Does Pollution Affect the Weather?

The pollution caused by Asian slums could be contributing to unpredictable weather events, according to a new collaborative study from research institutions across the globe. It’s thought that the contamination produced by the wood stoves used in slum living quarters in megacities on the eastern coast of India could inhibit rainfall but increase wind strengths in the surrounding area.

The findings were published in the International Journal of Environment and Pollution and were a team venture between VIT University in India, the University of Leeds and Cranfield University in the UK, Penn State College in the USA and the Universitaire de Beaulieu in France. They underline that while tropical storms may exacerbate pollution prevention, the relationship between the two entities is a cyclical one.

A contaminating chemical reaction

The team behind the study used as their starting point the fact that there already exists a significant body of evidence to suggest that emissions could contribute to how cyclonic storms develop and move. Indeed, just this year a separate study from the south of Australia and Germany found a direct link between coal-fired power stations and extreme rainfall events, with weather affected as far away as 1,000km from the initial source of emissions.

For this particular study, the researchers focused on the megacities which dot the eastern coast of India. In these vast metropoles live millions of impoverished Indian citizens who reside in slum conditions. To feed themselves, they are forced to use polluting forms of fuel to cook their meals, such as unseasoned wood stoves. The emissions generated by these appliances then gather over the cities, posing a threat to human health but also affecting weather patterns, as well.

Specifically, it’s the airborne biomass particles which are contained within the emissions that undergo a chemical aging process in the atmosphere, which converts them into cloud condensation nuclei. They are then less likely to fall back to Earth in the form of rain, but can encourage stronger wind speeds, resulting in dryer but more violent cyclones down the coast of India and in neighbouring regions.

A whirlwind case study

One prominent example which lent weight to the researchers’ findings is Hurricane Thane, which ravaged the coast of Tamil Nadu eight years ago. On the 30^th December 2011, the extreme weather event decimated the Indian shoreline, causing severe problems for those living there and the surrounding infrastructure.

The team behind the most recent study believe that the storm was exacerbated by such transient emissions as those emanating from the slums nearby. According to their calculations, the pollution affected the cloud’s ability to convert stored water into rain by as much as 12%, with around a fifth more water being retained in the atmosphere as a result.

Given that the region suffers from a scarcity of water on a regular basis, the findings are troubling ones and point to the urgent need for polluting stoves such as those used in the slums to be phased out. Indeed, it’s just one more reason why slum living is a concerning phenomenon not just for those poor unfortunates who find themselves in that environment, but others as well.