<p>The time for action is now.<br>The fate of the world's coasts rests on a knife edge as global warming melts ice sheets and glaciers from the Alps to the Andes. The choices we make now will determine whether oceans rise by a coast-swamping 1 metre by 2100 or whether we can save our coastal communities.<br>From the glaciers of Antarctica and the high Andes, to the small island states of the Pacific and the coastal cities of Miami, New York, Veni...