Prominent scientists dispute congressional science chairman on climate peril
Science and the Media:
By Steven T. Corneliussen
In a recent Washington Post op-ed, Representative Lamar Smith, the Texas Republican who chairs the House Committee on Science, Space and Technology, deplored 'hyped rhetoric' on climate change, condemned 'unfounded claims of impending catastrophe,' and called for calm assessment. Now Michael Oppenheimer, professor of geosciences and international affairs at Princeton University, and Kevin Trenberth, distinguished senior scientist at the National Center for Atmospheric Research, have answered. Their Post op-ed calls Smith's piece 'a reheated stew of isolated factoids' defending 'the destructive status quo' and substituting 'political talking points' for science.
Smith's commentary emphasized the 'great amount of uncertainty associated with climate science,' arguing that it undermines understanding of past effects of carbon dioxide and that it limits the reliability of predictions. Models have 'greatly overestimated warming,' he charged, and then repeated a claim heard widely lately, that temperatures have in fact held steady for a decade and a half. He rejected the possibility that even radical reduction of US emissions could improve global climate. He asserted that experts at the National Oceanic and Atmospheric Administration have said 'that climate change had nothing to do with Superstorm Sandy' and that Intergovernmental Panel on Climate Change (IPCC) experts share 'high agreement' that 'trends in weather disasters, floods, tornados and storms cannot be attributed to climate change.'
Oppenheimer and Trenberth contradict energetically. They invoke 'legions of studies' supporting the view that if 'left unabated . . . warming will produce dangerous effects.' They defend climate modeling:
Projections from an array of scientific analyses summarized by the National Academy of Sciences and most of the world's major scientific organizations indicate that by the end of this century, people will be experiencing higher temperatures than any known during human civilization—temperatures that our societies, crops and ecosystems are not adapted to.
Computer model projections from at least 27 groups at universities and other research institutes in nine countries have proved solid. In many cases, they have been too conservative, underestimating over the past 20 years the amounts of recent sea-level rise and Arctic sea ice melt.
The two scientists reject claims of 'a short-term reduction in the rate of atmospheric warming,' pointing out that ''global' warming requires looking at the entire planet,' including oceans, where warming has risen 'dramatically.' They take special aim at Smith's claims concerning the attribution of extreme weather events to human-caused climate disruption:
In recent years, our understanding of the relationship between climate and extreme weather has sharpened, along with our appreciation of the vast damages such events cause.
Contrary to Smith's assertions, there is conclusive evidence that climate change worsened the damage caused by Superstorm Sandy. Sea levels in New York City harbors have risen by more than a foot since the beginning of the 20th century. Had the storm surge not been riding on higher seas, there would have been less flooding and less damage. Warmer air also allows storms such as Sandy to hold more moisture and dump more rainfall, exacerbating flooding.
Smith referred to the IPCC's special report on extremes but did not mention that the report connects several types of extreme weather to climate change, including heat waves, extreme precipitation and, in some regions, drought. Furthermore, the last major IPCC report, in 2007, stated unequivocally that Earth is warming.
Oppenheimer and Trenberth disdain as 'ludicrous' what they call Smith's 'suggestion . . . that since we know nothing, we should do nothing.' They close their 9 June op-ed with something echoed in a 10 June news story in the same newspaper:
Increases in heat waves and record high temperatures; record lows in Arctic sea ice; more severe rainstorms, droughts and wildfires; and coastal communities threatened by rising seas all offer a preview of the new normal in a warmer world. Smith's policy plan amounts to 'wait and see.' But the longer we wait—effectively, like him, closing our eyes to science—the more difficult and expensive the solutions become, and the more irreversible the damage will be.
At the bottom of the 10 June front page, this teaser blurb points to a back-page article: 'Global emissions of carbon dioxide from energy rose 1.4 percent in 2012, setting a course for temperature gains well above climate goals.' The article discusses an International Energy Agency report foreseeing a temperature increase that 'IEA chief economist Fatih Birol warned 'would be a disaster for all countries.''
Steven T. Corneliussen, a media analyst for the American Institute of Physics, monitors three national newspapers, the weeklies Nature and Science, and occasionally other publications. He has published op-eds in the Washington Post and other newspapers, has written for NASA's history program, and is a science writer at a particle-accelerator laboratory.