Our Moderate Climate Crisis

Our Moderate Climate Crisis
November 1, 2007

Ours is a truly strange global warming crisis. The warming has been only about 0.7º C, spread over 150 years. Our ancestors lived through much more dramatic climate changes.

Just 10,000 years ago, insect fossils tell us, air temperatures dropped as much as 20º C over a few centuries. Then temperatures zoomed back up to levels warmer than today in perhaps 50 years, according to Dr. Dorothy Peteet of the Lamont-Doherty Earth Observatory in New York.

That period, at the end of the last major Ice Age, was also when humans killed off the last of the massive cave bears--because we wanted their caves. The caves were the best-insulated places for humans to live, so hunters risked their lives to attack the groups of massive bears with nothing more than stone-tipped spears.

Warming Has Decelerated

We are told that the mild crisis of the Modern Warming is due to human-emitted carbon dioxide (CO2). However, about 70 percent of this warming occurred before 1940, before big industries and automobile sales. That pre-1940 warming was almost certainly due to the natural, solar-linked 1,500-year cycle researchers have found recently in ice cores, seabed sediments, and fossil pollen.

After 1940, global temperatures dropped for 35 years before resuming an upward trend from 1976 to 1998. The net warming since 1940 is a tiny 0.2º C. We can blame humans for half of that, because the 1,500-year cycle is still affecting the picture. That makes Al Gore's inconvenient truth a human-driven warming of 0.1º C over 65 years.

That's less than 2/1000th of a degree per year.

Meanwhile, the climate-forcing impact of atmospheric CO2 has been declining rapidly. The laws of physics tell us the first 40 parts per million of human-added CO2, back in the 1940s, had more climate-forcing power than the next 360 ppm. Today's radically weakened CO2 effect cannot possibly drive Al Gore's predicted 20-foot sea-level rise and parboil the planet with auto exhaust.

Errant Computer Models

None of the CO2 has been as potent as the greenhouse computer models claimed it would be. Climate modeler James Hansen of NASA told Congress in 1988 that by the year 2000 the Earth would have warmed another 0.3º C and sea levels would have risen several feet.

Reality has been much more moderate. The temperatures in 2000 were only 0.1º warmer, and sea level has risen just one inch.

We've had no global warming at all over the past eight years, so the near-zero correlation between the Earth's temperatures and CO2 levels has been getting even weaker. The CO2 levels have continued to rise in linear fashion, but temperatures have remained stable.

The strong correlation between our temperatures and sunspots, meanwhile, continues to get stronger. This points to the sun as the most significant driving force in our recent climate change.

Natural Warming, Cooling Cycle

There is simply no reason to believe the computerized climate models, as they already have demonstrated their capacity to be radically wrong. On the contrary, it is time to acknowledge the physical and historical evidence of a moderate, natural 1,500-year climate cycle linked to the sun.

That cycle tells us we will continue to enjoy a slow, sunny, erratic warming through the next few centuries--which is far better than the alternative of another harsh, cloudy, unstable Little Ice Age. George Washington and his veterans, who suffered through that chilly time at Valley Forge, would have cast their votes for warming.


Dennis T. Avery (cgfi@hughes.net) is a senior fellow with The Heartland Institute and coauthor of the bestselling book Unstoppable Global Warming Every 1,500 Years.