THE MELTING GLACIERS BEHIND HYDROPOWER
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The Electricity Is Melting – As glaciers see diminishing returns, is hydropower worth it? by Sierraclub.org
[Abe Musselman – Sierraclub.org] Sep. 2, 2021
What can replace a glacier?
Even in places where the local community does benefit from hydropower, the calculus of whether or not a dam is worth it is changing as fast as the warming planet. As glacier-powered hydro projects start to see diminishing returns, some municipalities are starting to grapple with the prospect of allocating limited water.
“Is electricity production the only goal that we have? Clearly it’s not,” says Daniel Farinotti, a glaciologist at ETH Zürich, a research institute funded by the Swiss government. Whether or not hydropower is a good investment is often “a question of values,” he says. But for regions that rely heavily on meltwater, the choice is especially urgent. “Once the glaciers have melted away, there’s just nothing that will deliver your water.”
And it gets even more complicated. Melting glaciers mean less water in the long run, but in the short run the opposite is true, as increased warming chips away at ancient bodies of ice. Glaciologists speak in apocalyptic terms about “peak water,” a point in the not-so-distant future when meltwater from glaciers will be at its highest. As the world climbs the slope to peak water, some hydropower projects may temporarily become more valuable than ever, as more water melts away with each summer thaw.
“It’s like drawing down your bank account: You have a surplus of money available, but it’s then missing,” says Mathias Vuille, a professor of atmospheric and environmental sciences at the University of Albany who has watched glaciers in the Andes shrink before his eyes. Glaciers like Chacaltaya have long since passed peak water. For a time, global warming will boost the amount of water melting from glaciers. But after peak water, as the glaciers shrink, the water and energy they produce will drop to the point where the cost to local communities and ecosystems is too high to justify keeping a dam in place. The pressure to plan for this eventuality is already on in some places.
