A recent study has used a new method of estimating ocean warmth, which suggests that the world’s oceans absorbed 60 percent more heat energy between 1991 and 2016 than previous estimates have found.
The authors suggest the findings may make it harder for the world to limit the global average temperature increases to the targets set in the Paris Agreement on climate change.
31 October 2018: Researchers at Princeton University and the Scripps Institution of Oceanography published a study that warns that global warming may be happening faster than scientists have previously estimated. The study, published in Nature, suggests that these findings may mean that emitted greenhouse (GHG) gases have generated far more heat than scientists originally predicted, meaning that the Earth is more sensitive to carbon dioxide than scientists thought.
The study titled, ‘Quantification of Ocean Heath Uptake from Changes in Atmospheric Oxygen and Carbon Dioxide Composition’, assesses ocean warmth using “a whole-ocean thermometer” to measure carbon dioxide and atmospheric oxygen, both of which increase as the ocean warms and releases gases. In other words, the researchers measured the amount of carbon dioxide and oxygen lost by the oceans, and then calculated the amount of warming needed to explain that change in gases. Previous studies have estimated ocean temperature using hydrographic temperature measurements and data, which the authors argue is an “imperfect ocean dataset.”
The findings suggest that achieving the Paris Agreement targets is even harder than previously thought.
The study estimates that the world’s oceans absorbed 60 percent more heat energy between 1991 and 2016 than previous estimates have suggested. Further, the study suggests, GHG emissions generate more heat than scientists originally predicted, which, the authors argue, may make it harder for the world to limit the global average temperature increases to the targets set in the Paris Agreement on climate change. In addition, the findings indicate that extra heat will go into the world’s oceans, resulting in implications for marine ecosystems.
Laure Resplandy, the Princeton University researcher who led the study, said the study finds that the planet warmed more than researchers had previously thought. “It was just hidden from us because we didn’t sample it right,” she explained. Resplandy elaborated that the study suggests that achieving the Paris Agreement targets is “even harder because we close the window for those lower pathways” outlined by the Intergovernmental Panel on Climate Change (IPCC) recent Special Report on Global Warming of 1.5°C (SR15). [Ocean Action Hub Story] [WEF News Story] [Nature Abstract]