Delhi recorded only three days with an Air Quality Index (AQI) above 200 between September 15 and October 23 this year. During the same period in 2025, the number was 10. Its average AQI also fell from 169.3 to 142.6, a 15.8 per cent improvement.

But there is another number in the data. Delhi’s median AQI rose from 135 to 154 during the same period. This means that although the city experienced fewer days of severe pollution, the air quality on a typical day was worse than the previous year.

The difference matters when assessing the health effects of air pollution. People are exposed to the air they breathe every day, not just during episodes when pollution reaches severe levels. Prolonged exposure is associated with respiratory and cardiovascular diseases, while polluted air can also affect children’s lung development.

A new assessment by Climate Trends, covering Delhi’s air quality, crop-residue burning in Punjab and Haryana, and meteorological conditions between 2024 and 2026, examines this gap between seasonal averages and everyday exposure.

What the AQI Average Leaves Out

The mean AQI is calculated using daily readings across a given period. A few exceptionally polluted days can push this average upwards. The median, on the other hand, is the middle reading when all daily values are arranged in order. It offers a better indication of what a typical day looks like.

Climate Trends’ analysis found that Delhi’s mean AQI declined by 15.8 per cent between 2025 and 2026. However, the median increased by 14.1 per cent. The maximum AQI also came down from 353 to 245, while the number of days above 200 dropped from 10 to three.

The improvement in the mean, therefore, was largely associated with the reduction in extreme pollution days. It did not indicate an improvement in the typical daily reading.

Aarti Khosla, Director of Climate Trends, draws attention to this difference.

“The average AQI fell 15.8% this autumn, and that is the number that will get reported as improvement. But the typical day, the one most Delhiites actually live through, got worse, up 14.1%.”

She argues that air quality policies should be evaluated using the pollution levels people experience regularly, rather than seasonal averages alone.

Farm Fires and Delhi’s Pollution: Numbers Don’t Move Together

Every October, crop-residue burning in Punjab and Haryana becomes a major focus of Delhi’s air pollution debate. Smoke from these fires can travel towards the capital, contributing to particulate pollution. However, the extent of its impact depends on weather conditions and the movement of air.

The three-year assessment found that the relationship between farm fires and Delhi’s AQI varied considerably across the study period. Between September 15 and October 15, 2025, satellite observations recorded 201 crop-residue fire events in Punjab and Haryana. In 2026, the number was 193, a decline of just four per cent. Delhi’s mean AQI, meanwhile, fell by 15.8 per cent.

The statistical correlation between daily fire counts and Delhi’s AQI also weakened. The same-day correlation coefficient fell from 0.62 in 2025 to 0.17 in 2026. The previous year’s figures show a different pattern. Between 2024 and 2025, combined fire events declined by 88 per cent, but Delhi’s mean AQI fell by only 3.9 per cent.

These comparisons do not establish that agricultural burning has no effect on Delhi’s air. They show that the number of fires alone cannot explain the city’s year-to-year AQI changes.

Dr Palak Balyan, Research Lead at Climate Trends, explains that the movement of smoke depends on atmospheric conditions.

“Wind direction, wind speed, rainfall and atmospheric mixing determine whether smoke is transported towards Delhi, dispersed or removed from the atmosphere.”

The study also identifies traffic, industrial emissions, road and construction dust, and other regional combustion sources as contributors to Delhi’s pollution. However, it does not quantify how much each source contributed to the AQI changes recorded in 2026.

El Niño: Game Changer

The assessment also considers whether the strengthening El Niño conditions in 2026 could explain the changes in pollution and agricultural burning. El Niño refers to the periodic warming of sea-surface temperatures in the central and eastern equatorial Pacific Ocean. It influences large-scale atmospheric circulation and can affect rainfall and temperature patterns in different regions.

According to the NOAA Climate Prediction Center assessment cited in the report, the Niño-3.4 sea-surface temperature anomaly reached approximately +2.1°C by October 2026. NOAA also projected an 83 per cent or higher probability of strong-to-very-strong El Niño conditions continuing through January–March 2027.

Despite these conditions, the combined number of farm-fire events in Punjab and Haryana did not increase. Delhi’s mean AQI also declined.

The local meteorological data present a more complicated picture. Delhi’s accumulated rainfall between September 15 and October 23 fell from 46.70 mm in 2025 to 10.19 mm in 2026, a decline of 78.2 per cent. Its mean planetary boundary layer height (PBLH), which indicates the depth of the lower atmospheric layer where pollutants are mixed, decreased by 4.3 per cent.

Lower rainfall reduces the removal of airborne particles through precipitation. A lower boundary layer can also limit the vertical space available for pollutants to disperse.

Mean wind speed increased by 2.1 per cent, from 2.40 to 2.45 metres per second. Stronger winds can help disperse pollutants, but their effect depends on direction and the areas from which the air is moving.

