Scientists say that human-induced climate change made this year's record heat more likely, and project that extreme heat will become more common in the United States. But a Media Matters analysis of media coverage of record-breaking heat in July finds that major television outlets rarely made the connection between heat waves and a changing climate.
Climate Change Largely Absent From Media Reports On Extreme Heat
Only 14% Of Heat Wave Stories Mentioned Climate Change. In a study of major media outlets, only 8.7% of television segments and 25.5% of print articles reported on record-breaking July heat waves in the context of climate change.
CNN And ABC Stand Out In Their Incomplete Coverage. Of the six TV outlets included in our analysis, ABC mentioned climate change the least, in only 2% of coverage. Among the cable networks, CNN mentioned climate change the least, in less than 4% of coverage. MSNBC was the only television network to regularly incorporate climate change into primetime segments on extreme heat.
Fox Mentioned Climate Change Once, Only To Dismiss It. In six primetime segments on extreme heat, Fox News raised climate change once. The Five's only liberal co-host Bob Beckel noted that record July heat is consistent with global warming, and was promptly dismissed by co-host Greg Gutfeld, who routinely denies that manmade global warming is occurring.
Quality Of Heat Wave Coverage Varied Among Major Papers. Overall, the major print outlets mentioned climate change in just over a quarter of articles on extreme heat. The New York Times led the pack, mentioning climate change in more than half of its coverage (54.5%), and the Washington Post mentioned it in 26% of articles on July heat. But the Associated Press, the Los Angeles Times, and USA Today mentioned it in less than 15% of coverage. The Wall Street Journal didn't mention climate change at all, although the paper had significantly fewer stories on extreme heat.
Only 8% Of Coverage Pointed Out That Human Activities Are Driving Climate Change. Only 6% of television segments and 12% of print articles noted that climate change is fueled by human activities including the burning of fossil fuels, which emit greenhouse gases that are warming the planet. The Associated Press, USA Today, Fox News and the Wall Street Journal never made that connection.
METHODOLOGY: We searched Nexis and Factiva databases for articles and segments on (extreme heat or record heat or heat wave or record high!) between July 1, 2012, and July 31, 2012. Our analysis includes six major print outlets (New York Times, Washington Post, USA Today, Los Angeles Times, Associated Press and Wall Street Journal), the major broadcast networks (ABC, NBC and CBS), CNN and the primetime shows on MSNBC and Fox (daytime shows for these networks are not available in Nexis).
NOAA: July 2012 Was The Hottest Month On Record In The U.S.
Scientist: This Year's Extreme Heat Shows "Global Warming From Human Activities Has Reared Its Head." The National Oceanic and Atmospheric Administration recently announced that July 2012 was the hottest month in the contiguous United States since record keeping began in 1895. So far, this year has been the warmest on record in the U.S. As the Associated Press reported, scientists see a link between recent extreme heat and long-term warming trends:
"This would not have happened in the absence of human-caused climate change," said Pennsylvania State University climate scientist Michael Mann.
[NOAA's Jake] Crouch and Kevin Trenberth, climate analysis chief of the National Center for Atmospheric Research, said what's happening is a double whammy of weather and climate change. They point to long-term higher night temperatures from global warming and the short-term effect of localized heat and drought that spike daytime temperatures.
Drought is a major player because in the summer "if it is wet, it tends to be cool, while if it is dry, it tends to be hot," Trenberth said.
So the record in July isn't such a big deal, Trenberth said. "But the fact that the first seven months of the year are the hottest on record is much more impressive from a climate standpoint, and highlights the fact that there is more than just natural variability playing a role: Global warming from human activities has reared its head in a way that can only be a major warning for the future." [Associated Press, 8/9/12] [NOAA, 8/8/12]
The Washington Post's Capital Weather Gang noted that while U.S. temperatures don't necessarily reflect worldwide trends, "global temperatures have also been running warm":
When considering connections to global warming and increasing concentrations of greenhouse gases, it's important to recognize the area of the U.S. represents less than 4 percent of the globe and 2012 is just one year in a long history.
