Air pollution may lead to an increase in river flow, according to a recent study.
British researchers found that air pollution has had a significant impact on the amount of water flowing through many rivers in the northern hemisphere. They also show how such pollution, known as aerosols, can have an impact on the natural environment and highlight the importance of considering these factors in assessments of future climate change.
"We detect the impact of solar dimming on enhanced river flows over regions in the heavily industrialized northern extra-tropics," Nicola Gedney, lead author of the study, said in a statement. "We estimate that, in the most polluted central Europe river basin, this effect led to an increase in river flow of up to 25 percent when the aerosol levels were at their peak, around 1980. With water shortages likely to be one of the biggest impacts of climate change in the future, these findings are important in making projections for the future."
Researchers found that solar dimming increased river flows relative to that expected from surface meteorology, as the reduced amount of sunlight affected the rate of evaporation from Earth's surface. When the dimming began to reverse, reductions in river flows were observed.
"This study involved using detection and attribution techniques which were able to show a link between aerosols and changes in river flows," Chris Huntingford, one of the paper co-authors based at the Centre for Ecology and Hydrology, said in a statement. "These studies normally involve looking at how different factors affect temperature, but here we've been able to attribute this human-made influence to an environmental impact."
The study also tested for the effects of deforestation and carbon dioxide increases on river flow.
"In addition we find a further indication that increases in carbon dioxide may have increased river-flows by reducing water loss from plants," said co-author Peter Cox from the University of Exeter.
The findings were published in the journal Nature Geoscience.
