claim: The oceans have absorbed much of this increased heat, with the top 700 meters ( about 2,300 feet ) of ocean showing warming of more than 0.4 degrees Fahrenheit since 1969.
evidence: These isotope changes occurred due to the release of carbon from the ocean into the atmosphere that led to a temperature increase of 4-8 °C ( 7-14 °F ) at the surface of the ocean.