Plants have taken in carbon dioxide (CO2) more efficiently under polluted (hazy) skies in recent decades compared to a cleaner atmosphere, according to a new study from the UK's Centre for Ecology and Hydrology (CEH).
"Surprisingly, the effects of atmospheric pollution seem to have enhanced global plant productivity from 1960 to 1999. This resulted in a net 10% increase in the amount of carbon stored by the land once other effects were taken into account," said Dr. Lina Mercado, from the CEH and lead author of the study.
The atmospheric particles (aerosols), which can create these hazy days, scatter light so that the surface receives light from multiple directions (diffuse radiation) rather than coming straight from the sun. Plants are then able to convert more of the available sunlight into growth because fewer leaves are in the shade.
"Although many people believe that well-watered plants grow best on a bright sunny day, the reverse is true. Plants often thrive in hazy conditions such as those that exist during periods of increased atmospheric pollution," said co-author Dr. Stephen Sitch from the Met Office Hadley Centre.
The research team found that by cleaning up the atmosphere (reduction in sulphate aerosols through this century) even steeper cuts in global carbon dioxide emissions would be required to stabilize carbon dioxide concentrations below 450 parts per million by volume.
This study was published in the journal Nature just today.
Note: Some of the paragraphs from above were taken directly from the CEH press release.