SOS Forests

CO2, Negative Feedback, and the Earth’s Radiation Budget

Carbon dioxide does not cause runaway global warming because excess heat radiates into outer space, according to an “accidental discovery” by climate scientists.

Measurements taken by the Earth Radiation Budget Satellite (ERBS) [here] indicate that the Earth’s atmosphere can only contain so much heat energy. When the temperature “balance point” is exceeded, the heat escapes. Carbon dioxide, a trace gas in concentrations of parts per million, cannot contain the energy that global warming alarmists speculate will warm the planet.

This finding was explained by Dr. Richard Lindzen, PhD., Alfred P. Sloan Professor of Meteorology, Department of Earth, Atmospheric and Planetary Science at MIT, in an essay addendum to his address made at the 2009 International Conference on Climate Change and posted at Watts Up With That [here]. (Watts Up With That was rated the“Best Science Blog” of 2008 [here]).

Background: Solar radiation reaches the Earth in the form of visible light. The atmosphere is transparent to visible light which strikes the Earth’s surface (land and ocean) and is re-radiated upwards in the form of longer-wave (infrared) energy. Water vapor in the atmosphere is not transparent to long-wave (infrared) radiation and instead absorbs some of it. CO2 can also absorb long-wave radiation, although CO2 is present only in trace amounts. The water vapor is thus warmed, and provides a blanket that protects the Earth’s surface from rapid cooling at night.

That is a simple description of the so-called “greenhouse effect” which maintains moderate temperatures on the planet, although there is no glass ceiling on the Earth’s atmosphere.

Global warming alarmists have claimed that increases in the trace gas CO2 will cause runaway global warming, based on outputs from mathematical climate models running in super-computers. Their contention is that a doubling of CO2 concentration will raise global temperatures from 3 to 5 degrees Centigrade.

However, sensors aboard the ERB satellite (released into orbit by astronaut Sally Ride from the Space Shuttle) observed energy emissions from the upper atmosphere that were 7 times the expected (model) values during the warm years of 1989 to 2000.

That is evidence that the atmosphere cannot contain excess heat. The re-radiation of heat into outer space is termed a “negative feedback” that mitigates climate change. The new calculations indicate that a doubling of CO2 concentration will increase global temperatures by only 0.3 degrees C, an effect so small as to be swamped by normal climate variation (and thus be undetectable, more or less).

Our atmospheric blanket is self-regulating. It contains as much heat as it can contain, and any excess is lost in space. From Dr. Lindzen’s essay:

The Bottom Line

The earth’s climate (in contrast to the climate in current climate GCMs) is dominated by a strong net negative feedback. Climate sensitivity is on the order of 0.3°C, and such warming as may arise from increasing greenhouse gases will be indistinguishable from the fluctuations in climate that occur naturally from processes internal to the climate system itself. …

Alarming climate predictions depend critically on the fact that models have large positive feedbacks. The crucial question is whether nature actually behaves this way? The answer, as we have just seen, is unambiguously no.

Chief climate alarmist (adviser to Al Gore) James Hansen claims that positive feedback from CO2 will cause runaway global warming and the “Venus Syndrome” where all the earth’s oceans boil away, leaving a dry, dead planet [here].

However, in past geological epochs the atmosphere has had concentrations of CO2 that were 10 to 15 times current levels, and the oceans did not boil away (obviously). The positive feedback theory promoted by Hansen has now been shown to be false (as if that were necessary) by satellite data. Ironically, Hansen is a NASA employee, the same NASA responsible for the ERB satellite!

The empirical data constitute strong evidence that global warming theories are false, and that increased CO2 emissions will have no effect on global climate, or at least an effect so small as to be undetectable.

The current hysteria to limit CO2 emissions is based on a false premise, demonstrably false, and proved to be false by the latest and best science.