Via The Energy Collective, some interesting commentary on the water-energy-climate change conundrum. As the article notes:
“…The energy-water-climate nexus is one of the nastiest and most perverse facets of the complex of sustainability challenges humanity is currently facing. We’ve all heard and used the mantra — “it takes energy to deliver water, it takes water to deliver energy”. To cite just about everyone’s favorite example, California expends 19% of its electricity, 30% of its natural gas, and 88 billion gallons of diesel fuel a year on water-related energy use.[1]
A warming world means a reduction in glaciers, which reduces summer water supplies to some population centers around the world when nature’s reservoirs aren’t as productive as we’ve come to expect. The situation is most attention grabbing in Asia, where the Tibetan Plateau, also known as the planet’s third pole or Asia’s water tower, feeds major rivers, including the Brahmaputra, the Ganges, and the Yangtze, which provide water to roughly a billion people for direct consumption, hygiene, agriculture, hydroelectric generation, and industrial uses.
This problem isn’t isolated to Asia, and has helped create “Ecuador’s environmental timebomb”:
Also with us was Bolivar Cereces, Ecuador’s leading glaciologist. He is a conservative when it comes to glacier retreat, but he reckons that all Andean glaciers below 5,000 metres will be gone within 10-15 years. His forecast is based on a 1C predicted rise in global temperatures in the next 80 years. But with a 0.8C rise already recorded in the last 100 years, and temperatures in the Himalayas and other mountain regions rising much faster than expected, this may need to be revised.
What is certain is that most of the 20 glaciers on Cayambe are in full retreat. But Ecuador has no resources to monitor closely its seven icecaps, and all figures are estimates based on aerial photography, old photographs and local observation. The consenus is that nearly 40% of Cayambe’s ice mass has been lost in a generation, with nearly 10% in the last decade.
For the next few years, glacier retreat may not be a great problem around Cayambe, because the extra melt water from the icecap makes up for the lack of rain that is being experienced. But this cannot last. Soon, the melting of the Andean cryosphere – or iceworld – will impact heavily on urban water supplies and therefore on some of the poorest people in the world, who depend on the rivers, which in turn depend on the melt water off mountains like Cayambe.
Desalination is at best a partial solution, as it requires much higher energy inputs per unit of fresh water delivered to consumers. But, much like the inevitability of geoengineering, it seems clear that we will turn to it to in the future to an even greater degree than we do already.
And then there are the slightly less obvious water impacts, like restricting the water required to cool thermoelectric generating plants, including nuclear, coal, oil, natural gas and any other water-cooled plant. When rivers warm and their flow subsides, generating plants suddenly can wind up without enough cooling capacity to operate, forcing partial or even full shutdowns, as happened in the US in 2007:
One reactor at a north Alabama nuclear plant was idle Friday and two others operated at reduced power because of the record-breaking heat wave, an outage that an industry watchdog said could be a sign of trouble for nuclear energy in a warming climate.
The Tennessee Valley Authority said it shut down the Unit 2 reactor at Browns Ferry Nuclear Plant and scaled back operations 25 percent at the plant’s other two reactors because of overheated water in the Tennessee River, which is used to cool the plant.
“This all comes down to the drought and the hot weather,” said plant spokesman Jason Huffine.
Industry watchdog David Lochbaum said the shutdown highlights a problem for nuclear power even as it is touted as environmentally friendly by President Bush, who visited Browns Ferry in June.
“This is an unforeseen impact of global warming. These plants don’t do very well in extremely hot weather,” said Lochbaum, a former Browns Ferry engineer now with the Union of Concerned Scientists in Washington.
and again this year:
As a result of the record high temperatures engulfing the South (and much of the planet) the Tennessee Valley Authority has had to shut down its largest nuclear power plant for the 40th day since July 8th, the TimesFreePress reports. The Tennessee River in Alabama is just much too hot.
Yet another nasty reality of water is that we’re pumping it out of the ground at an astonishing rate. This is usually expressed in the form of statistics about how the Ogallala Aquifer in the US or the water table in Japan or India or wherever is declining by X centimeters per year as we relentlessly mine this fossil water. The flip side to those numbers is where all that pumped water winds up:
Melting glaciers aren’t the only reason coastal cities need to worry about sea-level rise.
Agriculture is pumping groundwater for irrigation at such a rate that the runoff equals the contribution from melting of glaciers and ice caps outside of Greenland and Antarctica, according to a new study looking at groundwater depletion.
It also exceeds or falls into the high-end of previous estimates of groundwater’s contribution to sea-level rise, the researchers found.
Most water extracted from underground aquifers ends up in the ocean. The ceaseless pumping contributes about 0.8 millimeters of sea-level rise annually, about a quarter of the 3.1 millimeters per year scientists are observing worldwide, researchers reported.
The study, headed by Marc Bierkens of Utrecht University in Utrecht, the Netherlands, is to be published in an upcoming issue of the journal Geophysical Research Letters, the publication announced Thursday.
The study’s main point was to assess the depletion rate of the vast underground stores that billions of people depend on for agriculture and drinking water and that sustain countless streams, wetlands and ecosystems.
The news wasn’t good: The depletion rate has more than doubled between 1960 and 2000, with aquifers losing almost 70 cubic miles of water per year.
See also the AGU press release about this study, Groundwater depletion rate accelerating worldwide.
Oh, and did I mention that little problem of rising sea levels and the many millions of people plus farmland exposed to flooding in low-lying coastal areas around the world? Or the issues of increased torrential rains due to shifting weather patterns and the greater amount of moisture the air holds at warmer temperatures?
This is why I so often say here and elsewhere online that the primary vector for climate change impacts on humanity will be water. We often talk about how dependent we are on our supply of fossil fuels, or the risks of running an increasingly electricity-addicted world on “dumb” grids, which are certainly real and huge worries, but water in its various guises is just as big a threat.”
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