These notes were compiled for a project that was later abandoned for reasons unrelated to the project’s promise. I’m sharing here on the off chance that they might be useful to someone. I’m certainly not an expert in this subject, so the claims below should be independently verified before any significant actions are taken.
Outdoor air pollution in India
India has among the worst outdoor air pollution anywhere in the world. Approximately 99.9% of the Indian population reside in areas that regularly exceed the WHO air quality guideline of 10 micrograms (µg) of PM2.5 per cubic meter, and almost 90% of the population live in areas that regularly exceed 35 µg per cubic meter for PM2.5. Average exposure has increased from 60 µg per cubic meter for PM2.5 in 1990 to 74 µg per cubic meter in 2015. This exposure is linked “to many adverse health effects, including diminished lung function, acute and chronic respiratory symptoms (such as asthma and cough and wheeze), and increased risk of mortality from non-communicable diseases such as chronic obstructive pulmonary (lung) disease, heart disease, stroke, and lung cancer, and from lower-respiratory infections in children and adults” (GBD MAPS Working Group, 2018: 3). It’s estimated that in 2015 outdoor PM2.5 air pollution was responsible for ~29.6 million DALYs and ~1.09 million premature deaths (GBD MAPS Working Group, 2018: 1-3). By way of comparison, it’s estimated that in 2019 malaria was responsible for ~46.4 million DALYS and ~643,000 premature deaths (Institute for Health Metrics and Evaluation, 2020).
Stubble burning in north India is a major contributor to seasonal decreases in ambient air quality.
What is stubble burning?
Many farmers in northwest India use an intensive rice-wheat rotation system that generates large amounts of agricultural residue (“stubble”) (Abdurrahman, Chaki, & Saini 2020). For every ton of rice harvested, about 1.4 tons of stubble is left behind (Satpathy & Pradhan 2020). There are currently four primary methods to manage the residue: mulching by cutting and on-field distribution, baling and removal from the field, incorporation by tilling into the field, and on-field burning (Shyamsundar et al. 2019). Because it is rapid and inexpensive, on-field burning is by far the most popular method. Around October about 2.5 million farmers in northwest India burn stubble to prepare their fields for the subsequent wheat crop (Keil et al. 2020), which typically must be sown about two weeks after the rice harvest. These farmers collectively burn 90-140 billion kilograms of rice residue each year (Bisen & Rahangdale 2017).
What problems does it cause?
Stubble burning releases carbon dioxide, carbon monoxide, nitrogen oxides, sulfur oxides, and methane as well as particulate matters (PM10and PM2.5) (Abdurrahman, Chaki, & Saini 2020). These pollutants affect the immediate area and also drift southeast to Delhi, smothering the city of ~22 million in thick haze. At their peak, these fires are responsible for ~58% of Delhi air pollution (Beig et al. 2020). The consequences of this air pollution include skin and eye irritation, respiratory problems (dry cough, wheezing, breathlessness, chest discomfort, asthma), and hypertension (Rizwan, Nongkynrih, & Gupta 2013). Air pollution is estimated to be responsible for at least 48,000 premature deaths in Delhi alone in 2020 (Greenpeace, n.d.). Nationwide, the open burning of agricultural residue is estimated to be responsible for more than 66,000 premature deaths in India (GBD MAPS Working Group 2018).
How do we fix it?
There are many potential methods for reducing the prevalence of stubble burning in India:
Pay farmers directly not to burn: In 2019 the Indian Supreme Court ordered a handful of northern states to pay 2,400 rupees (~$33) per acre to farmers who didn’t burn their stubble. The program was popular but underfunded and quickly ran out of money (BBC 2020).
Subsidize mechanical tillage equipment: The tractor-mounted “happy seeder” can till rice stubble and sow wheat seed simultaneously. The government of Punjab has experimented with distributing these machines to farmers, but the program has been riddled with supply shortages and logistical problems. Many farmers cannot afford the upfront cost of a tractor or the ongoing diesel fuel costs required to operate the happy seeder. However, research suggests that these investments eventually pay for themselves (Shyamsundar et al. 2019, Keil et al. 2020).
Grow the market for baled stubble: The carbon-rich biomass of crop residue can be converted to clean energy via anaerobic digestion in biogas power plants (Satpathy & Pradhan 2020). A handful of biogas plants already exist in Punjab, and these plants pay good money for baled stubble. The upfront investment for a new 1 MW biogas plant runs between $600,000 to $1 million (Shyamsundar et al. 2019).
