The Effect of Rising Temperatures on the Energy-Water Nexus
May and June this year were the hottest ever since record-keeping began in 1880, according to a new National Oceanic and Atmospheric Administration report. 2014 could go down as the warmest year yet, exceeding the previous records set in 2003 and 2013.
There’s no question that the Earth is warming, ancient ice is melting and sea levels are rising. Friends of Global Footprint Network are well aware of many of the risks that anthropogenic climate change poses, particularly to the world’s poorest regions.
A risk that remains under-appreciated, however, is the impact that water availability will have on energy, and that constrained energy supply will have on water.
After food production, electricity generation is the second-largest consumer of water globally. Thermal power plants – those powered by coal, natural gas, oil and nuclear – consume vast amounts of water in their cooling cycles. A single nuclear reactor can consume over 15 million gallons of water per day. Power generation accounts for 41 percent of freshwater withdrawals and about three percent of freshwater consumption (3.3 billion gallons of water per day) in the United States.
Warmer temperatures have been taking a toll on these thirsty facilities. Every summer, a lack of water (or of water that is sufficiently cold) forces power plants to shut down. Inadequate and irregular rainfall has also forced hydropower facilities to shut down, such as the Shivanasamudra plant in southern India this month.
Just as producing power requires water, producing water requires power. In California, one-fifth of the state’s electrical power is used to pump, treat, transport, heat, cool and recycle water. Agriculture consumes 80 percent of the water in the state, which produces one-third of the vegetables and two-thirds of the fruits and nuts consumed in the United States.
This year is on track to be the driest in the history of recorded rainfall in the state, and has already forced cattle ranchers to pare down their herds and almond farmers to plow under their trees. Food prices across the nation have crept up due to the drought.
California is emblematic of the predicament that the world now faces. A growing population puts water, food, and energy supplies under even more pressure even as they are increasingly strained by climate change. But the most accessible solutions often lead to destructive feedback loops. For example, California’s current plan to replace the 2.2 gigawatts of power generation from the San Onofre Nuclear Generation Station, which was shut down in 2012, is likely to rely substantially on new power generation from natural gas, which will pump even more CO2 into the atmosphere and increase the probability of future droughts.
As we anticipate the announcement of Earth Overshoot Day this year, which will arrive earlier than ever, it’s worth contemplating how we can find a way out of our predicament, and find real and enduring solutions to the knot of problems in the energy-water nexus. As many have observed, it is really an energy-water-food-economy-security-and-everything nexus, because energy and water are so fundamental to life. Eliminating waste, and using the precious resources we have as efficiently as possible, is the obvious place to start – and that’s a challenge we can all help to answer.