Policy Documents

Climate Change Reconsidered

June 1, 2009

This 880-page rebuttal of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), three years in the making, was released in June 2009 by The Heartland Institute. Coauthored and edited by S. Fred Singer, Ph.D., and Craig Idso, Ph.D. and produced with contributions and reviews by an international coalition of scientists, it provides an independent examination of the evidence available on the causes and consequences of climate change in the published, peer-reviewed literature examined without bias and selectivity. It includes many research papers ignored by the IPCC plus additional scientific results that became available after the IPCC deadline of May 2006.

Chapter 1 describes the limitations of the IPCC s attempt to forecast future climate with computer models. The IPCC violates many of the rules and procedures required for scientific forecasting, making its projections of little use to policymakers.

Chapter 2 describes feedback factors that reduce the earth s sensitivity to changes in atmospheric CO2. Scientific studies suggest the model-derived temperature sensitivity of the earth for a doubling of the pre-industrial CO2 level is much lower than the IPCC s estimate.

Chapter 3 reviews empirical data on past temperatures. We find no support for the IPCC s claim that climate observations during the twentieth century are unprecedented or provide evidence of an anthropogenic effect on climate.

Chapter 4 reviews observational data on glacier melting, sea ice area, variation in precipitation, and sea level rise. We find no evidence of trends that could be attributed to the supposedly anthropogenic global warming of the twentieth century.

Chapter 5 summarizes the research of a growing number of scientists who say variations in solar activity, not greenhouse gases, are the true driver of climate change. We describe the evidence of a solar-climate.

Chapter 6 investigates and debunks the widespread fears that global warming might cause more extreme weather. The IPCC claims global warming will cause (or already is causing) more droughts, floods, hurricanes, storms, storm surges, heat waves, and wildfires. We find little or no support in the peer-reviewed literature for these predictions and considerable evidence to support an opposite prediction: That weather would be less extreme in a warmer world.

Chapter 7 examines the biological effects of rising CO2 concentrations and warmer temperatures. This is the largely unreported side of the global warming debate, perhaps because it is unequivocally good news. Rising CO2 levels increase plant growth and make plants more resistant to drought and pests. It is a boon to the world s forests and prairies, as well as to farmers and ranchers and the growing populations of the developing world.

Chapter 8 examines the IPCC s claim that CO2-induced increases in air temperature will cause unprecedented plant and animal extinctions, both on land and in the world s oceans. We find there little real-world evidence in support of such claims and an abundance of counter evidence that suggests ecosystem biodiversity will increase in a warmer and CO2-enriched world.

Chapter 9 challenges the IPCC s claim that CO2-induced global warming is harmful to human health. The IPCC blames high-temperature events for increasing the number of cardiovascular-related deaths, enhancing respiratory problems, and fueling a more rapid and widespread distribution of deadly infectious diseases, such as malaria, dengue and yellow fever. The peer-reviewed scientific literature reveals that further global warming would likely do just the opposite and actually reduce the number of lives lost to extreme thermal conditions.