Research bio-decomposers: The Indian Agricultural Research Institute recently released a proprietary microbial solution that decomposes rice stubble in 15-25 days (Haq 2020). It’s unclear if the microbial solution acts quickly enough to be useful to farmers (who typically have less than two weeks to clear rice stubble), but if the speed of bio-decomposition can be slightly increased, it may present a cost-effective alternative to stubble burning. The decomposer is extremely cheap: approximately 20 rupees (~$0.27) per hectare of field (Bhatnagar 2020).
Encourage the cultivation of different crops or different rice cultivars: A key benefit of burning to farmers is how quickly it can eliminate stubble. Speed is important because the turnaround between rice harvest and wheat planting is so short (~two weeks). Increasing that window by planting shorter duration rice cultivars, such as Pusa Basmati-1509 and PR-126, may make alternatives to burning more palatable (Reddy 2020). More ambitiously, farmers could be incentivised to plant more fruit and vegetable crops and less rice paddy, as India has a surfeit of rice but a deficit of vegetable and fruit production, and rice paddy is not particularly well-suited to northwest India (BBC 2020).
Who is working on it?
Academics, civil servants, and environmental advocates are working to reduce the prevalence of stubble burning, making the area not particularly neglected. However, the COVID-19 pandemic is likely to devastate state and federal budgets in India, creating an opportunity for well-financed philanthropists to fill crucial funding gaps. Here are the known groups working on the issue in some capacity (not exhaustive):
University of Minnesota
Indian National Centers
Indian Agricultural Research Institute
National Agricultural Science Centre
Indian Institute of Tropical Meteorology
National Atmospheric Research Laboratory
Central Pollution Control Board
Energy Harvest Trust
Centre for Science and Environment
The Energy and Resources Institute
International Maize and Wheat Improvement Center
Health Effects Institute
What are the key uncertainties?
- What is the counterfactual? Would the Indian government solve this problem without outside resources? How much (if at all) can outside resources accelerate the solution to this problem?
- Is there room for nonprofits to effectively intervene? It seems like many of the interventions probably require heavy government involvement, so there may not be many opportunities for nonprofits to contribute.
- Would campaigning on this issue generate a backlash from Indian farmers? Agricultural reforms are a sensitive topic in India (see current ongoing farmers protest), so we would probably want to ensure that farmers stand to gain from whatever intervention we recommend.
What are the next steps?
Determine the cost-effectiveness of different approaches
- First, we need to more thoroughly quantify the harms of the pollution. What is the DALY burden per acre burned?
- Second, we need to estimate the costs and consequences of various interventions. How much does it cost to administer and enforce a program that pays farmers not to burn? What level of subsidization would be required to ensure adoption of the happy seeder? What incentives would motivate farmers to plant different crops?
- Finally, we need to combine (a) and (b) to generate plausible models of the cost-effectiveness of different (combinations of) interventions in different scenarios.
Find willing partners
- If it is determined that this area is competitive with other neartermist interventions, we need to figure out the logistics of a potential intervention.
- We’ll want to make contact with academics, civil servants, and NGOs working on this issue.
- If the most cost-effective intervention requires a new charity, we will need to assess the difficulty of finding talent to staff the organization.
Abdurrahman, M. I., Chaki, S., & Saini, G. (2020). Stubble burning: Effects on health & environment, regulations and management practices. Environmental Advances, 2, 100011. https://doi.org/10.1016/j.envadv.2020.100011
Beig, G., Sahu, S. K., Singh, V., Tikle, S., Sobhana, S. B., Gargeva, P., Ramakrishna, K., Rathod, A., & Murthy, B. S. (2020). Objective evaluation of stubble emission of North India and quantifying its impact on air quality of Delhi. Science of The Total Environment, 709, 136126. https://doi.org/10.1016/j.scitotenv.2019.136126
Bisen, N., & Rahangdale, C. P. (2017). Crop residues management option for sustainable soil health in rice-wheat system: A review. International Journal of Chemical Studies 2321–4902, 5, 1038–1042.
