How we broke the water cycle and can no longer rely on rain to fall

I TRAVEL a lot for work, and everywhere I go people talk about rain. I was in Uganda last November and heard grumbles that the rainy season had failed to arrive. In Albania in March, I read about plans to export water to drought-stricken Italy. I visited Saudi Arabia in June and was told about an unexpected torrential downpour in the desert.

It is easy to shrug at all this. After all, we already know climate change is disrupting the weather. And the rain will fall eventually because water is infinitely renewable. It falls from the sky as rain, variably but reliably. Doesn’t it?

The answer, increasingly, is no. “We’ve allowed ourselves to think that water is simply something that comes back every year and there’s a stable water cycle and we can trust it,” says Johan Rockström at the Potsdam Institute for Climate Impact Research in Germany. But that is changing as a result of human activity. “We must recognise that – oh my God – we’re actually not able to trust the source any more.”

This isn’t vague scaremongering. Rockström has just carried out a serious analysis of our water systems and concluded that they are broken. So how bad is the damage? And is there anything we can do as individuals or as a society? Broadly, the answers are that the damage runs deep, but it is still fixable – just.

The hydrological cycle is a complex, interconnected system that circulates freshwater between rivers, lakes, wetlands, groundwater, ice, water vapour in the atmosphere, clouds and precipitation. It has been extremely stable during the Holocene, or the past …