and natural systems,” the report says.

A statement about the ACC by our center's president Eileen Claussen is available here.

We will be sure to let you know when the remaining pieces of the ACC report come out later this year.

Jay Gulledge is Senior Scientist and Director of the Science & Impacts Program

Climate Change: "Unequivocal"

The following first appeared as a "Letter to the Editor" in today's Washington Post.

In his Feb. 21 op-ed column, "Global warming advocates ignore the boulders," George F. Will concluded, incorrectly, that the Earth isn't warming. Mr. Will referred to climate scientist Phil Jones, who said that the planet did warm from 1995 to 2009 but not "at the 95 percent significance level." But Mr. Jones also cautioned that 15 years is too short to expect statistical significance. That is why climate norms -- such as the "normal" daily temperatures that forecasters show on the local news -- are 30-year averages. The Post's readers might be interested to know, therefore, that the global warming trend from 1980 to 2009 -- a little over 1 degree Fahrenheit -- is statistically significant at the 99.9999 percent level.

Climate scientists have always stated clearly that it takes decades to detect a change in the climate, so why focus on just the last 15 years?

From its own reading of the peer-reviewed literature, the National Academy of Sciences concluded, "It is unequivocal that the climate is changing, and it is very likely that this is predominantly caused by the increasing human interference with the atmosphere. These changes will transform the environmental conditions on Earth unless counter-measures are taken."