Clouds caused by air pollution have been overestimated in their ability to to reflect sunlight back into space, thus helping to cool the earth.
Sulphate pollution was believed to cause cooling clouds, but a closer look at how the sulphates are formed revealed clouds are likely to be less long-lasting than thought.
Researchers say this information is important so we can begin to readjust climate models.
Read more at Max Planck Institute for Chemistry