The Keys to Energy Sustainability
by Bill Chameides | November 21st, 2011
posted by Erica Rowell (Editor)
Can we open the door to sustainable energy without addressing water scarcity?
Check out the commentary published last week in the journal Nature Climate Change by David McCollum of the University of California, Davis, and colleagues. In it McCollum et al argue that there are “three … key objectives [i.e., issues] driving energy-sustainability policy — security of supply, climate change mitigation and air-pollution reduction.” They go on to point out that although each of these is quite closely interrelated and coupled, policy makers often address them in “isolation,” causing them to “compete against each other for attention” and by extension for limited resources.
Far better, McCollum et al argue, would be to take a more holistic approach, considering all three simultaneously and looking for policies that provide co-benefits for all. For example, developing a more efficient energy system could clearly address all three issues: burning less fuel would improve energy security and lower both air pollution and greenhouse gas emissions.
Rethinking the Factor of Time
Especially problematic, the authors argue, is the perception of different timelines for dealing with these issues. Energy security and air pollution, because they tend to be viewed as short-term issues, require timely responses while the longer-term issue of climate change tends to be shoved to the back burner because it will play out over decades. It would be more effective, the commentary suggests, to move climate to the front burner because so many of the steps needed to address climate change will help address the other two at the same time. Timely emphasis on energy security or air pollution, on the other hand, doesn’t reap the same synergies.
Examples: putting air-pollution controls on coal plants will clean the air, but it does nothing to remove carbon dioxide (CO2); using tar sands and coal-to-liquids technology to generate oil for our cars will relieve national security concerns but not help reduce air pollution or mitigate against climate change. But, go for climate as a priority, and in spite of its long time horizon, the vast majority of dollars spent will not only help reduce the impact of hotter temps, but will also improve air quality and reduce our need to get energy from beyond our borders.
An interesting argument, although there is a bit of circularity. We should adopt a holistic approach that puts the emphasis on one of the three issues: climate. Is that holistic? The authors kind of finesse this conundrum by arguing that a comprehensive, integrated analysis will shine a light on the centrality of climate for policymakers and, in effect, bring it to the front burner where it rightly deserves to be. Could be.
Water Woes: Another Piece of the Energy Sustainability Puzzle
|SIDEBAR: Water use by thermoelectric power plants is categorized as water withdrawn or consumed. Thermoelectric power plants use large quantities in each category, but withdraw more than is actually consumed.|
On a related front, a report released last Tuesday by the Union of Concerned Scientists and a team of independent scientists (two of whom are colleagues of mine here at Duke’s Nicholas School) suggests that a fourth issue — that of water scarcity — also impedes our path to energy sustainability.
“Freshwater Use by U.S. Power Plants: Electricity’s Thirst for a Precious Resource” highlights how our use of water to generate power is impacting water resources in basins across the United States. Using 2008 data, the report’s authors estimate that U.S. power generation withdraws anywhere between 60 billion to 170 billion gallons of freshwater a day, leading to the daily consumption of three billion to six billion gallons. This jibes with other studies on the issue. In 2005 the U.S. Geological Survey estimated that power generation withdrew 143 billion gallons a day accounting for about 40 percent of all freshwater withdrawals; an earlier look, using 1995 data, found that power generation accounted for about three percent of national consumption (or almost 20 percent of non-irrigation nationwide consumption).
But this demand doesn’t hit all basins equally. The Union of Concerned Scientists report found that of the country’s 400 water-stressed basins, power generation contributed to water stress in 78. It also found power generation to be the primary driver of water stress in 25 watersheds in 17 states including North Carolina, South Carolina, Michigan and Missouri.* Of course, water dedicated for energy supplies must compete against the imperatives of using water for agriculture and drinking water and therein lies the rub. Water scarcity is not just a major problem for energy generation; given that our species cannot survive without water, this fundamental-to-life resource is even more critical than achieving energy sustainability.
Water Woes, Part Two
While we’re on the subject, it’s worth noting that water scarcity is about a lot more than energy security. It’s about … well, water is something we obviously can’t do without. Addressing water scarcity will require prioritizing needs for agriculture and drinking water relative to energy production as well as coping with increasing pressure from future development and rising population. And there’s another variable impacting water scarcity and that is … you got it, climate change and the likelihood that a warmer planet will lead to increased water shortages in many regions around the globe.
Here’s a suggestion. Why not widen McCollum et al’s argument to include the coupling between energy and water? And if you do, you perhaps further strengthen the imperative to move climate change to the front burner. To more politely borrow from James Carville: It’s not just energy, and it’s not just water; it’s energy, water, and a whole lot more. Smart?
The report defines water stress as when demand for water exceeds a threshold of 40 percent of the available supply provided by local sources (typically surface and groundwater).filed under: agriculture, climate change, energy, faculty, global warming, sustainability, water
and: air pollution, drinking water, greenhouse gas emissions, power plants