January 16, 2013 | Pippa

During these cold winter nights I love nothing better than sitting by a roaring fire.

But new research suggests wood fires might not be so innocent a pleasure. The soot they give off, which diesel engines also produce, may have a much greater role in warming the atmosphere than we previously realised.

Some scientists say that if we cut soot emissions we could slow down the warming dramatically. Others think it’s more complicated than that because some of the chemicals released when wood burns have a cooling effect instead.