Till the 1970s the world’s industries were unaware of any hazard associated with burning sulfurous coal. It was only when the hole in the ozone layer started causing climatic problems that the release of aerosols from this process was finally acknowledged. It was due to the presence of these polluting aerosols in the atmosphere that the amount of sunlight reaching the planet’s surface was reduced. This was known as Solar Dimming.

As the world became more environmentally conscious and started to reduce the release of aerosols and other pollutants into the atmosphere the process of solar dimming gradually began to reverse itself. It was at its worst in the 1980s when the pollution was at its highest, but with decades of care and controlling air pollution, the atmosphere is finally beginning to clear out.

A study conducted by researchers at the University of Exeter have shown that solar dimming managed to enhance river flows over regions in the heavily industrialised northern extra-tropics of Europe. They estimated that in the most polluted central Europe river basin, this effect led to an increase in river flow of up to 25% 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, said Nicola Gedney, lead author of the scientific study.