A Primer on Global Warming: Dispelling CO2 Myths

Published July 1, 2009

Editor’s note: Heartland Institute Science Director Jay Lehr presents evidence that mankind has no significant impact on the Earth’s climate. This is the first installment in a series.

The scientific facts clearly show carbon dioxide is a good thing, not something we should fear.

CO2 is not a pollutant.

On the contrary, carbon dioxide makes crops and forests grow faster. Satellite mapping shows the Earth has become about 6 percent greener overall in the past two decades, with forests expanding into arid regions. The Amazon rain forest was the biggest gainer, with two tons of additional biomass per acre per year.

Certainly climate change does not help every region equally, but careful studies predict overall benefits—fewer storms, more rain, better crop yields, longer growing seasons, milder winters, and lower heating costs in colder climates. The news is certainly not bad and on balance may be rather good.

CO2 is merely a trace atmospheric gas.

The world will laugh when we finally understand the pursuit of economic ruin in the name of saving the planet from carbon dioxide has been a terrible joke. It is an unarguable fact that the portion of the Earth’s greenhouse gas envelope contributed by man is barely one-tenth of 1 percent of the total.

Do the numbers yourself. Carbon dioxide is no more than 4 percent of the greenhouse gas envelope—with water vapor being more than 90 percent, followed by methane and sulfur and nitrous oxides. Of that 4 percent, man contributes a little more than 3 percent. Three percent of 4 percent is .12 percent, and for that we are sentencing people to numerous damaging economic impacts.

Added CO2 increments have less effect.

The effect of additional carbon dioxide in the atmosphere is limited because CO2 absorbs only certain wavelengths of radiant energy. As the radiation in that particular wavelength band is used up, the amount left for absorption by more of the gas is reduced.

A simple analogy is to consider drawing a curtain across a window. Much of the light will be shut out, but some will still get through. Add a second curtain to the first, and most of the remaining light will be excluded. A point will quickly be reached however, where adding more curtains has a negligible effect, because there is no light left to stop.

This is the case with the absorption of energy as more carbon dioxide is added to the atmosphere.

Anthropogenic warming hasn’t happened.

If greenhouse gases were responsible for global temperature increases in recent decades, atmospheric physics require that higher levels of our atmosphere would show greater warming than lower levels. This did not happen during the 1978-1998 period of 0.3 degrees Celsius warming.

Warming precedes CO2 increases.

A full 900,000 years of ice core temperature records and carbon dioxide content records show CO2 increases follow increases in Earth’s temperature instead of leading them. This makes sense because the oceans are the primary source of CO2, and they hold more CO2 when cool than when warm. Warming causes the oceans to release more CO2.

Jay Lehr, Ph.D. ([email protected]) is science director of The Heartland Institute.