Climate more sensitive to CO2 than previously thought

A new research has found that earth's climate is more sensitive to carbon dioxide (CO2) than previously thought.

Binghamton University researchers examined nahcolite crystals found in Colorado's Green River Formation, formed 50 million years old during a hothouse climate and found that CO2 levels during this time might have been as low as 680 parts per million (ppm), nearly half the 1,125 ppm predicted by previous experiments.

Researcher Tim Lowenstein said that the significance of this was that CO2 50 million years ago might not have been as high as they once thought it was, but the climate back then was significantly warmer than it is today.

According to current projections, doubling the CO2 will result in a rise in the global average temperature of 3 degrees Centigrade.

This new research suggested that the effects of CO2 on global warming might be underestimated.

Lowenstein said that CO2 and other climate forcings might be more important for global warming than they might have realised.

The only direct measurement of carbon dioxide is from ice cores, which only go back less than 1 million years.

Lowenstein said that these were direct chemical measurements that were based on equilibrium thermodynamics and according to him they were really reliable.

The study is published in the Journal Geology.