Rising temperatures could speed up climate change by increasing the amount of methane released by ponds and reducing Carbon Dioxide (CO2) stored in them.
That’s according to new research, which saw scientists warming an array of ponds over seven years by 4-5ºC and studying the impacts on greenhouse gas emissions.
They found changes after the first year were “amplified” over a longer period and after seven years, a pond’s ability to absorb CO2 was reduced by almost half, while methane release almost doubled.
Lakes and ponds cover around 4% of Earth’s surface – excluding areas covered by glaciers and ice sheets – but they are “disproportionately large sources” of methane and CO2, say scientists at the University of Exeter and Queen Mary University of London.
Ponds of less than one square metre are said to be responsible for releasing around 40% of all methane emission from inland waters.
Lead Author and Professor Gabriel Yvon-Durocher of the Environment and Sustainability Institute at the University of Exeter said: “This is the first experiment to investigate the long term effects of warming in aquatic ecosystems.
“Given the substantial contribution small ponds make to the emission of greenhouse gases, it is vital to understand how they might respond to global warming. 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.”
He adds the accelerating effect in ponds, “which could have serious impacts on climate change”, is not currently accounted for in Intergovernmental Panel on Climate Change models.