Oceans Storing Excess Heat

The oceans are becoming a repository for almost all of Earth’s excess heat, driving up sea levels and threatening coastlines, according to a leaked draft of the most comprehensive United Nations report addressing climate science.

Temperatures in the shallowest waters rose by more than 0.1 degree Celsius (0.18 degree Fahrenheit) a decade for the 40 years through 2010, the study found. Average sea levels have increased worldwide by about 19 centimeters (7.5 inches) since 1901 and researchers said it’s “very likely” the system of ocean currents that includes the Gulf Stream will slow in the coming decades.

The findings are detailed in a 2,200-page report that will guide UN envoys as they devise a new treaty to fight climate change by 2015. It was obtained by Bloomberg from a person with official access to the report who declined to be further identified because it hasn’t been published. The UN declined to comment.

“The Earth is absorbing more heat than it is emitting back into space, and nearly all this excess heat is entering the oceans and being stored there,” the report’s authors wrote. “Changes have been observed in ocean properties of relevance to climate during the past 40 years, including temperature, salinity, sea level, carbon, pH and oxygen.”

The report, entitled “The Physical Science Basis,” is the first of three parts that will make up the UN Intergovernmental Panel on Climate Change’s fifth Assessment Report, or AR5, into climate science. The research includes a 31-page “Summary for Policymakers” that condenses the main findings of the first part into a single document that ministers may consult when devising a global policy.