It's the clouds that stop the oceans boiling. But as the planet warms, our main defence against the sun's fierce heat is weakening
AMONG the ranks of fluffy clouds stretching across the summer sky, one catches your eye. There is something familiar in the shape. Is it a dog? A bear on its hind legs? Not quite. As the pale billows shift, the cloud spreads out something like a pair of wings. Aha – a guardian angel. A little lopsided, but somehow reassuring. Until another change catches the air. The wings melt away and the cloud shrinks. Slowly it takes on a form that is less comforting. Starker. More... skeletal.
As well as providing entertainment on a lazy day, cloud-watching has a more serious side. Clouds have a vital role that few people appreciate: their overall effect is as a global heat shield, reflecting sunlight that would otherwise bake the ...
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