Dr Sagnik Dey, Head and Vipula and Mahesh Chaturvedi Chair Professor in Policy Studies at the Centre for Atmospheric Sciences, IIT Delhi, cautions against using El Niño as a direct indicator of air pollution.

“El Niño should not be viewed as a direct predictor of air pollution. Its influence on regional air quality depends on how large-scale climate variability interacts with local rainfall, temperature, wind patterns and atmospheric stability.”

The assessment does not establish that El Niño caused the observed changes in Delhi’s AQI. It also cannot isolate the contribution of individual weather conditions or pollution sources to the decline in the city’s average reading.

Health Cost of an Ordinary Day

The distinction between average and median AQI has implications beyond how Delhi’s annual pollution figures are reported.

Dr Harshal Ramesh Salve, Professor at the All India Institute of Medical Sciences (AIIMS), Delhi, points out that the health burden of pollution develops through prolonged exposure, rather than only during a handful of severe pollution episodes.

He identifies impaired lung development in children and increased lifetime cardiovascular risks among adults as concerns associated with sustained exposure. He also recommends early screening for high-risk adults and treating clean air as a year-round public health priority.

The 2026 assessment does not show that Delhi has solved its pollution problem. Its findings show that a decline in the number of severe days can improve the seasonal average without improving the air quality people experience on most days.

The study points to a need to examine Delhi’s pollution beyond the seasonal AQI average. With the median AQI rising despite fewer severe pollution days, the improvement recorded in 2026 does not reflect cleaner everyday air. The contribution of traffic, industrial activity, construction dust and other local sources needs closer assessment, particularly since the study could not isolate their individual impact. Without that understanding, the reasons behind Delhi’s changing air quality will remain only partially explained.

Global efforts to restore degraded ecosystems have reached 252 million hectares across 149 countries, generating more than one million green jobs. However, a new United Nations assessment warns that restoration efforts remain insufficient to meet international biodiversity targets by 2030, calling for a more than fourfold increase in annual investment.

The findings are presented in the Restoration Progress Report: Nature’s Comeback – Scaling Ecosystem Restoration for People and Planet, released on October 29, 2026, by the United Nations Environment Programme (UNEP), the Food and Agriculture Organization (FAO) and the Secretariat of the Convention on Biological Diversity (CBD).

The report provides the first comprehensive global assessment of progress towards commitments to restore approximately one billion hectares of degraded ecosystems. These commitments are linked to the UN Decade on Ecosystem Restoration (2021–2030) and the Kunming-Montreal Global Biodiversity Framework, which calls for at least 30 per cent of degraded terrestrial, freshwater, marine and coastal ecosystems to be under effective restoration by 2030.

According to the assessment, the 252 million hectares currently documented under restoration represent the largest recorded global restoration effort. However, this accounts for only 34 per cent of the indicative global benchmark associated with the 2030 target.

Freshwater and marine ecosystems lag behind

The report identifies considerable differences in restoration progress across regions and ecosystem types. Asia accounts for the largest share of documented restoration, with 192.2 million hectares, followed by Africa with 36.3 million hectares and Europe with 9.1 million hectares. North and Central America account for 5.8 million hectares, South America 5.4 million hectares and Oceania 3.2 million hectares.

However, the report cautions that these figures should not be interpreted as a ranking of restoration performance, as they also reflect differences in regional land area and monitoring and reporting capacities.

Restoration of terrestrial ecosystems has reached nearly half of the global 2030 target. China reports the largest terrestrial restoration area, with 127.4 million hectares, while substantial restoration activities have also been documented in Mongolia and Kazakhstan.

Progress remains considerably slower in freshwater, marine and coastal ecosystems, despite these environments experiencing rapid degradation.

A river along the side of a dense forest. Image credit: Pexels

The assessment documents 11 million hectares of freshwater ecosystems under restoration across 62 countries and 5.7 million hectares of marine and coastal ecosystems across 46 countries. The report also notes that limited monitoring and reporting may mean that actual restoration activities in these ecosystems are higher than the documented figures.

Meanwhile, the share of countries reporting implemented wetland restoration or rehabilitation programmes has increased from 8 per cent in 2022 to 54 per cent.

Restoration financing needs to increase fourfold

Insufficient investment remains a major obstacle to achieving global restoration commitments. The report estimates that annual restoration financing must increase from US$64 billion to US$296 billion by 2030, representing more than a fourfold rise.

Agroforestry requires the largest estimated annual investment, at US$87 billion, followed by restorative reforestation at US$52 billion, peatland restoration at US$44 billion and seagrass restoration at US$28 billion.

The report identifies employment generation as another potential benefit of scaling up restoration. While more than one million green jobs have already been associated with restoration initiatives, increased global investment could generate up to 32 million additional jobs by 2030.

