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Nearly 20 US states have started to implement former
president Barack Obama’s Clean Power Plan, which
places limits on carbon dioxide emissions from power
plants in an effort to reduce the impacts of climate
change. The plan has been in legal limbo for the past
year, yet scientists have now calculated another
outcome of the policy: harm to crop yields if the plan is
stopped. Along with carbon pollution, coal-fired power
plants spew pollutants that form smog, which was
already known to contribute to increased rates of
asthma and premature deaths. The new research
estimates the extent to which smog, under air-pollution
policies in place before the Clean Power Plan, would
limit production in 2020 of four major crops: corn, cotton,
potatoes, and soybeans. Led by environmental engineer
Shannon Capps, the research team also estimated the
extent to which those crop production losses would
shrink under three nationwide counter scenarios. One
improved the efficiency of individual power plants.
Another modelled a policy similar to the Obama plan,
setting state carbon dioxide emission goals for the
electricity sector. And the third established a tax on
carbon emissions, under which emissions decreased
the most. But the greatest drop in smog-forming
pollutants – and the greatest gains in crop yields – came
from policies such as the Clean Power Plan.