Having said that, global temperatures have also been running warm. While NOAA's global report for July temperatures has not yet been issued, June ranked 4th warmest on record globally and marked the 328th consecutive month of above average temperatures. [The Washington Post, 8/8/12]
Manmade Climate Change Has Increased The Likelihood Of Heat Waves
IPCC: "Virtually Certain" That Heat Extremes Will Intensify. A 2012 Special Report by the Intergovernmental Panel on Climate Change (IPCC) deemed it "virtually certain" that heat extremes will become stronger and more frequent on a global scale in the 21st century, and "very likely" that heat waves will increase in "length, frequency, and/or intensity ... over most land areas." The report noted that "[p]rojected changes at subcontinental scales are less certain than is the case for the global scale" and that "[m]ean global warming does not necessarily imply warming in all regions and seasons." [IPCC, June 2012]
Studies Project U.S. Heat Extremes Will Become More Frequent. A 2009 report to Congress and the White House from the U.S. Global Change Research Program stated:
Scientific research has concluded that human influences on climate are indeed changing the likelihood of certain types of extreme events. For example, an analysis of the European summer heat wave of 2003 found that the risk of such a heat wave is now roughly four times greater than it would have been in the absence of human-induced climate change.
With rising high temperatures, extreme heat waves that are currently considered rare will occur more frequently in the future. Recent studies using an ensemble of models show that events that now occur once every 20 years are projected to occur about every other year in much of the country by the end of this century. In addition to occurring more frequently, at the end of this century these very hot days are projected to be about 10°F hotter than they are today.
The report illustrated this increase in the frequency of heat extremes:
[Global Climate Change Impacts in the United States, 2009]
NASA Study: Heat Waves Are "Very Likely" A Consequence Of Global Warming. A study by the National Aeronautics and Space Administration's James Hansen and other scientists found that land areas across the globe are "much more likely to experience an extreme summer heat wave than they were in the middle of the 20th century":
The statistics show that the recent bouts of extremely warm summers, including the intense heat wave afflicting the U.S. Midwest this year, very likely are the consequence of global warming, according to lead author James Hansen of NASA's Goddard Institute for Space Studies (GISS) in New York.
"This summer people are seeing extreme heat and agricultural impacts," Hansen says. "We're asserting that this is causally connected to global warming, and in this paper we present the scientific evidence for that."
The NASA report included this chart showing the shift:
[NASA, August 2012]
There Is "Strong Evidence" Linking Heat Waves To Manmade Climate Change. A review of extreme weather events published in Nature Climate Change in 2012 concluded that, for heat waves and extreme precipitation, there is "strong evidence linking specific events or an increase in their numbers to the human influence on climate." [Nature Climate Change, 3/25/12]
NOAA: Some Heat Waves Now 20 Times More Likely. NOAA's "State of the Climate in 2011" report stated that although "scientists cannot trace specific events to climate change with absolute certainty," new research on the probability of those events found that "La Niña-related heat waves, like that experienced in Texas in 2011, are now 20 times more likely to occur during La Niña years today than La Niña years fifty years ago" due to broader warming. [NOAA, 7/10/12]
Study: 80% Probability That Deadly 2010 Moscow Heat Wave Wouldn't Have Happened Without Climate Change. In a 2011 report published in the Proceedings of the National Academy of Sciences, scientists from the Potsdam Institute for Climate Impact Research found that record-breaking heat events, while not necessarily individually attributable to climate change, are made more likely by broader warming. Specifically, the report concluded with "approximate 80% probability" that the July 2010 heat wave that killed hundreds of people in Moscow and thousands throughout Russia "would not have occurred without climate warming." A 2012 study led by Oxford University scientists similarly concluded that Russia's 2010 heat wave was partly influenced by "manmade factors," and that "the frequency of occurrence of such heat waves has increased by a factor of three over recent decades." [University of Oxford, 2/21/12] [Proceedings of the National Academy of Sciences, September 2011]