Straw Men And The Little Ice Age

The Heartland Institute's James Taylor is on the defensive after an independent study undermined critics of the temperature records establishing global warming. In his most recent column, Taylor accuses media outlets of knocking down a straw man in their reports on the study. But in doing so, Taylor himself advances a bad argument which misconstrues the basic physics of the climate.

Forbes/HeartlandDismissing as old news the warming trend confirmed by the study, Taylor writes that temperatures have increased because the climate is “recovering from the Little Ice Age”:

Very few if any skeptics assert that the earth is still in the Little Ice Age. While the Little Ice Age raged from approximately 1300 to 1900 AD, it is pretty well accepted that the Little Ice Age did indeed end by approximately 1900 AD. The mere fact that the Little Ice Age ended a little over 100 years ago, and that temperatures have warmed during the course of recovering from the Little Ice Age, tells us absolutely nothing about the remaining components necessary to support an assertion that humans are creating a global warming crisis.

This is not the first time Taylor has claimed in his weekly Forbes column that “the earth continues to recover from the abnormally cold conditions of the centuries-long Little Ice Age” and that “there was little room for temperatures to go at the time but up.” But it's an entirely hollow argument.

“Recovery” from the Little Ice Age is not an explanation for warming any more than “recovery from falling” is an explanation for why a basketball bounces. University of Arizona climatologist Malcolm Hughes said via email that Taylor's claim is “as unscientific and uninformative as that other old chestnut, that 'climate has always varied,'” adding, “Science is about how things work.”

Penn State's Michael Mann also said that “The climate doesn't 'rebound'” and that such a claim “belies a complete lack of understanding of the physics of the climate.” There is no default or normal state to which the climate “recovers” after warm and cold periods. Rather, the global temperature is determined by the amount of energy entering and leaving the atmosphere, which, in turn, can be altered by a variety of factors including the Earth's orbit, greenhouse gases, volcanic eruptions, air pollution, solar changes, and feedback effects.

Climate scientists have tried to account for the recent warming trend without including the effects of human activities like the burning of fossil fuels. But only when human influence is added can model simulations match up with the observed temperatures. As Mann and his colleagues at explained, “none of the natural factors which could potentially cause warming ... show a trend since the mid 20th century.”

Hughes also said that “the rapidity, scale and character of the global warming of recent decades” fits well with “what is expected as a result of human activities, especially the increase in carbon dioxide in the air produced by burning oil, coal and gas.” For instance, “warming near the surface is combined with cooling in the stratosphere. This is something a change in the Sun could not produce,” Hughes said.

Scientists have identified a number of such "fingerprints" that point to human activities as a driver of recent climate change. To say that global temperatures are “recovering from the Little Ice Age” is to gloss over decades of climate research.

The new study, called the Berkeley Earth Surface Temperature Project, was conducted by physicist Richard Muller to investigate what he said were “legitimate” criticisms of the three prevailing global land surface temperature records. After employing a different methodology and more raw data, Muller's results, which have yet to be published in a peer-reviewed journal, confirmed the previous records. In fact, the study found slightly more recent warming than did the University of East Anglia's Climate Research Unit (CRU), the group at the center of the so-called “Climategate” controversy. Muller concluded that the other groups “had truly been very careful in their work ... They managed to avoid bias in their data selection, homogenization and other corrections.”

BEST temperature record

Those who maintain that climate change is not a serious problem have been trying to downplay the new research. Taylor writes in his column that the study “brings almost nothing new to the global warming debate” since it “hasn't been in dispute” that global temperatures are rising.

But the Heartland Institute itself claimed in 2009 that the “Climategate” emails “appear to show a conspiracy to falsify data and suppress academic debate in order to exaggerate the possible threat of man-made global warming.” And that was certainly the takeaway for conservative media outlets, which continue to claim that “Climategate” proved CRU's data fraudulent and unreliable. In fact, it was actually Fox News' policy to shed doubt on the temperature record, as an internal email revealed last December.

Muller said back in February that “With CRU's credibility undergoing a severe test, it was all the more important to have a new team jump in, do the analysis fresh and address all of the legitimate issues raised by sceptics.” Now that the research has roundly rejected allegations that CRU exaggerated warming, Taylor pretends that those allegations never existed.

Taylor previously spurred a media storm when his Forbes column distorted a study by Roy Spencer of the University of Alabama to claim the research blows a “gaping hole in global warming alarmism.” In the ensuing controversy, Spencer stated that Taylor misrepresented the study, which itself suffered from methodological flaws according to several climate experts. The editor of the journal that published Spencer's study later resigned after concluding that it should “not have been published.” The editor also criticized Forbes for “exaggerat[ing] the paper's conclusions.”

Taylor's principled opposition to the use of straw man arguments is something of a recent development. In June, he argued in a Forbes column that those seeking reductions in greenhouse gas emissions “yearn for a return to the cold, miserable conditions that spawned the Black Death.”