Late last year, flights were diverted from Delhi, thousands of schools were closed and people in the Indian capital were advised to stay indoors or wear masks.
You might assume that these precautions were related to some kind of viral outbreak. But, in fact, they were a response to a spike in air pollution, which imperiled residents and decreased visibility so dramatically that airline travel became hazardous.
Now, India is gearing up for another surge in toxic air. In autumn, farmers across the northern part of the country will burn their fields to make way for a new crop. During the blazes, air pollution in Delhi can be 14 times greater than what the World Health Organization considers safe, with much of the country blanketed in a haze so thick, it can be seen from space.
The case of India is striking – but it is not unique. Around the world, large areas of agricultural lands are set ablaze every year, contributing to the air pollution that is killing millions.
“Improving the quality of the air we breathe is absolutely necessary for our health and well-being,” says Helena Molin Valdés, Head of the UN Environment Programme-hosted Climate and Clean Air Coalition Secretariat. “It is also critical to food security, climate action, responsible production and consumption – and fundamental to equality. In fact, we can’t talk about the 2030 Agenda for Sustainable Development unless we are serious about air quality."
Black carbon
Many farmers consider agricultural burning the most effective and cost-efficient way to clear land, fertilize the soil and prepare it for new plantation. However, these fires and the wildfires that spread from them are the world’s largest source of black carbon, a threat both to human and environmental health.
Black carbon is a component of PM2.5, a microscopic pollutant that penetrates deep into the lungs and bloodstream. PM2.5 increases the risk of dying from heart and lung disease, stroke and some cancers, causing an estimated 7 million people to perish prematurely every year. In children, PM2.5 can also cause psychological and behavioural problems; in older people, it is associated with Alzheimer’s, Parkinson’s disease and dementia. And because air pollution compromises respiratory health, it may also increase vulnerability to COVID-19.
Black carbon is also a short-lived climate pollutant, meaning that, although it exists only for a few days or weeks, its impact on global warming is 460 –1,500 times stronger than carbon dioxide.
These fires and the wildfires that spread from them are the world’s largest source of black carbon, a threat both to human and environmental health.
A better way
Ironically, far from stimulating growth, agricultural burning actually reduces water retention and soil fertility by 25 to 30 per cent, and thus requires farmers to invest in expensive fertilizers and irrigation systems to compensate. Black carbon can also modify rainfall patterns, especially the Asian monsoon, disrupting the weather events necessary to support agriculture.
“Burned lands actually have lower fertility and higher erosion rates, requiring farmers to overcompensate with fertilizer,” says Pam Pearson, Director of the International Cryosphere Climate Initiative, which has worked with farmers globally to introduce fire-free cultivation.
“The no-burn alternatives, such as incorporating stubble back into fields or even planting right through the stubble, almost always save the farmer money.”
Pearson notes that changing the long-established habit of burning agricultural waste will require education, awareness-raising and capacity-building for farmers. It is a lofty undertaking, but the impacts would be considerable and far-reaching. Reducing air pollution from farms in Northern India, for example, could prevent increased flooding and drought caused by soot (black carbon) accelerating the melting of Himalayan ice and glaciers – a life-changing outcome to the billions who depend on rivers fed by those mountains.
Worldwide effort
The Climate and Clean Air Coalition works in countries and with regional networks to promote alternatives to field-burning. In India, for example, it provides farmers with information and assistance to access alternatives to field-burning, using satellites to monitor fires and track their impact, supporting policy interventions, subsidizing farmers and ultimately turning agricultural waste into a resource.
The efforts of countries to reduce their own air pollution are part of a cohesive, global push to improve air quality. This year on 7 September, for the first time ever, the world will join together in celebrating the International Day of Clean Air for blue skies, designated by the UN General Assembly in recognition of air quality as an urgent priority. It is a call to work together to change the way we live – reducing the amount of air pollution we produce – until every person in every part of the world breathes clean air.
For more information about agriculture and black carbon, contact Tiy Chung: tiy.chung@un.org
