SOURCE: Phys.org
DATE: February 20, 2017
SNIP: Rising temperatures could accelerate climate change by reducing the amount of carbon dioxide stored in ponds and increasing the methane they release, new research shows.
The scientists experimentally warmed an array of ponds over seven years by 4-5ºC and studied the impacts on greenhouse gas emissions and rates of metabolism.
Changes observed after the first year became “amplified” over a longer period, according to the study by the University of Exeter and Queen Mary University of London. After seven years, a pond’s ability to absorb carbon dioxide (CO2) was reduced by almost half, while methane release almost doubled.
Lakes and ponds cover about 4% of Earth’s surface (excluding areas covered by glaciers and ice sheets) but they are disproportionately large sources of methane and CO2 to the atmosphere.
Ponds of less than one square metre are responsible for releasing about 40% of all methane emissions from inland waters.
“Our findings show that warming can fundamentally alter the carbon balance of small ponds over a number of years, reducing their capacity to absorb carbon dioxide and increasing emissions of methane.
“This could ultimately accelerate climate change.”