Re: “Global Warming? Not Always,” by Martin P. Hoerling (Sunday Review, March 9, 2014):
As California’s severe drought has worsened, there has been persistent debate about the links between drought and climate change (or indeed any extreme weather event). Three key, but very different, questions are often confused: Has climate change caused the current drought? Is it already influencing or affecting the drought (no matter its cause)? And how will climate change affect future droughts?
The most rigorous answer to the “causality” question for the California drought is neither yes nor no. We simply cannot say for certain.
But this is the wrong question to ask. The current drought has certainly been exacerbated by climate change for one simple reason: Temperatures in California are now higher today, as they are globally. This alone increases water demand by crops and ecosystems, accelerates snowpack loss, and worsens evaporation from reservoirs. There are other complicating effects, but the influence of higher temperatures on drought is already real and cannot be ignored.
We are now unambiguously altering the climate, threatening water supplies for human and natural systems. This is but one example of how even today we are paying the cost of unavoidable climate changes.
PETER GLEICK, JONATHAN OVERPECK, CONNIE WOODHOUSE
Oakland, Calif., March 10, 2014
Dr. Gleick is president of the Pacific Institute. Dr. Overpeck is a professor of geosciences and atmospheric sciences and Dr. Woodhouse is a professor of geography and geosciences at the University of Arizona, Tucson.
To the Editor:
Re “In Parched California, Town Taps Run Nearly Dry” (front page, March 8):
The California drought has been exacerbated by misguided government policies that encouraged large-scale agricultural farming. Agriculture accounts for 80% of water use while contributing a minuscule 2% to the state economy, according to a recent article in The Economist.
Farmers continue to grow alfalfa, rice and other thirsty crops. Their resource use has been heavily subsidized by the government. According to The Economist, they have paid a paltry 15% of the capital costs of the federal system that delivers much of the water to their fields. Thus, farmers have no incentive to irrigate their farmlands efficiently.
After a few more weeks of the rainy season, much of California will bake, increasing the likelihood of wildfires. The water table has decreased in many areas, prompting farmers to drill deeper to reach groundwater, further depleting aquifers.
In January, Gov. Jerry Brown issued a drought declaration and urged Californians to cut water use by 20%. About $183 million in federal aid that has been pledged, coupled with $687 million in California aid, should bring some relief.
However, we need details about how the funds will be spent, and much greater pressure needs to be directed at farmers.
JAGJIT SINGH
Los Altos, Calif., March 9, 2014
Los Altos, Calif., March 9, 2014
To the Editor:
Your article includes no mention of desalination plants. In many cases, digging deeper and deeper has not found any water. Why not do what Israel does with its drought areas and build these plants?
LEORA KORB
Monmouth Beach, N.J., March 9, 2014
To the Editor:
As California endures a historic drought, many are wondering why Gov. Jerry Brown supports expanding a practice that severely jeopardizes our water: hydraulic fracturing, or fracking.
Fracking uses tremendous quantities of water that are permanently removed from our supply. California’s aquifers are also threatened with contamination by toxic fracking chemicals through spills, faulty well casings and fractures in the earth.
Farmers are particularly concerned about fracking and its dangers to water. Last week nearly 150 farmers signed a letter to Governor Brown urging him to stop fracking. As California grapples with a thirsty future, Governor Brown must protect our precious water by halting this dangerous practice.
HILLARY AIDUN
San Francisco, March 9, 2014
The writer is an anti-fracking organizer for the Center for Biological Diversity.
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