Pollution from Europe caused a drought in India that was one of its worst ever natural disasters, affecting more than 13 crore people, according to new research.

Sulphur dioxide -produced mainly by coal-fired power plants causes a number of harmful effects, like acid rain, heart and lung diseases, and damage to plant growth. But sulphate aerosols also have a cooling effect on the atmosphere because it reflects sunlight back into space. However, emissions from the northern hemisphere can change the relative rate of warming in the south, causing the tropical rain-band to shift -with potentially devastating results.

Now researchers at Imperial College London have calcula ted just how big an effect emissions of sulphur dioxide had on rainfall in India in 2000.

The north-west of India experienced a staggering drop of about 40% because of emissions from the northern hemisphere's main industrial areas. Europe's emissions alone caused reductions of up to 10% in the north-west and southwest regions. One of the researchers, Apostolos Voulgarakis, of ICL's Grantham Institute, said the study showed how emissions in one part of the world could have a significant effect on another -even if the pollution itself didn't actually get there. "East Asia is contributing more because [of an ef fect] because it's closer, but there is an effect from Europe and also the US," he said.

The figures were produced suing a climate model.
A briefing note prepared by Grantham researchers about the techniques to assess air pollutants said they could have "complex and diverse" effects.Sulphate aerosols could "cool the atmosphere and so off-set some global warming" but "also increase air pollution levels and cause drought".

Despite a fall in European sulphur dioxide emissions by around 74% between 1990 and 2011, India's droughts have continued as the world has got warmer.

Source: April 22, 2017, The Times of India