Global Warming 101: Science

A “planetary emergency—a crisis that threatens the survival of our civilization and the habitability of the Earth”—that is how former Vice President Al Gore describes global warming. Most environmental groups preach the same message. So do many journalists. So do some scientists.

In fact, at the 2008 annual meeting of Nobel Prize winners in Lindau, Germany, half the laureates on the climate change panel disputed the so-called consensus on global warming.

The Greenhouse Effect

You have probably heard the dire warnings many times. Carbon dioxide (CO2) from mankind’s use of fossil fuels like coal, oil, and natural gas is building up in the atmosphere. Carbon dioxide is a greenhouse gas—it traps heat that would otherwise escape into outer space. Al Gore warns that global warming caused by carbon dioxide emissions could increase sea levels by 20 feet, spin up deadly hurricanes. It could even plunge Europe into an ice age.

Science does not support these and other scary predictions, which Gore and his allies repeatedly tout as a “scientific consensus.” Global warming is real and carbon dioxide emissions are contributing to it, but it is not a crisis. Global warming in the 21 st century is likely to be modest, and the net impacts may well be beneficial in some places. Even in the worst case, humanity will be much better off in 2100 than it is today.

The following is a summary of key points:

• Average Annual Heat-Related Mortality: People will not drop like flies from heat waves in a warming world. Heat-related mortality will continue to decline as the world warms.
  

  Average Annual Heat-Related Mortality

• Far more people die each year from excess cold than from excess heat.
• Global warming will not make air pollution worse.
• Global warming will not lead to malaria epidemics in Northern Hemisphere countries.
• Contrary to Gore, no “strong, new scientific consensus is emerging” that global warming is making hurricanes stronger.
• Global Death & Death Rates Due to Extreme Events, 1900-2004: Since the 1920s, death rates related to extreme weather declined by more than 98 percent globally. The impression conveyed by An Inconvenient Truth—that global warming is making the world a more dangerous place—is false.
  

  Global Death & Death Rates Due to Extreme Events, 1900-2004

• Gore’s warning that global warming could shut down the Atlantic branch of the oceanic thermohaline circulation (THC) and plunge Europe into an ice age is science fiction.
• Gore’s warning that sea levels could rise by 20 feet is science fiction. Sea level rise in the 21 st century is likely to be measured in inches, not in feet.
• The world warmed at a rate of 0.17°C per decade since 1978, according to the temperature record compiled by the United Nations Intergovernmental Panel on Climate Change (IPCC). Since most climate models predict that warming will occur at a constant—that is, non-accelerating—rate, it is reasonable to expect that global warming in the 21 st century will be close to the low end of the IPCC’s forecast range, of 1.4°C to 5.8°C.
• Temperature Measuring Station on Aspault Parking Lot: The actual warming rate may be only half the 0.17°C per decade rate implied in the IPCC temperature record, because the IPCC has not adequately filtered out the warming biases from local factors like urbanization and improper management of monitoring equipment.
  

  Temperature Measuring Station on Aspault Parking Lot

• A warming near the low end of the IPCC range would produce both benefits—longer growing seasons, more rainfall, fewer cold deaths—and harms—more heat waves, more drought, some acceleration of sea level rise—but nothing resembling catastrophe.
• Even in the IPCC high-end warming forecasts, human welfare would improve dramatically over the next 100 years. In the IPCC fossil-fuel-intensive development scenario, per capita GDP in developing countries increases from $875 per year in 1990 to $43,000 per year in 2100—even after taking into account an additional 110 years of global warming. Even in the IPCC worst-case scenario, global warming is not the civilization-ending catastrophe Al Gore purports it to be.