June 27, 2015
Breathing in Beijing could be like passive smoking without the short-lived pleasure of a tobacco-high. Writing in The Guardian in December 2014, Oliver Wainwright described an atmosphere akin to one in the aftermath of a nuclear explosion – instead of radioactive particles and clouds of ash, China’s capital city was enveloped in a dense suspension of smoke and dust that refused to blow away. The US Embassy in the city has an air-quality monitor that automatically tweets its readings, and for more than two years now, it has been pinging “Unhealthy”. In January 2013, it briefly went off the charts. During the Beijing marathon last year, many dropped out so they wouldn’t have to pant in the smog.
In fact, it was a sports-related concern back in 2006 that prompted officials to act. Chinese and American scientists were trying to understand how a worsening atmosphere could affect performance in the Beijing Summer Olympics, which was two years away.
They found that fine particulate emissions from the nearby Hebei and Shandong Provinces and the Tianjin Municipality contributed 50-70% of Beijing’s overhang. To improve the air quality, this meant officials couldn’t focus simply on emissions within the city but within the region as a whole, considering the winds carrying the most pollutants flow into Beijing from the south and the southeast. However, the same administration that has committed to reduce coal-burning in and around the city by 2.6 million tonnes by 2017 will be disappointed to find out that a more immovable hurdle now stands in their way.
NASA scientists used data from a space-borne radar to study how Beijing has grown, and how that has affected the patterns of winds blowing in the region. While the city has been expanding in all directions, large-scale constructions are still about to begin in some areas while in others, towering buildings are already silhouetted against the skyline. The lead scientist, Mark Jacobson from Stanford University, developed a technique to see how the wind blows around these areas.
He found that Beijing has acquired an outcrop of buildings that are trapping the air within the city, caging it and preventing it from escaping as easily as it would have if the buildings hadn’t been there. Jacobson stated, “Buildings slow down winds just by blocking the air, and also by creating friction.” And because more buildings cover up more of the soil beneath them, there’s less water evaporating than before, heating up the ground. The result is that there are now parts of Beijing where the air is cooking its own dirt, within a dome circumscribed by retarded winds.
The scientists write in their paper: “The astounding urbanisation … created a ring of impact that decreased surface albedo, increased ground and near-surface air temperatures … and decreased the near-surface relative humidity and wind speed.” The paper was published in the Journal of Geophysical Research on June 19. According to them, even if a city didn’t allow any sources of pollution to operate within its limits, “not even a single gas-powered car”, large structures and winds would result in similar impacts on the atmosphere – leave alone what’s happening in New Delhi.
It’s worse in India
A WHO survey in 2014 found that 13 of the 20 cities with the worst air on the planet were in India. The Economist used data from the survey to estimate that every year 1.6 million Indians lost their lives thanks to the plummeting air quality. The problem was, and is, the worst in the national capital, whose PM2.5 measure stands at 153. To compare, Beijing’s has been hovering between 100-135 in the last few days. PM2.5 refers to solid and liquid particulate matter that’s smaller than 2.5 microns. They are able to sink deep into the lungs and cause lung and heart diseases that can be fatal, so their levels are used by the WHO as indicators of air quality.
To the southwest of Delhi are two other very-polluted cities: Lucknow (PM2.5 100) and Gwalior (PM2.5 144), while further down in that direction is Patna (PM2.5 149). All four cities have been rapidly urbanizing, often at a rate that the region’s electricity generation and distribution system hasn’t been able to keep up with. Many have been able to afford diesel generators for auxiliary power for their homes during power-cuts, and the fumes from those generators have also been contributing to lowering air quality, while their ozone emissions are among the leading reasons why rice- and wheat-crop yields have been falling, too. However, like with Beijing, the cities are also part of a more ‘regional’ assault.
Over 40% of Indonesia’s greenhouse gas emissions are due to peat smoke. Peat is a form of partially decomposed vegetable matter, and the archipelago is home to swaths of peatland that are burnt every year to clear space for the profitable oil palms that fuel a $50 billion industry in the country. As Mike Ives reported in January 2015, the resultant smoke contains large amounts of PM2.5 that’re blown into the mainland, carried into currents that then blow across southeast Asia.
Similarly and closer home, crop-burning is widespread in Punjab, Haryana and Uttar Pradesh despite the fact that the activity is prohibited by law in these states. They border New Delhi to the north south and east. The crop-burning came to light recently when images taken by the NASA Aqua satellite were released, in November 2013. They showed a large cloud of smoke floating over western Uttar Pradesh, “obscuring the satellite’s view of cities such as … Lucknow and Kanpur”. The petitioner who took the matter to the National Green Tribunal, Vikrant Tongad, later alleged that had the cloud not wafted over to Delhi to afflict the people of the city, the government wouldn’t have bothered to check on crop-burnings in the three states. In rural areas, the issue is compounded by the widespread use of fuelwood for cooking and heating.
While Beijing may have a better grip on air pollution control than New Delhi does, its problems are indicative of the world’s growing centres of urbanization. As much as civil engineers and planners try to accommodate gardens and lakes into their ideas of the environmentally perfect city, the winds of change will continue to blow in just as strongly from the farms of Punjab, the power plants of Shandong and the peatlands of Indonesia. The problem speaks to the greater challenge of being environmentally conscious about all the developmental projects we undertake instead of thinking about emissions only in terms of the cars in our cities.