BBC: A Norwegian scientist says he has shown how much aerosols influence climate. Aerosol particles scatter and reflect the Sun’s rays – an effect that “masks” global warming. This study aimed to bring together models and observations of this “direct aerosol effect”, to accurately estimate the magnitude of this cooling. Reporting in the journal Science, climate scientist Gunnar Myhre has found that the effect is weaker than previous studies have estimated. Dr Myhre, …