Ancient climates may have been more sensitive to carbon dioxide than we thought.
(Mirror Daily, United States) – Earth’s climate was more sensitive to carbon dioxide than expected originally according to a recent study conducted at Binghamton University. According to the information gathered by the team, led by professors Tim Lowenstein, David Jenkins and Robert Demicco, some of the Earth’s ancient climates were significantly more sensitive to the presence of carbon dioxide than it was initially thought.
During their research, they analyzed nahcolite crystals that had been unearthed from the Green River Formation in Colorado. The crystals were formed 50 million years ago during what scientists consider a hothouse period. They discovered that the levels of carbon dioxide during this period of time were a lot lower that what scientists had predicted them to be, only approximately 680 parts per million. The predicted concentration had been around 1,125 parts per million in previous experiments.
The new study shows that the previous predictions severely underestimated the impact that global warming caused by greenhouse gases has had on the planet’s climate and that the climate itself may be a lot more sensitive to rising carbon dioxide concentrations than it was previously thought.
Lowenstein explained that the amount of carbon dioxide contained in the air 50 million years ago was not as high as it was previously thought. Instead, the climate was a lot warmer back than compared to how it is today.
Present carbon dioxide levels in our atmosphere are of 400 parts per million and according to current climate models and predictions if this amount doubles it will cause a rise in average global temperatures of 3 degrees Celsius. This could suggest that the effects that carbon dioxide has on global warming have been significantly underestimated.
Reaching that level of carbon dioxide is possible during the next century and scientists have now found that if that happens, the impact that this new high concentration of carbon dioxide will have on global warming may be a lot more severe than previously predicted.
It is also not clear to scientists how much high concentrations of carbon dioxide in the atmosphere affected the Earth 50 million years ago, since the only direct measurement of carbon dioxide can be performed on ice cores and these ice cores only date back as far as less than a million years. The team that has conducted the research is now trying to find a way of approximating ancient carbon dioxide in the atmosphere using indirect methods.
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