Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities and has contributed the most to climate change. A new research has found that earth's climate is more sensitive to 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.
‘Currently it is believed that doubling the CO2 will result in a rise in the global average temperature of three degrees Centigrade. However, a new research has suggested that the effects of CO2 on global warming might be underestimated.’
Researcher Tim Lowenstein said, "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 three degrees Centigrade. This new research suggested that the effects of CO2 on global warming might be underestimated. CO2 and other climate forcings might be more important for global warming than they might have realized."
Lowenstein further added, "The only direct measurement of carbon dioxide is from ice cores, which only go back less than 1 million years. These were direct chemical measurements that were based on equilibrium thermodynamics and according to him they were really reliable."
The study is published in Geology.