The world’s lakes are coming to a boil, reports National Geographic. Only a minute difference in global climate is already causing some major changes in big bodies of water:
In the last 25 years, the world’s largest lakes have been steadily warming, confirms the new study, some by as much as 4°F (2.2°C). In some cases that is seven times faster than air temperatures have risen over the same period.
It’s an important find, scientists say, because lake ecology can be extremely temperature-sensitive. “A small change in temperature can have quite a dramatic effect,” says study author Simon Hook, a geologist and remote sensing expert at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.
The two scientists measured lake temperatures by digging through 25 years of stored data from satellites that had imaged the entire surface of the Earth (sometimes several times a day).
Eventually they whittled the data down to nighttime measurements of thermal infrared emissions for 104 lakes large enough so that the satellites got good readings of their water surfaces.
Schneider and Hook found that for the lakes they studied, midsummer surface temperatures have, on average, warmed at the rate of 0.81°F per decade (0.45°C)—or slightly more than 2°F (1.1°C) during the 25-year study period.
Some lakes warmed at more than twice that rate. In general, lakes in northern regions—the United States, Canada, and Europe—warmed the most quickly.
(By the way, the headline on the source article, “Global Warming Burning Lakes?” ties for best of the week with Reason’s strikingly poetic “Lavatory of the Gods?”)