CO2

                      

Today's CO2 levels are at a comparable 414ppm and levels are rising.

Dr Thomas Chalk, who co-authored the study, said: "Focusing on a past interval when the incoming insolation from the Sun was the same as today gives us a way to study how Earth responds to CO2 forcing."Currently, our CO2 levels are rising at about 2.5 ppm per year, meaning that by 2025 we will have exceeded anything seen in the last 3.3 million years."

The Southampton researchers analysed tiny fossils from the Caribbean Sea to reconstruct Earth's ancient atmosphere.

Dr Elwyn de la Vega, who led the study, said: “Knowledge of CO2 during the geological past is of great interest because it tells us how the climate system, ice sheets and sea-level previously responded to the elevated CO2 levels.

"We studied this particular interval in unprecedented detail because it provides great contextual information for our current climate state”.According to the US space agency NASA, CO2 measurements taken in May 2020 show atmospheric CO2 is 414ppm.

Although natural events such as volcanic eruptions can raise CO2 levels, most of the greenhouse gas has been attributed to emissions from human activities.

In particular, the burning of fossil fuels, as well as deforestation, are big contributor.

Carbon dioxide is a greenhouse gas, meaning it traps heat from the Sun from escaping into space after it reaches our planet.