Ponds could be playing a major role in climate change, a new study published by scientists at University of Exeter and Queen Mary University of London has shown.
Researchers found that over a period of seven years warming of ponds impact greenhouse gas emissions and rates of metabolism in ponds. Researchers found that ponds start losing their capability to absorb carbon dioxide while the release of methane increases. Over the period of seven years, scientists warmed an array of ponds by 4-5ºC and found that the ponds lost their ability to absorb carbon dioxide by 50 per cent while methane emissions doubled.
Scientists point out that while lakes and ponds do not cover major portion of the Earth – just 4 per cent – as per latest statistics, they play a massive role in methane and carbon dioxide emissions. Researchers say that these water bodies are disproportionately large sources of methane and CO2 to the atmosphere. Statistics from studies indicate that ponds of less than one square metre are responsible for releasing about 40 per cent of all methane emissions from inland waters.
According to authors of the study, their study is the first of its kind that investigates the long-term effect of warming in aquatic ecosystems on climate change. Because these smaller water bodies substantially contribute to global emissions, scientists say that a greater understanding would help us respond to and tackle global warming.
Researchers were able to show through the study that warming can fundamentally alter the carbon balance of small ponds over a number of years by not only reducing their ability to absorb carbon dioxide, but also increasing methane emissions. The lost ability to absorb carbon dioxide and increased methane emissions could ultimately accelerate climate change.
Such effects are known as “positive feedbacks” – where the effects of global warming on components of the biosphere lead to changes that further climate change.
“The amplified effects of experimental warming we have observed in ponds are different to those we typically see on land, where large initial effects of warming appear to diminish over the long term,” said professor Gabriel Yvon-Durocher, of the Environment and Sustainability Institute on the University of Exeter’s Penryn Campus in Cornwall. “This accelerating effect in ponds, which could have serious impacts on climate change, is not currently accounted for in Intergovernmental Panel on Climate Change models.”