The Guardian Disasters cost lives and blight economies for years to come.
Compassion is expensive, too.
Disaster prevention, on the other hand, is relatively cheap. But astonishingly, there is no international obligation, nor much international machinery, to share information about what happens after water hits the ground running and heads downstream. There are problems even when there is goodwill. Yet the world is now ringed by satellites with instruments to measure soil moisture levels to detect imminent drought, and river levels to an accuracy of about 5 cms to warn of flood dangers. The 1990s was the UN's decade for natural disaster reduction.