The Earth's largest lakes have warmed up over the past 25 years in response to climate change, the US space agency said on November 23, announcing the first such global study of its kind. Scientists Philipp Schneider and Simon Hook of NASA's Jet Propulsion Laboratory in Pasadena, California used satellite data to measure the surface temperature of 167 lakes around the world, NASA said.
"They reported an average warming rate of 0.81 degrees Fahrenheit per decade, with some lakes warming as much as 1.8 degrees Fahrenheit per decade," NASA said in a statement.
"The results were consistent with the expected changes associated with global warming," it said.
Researchers found the "largest and most consistent area of warming was northern Europe," while the "warming trend was slightly weaker in south-eastern Europe, around the Black and Caspian seas and Kazakhstan," NASA said.
"The trends increased slightly farther east in Siberia, Mongolia and northern China."
The south-western United States experienced "slightly higher" trends than the Great Lakes region, while the tropics and mid-latitudes of the Southern Hemisphere showed "weaker" warming, NASA said.
"Our analysis provides a new, independent data source for assessing the impact of climate change over land around the world," said Schneider, lead author of the study published this week in the journal Geophysical Research Letters. "The results have implications for lake ecosystems, which can be adversely affected by even small water temperature changes." NASA selected bodies of water that were at least 193 square miles (500 square kilometers) or larger, and had significant amounts of water away from the shoreline so that land temperature changes did not interfere with measurements.