Forest Fires were Main Cause for Hot Climate 3 Million Years Ago

Nadine Unger and her research team at Yale University have found forest fires that occurred three million years ago had a much more detrimental effect on global warming than did the atmospheric levels of carbon dioxide.

Unger and her team at the Yale School of Forestry and Environmental Studies do not address or dispute any evidence of human generated carbon dioxide emissions as a catalyst for climate change. She mentions that "reducing and preventing the accumulation of fossil-fuel CO2 is the only way to ensure a safe climate future for now," in this Yale News article. The details of this study were published in the journal Geophysical Research Letters.

The research team was able to calculate the concentrations of tropospheric ozone, aerosol particles and methane during the mid-Pliocene epoch--the period in the geological timescale that spans from 5.332 million to 2.588 million years before present. The average global climate during that time period was two to three degrees Celsius higher than today. The concentration of these particles in the atmosphere was twice the levels that the researchers observed in the pre-industrial era, mainly because most of the planet was covered in forests at the time.

The reactive compounds that resulted from these forest fire emissions were seen as two to three times greater than carbon dioxide's effect on global warming. This revealed why the global climate was two to three degree Celsius warmer than it is today, even with both time periods possessing similar atmospheric levels of carbon dioxide.

A simulation of the emissions from the Pilocene and pre-industrial era were made possible thanks to the NASA Goddard Institute for Space Studies Model-E2 global Earth system model. Calculations were then performed by Yale's omega supercomputer, a 704-node cluster with the ability to process more than 52 trillion calculations per second.

However, forest fire emissions were not the only cause for concern regarding global climate, according to the remainder of Unger's study.

To read more about the details of the Yale School of Forestry and Environmental studies, click here.