Research conducted at Mainz University shows that it took the climate 20,000 to 50,000 years to stabilize after the rise in global temperatures of five to eight degrees Celsius 56 million years ago.
Climate change is causing temperatures to rise and is also increasing the likelihood of storms, heavy rain, and flooding – the recent flood disaster in the Ahr valley in Germany is just one such example. What we need to ask ourselves in this connection is how quickly the climate can recover from the warming caused by an increase in carbon dioxide in the atmosphere.
Professor Philip Pogge von Strandmann of Johannes Gutenberg University Mainz (JGU) set out to investigate this aspect by considering the significant rise in global temperatures of five to eight degrees Celsius that took place 56 million years ago – the fastest natural period of global warming that has impacted on our climate, known as the Paleocene-Eocene Thermal Maximum (PETM). It was most likely triggered by a volcanic eruption that released huge amounts of carbon dioxide or CO2 into the atmosphere. We know that the higher the temperature, the faster rock will weather, and, in addition, if there is a lot of CO2 in the atmosphere, some of it will react with water, forming carbonic acid – the very acid that promotes and accelerates the weathering process. Because of the weathering process, this atmospheric carbon will eventually find its way into the seas via rivers, where it binds CO2 as carbonate and form a persistent ocean-based reservoir of carbon dioxide. "Our theory was that if rock weathers faster due to the increased temperatures, it also helps convert a lot of carbon dioxide from the atmosphere into insoluble carbonate in seawater – meaning that, over the long term, CO2 levels would end up falling again and the climate would ultimately recover," explained Pogge von Strandmann. This effect could have helped to keep the Earth's climate fairly stable over billions of years and it could have even prevented the total extinction of all life on the planet.
Read more at Johannes Gutenberg University Mainz
Image: The analyzed sediments from the Paleocene-Eocene Thermal Maximum (PETM) came from the Danish island of Fur. (Credit: photo/©: Morgan Jones)