Proc. Natl Acad. Sci. USA http://doi.org/w3b (2014)

Credit: STOCKBYTE

Anthropogenic climate changes result from emissions of long-lived greenhouse gases and other short-lived climate pollutants (SLCPs). In addition to impacting crop production through their influence on the climate system, SLCPs such as tropospheric ozone and black carbon, can have direct negative impacts on crops.

Jennifer Burney and V. Ramanathan from the University of California, San Diego, USA, investigated the direct and indirect (climatic) effects of these SLCPs on wheat and rice yields in India. They studied the period 1980–2010 when black carbon and ozone precursor emissions increased dramatically.

Their statistical model shows that average wheat yields for India as a whole were up to 36% lower in 2010 than they would have been without climate change and increases in pollution emissions. Impacts on rice were less clear. Around 90% of the yield losses were attributed to the direct polluting effects of SLCPs. The authors conclude therefore that addressing regional air pollution could go some way to countering the expected yield losses resulting from trends in long-lived greenhouse gases.