Research Highlights Deserts' Role in Sequestering Carbon

New research by the University of California suggests we should take a harder look at the potential carbon sequestration capacity of America's deserts.  According to the study, disturbing approximately 11 square miles of desert habitat could release 6,000 metric tons of carbon per year.  That is roughly the equivalent of putting a fleet of 5,300 SUVs on the road, each traveling 120 miles per month.  Desert plants and soil organisms take in and store tons of carbon each year.   When the desert habitat is destroyed, not only does it lose its ability to capture and store carbon, but carbon locked into the soils is likely to be released. According to the study:
When desert plants grow, they absorb carbon dioxide (CO2). The carbons (C), as sugars, move into the roots and soil organisms.  Carbon dioxide is respired back into the soil, part of which reacts with calcium (Ca) in the soil to form calcium carbonate.  This is how our deserts sequester large amounts of C and thus function to reduce atmospheric CO2.  The magnitude of this carbon storage function is still a crucial research question and remains unknown for our California deserts.
The study, which can be downloaded from Basin and Range Watch's website, also highlights the potentially unknown cumulative impacts that will result from plans to bulldoze hundreds of square miles of desert for proposed solar facilities.   The Department of Interior is rushing to destroy vast swaths of desert even when major ecological questions remain unanswered, including how climate change will impact endangered species' habitat and migration paths, trends in invasive plant species, and impacts on groundwater resources. 

As an example, the report notes that a typical solar facilities will use millions of gallons of groundwater each year, which is likely to affect plants like the Amargosa nitewort and wildlife like the desert pupfish.  These dangers are real.  Just recently, the Nevada Public Utilities Commission approved Solar Millennium's Amargosa Solar power project. The 250MW solar facility in the Mojave Desert will use three water wells to pump nearly 1,300 acre-feet of water each year to run steam generators, according to the environmental impact statement.  A single acre foot of water is the equivalent of 325,851 gallons, so the project would be using well over 423 million gallons of water each year.  Biologists are concerned that this draw on groundwater will lower spring-fed pools in nearby desert habitat that host rare desert pupfish and support treasured aquatic habitats. 

Wasting millions of gallons of water, releasing thousands of tons of carbon, destroying habitat, and pushing species toward extinction -- this does not sound like "green" energy.  Ironically, massive concentrating solar power facilities that destroy desert habitat--such as the Amargosa project--have already been rendered obsolete by rooftop solar panels that avoid all of the pitfalls of middle-of-the-desert facilities, and do not require hundreds of miles of expensive transmission lines...the Department of Interior just refuses to recognize this development.


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