NEW YORK: According to research scientists, new facts showing the level of atmospheric CO2 millions of years ago support recent climate change predications from the Intergovernmental Panel on Climate Change.
A multinational research team, led by scientists at the University of Southampton, has analysed new records showing the CO2 content of the Earth’s atmosphere between 2.3 to 3.3 million years ago, during the Pliocene era.
During the Pliocene, the Earth was around 2C warmer than it is today and atmospheric CO2 levels were around 350-400 parts per million (ppm), similar to the levels reached in recent years.
By studying the relationship between CO2 levels and climate change during a warmer period in Earth’s history, the scientists have been able to estimate how the climate will respond to increasing levels of carbon dioxide, a parameter known as climate sensitivity.
The findings, which have been published in Nature, also show how climate sensitivity can vary over the long term.
Dr Gavin Foster, co-author of the study, said: “Today the Earth is still adjusting to the recent rapid rise of CO2 caused by human activities, whereas the longer-term Pliocene records document the full response of CO2-related warming.