Over the past 25 years, nearly all working climate scientists arrived at the conclusion that the Earth is warming and that human activity is largely responsible for it. The method for reaching these conclusions involved amassing a wide range of direct temperature readings, including surface thermometers, weather balloons, satellite measurements, and numerous proxy measures. The proxy measurements included tree ring data and ice core samples. By joining these data with our knowledge of various climate forcing factors (e.g., greenhouse gases, particulate matter from volcanoes, variations in solar radiation, periodic weather cycles), computer models explain not only past temperature changes, but also can make predictions about future temperatures. The most recent IPCC report examined the results from 24 computer models to arrive at their conclusions: again, the Earth is warming and human activity is largely responsible for it.
Just one year following the publication of the IPCC report, S. Fred Singer and Dennis T. Avery published a book directly contradicting these conclusions. They asserted that "the only explanation for modern warming that is supported by physical evidence" is a 1,500 year climate cycle known as the Dansgaard-Oeschger cycle. The conclusion they draw from this is that we must concentrate our efforts in adapting to climate change and not trying to mitigate it through the reduction of greenhouse gas emissions. Above all, we must not regulate carbon emissions.
The notion that the Dansgaard-Oeschger cycle is primarily responsible for the recent global warming is puzzling; after all, research conducted even before Singer and Avery's assertion indicates that the Dansgaard-Oescher cycle is part of a periodic heat transfer between the southern and northern hemisphere. It is not evidence of or responsible for overall global warming. The Dansgaard-Oeschger cycle is based on an ice core taken from Greenland and as such is evidence of local temperature changes. It is, however, properly generalized to the higher latitudes of the northern hemisphere and is believed to be connected to temperature changes in the southern hemisphere by the Atlantic meridional overturning circulation.
Why Singer and Avery would advance such a flimsy argument might be understood by noting the past and current role that Singer and Avery play in scientific debates. Singer began his career in physics studying the atmosphere, but eventually became more prominent as a government adviser, producing relatively little primary research. He is among a handful of scientists that have been involved in campaigns to sew doubt about scientific results that might lead to the regulation of harmful substances. Singer sought to discredit the science showing the link between CFCs and ozone depletion, the dangers of second-hand tobacco smoke, and now the role of carbon dioxide in warming the planet. His work has been supported by the George C. Marshall Institute and the Heartland Institute (two libertarian think tanks), the tobacco industry's public relations firm APCO, and several major oil companies. Perhaps the one unifying theme in his scientific assertions is that any scientific result that might compromise the freedom of corporations to do as they please is, according to Singer, suspect.
Dennis Avery's climate science expertise is highly dubious. He is neither a climate scientist nor a meteorologists. He is an environmental economist specializing in agriculture. Currently, he is the director of the libertarian Hudson Institution's Center for Global Food Issues. His blog posts indicate that he is primarily concerned with promoting free market government policies against environmental regulation.
Unstoppable Global Warming should be added to the growing list of faux science monographs cluttering up the literature on climate change. There are certainly important controversies within climate science. It's unfortunately that they are not receiving greater public attention, while groundless, frivolous, and most likely disingenuous critiques of science are getting published by climate change deniers.