World’s lakes warming more rapidly than oceans

The world’s lakes are warming more rapidly than the

oceans or the atmosphere, according to new research which includes data from the Marine Institute research station in Co Mayo.

A study of 235 lakes on six continents has found that the temperature is increasing at an average of 0.34 degrees (0.61 degrees Fahrenheit) each decade.

The research by more than 60 scientists, published in the Geophysical Research Letters journal, concludes that the warming could have "profound" effects in threatening freshwater supplies and ecosystems.

The study is the largest of its kind and the first to use a combination of long-term hand measurements and satellite information.

Surface temperature

Significantly, satellite data dating back 30 years measures only surface temperature, while hand measurements dating back over a century can detect changes in temperature throughout a lake.

The research was funded in part by Nasa and the US National Science Foundation.

Long-term data from the Marine Institute’s catchment research facility in Newport, Co Mayo, contributed to the study.

The Marine Institute measures the surface water temperature of Lough Feeagh as part of the long-term ecological monitoring of the Burrishoole catchment.

The surface water of Lough Feeagh warmed at a rate of 0.35 degrees per decade between 1985 and 2009, although the rate of warming was lower than in some other northern hemisphere lakes.

The warming of more than half the world’s freshwater supply could lead to increased frequency of algal blooms, which can strip water of oxygen and are toxic to fish and animals, the authors note. The rates imply that emissions of methane, a greenhouse gas 25 times more powerful than carbon dioxide, will increase 4 per cent over the next decade.

Human uses

“Lakes are important because society depends on surface water for the vast majority of human uses,” said the study’s co-author

Stephanie Hampton

, director of Washington State University’s Center for Environmental Research, Education and Outreach.

These range from provision of drinking water to use in manufacturing, energy production, and crop irrigation, while protein from freshwater fish was especially important in the developing world.