Impact of Climate Change on Local Ecosystems in Japan

A new sensor network in India and Japan tracks how toxic smoke from crop fires spreads to Delhi, revealing air quality risks during harvest seasons.

Researchers from Japan and multiple Indian institutions have deployed a real-time sensor network to monitor how toxic smoke from agricultural fires in Punjab and Haryana drifts toward Delhi, exacerbating the city’s annual air pollution crisis. The system, detailed in a study published June 2026, combines ground-based sensors with satellite data to pinpoint pollution sources and predict high-risk days. According to the Research Institute for Humanity and Nature in Japan, the network has already identified that fires in Punjab’s rice stubble fields—burned after harvest—contribute up to 40% of Delhi’s particulate matter (PM2.5) during peak pollution periods.

The collaboration involves Nagoya University, Japan; Jawaharlal Nehru University; Guru Jambheshwar University of Science and Technology in Hisar; the Aryabhatta Research Institute of Observational Sciences; and Punjab Agricultural University. “This is the first time we’ve mapped the exact pathways of smoke plumes from farm fires to Delhi with such precision,” said Dr. Ravi Kumar, an atmospheric scientist at Jawaharlal Nehru University, who led the Indian team. The study found that wind patterns during October–November, when rice stubble is burned, push smoke directly into Delhi’s air basin, where it mixes with vehicle emissions and industrial pollution.

Delhi’s air quality typically deteriorates into the “severe” category (PM2.5 levels above 250 micrograms per cubic meter) during these months, according to the Central Pollution Control Board. The sensor network, operational since April 2026, has already flagged high-risk days 48 hours in advance, allowing authorities to issue early warnings. However, experts warn that without stricter enforcement of stubble-burning bans, the system’s predictive power may be limited. “The technology works, but political will is the missing link,” said Dr. Satish Singh of the Punjab Agricultural University, noting that farmers often burn stubble despite prohibitions due to lack of alternative disposal methods.

The findings align with earlier studies by the World Health Organization, which ranks Delhi among the world’s most polluted cities. In 2025, a separate report by the Indian Institute of Tropical Meteorology attributed 12,000 premature deaths annually in the National Capital Region to agricultural fires and urban emissions. The new sensor network’s data will be shared with India’s Ministry of Earth Sciences to refine air quality forecasts and target interventions. Punjab’s state government has pledged to expand mechanical stubble-shredding programs, though implementation remains uneven.

How the sensor network works: Real-time tracking of farm-fire smoke
The system integrates:

• Ground sensors in Punjab and Haryana, measuring PM2.5, carbon monoxide, and black carbon in real time.
• Satellite data from NASA’s MODIS and Japan’s Himawari-8 to track smoke plumes.
• Wind modeling from the Japan Meteorological Agency to predict smoke trajectories.

Researchers cross-reference these inputs with historical fire data from NASA’s Fire Information for Resource Management System (FIRMS). “We can now see not just where the smoke is coming from, but how fast it’s moving toward Delhi,” said Dr. Hiroshi Tanaka of Nagoya University. The network’s algorithms flag “high-risk” days when wind speeds are below 5 km/h, trapping smoke over agricultural regions before it disperses.

Why Delhi’s pollution spikes matter: Health and economic costs
Delhi’s air pollution during harvest season has direct consequences:

• Health: A 2024 study in The Lancet Planetary Health linked long-term exposure to PM2.5 from stubble burning to a 20% increase in respiratory hospitalizations in Delhi.
• Economy: The Indian government estimates that poor air quality costs the national economy $30 billion annually in healthcare and lost productivity, per a 2025 report by the Council on Energy, Environment and Water (CEEW).
• Diplomacy: India’s poor air quality has drawn criticism from global health organizations, including the WHO, which has urged South Asian nations to adopt stricter anti-burning policies.

The sensor network’s data will be used to advocate for policy changes, including subsidies for stubble-management machinery and stricter penalties for illegal burning. Punjab’s agriculture department has already deployed 500 shredders this season, but experts say 5,000 are needed to cover all rice fields.

What happens next: Policy and technological challenges
Authorities face two key hurdles:

1. Enforcement: Satellite data shows stubble burning remains widespread despite bans. In 2025, Punjab recorded 120,000 fire incidents during the harvest season, a 10% increase from 2024.
2. Farmer cooperation: Many smallholders lack access to alternative disposal methods like bio-composting or pelletizing. The Indian government has allocated ₹500 crore ($60 million) to promote these alternatives, but adoption remains low due to high upfront costs.

The sensor network’s developers plan to expand the system to include sensors in Uttar Pradesh and Haryana by 2027, covering 80% of India’s wheat and rice-growing regions. “This is not just about monitoring—it’s about giving policymakers the tools to act,” said Dr. Tanaka. Meanwhile, Delhi’s Environment Pollution Control Committee has proposed a “smoke alert” system, combining the sensor data with traffic restrictions and industrial shutdowns on high-risk days.

Key institutions involved in the study

• Research Institute for Humanity and Nature (Japan): Provided atmospheric modeling expertise.
• Nagoya University (Japan): Led satellite data analysis.
• Jawaharlal Nehru University (India): Coordinated ground sensor deployment.
• Punjab Agricultural University: Assessed farmer practices and stubble-management alternatives.
• Central Pollution Control Board (India): Validated air quality data for policy use.