Record-breaking sea surface temperatures repeatedly made headlines this summer, but NBC News covered a new study that identified additional water warming trends.
What’s happening?
Rivers in America are “running hot,” the outlet began.
That’s according to a new analysis published in a peer-reviewed journal, the Proceedings of the National Academy of Sciences (PNAS).
Researchers assessed more than 1,500 American rivers in what NBC described as the “first in-depth study of riverine heat waves.”
Riverine heat waves are defined as a period of five days or more during which water temperatures exceed a “local, seasonally varying 90th percentile threshold,” according to research published in 2022.
Penn State University environmental engineering professor Li Li co-authored the study and explained why the findings were an unpleasant surprise.
“The trend of river heat waves is actually increasing faster than the air heat waves. So, that’s one thing that is very surprising,” Li said. In the analysis, authors observed that riverine heat waves occurred more frequently than “air heat waves in 65 to 76% of the sites” examined.
Why is this analysis concerning?
The analysis identified several worrisome aspects in the findings.
Heatwaves tend to make headlines, but “riverine heat waves have gone quietly unnoticed because rivers are commonly perceived as cool refuges,” the abstract reads, pointing to factors researchers could otherwise overlook.
Rising river water temperatures and prolonged periods of abnormally high heat pose a threat to the delicate balance of aquatic ecosystems. Riverine heat waves account for “about 12 more days of heat stress, on average, for species that need cold water,” Li said.
How often do you worry about the quality of your drinking water?
Click your choice to see results and speak your mind.
The authors identified the culprit behind warmer rivers: an overheating planet. Riverine heat waves are “driven predominantly by climate-induced changes such as warming and dwindling snowpacks and water flow,” the analysis explained.
“Human-induced structural changes,” like dam building, were cited as secondary factors.
UC Davis Center for Watershed Sciences research scientist Jonathan Walter didn’t participate in the analysis, but he told NBC News that the research could facilitate changes to water management as a potential adaptation strategy.
“The way that we use water, the way we manage those resources can have an impact on heat waves,” Walter stated.
What can be done about rising river water temperatures?
Although the findings were characterized as relatively novel, that doesn’t mean solutions exist in the far-flung future.
Awareness of key climate issues is a critical individual step to mitigating the effects of rising temperatures, warmer seas, and hotter rivers, as Li emphasized.
The author said water quantity is easier to observe and thus easier to consider than its quality.
“We’re hoping this kind of study will increase the public awareness of the water quality issue related to climate change,” Li told NBC.
Join our free newsletter for good news and useful tips, and don’t miss this cool list of easy ways to help yourself while helping the planet.