Clean Air Counter. (n.d.). Greenpeace International. Retrieved December 5, 2020, from https://www.greenpeace.org/international/campaign/tracking-cost-air-pollution
GBD MAPS Working Group. (2018). Burden of Disease Attributable to Major Air Pollution Sources in India. Special Report 21. Health Effects Institute https://www.healtheffects.org/system/files/GBD-MAPS-SpecRep21-India-revised_0.pdf
Keil, A., Krishnapriya, P. P., Mitra, A., Jat, M. L., Sidhu, H. S., Krishna, V. V., & Shyamsundar, P. (2020). Changing agricultural stubble burning practices in the Indo-Gangetic plains: Is the Happy Seeder a profitable alternative? International Journal of Agricultural Sustainability, 0(0), 1–24. https://doi.org/10.1080/14735903.2020.1834277
Reddy, A. A. (2020, October 11). How Can We Solve the Problem of Stubble Burning? The Wire Science. https://science.thewire.in/environment/stubble-burning-punjab-haryana-rice-harvesting-wheat-sowing-delhi-air-pollution/
Rizwan, S. A., Nongkynrih, B., & Gupta, S. K. (2013). Air pollution in Delhi: Its Magnitude and Effects on Health. Indian Journal of Community Medicine, 38(1), 4. https://doi.org/10.4103/0970-0218.106617
Satpathy, P., & Pradhan, C. (2020). Biogas as an alternative to stubble burning in India. Biomass Conversion and Biorefinery. https://doi.org/10.1007/s13399-020-01131-z
Shyamsundar, P., Springer, N. P., Tallis, H., Polasky, S., Jat, M. L., Sidhu, H. S., Krishnapriya, P. P., Skiba, N., Ginn, W., Ahuja, V., Cummins, J., Datta, I., Dholakia, H. H., Dixon, J., Gerard, B., Gupta, R., Hellmann, J., Jadhav, A., Jat, H. S., … Somanathan, R. (2019). Fields on fire: Alternatives to crop residue burning in India. Science, 365(6453), 536–538. https://doi.org/10.1126/science.aaw4085
Stubble burning: Why it continues to smother north India. (2020, November 30). BBC News. https://www.bbc.com/news/world-asia-india-54930380
Why a new decomposer may hold hope of dousing farm stubble fires. (2020, December 5). Hindustan Times. https://www.hindustantimes.com/india-news/why-a-new-decomposer-may-hold-hope-of-dousing-farm-stubble-fires/story-3Y3ujv4gkmLuXl2GUS7CwI.html
With Pusa Decomposer, IARI Hopes to Offer Organic Solution To Stubble Burning Problem. (2020, October 7). The Wire. https://thewire.in/agriculture/pusa-decomposer-iari-stubble-burning
PM2.5 refers to particulate matter less than 2.5 micrometers in diameter. Whilst larger particles are generally filtered by the nose and throat, particulate matter less than 10 micrometers in diameter (PM10) can settle in the lungs and cause severe health problems. PM2.5 is particularly dangerous because particles that fine can penetrate into the deep parts of your lungs (the alveolus). ↩︎
GBD MAPS = Global Burden of Disease from Major Air Pollution Sources. GBD MAPS is “a multiyear collaboration between the Health Effects Institute (HEI), the Institute for Health Metrics and Evaluation, the India Institute of Technology (IIT)–Bombay, Tsinghua University, the University of British Columbia, Sri Ramachandra Medical College and Research Institute, and other leading academic centers” (GBD MAPS Working Group, 2018: 4). ↩︎
Presumably, ambient air pollution also negatively affects nonhuman animals living in the region. ↩︎
Stubble burning is a major contributor, but far from the top contributor. Windblown mineral dust is the largest contributor to ambient PM2.5 exposure and PM2.5 related mortality in India, responsible for an estimated 313,000 premature deaths in 2015 (GBD MAPS Working Group, 2018: 44). Although windblown mineral dust is typically considered a non-anthropogenic source, poor agricultural and forestry management, coupled with the ongoing effects of global climate change, has increased the sort of desertification that exacerbates windblown mineral dust. Of anthropogenic sources, residential biomass burning (cooking, lighting, heating) is the largest contributor to ambient PM2.5 exposure and PM2.5 related mortality, responsible for roughly a quarter of total Indian PM2.5 related mortality in 2015 (approximately 268,000 premature deaths). The same year, coal combustion was responsible for approximately 169,000 premature deaths and the burning of agricultural stubble was responsible for approximately 66,000 premature deaths (GBD MAPS Working Group, 2018: 71). Somewhat surprisingly, air pollution from transportation is not a major contributor to PM2.5 mortality, with only ~23,000 attributable premature deaths in 2015 (GBD MAPS Working Group, 2018: 7). Other sources of outdoor air pollution include brick production, industrial dust, agricultural tractors, diesel water pumps, and diesel generators (GBD MAPS Working Group, 2018: 6). ↩︎
To be clear, stubble burning is responsible for only a fraction of the air pollution deaths in Delhi. There are many other sources of air pollution in Delhi. ↩︎
There are environmental consequences as well. Stubble burning contributes to climate change and soil degradation. ↩︎
India has enshrined the right to live in a healthy environment in its federal constitution, giving the Supreme Court wide latitude to protect that right via regulatory action. ↩︎