New York, Nov 17 (IANS): The rise in carbon dioxide (CO2) levels would have more catastrophic impact on the climate than currently estimated, suggests new research.

The researchers found that climates on Earth may be more sensitive to rise in CO2 levels than was previously thought.

The new data suggests that past predictions significantly underestimate the impact of greenhouse warming and that Earth's climate may be more sensitive to increased carbon dioxide than was once thought, said one of the researchers Tim Lowenstein, professor at Binghamton University in New York.

The study examined nahcolite crystals found in Green River Formation in Colorado, US. The crystals were formed 50 million years ago during a hothouse climate.

They found that CO2 levels during this time may have been as low as 680 parts per million (ppm), nearly half the 1,125 ppm predicted by previous experiments.

"The significance of this is that CO2 50 million years ago may not have been as high as we once thought it was, but the climate back then was significantly warmer than it is today," Lowenstein explained.

Carbon dioxide levels in the atmosphere today have reached 400 ppm. According to current projections, doubling the CO2 will result in a rise in the global average temperature of three degrees Centigrade.

This new research suggests that the effects of CO2 on global warming may be underestimated.

"These are direct chemical measurements that are based on equilibrium thermodynamics," Lowenstein said.

"These are direct laboratory experiments, so I think they are really reliable,” he noted.

The findings appeared in the journal Geology.