One of the largely unanticipated impacts of a changing climate may be a decline in sunlight's ability to disinfect lakes, rivers, and coastal waters, possibly leading to an increase in waterborne pathogens and the diseases they can cause in humans and wildlife.
One of the largely unanticipated impacts of a changing climate may be a decline in sunlight's ability to disinfect lakes, rivers, and coastal waters, possibly leading to an increase in waterborne pathogens and the diseases they can cause in humans and wildlife.
A new study published in the journal Scientific Reports outlines how a rise in the amount of organic matter washed into bodies of water can stunt the ability of pathogen-killing ultraviolet rays from the Sun to penetrate the water's surface.
Scientists have already measured an increase in "browning" of the world's waters, a phenomenon caused by more organic matter washing in from the surrounding land. This trend is expected to continue as a warming climate leads to more extreme rainfall and thawing permafrost, both of which contribute to the problem.
In the new study, led by Miami University in Ohio, researchers analyzed water samples and used a model based at the National Center for Atmospheric Research (NCAR) to quantify, for the first time, the impact of dissolved organic matter on the potential for UV radiation from the Sun to kill pathogens in the water.
Continue reading at National Center for Atmospheric Research (NCAR)
Photo: The pristine waters of Lake Tahoe's Sand Harbor contrast with the brown water in the lake's Star Harbor, where people and boats are active. Dissolved organic matter from human activity and from heavy rains can cloud the water and reduce solar disinfection. (Photo courtesy Andrew Tucker.)
