However, water vapour is also a very
powerful greenhouse gas and so, in a warmer
climate with subsequent increases in evaporation
from the ocean, an increase in cloud cover would
have a compounding warming effect—a so-called
‘positive feedback’ of climate change. Despite the
importance of climate feedback, they were notable
by their absence in the research discussed by the
recent, and very cautious, 2007 Intergovernmental
Panel on Climate Change (IPCC) report on climate
science. Further to this dichotomy of cloud–
climate effects, the representation of the amount
and different types of cloud in climate models
(box 1) is not particularly good. All in all, the
study of clouds is not a fluffy matter