The Temperature Record, Surface Temperatures
THE DENIER: If you look at the science, you’ll see that, since 1998, global land and marine surface temperatures are actually on the decline. Even the lamestream media has been forced to admit this. From a 2009 BBC article: “For the last 11 years we have not observed any increase in global temperatures. And our climate models did not forecast it, even though man-made carbon dioxide, the gas thought to be responsible for warming our planet, has continued to rise.” The article proceeds to point out what real scientists have been saying all along, that the Earth is cyclical, that global temperatures have historically ebbed and flowed for naturally reasons and that humans can have very little impact on nature.
THE PHILOSOPHER: It’s true that 1998 was the warmest year in Climatic Research Unit’s data set, which goes back to 1850. Although NASA, it should be pointed out, claims that 2005 was slightly hotter. Whatever the case, there’s no reason to believe we’ve entered into a period of global cooling. For the fact is that any number of factors can cause global temperatures to temporarily rise or fall. For instance, many believe that 1998 was so hot because an especially strong El Nino hit that year. In order to determine whether or not global warming exists, we can’t cherry pick the data but must instead look at the big picture, at long-term trend.
And when we look at long-term trend, it becomes clear that the planet is warming. According to the Climatic Research Unit, temperatures have been steadily rising since around 1910 with the first decade of this century being the hottest century on record. After 1998, the next nine warmest years on record all occurred between 2001-2010. Although 2008 has thus far been the coldest year of the century, it’s still the 12th hottest year on record.
THE DENIER: Your whole argument presupposes that the temperature data we have is accurate. But it’s not. Temperature stations are unevenly distributed; “the stations are preferentially located in growing urban and industrial areas (‘heat islands’), which show substantially higher readings than adjacent rural areas (‘land use effects’).”
THE PHILOSOPHER: Have you ever heard of Richard Muller? Richard Muller is a physics professor who for years claimed that the urban heat island effect had rendered the data coming from temperature stations unreliable. Along with ten other scientists, Muller recently started the Berkeley Earth Surface Temperature project in the hopes of “resolv[ing] current criticism of the former temperature analyses.” The project’s biggest funder, I should point out, is none other than the Charles G. Koch Charitable Foundation. “Oil billionaires Charles and David Koch,” the LA Times reminds us, “are the nation’s most prominent funders of efforts to prevent curbs on the burning of fossil fuels, the largest contributor to planet-warming greenhouse gases.”
And what did Muller’s team find? Let me allow Muller to speak for himself: “Our biggest surprise was that the new results agreed so closely with the warming values published previously by other teams in the US and the UK. This confirms that these studies were done carefully and that potential biases identified by climate change sceptics did not seriously affect their conclusions.”
The Temperature Record, Ocean Temperatures
THE DENIER: Surface temperatures don’t even matter that much anyway. Ocean temperatures are a far more accurate measure of overall global temperatures. And ocean temperatures are undoubtedly falling. For example, in 2006 NASA’s Jet Propulsion Laboratory (JPL) reported that its 3,000 Argo floats had found that oceanic temperatures were cooling. Given that even environmentalists have claimed that “80 percent to 90 percent of global warming involves heating up ocean waters,” I think this is a pretty resounding deathblowm. Or as you philosophers are fond of saying, QED.
THE PHILOSOPHER: It’s true that in 2006, Josh Willis and another scientist at the JPL reported that oceanic temperatures had fallen between 2003 and 2005. But this data contradicted other scientific data. For example, researchers at NASA’s Langley Research Center in Virginia had long studied the amount of solar energy entering and leaving the Earth and had found that more energy was entering than leaving. This and other contradictory data caused Willis to scrutinize his data. When he did so, he found that a software glitch existed in some of the floats, causing “the temperature and salinity data to be associated with the wrong depths. When the problem data [was] excluded from the analysis, the cooling trend [dropped] below the level of statistical significance.”
THE DENIER: Funny how you word that: “the cooling trend dropped below the level of statistical significance.” So in other words, the oceans are still cooling, they’re just not cooling as much as previously claimed. But still, the fact remains that they’re cooling. Which obviously contradicts the claims of global warming.
THE PHILOSOPHER: First, it’s not at all clear that ocean temperatures are falling, even slightly. The Argo float data has been interpreted differently by different scientists. Willis’ analysis shows that temperatures have slightly fallen, while other analyses have shown temperature increases. Second, even if ocean temperatures have fallen, this in no way disproves global warming. As I argued earlier, we need to look at long-term trends, not cherry pick the data to suit our needs. If you look at ocean temperatures over the past half century, you’ll see periods, sometimes consisting of a couple years or more, in which temperatures fell. If you look at the entire data set, however, you’ll see that ocean temperatures have been trending upwards. Numerous factors can cause ocean temperatures to temporarily fall; Josh Willis believes that the recent fall in ocean temperatures (if they have in fact fallen) is largely attributable to ice melt. What matters is the long-term trend, which unmistakably shows ocean temperatures rising.
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 “What happened to global warming?” Paul Hudson, BBC, 9 October 2009. See also “Reconciling anthropogenic climate change with observed temperature 1998-2008,” Robert K. Kaufmann, et al., Proceedings of the National Academy of Sciences of the United States, 2 June 2011.
 “Warming Stopped in 1998,” A Few Things Illconsidered, 2006 April 25.
 “Myths and Facts,” Climate Change 101.
 “Critics’ review unexpectedly supports scientific consensus on global warming,” Margot Roosevelt, Los Angeles Times, 4 April 2011.
 “Global warming ‘confirmed’ by independent study,” Richard Black, BBC, 20 October 2011.
 “The Mystery of Global Warming’s Missing Heat,” Richard Harris, NPR, 19 March 2008.
 “Correcting Ocean Cooling,” Rebecca Lindsey, NASA Earth Observatory, 5 November 2008. See also “Is It Me, or Did the Oceans Cool?” Josh Willis, U.S. Clivar, Vol. 6, No. 2, September 2008.
 “Artefacts in ocean data hide rising temperatures” [.pdf], Nature, Volume 447.3, May 2007.
 “How we know global warming is still happening,” John Cook, Skeptical Science, 28 September 2009.
 “Does ocean cooling prove global warming has ended?” Skeptical Science, 6 September 2010.