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WATER POLITICS

Via The Economist, a reminder of why water and climate are inseparable:

Rising temperatures do more than make the world hotter. Widespread weather impacts are one of the reasons why scientists prefer the term “climate change” to “global warming”.

But it can be hard to grasp just how connected the climate and the water cycle are, and to untangle the complex web of interactions between them. In school, children learn a simplified version of the Earth’s vital machinery: energy from the sun heats the planet’s surface and atmosphere, fuels plants through photosynthesis and is eventually radiated back into space. Water moves from the oceans to the atmosphere, to the land and back to the oceans again. The first process drives the second, meaning that any changes to it—like greenhouse gases trapping more heat in the atmosphere—have broad, rippling consequences.

The upshot is that catchphrases like “the climate crisis is a water crisis” (a particular favourite of NGOs) might sound like sloganeering, but they are actually true. The Intergovernmental Panel on Climate Change describes rising temperatures as “intensifying” the water cycle, heightening its extremes and making the swings between them more erratic. Storms and rainfall become heavier and more destructive, droughts last longer and are more severe. Countries used to coping with one type of disaster are forced to grapple with others; crucial regional weather patterns like India’s monsoon become ever-harder to predict. 

The ways in which warming alters the water system make adapting to a warmer world harder. Rising sea levels, driven by melting ice and the expansion of ocean water as it warms, turn groundwater salty. Flooding from tides and storms disrupts sewage and drinking systems, spreading waterborne pathogens that are already replicating faster because of warmer temperatures. Hot weather damages crops and increases demand for irrigation, driving up freshwater use by agriculture (now over 70%). Where water is a source of renewable energy—such as the hydroelectric dams and reservoirs meant to provide 15% of California’s electricity—dwindling levels can force grids back to fossil fuels. And when droughts or disasters force people to migrate, they tend to move to cities without adequate water infrastructure to support them, making it more likely that they’ll resort to getting water from illegal and unsustainable sources. 

We wrote recently about how fraught the politics of water has become as global temperatures climb, and how important it is for countries to manage it more effectively. Water influences almost everything that humans do; the climate influences almost everything about water. One cannot be tackled without the other.