CLIMATE COOLING MYTH

How can the scientific community be so certain the Earth is warming when in the 1970's there was a perception the planet was headed into an ice age? Could we be headed into an ice age or was this just a myth?

Scientific evidence has shown the Earth is warming as a direct consequence of human anthropogenic activity. This theory that increasing atmospheric CO2 emissions made the Earth warmer is shown to be a fact and no longer theory. The concept has been around since the nineteenth century when a Swedish scientist, Svante Arrhenius, calculated that increasing CO2 would raise the Earth's temperature. Only recently has the debate taken on political values.

So how is it an international group of climate scientist's concluded the Earth is warming and that it is caused by man made activities? Didn't the temperature record show the planet was cooling? The answer: yes. The record of temperatures compiled since the 1870s showed cooling during the 1940s through the 1960s.At this time the notion of global cooling had been accepted but not understood. Up to this period temperatures were getting warmer. But two revelations were discovered, CO2 and orbital oscillations, which could explain the unsteady state of global temperatures.

In the early years of climate science, preliminary evidence lead a few researchers to speculate a new ice age would spread over the Northern Hemisphere. In 1930, engineer and geophysicist Milutin Milankovitch calculated that sunlight concentrations hitting Earth would change based on regular changes to Earth's tilt and orbit. This explained why the planet warms and cools over timescales of thousands of years. Earth's climate clock fluctuates over long periods of time but it has never shown such a rapid record rise in temperatures since humans have walked the planet. So the most unequivocal reason for the warm up was discovered on a mountaintop in Hawaii.

It is called Carbon dioxide. A scientist named Charles David Keeling measured CO2 and found a direct trend in the molecules properties to trap heat and cause the Earth's rise in temperatures. This data made it clear and conclusive that fossil fuel burning increased this heat trapping gas.


But attention grabbing global cooling headlines in the 1970s overshadowed the scientific literature. The New York Times, Time Magazine, and Science News all ran articles about how the planet may be headed colder. Popular media helped increase the global cooling perception.

If you would like to read more, I would suggest an article written by Thomas C. Peterson who I met at a weather fellowship at the SPC in Norman Oklahoma. He was is a climate expert at the National Climate Data Center and wrote part of the 4th assessment of the IPCC report.