Earth warmer than 100,000 years ago: study

By Barry Eitel

SAN FRANCISCO

Earth is now warmer than at any time in the past 120,000 years, according to a new study Monday that provided global climate data for the past 2 million years.

The research also suggests the planet may be “locked in” to eventually hitting its warmest temperature for the past 2 million years.

The research was based on 61 different sea surface temperature records from across the world. Fewer and fewer of these records available, however, as researchers look back in time but the study provides rough estimates, the paper said.

The study in the journal Nature was part of the doctoral dissertation of Carolyn Snyder, who is now a climate policy official at the Environmental Protection Agency.

Snyder used past records in an attempt to forecast what climate change might look like in the future and found that the predictions appear dire.

“This result suggests that stabilization at today’s greenhouse gas levels may already commit Earth to an eventual total warming of 5 degrees Celsius (range 3 to 7 degrees Celsius, 95 percent credible interval) over the next few millennia as ice sheets, vegetation and atmospheric dust continue to respond to global warming,” she wrote in the study.

But the predictions have been met with criticism from other climate scientists.

Gavin Schmidt, the director of NASA’s Goddard Institute for Space Studies in New York City, published a counter argument Monday that claimed Snyder did not take into account how carbon dioxide emissions can affect Earth System Sensitivity (ESS), a metric of how different environmental feedbacks affect the climate.

“This is simply wrong,” Schmidt said of Snyder’s forecast in a post published on RealClimate, a site focused on publishing commentary from climate scientists.

Schmidt said Snyder’s projection of the Earth warming in the next few thousand years “is based on an incorrect method for defining ESS.”