Posted 27 June 2013 - 01:11 AM
President Obama’s climate change speech on Tuesday from Georgetown University was full of references to climate change impacts on water availability, flooding and drought. He dealt head on with key issues of changing water cycle intensity, and in particular, with the increasing frequency of hydrologic extremes. From the outset, the President invoked the Blue Marble view of Earth from space that has served as the inspiration for modern environmental stewardship.
“It was an image of Earth -– beautiful; breathtaking; a glowing marble of blue oceans, and green forests, and brown mountains brushed with white clouds, rising over the surface of the moon,” the President said.
View of Earth from Apollo 8.
However, President Obama moved quickly to the subject at hand, and also, almost immediately, to water and fire issues:
“The 12 warmest years in recorded history have all come in the last 15 years… Droughts and fires and floods, they go back to ancient times. But we also know that in a world that’s warmer than it used to be, all weather events are affected by a warming planet.
Here at home, 2012 was the warmest year in our history. Midwest farms were parched by the worst drought since the Dust Bowl, and then drenched by the wettest spring on record. Western wildfires scorched an area larger than the state of Maryland. Just last week, a heat wave in Alaska shot temperatures into the 90s.
Farmers see crops wilted one year, washed away the next; and the higher food prices get passed on to you, the American consumer. Mountain communities worry about what smaller snowpacks will mean for tourism — and then, families at the bottom of the mountains wonder what it will mean for their drinking water. Americans across the country are already paying the price of inaction in insurance premiums, state and local taxes, and the costs of rebuilding and disaster relief.”
Most scientists, myself included, expect that this is what our future has in store for us. We’ll see a stronger and more variable water cycle, with well-defined regions of haves and have-nots: the dry areas of the world will become drier, and the wet areas will become wetter. Prolonged drought will be the norm in some regions, and more severe storms and flooding will become routine in others. And as the President points out, we can expect our western U. S. snowpack to shrink continuously in the coming decades.
Have a look at this figure from our recent paper on how climate change will pose new challenges for water management. It was derived using data from the NASA GRACE satellite mission, and it shows how total freshwater storage (all of snow, surface water, soil moisture and groundwater combined) has changed over the last decade. In the figure, we can see that the United States is headed towards two categories of water availability: having too much, as in the northern tier (shown by the blue colors), and having too little, as in the southern tier (shown in yellows and reds). Embedded within these regions are hotspots where groundwater depletion (California’s Central Valley, the southern High Plains aquifer, and a broad swath of the southeastern U. S. from Houston to Alabama to the Mid-Atlantic states) or flooding (the Upper Missouri River basin) have been the source of major water problems over the last decade.
Groundwater storage trends around the United States as measured by the NASA Gravity Recovery and Climate Experiment (GRACE) satellites between 2003 and 2012.
Credit: J. S. Famiglietti and M. Rodell, Water in the Balance, Science, 340, 1300 (2013). Figure appears as Figure S1 in Supplementary Online Materials, www.sciencemag.org/cgi/content/full/science.1236460/DC1. Prepared by Caroline de Linage, UC Irvine and Preston Huey, Science Magazine.
Much of the President’s talk focused on energy sources, energy policy, and greenhouse gas emissions. While these critical choices will affect our waters through the climate and associated hydrological changes that the President highlighted, they are also intimately linked to water supply. It takes huge amounts of water to produce energy. Roughly 40% of all freshwater withdrawals in the U. S. are used in energy production. Meanwhile, the heating, treatment and transport of water accounts for over 12% of energy use in the United States. That number approaches 20% in California.
But it was the President’s statements on the Alberta oil sands and the Keystone Pipeline, or really what he did not say, that warrant our close attention. Developing the Canadian oil sands (we also call them tar sands in the U.S., which is now politically incorrect up north) directly impacts water quantity and quality. For example, oil sands production requires vast amounts of water – something like a 4 to 1 ratio of water to oil – so this must absolutely be considered in the full environmental cost. Oil companies should be required, once the water is used for production, to return it to the environment at a quality that is equal to or better than that before its use. However, they are not.
Dust rises off the Sycrude oils sands open pit mine in Alberta, Canada. (Michael S. Williamson/The Washington Post)
“Now, I know there’s been, for example, a lot of controversy surrounding the proposal to build a pipeline, the Keystone pipeline, that would carry oil from Canadian tar sands down to refineries in the Gulf. And the State Department is going through the final stages of evaluating the proposal. That’s how it’s always been done. But I do want to be clear: Allowing the Keystone pipeline to be built requires a finding that doing so would be in our nation’s interest. And our national interest will be served only if this project does not significantly exacerbate the problem of carbon pollution. (Applause.) The net effects of the pipeline’s impact on our climate will be absolutely critical to determining whether this project is allowed to go forward. It’s relevant.”
When it comes to huge infrastructure projects like this one, transparency in the evaluation process is essential to build trust between the public, the oil companies, the pipeline company (TransCanada) and the many stakeholders. My personal opinion is that such evaluation is fraught with challenges, that it typically ignores important environmental costs (like those associated with water, ecology and habitat), and that the modeling tools available for the job are woefully inadequate.
And then there’s the issue of the pipeline’s route, which, unfortunately, still includes at least one phase that would traverse the northern section of the United States’ largest and most important aquifer, the High Plains (Ogallala) aquifer. The proposed pipeline route has already been modified once, in order to largely bypass the environmentally sensitive Nebraska Sand Hills, where much of the water in the aquifer is replenished. A possible pipeline rupture there would have posed an unacceptable level of risk to our nation’s water and food supply. The risk of other such ruptures, and of the full environmental impacts, must be fully evaluated, and openly reviewed, along every inch of the pipeline’s proposed route. Go State!
Keystone XL Pipeline map, from the Washington Post
Now seems like a good time to bring up the President’s fracking comments from his State of the Union address. You may recall that President Obama became very excited about the tremendous reserves of shale gas that we have in the United States. In case you missed it, he was talking about fracking, then, and on Tuesday. There are clear benefits to using shale gas. It does burn clean, we do have a lot of it, and it does create jobs. However, the jobs are short-term boom and bust, and are often filled by a transient work force. Importantly, fracking is an environmental disaster of the highest order. It uses ridiculous amounts of water, and it injects highly toxic, secret chemical cocktails into the fracked wells, some of which leak through the hydraulically fractured rock, through or along well casings, or onto the land surface…ultimately contaminating local groundwater supplies. All I can say is, I’m glad I’m not the President.