Our Moderate Climate Crisis

Published October 18, 2007

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

Just ten thousand years ago, insect fossils tell us air temperatures dropped as much as 20 degrees C over a few centuries. Then temperatures zoomed back up to warmer-than-today levels in perhaps fifty 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 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.

We’re told that the mild crisis of the Modern Warming is due to human-emitted CO2. However, about 70 percent of this warming occurred before 1940, before big industries and auto sales. That pre-1940 warming was almost certainly due to the natural, moderate 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 1976-1998. The net warming since 1940 is a tiny 0.2 degrees C. We can blame humans for half of that–remember, the 1,500-year cycle is still affecting the picture. But that makes Al Gore’s inconvenient truth a human-driven warming of 0.1 degree 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 that the first 40 parts per million of human-added CO2, back in the 1940s, had more climate-forcing power than the next 360 ppm. How can today’s radically weakened CO2 drive Al Gore’s 20-foot sea-level rise, and parboil the planet with auto exhaust?

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 0.3 degrees C and sea levels would have risen several feet. Reality has been much more moderate. The temperatures in 2000 were only 0.1 degree warmer, and the sea levels had 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. That points to the sun as the big driving force in our climate change.

Why do we believe the computerized climate models, which have already demonstrated their capacity to be radically wrong? When will we begin to believe the physical and historical evidence of a moderate, natural 1,500-year climate cycle linked to the sun?

The cycle tells us we’ll continue to get 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 icy age at Valley Forge, would have cast their votes for warming.

Dennis Avery ( [email protected]) is a senior fellow at The Heartland Institute.