The politics of pollution

Stubble burning in northern India and Pakistan darkens the sky over the region every year in October. We cannot wait for next October to try to fix the problem — planning to resolve the problem should begin now. 

Farmers even in the Nepal Tarai have started burning wheat harvest residue because of the shortage of farm hands, and this April the haze combined with wildfire smoke made people sick, blocked off mountain views forced flight cancellations.

Apart from Kathmandu Valley’s vehicular emissions, transboundary smoke blown in by prevailing winds from India accounts for much of the pollution in the country.

“The westerly wind cannot cross over the high Himalaya, and remains trapped on the southern side in Nepal, Bangladesh and India,” explains R L Verma, a transboundary air pollution expert at the Asian Institute of Technology (AIT) in Bangkok. "The pollution cannot disperse and is especially bad during winter due to inversion where it mixes with the fog.” 

Prabhakar Shrestha, a research scientist at Bonn University, wrote in Nepali Times in 2021 that the long-term average of winter Aerosol Optical Depth (AOD) from December-February over the last 20 years in the region shows that winter haze extends throughout the Indo-Gangetic plains, with higher readings for eastern Bihar, West Bengal and Bangladesh, adjoining the Nepal Tarai.

"This alarming increase in winter AOD is due to an increase in crop-residue burning, rapid urbanisation, and industrialisation in the Indo-Gangetic belt," he stated.

There are now modelling studies that can trace emissions to their source which allow atmospheric scientists to pinpoint how much of certain particulate matter is coming from within Nepal, or from across the border. These models can also be used to predict future concentrations.

“Increasingly we now have more and more pollution data which has empowered people to demand,” added Verma, who was in Kathmandu recently to train researchers here on air quality monitoring, forecasting and developing an emissions inventory.

In the 1990s, air pollution levels in China were much worse than in India, but Beijing systematically improved AQI levels. A similar clean up campaign in northern India would have downwind benefits for Nepal as well.

The Malé Declaration on Control and Prevention of Air Pollution and Its Likely Transboundary Effects for South Asia, signed between Bangladesh, Bhutan, India, Iran, Maldives, Nepal, Pakistan and Sri Lanka in 1998 set a precedent for regional cooperation for transboundary problems.

For the last 25 years, the group has supported national governments in policy formulation and strengthening regional cooperation as well as establishing monitoring networks. But the fact that air pollution levels in the region have got much worse means that the Malé Declaration has failed to meet its lofty goals. 

There are now plans to revive regional cooperation in transboundary pollution control, but most policy changes have to be made and implemented within national and sub-national jurisdictions. For example, in October 2023 crop residue burning was much reduced in the Indian state of Haryana because of strict policy, but it increased in Punjab because of laxer controls (photo, above).

All this soot is blown up to the mountains, where it accelerates the melting of glaciers which are already shrinking due to global warming. The ‘black carbon’ particles are deposited on the ice and snow, making them melt faster. 

Black carbon is also a short-lived climate pollutant along with methane, hydrofluorocarbons and tropospheric ozone which are responsible for up to 45% of current global warming. 

They are expected to account for half the warming effect in the coming decades if emissions are not reduced, but because of their shorter shelf life, reducing them is a low-hanging fruit that also has public health benefits. 

Two factors affect air quality: emissions and seasonal weather. We cannot control weather, but can reduce emissions by switching to cleaner alternative fuels such as hydroelectricity, Compressed Natural Gas (CNG) and solar power. Similarly, farmers need incentives to adopt alternatives to open burning after harvests.

“Every scientific problem has a political solution. We need to involve the government in finding solutions,” says Verma. “Air pollution can be controlled, it just needs political will to work regionally.”