Global temperature is likely to rise 3.3-5.6 degrees Celsius by the end of this century, unless international climate negotiations in Paris next year are more effective than expected, according to a report released Monday by the MIT Joint Program on the Science and Policy of Global Change. The predicted temperature increase surpasses the threshold identified by the United Nations as necessary to avoid the most serious impacts of climate change, altering precipitation patterns and heightening the pressures of population and economic growth.

 

"Our world is rapidly changing," says John Reilly, co-director of the MIT Joint Program and a coauthor of the report. "We need to understand the nature of the risks we're facing so we can prepare for them."

 

Publication of the report, "2014 Climate and Energy Outlook," comes on the heels of last week's UN Climate Summit in New York City, where more than 120 heads of state gathered in preparation for climate negotiations next year. The agreement that comes out of the 2015 talks will inform global climate action after 2020, when existing measures agreed to in Copenhagen and Cancun expire.

 

The outlook report extends the existing measures after they end to evaluate global changes under possible post-2020 climate action. It uses UN population data and projects economic growth to explore the connections between socioeconomic factors and changing climate, land use, and water.

 

"Population and economic growth are key drivers of change," Reilly says. "Developing countries like China and India are growing fast, and will play a big role in future emissions. They're also facing the unique challenge of trying to plan for this growth under a changing climate."