New research reconstructs Earth's climate in the 24,000 years since the last ice age, highlighting the main drivers of climate change and the extent to which human activity has affected the climate system.

The study, led by the University of Arizona with a co-author at the National Center for Atmospheric Research, has three main findings: 

• It verifies that the main drivers of climate change since the last ice age are rising greenhouse gas concentrations and the retreat of the ice sheets.
• It suggests a general warming trend over the last 10,000 years, settling a decade-long debate in the paleoclimatology community about whether this period trended warmer or cooler.
• The magnitude and rate warming over the last 150 years far surpasses the magnitude and rate of changes over the last 24,000 years.

“One of the most important aspects of this study is it resolves differences between computer models, which showed a warming trend during the Holocene (the last 10,000 years), and temperature data from the geological record that suggested a cooling trend,” said NCAR scientist Jiang Zhu, a co-author. “Our study supports the model simulations and attributes the mismatch to the poor spatial coverage of the geological data. As a result, we can now confirm temperature trends since that period and understand the ongoing global warming in a longer geological context.”

For more, see the University of Arizona news release.

See all News