Image by Wolfgang Staudt (source: Flickr)

In a global survey of temperature trends in major lakes, a first of it’s kind, NASA researchers have found that the Earth’s largest lakes have warmed up in the past 25 years in response to climate change.

For the study, researchers at NASA measured and monitored the surface temperatures of 167 large lakes worldwide. Per decade, an average warming rate of 0,45 degrees Celsius (0,81 degrees Fahrenheit) was reported, with some exceptions where surface temperature warm-up reached as much as 1 degree Celsius (1,8 degrees Fahrenheit) per decade. The overall warming of lakes is not local trend but of global nature, with the greatest temperature increases measured in the Northern Hemisphere (Northern Europe).

To measure the surface temperatures of the lakes, the NASA researchers used thermal infrared imagery from National Oceanic and Atmospheric Administration and European Space Agency satellites. Temperatures where measured at nighttime during summer in the Northern hemisphere and during winter in the Southern Hemisphere. Data collection at other times is difficult due to seasonal ice covering of the lakes or cloudy weather hiding them.

The warming of the lakes is consistent with global warming and this in turn is alarming. Small changes in water temperature can change the lake’s natural ecosystems, introduce new non-native species or even make the water toxic for fish.

For more information visit the NASA website