The Global Warming Yardstick: What warming oceans and rising seas tell us about anthropogenic climate change
The majority of modern day sea level rise is a result of global warming. The warming climate melts glaciers and causes ice sheets to lose extra mass to the oceans. This accounts for half to two-thirds of present day sea level rise. The remaining rise is driven by the simple thermal expansion of warming ocean water. But the warming ocean also tells a bigger story. The oceans are by far the largest reservoir for storage of excess heat in the climate system and more than 90 percent of the heat trapped by anthropogenic greenhouse gases goes toward warming the oceans. This means that ocean warming provides a direct proxy for the net radiation imbalance caused by greenhouse forcing. This talk will consider observations of global sea level rise and its components, and compare them with direct satellite observations of the radiation imbalance. In addition, the observational and modeling evidence for storage of heat in the deep ocean will also be discussed.