It also highlights the potential contribution of ecosystem restoration to climate mitigation and biodiversity protection. Research cited in the assessment indicates that restoring just 15 per cent of global priority areas could capture and store 30 per cent of carbon dioxide-equivalent emissions released since the Industrial Revolution and help prevent 60 per cent of projected species extinctions.

The report further identifies the participation and leadership of Indigenous Peoples and local communities as essential to ensuring long-term restoration outcomes. Secure land rights, stronger monitoring systems and sustained political commitment are among the priorities identified.

With five years remaining in the UN Decade on Ecosystem Restoration, the assessment calls on governments to move beyond isolated restoration projects towards coordinated, long-term programmes that address the underlying causes of ecosystem degradation.

It emphasises that the 2030 targets should serve as a milestone in the restoration process rather than its conclusion, as ecological recovery requires sustained action and investment beyond the end of the decade.

India could gain up to six months to prepare for the risks of extreme humid heat, as researchers have identified a link between El Niño and heat-related losses in working capacity. The findings could help authorities strengthen heat action plans, prepare health services and protect workers in agriculture, construction and other outdoor occupations.

The study, published in the Journal of Geophysical Research: Atmospheres in July 2026, found that the El Niño–Southern Oscillation (ENSO), a climate pattern involving changes in tropical Pacific Ocean temperatures and atmospheric circulation, is strongly associated with year-to-year variations in potential productivity losses caused by humid heat. The research, led by researchers at the Indian Institute of Tropical Meteorology (IITM), Pune, suggests that these losses could be predicted up to six months in advance.

According to a report published by Nature India on October 28, the researchers analysed historical climate and population data from 1950 to 2020, using heat-stress measures including Humidex and wet-bulb globe temperature (WBGT). Their analysis found that tropical Indo-Pacific ocean temperatures could explain approximately 42% of the variation in India’s potential productivity losses associated with humid heat.

The findings offer a possible early-warning tool for a country where millions of people work outdoors and exposure to high temperatures can threaten both their health and livelihoods.

Rising heat stress and its economic consequences

The study found that global potential productivity losses associated with Humidex values exceeding 45°C increased approximately 18-fold between 1950–1954 and 2016–2020. India’s estimated losses rose around 23-fold over the same period, accounting for more than half of the global increase.

Researchers attributed the rise in India to climate change and population growth, which contributed almost equally to the increase. Even if population had remained constant, climate change alone would have driven a four-to-fivefold increase in potential productivity losses, the study found.

The researchers also identified a faster rise in humid-heat risks from the mid-1980s, coinciding with average sea-surface temperatures in the Indo-Pacific warm pool crossing 28°C.

The findings are particularly relevant to India’s informal workforce, where outdoor workers often have limited opportunities to avoid heat exposure without losing income.

A separate study published in Scientific Reports in March 2026 examined heat stress among 1,560 outdoor workers across 11 districts of Tamil Nadu. Researchers found that WBGT measurements exceeded the critical threshold of 30°C. Workers exposed to elevated heat stress had 1.4 times the risk of reporting productivity losses compared with those without such exposure.

The study also found that 15% of surveyed workers reported losing daily wages because of heat during summer. The findings provide region-specific evidence of how rising temperatures can affect both working capacity and household incomes.

Turning forecasts into worker protection

The new research could help authorities move beyond responding to heatwaves after they develop. Longer-range risk estimates could give health departments time to review heatstroke treatment capacity, disaster-management agencies time to prepare resources, and labour departments time to plan protective measures for outdoor workers.

Silhoutte of a farmer working in a hot summer.Image credit:Pexels

India already issues seasonal temperature and heatwave outlooks, alongside shorter-range heat-index forecasts. Integrating longer-range climate signals with these systems could strengthen preparedness, provided the forecasts are tested and translated into practical protocols.

However, the researchers and climate experts caution that predictability does not eliminate uncertainty. India’s weather is influenced by several interacting oceanic and atmospheric systems, and El Niño does not produce identical rainfall or temperature outcomes every year.

The term “super El Niño” also has no formally defined category under the India Meteorological Department or the World Meteorological Organization. In a July 2026 parliamentary response, the Ministry of Earth Sciences said El Niño conditions could strengthen during October–December, potentially reaching the very strong category, while noting that regional impacts depend on several factors.

The central challenge, therefore, is to ensure that improved climate information leads to timely action. Forecasts must be combined with local weather observations, workplace conditions and workers’ experiences to identify those facing the greatest risks.

As humid heat intensifies, advance warning could become an important tool for reducing avoidable health and economic losses. But its effectiveness will depend on whether governments and employers can turn that warning into safer working conditions without forcing vulnerable workers to choose between their health and their income.