Until 1802, when Howard delivered his groundbreaking paper, "On the Modification of Clouds, " an aerial nomenclature had eluded even such keen observers of the natural world as Aristotle, Seneca and Descartes.
In a recent paper in Climate Dynamics, Mark Webb of Britain's Hadley Centre for Climate Change and his colleagues reported that clouds account for 66% of the differences between members of one important group of models and for 85% of them in another group.