Pollution slowing global warming
The first study found that the hole in the ozone layer, caused by the use of CFCs, has prevented the melting of Antarctica even as the rest of the world warms.
A separate study found that plants absorb more carbon dioxide under polluted skies, therefore slowing global warming.
Scientists said the findings made it even more important to cut carbon emissions in the future as pollution from CFCs and other sources is expected to decrease.
The survey of Antarctica by the British Antarctic Survey and Nasa found sea ice in the South Pole has increased at a rate of 100,000 square kilometres (38,601 square miles) a decade over the last 40 years even as the ice cap in the North Pole melts.
The scientists said the reason was the hole in the ozone layer, caused by the use of CFCs. The ozone layer absorbs heat in the atmosphere, but the emergence of the hole – almost the size of North America – has cooled temperatures, resulting in more ice.
However following a ban on CFCs the hole in the ozone layer is expected to repair, causing temperatures in the South Pole to rise again.
The study of plants by scientists from across the UK, including the Met Office, found that “global dimming” caused by polluted skies over the last 40 years has increased the ability of plants to absorb carbon dioxide by as much as a quarter. The study published in Nature said this is because the diffusion of sunlight means the land receives light from different directions rather than just directly from the sun. As a result, plants are able to convert more of the sunlight energy into growth, trapping carbon dioxide as they do so, because more leaves are in the sun.
The increase in the amount of carbon dioxide, which is a greenhouse gas, may have helped to slow global warming. However as the world cuts pollution it will speed up again.
Both studies concluded that it was even more important to cut carbon emissions in the future as the reduction in pollution will mean global warming is speeding up.