Stream Temperatures Warming Slower Than Previously Thought

Stream temperatures in the western U.S. are not warming as quickly as scientists expected, according to a new study in Geophysical Research Letters. The authors used long-term stream temperature data from sites that were minimally and highly impacted by humans to determine the amount of warming in maximum, average, and minimum temperatures. They found that since the 1950s, warming trends were only prevalent in a small number of locations, while observations since 1987 exhibited more cooling trends. Science Daily reports that these results do not parallel atmospheric warming trends, possibly due to factors such as snowmelt, groundwater interaction, wind, humidity, and solar radiation.