Recent droughts in several western states have led to well-publicized problems including wildfires, loss of trees, and damage to crops. A lesser-known impact of drought conditions has been increases in emissions of carbon dioxide and harmful air pollutants from power generation.
When hydropower runs low in a drought, western states tend to ramp up
power generation – and therefore emissions – from fossil fuels. According to a new study from Stanford
University, droughts caused about 10 percent of the average annual carbon
dioxide emissions from power generation in California, Idaho, Oregon and
Washington between 2001 and 2015.
Water is used in electricity generation both directly for
hydroelectric power and indirectly for cooling in thermoelectric power
plants. When water for hydropower comes
up short because of drought conditions, natural gas or coal-fired power plants
are brought online to pick up the slack.
These drought-induced shifts in energy sources led to an estimated 100
million tons of carbon dioxide across 11 western states between 2001 and
2015. That is the equivalent of adding
1.4 million vehicles to the region’s roadways.
California, whose legislature has mandated that the state be carbon-free
by 2045, contributed about half of this total.
Washington, which is considering a similar mandate, contributed nearly a
Western states in recent years have suffered intense droughts that
scientists expect to become more common as global warming continues to
intensify. The new study indicates that
in regions where clean, reliable hydropower has been an important part of the
energy mix, it will be increasingly necessary to provide clean backup energy
sources in order to meet emission reduction targets.
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Droughts boost emissions as hydropower dries up
Photo, posted March 7, 2016, courtesy of Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.