More myths and falsehoods about global warming

Since the release of the film An Inconvenient Truth (Paramount Classics, May 2006) featuring former Vice President Al Gore, the issue of global warming has received increased media attention. In March 2007, Media Matters for America documented several false, misleading, or baseless claims about the causes and seriousness of global warming that were circulating in the media at the time. Since then, media figures have continued to advance misinformation about global warming:

1. 1934 was the hottest year globally

Several media figures have misrepresented an August 2007 correction made by NASA's Goddard Institute for Space Studies (GISS) to its climate figures after the discovery of inconsistencies in its U.S. temperature data. According to Gavin A. Schmidt, a climate modeler at GISS, the correction resulted in a re-ranking of NASA's list of the warmest years in the United States. For example, whereas 1998 was previously ranked as the warmest year in the United States, it is now ranked second, behind 1934. According to Schmidt, the temperature difference between 1934 and 1998 in the United States -- both before and after the correction -- is not statistically significant. Further, the GISS stated that the revisions to the climate data have “no effect on the rankings of global temperature.” However, during the August 10, 2007, edition of Fox News' Special Report, chief Washington correspondent Jim Angle reported that NASA was forced “to admit it was wrong when it said that 1998 was the hottest year on record” and that NASA “now says 1934 was the hottest year, followed by 1998, then 1921” but did not note that those rankings applied only to the United States. Glenn Beck made a similar claim during the October 24, 2007, edition of his nationally syndicated radio show. Beck declared that “the globe was the hottest” in 1934 and claimed that this “stat ... was, I believe, intentionally distorted by the guy the left holds up as the scientist on global warming,” an apparent reference to James Hansen, director of GISS.

In fact, according to GISS, 2005 remained the warmest year globally in the instrumental record, followed by 1998. (2007 is now tied with 1998 as the second warmest year in the global instrumental record.) According to a January 16 GISS statement, “The eight warmest years in the [global] GISS record have all occurred since 1998, and the 14 warmest years in the record have all occurred since 1990.”

2. The sun, not human activity, causes global warming

Echoing earlier claims by nationally syndicated radio host Rush Limbaugh and columnist John McCaslin, media figures have distorted scientific research to claim that the sun -- rather than human activity -- is primarily responsible for global warming. During the August 21, 2007, edition of Special Report, host Brit Hume cited “new research by University of Washington mathematicians [that] shows a correlation between high solar activity and periods of global warming” as evidence to support his claim that "[global warming] skeptics are increasingly certain that the scare is vastly overblown." But an August 9, 2007, New Scientist article on the mathematicians' research warned that "[c]limate-change skeptics may seize on the findings as evidence that the sun's variability can explain global warming -- but [the report's co-author] mathematician Ka-Kit Tung says quite the contrary is true." According to the article, Tung, who is a University of Washington professor of applied mathematics and an adjunct professor in Atmospheric Science, says his finding, in the New Scientist's words, “adds to the evidence that mainstream climate models are right about the likely extent of future human-generated warming.”

Similarly, in a March 22, 2007, National Review Online (NRO) commentary, former Sen. Fred Thompson (R-TN) mocked those who “think that our planet is suffering from a fever,” saying: “Now scientists are telling us that Mars is experiencing its own planetary warming: Martian warming. ... I wonder what all those planets, dwarf planets and moons in our SOLAR system have in common. Hmmmm. SOLAR system. Hmmmm. Solar? I wonder.” In a July 27, 2007, Washington Post article, then-staff writer John Solomon quoted portions of Thompson's commentary, but failed to note that Thompson's argument -- that warming on other planets is evidence that warming on Earth is the result of natural circumstances, and not human activity -- is one, according to a scientist interviewed in National Geographic about the theory, that is “completely at odds with the mainstream scientific opinion.” Indeed, according to the most recent Intergovernmental Panel on Climate Change (IPCC) report, “Most of the observed increase in globally-averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG (greenhouse gas) concentrations.” The authors of the IPCC report noted that the phrase “very likely” translates to greater than 90 percent probability. The IPCC further reported that “it is very unlikely [less than a 10-percent chance] that the contribution from solar forcing to the warming of the last 50 years was larger than that from greenhouse gas forcing.”

3. Gore is exaggerating about rising sea levels

Since the release of An Inconvenient Truth, media figures have attacked Gore and the film by accusing him of exaggerating scientific assessments and predictions about rising sea levels, the possible links between global warming and hurricanes, and arctic melting. The attacks have taken the form of false comparisons and misrepresentations of his claims. Indeed, during the June 1, 2007, edition of Fox News' Special Report, Weekly Standard executive editor Fred Barnes falsely claimed that there is a “difference between Al Gore and the Intergovernmental Panel on Climate Change” because “Al Gore says that over the next century sea level rises 20 feet” but the IPCC “says, 'Well, maybe 17 to 23 inches.' ” In fact, Gore never said in either the film or the book version of An Inconvenient Truth that the potential 20-foot rise in sea levels would happen “over the next century,” as Barnes claimed. Rather, the supposed “difference” between Gore and the IPCC on the issue of sea levels relies on a false comparison. While the February 2007 IPCC report projected a maximum 23-inch sea-level rise before 2100 as a result of rising temperatures, Gore's statement predicted a 20-foot rise in sea levels if the Greenland or West Antarctic ice sheets were to melt completely or collapse at an indefinite point in the future. Indeed, the IPCC reported that "[c]ontraction of the Greenland Ice Sheet is projected to continue to contribute to sea level rise after 2100" and that "[i]f a negative surface mass balance were sustained for millennia, that would lead to virtually complete elimination of the Greenland ice sheet and a resulting contribution to sea level rise of about 7 m," which is equivalent to approximately 23 feet. The IPCC also supports Gore's claim that a collapse of the West Antarctic Ice Sheet would result in a sea level rise as high as 20 feet:

Recent satellite and in situ observations of ice streams behind disintegrating ice shelves highlight some rapid reactions of ice sheet systems. This raises new concern about the overall stability of the West Antarctic Ice Sheet, the collapse of which would trigger another five to six metres of sea level rise. While these streams appear buttressed by the shelves in front of them, it is currently unknown whether a reduction or failure of this buttressing of relatively limited areas of the ice sheet could actually trigger a widespread discharge of many ice streams and hence a destabilisation of the entire West Antarctic Ice Sheet.

Similarly, on the May 2, 2007, edition of his CNN Headline News show, Beck aired an hour-long “special report” titled "Exposed: The Climate of Fear," which he promised would present the “other side of the climate debate that you don't hear anymore.” During the program, Beck stated: “Just look at the difference between Greenland's ice melt in Al Gore's scenario when spread out over a century versus what the IPCC projects.”