Ocean has absorbed more than 90% of heat gained by planet, shows new reconstruction
NCAS’ Professor Jonathan Gregory has helped reconstruct ocean temperature change over the last 150 years.
A team of researchers, led by the University of Oxford, have estimated that the ocean absorbed more than 90% of the heat gained by the planet between 1971 and 2010. The study also shows that comparable ocean warming happened between 1920-1945 and 1990-2015.
Much of the heat has been stored in the ocean depths, where measurements only started in recent decades, and existing estimates of the total heat absorbed by the ocean only started around 1950. The new research estimates ocean heat change back to 1871.
Over the past century, rising greenhouse gas emissions have led to excess heat energy within our climate system. This latest research, published in the Proceedings of the National Academy of Sciences, supports evidence that oceans are absorbing most of the excess energy in our climate system. This process causes ocean temperature to increase and sea levels to rise.
Scientists also found that substantial amounts of heat accumulated in the ocean can be influenced by ocean circulation changes. Therefore, monitoring and understanding the role of circulation remains key to predicting global and regional climate change and sea-level rise.
Professor Jonathan Gregory, from the National Centre for Atmospheric Science, University of Reading and the Met Office Hadley Centre said: “This new method agrees with others for the period during which observations of ocean temperatures below the surface are available, namely the last few decades.
“Secondly, the new method allows us to do things which can't be done with existing ocean temperature observations alone. It allows us to estimate heat uptake for periods before these records began, and to show for the first time that changes in ocean transport have had an important effect.
"Understanding the way heat is transported around the oceans is important to give us confidence in predicting sea level rises that could be caused by climate change in the future."
Professor Jonathan Gregory has recently received a BBVA Foundation Frontiers of Knowledge Award recognising his cutting-edge research into sea level rise under climate change.