Environment

Groundwater CO2

Using water from underground aquifers faster than it is being replenished is releasing large amounts of the greenhouse gas carbon dioxide into the atmosphere.

While small compared to the burning of fossil fuels, this groundwater depletion in the U.S. alone could be responsible for 1.7 million metric tons of atmospheric CO2 pollution each year, scientists from Michigan State University estimate.

That would rank among the top 20 sources of carbon pollution outlined by the U.S. Environmental Protection Agency (EPA) and the Intergovernmental Panel on Climate Change (IPCC).

“We were somewhat surprised that this hasn’t been accounted for … in the [EPA and IPCC] evaluations,” said study hydrogeologist David Hyndman.