Smog Stories: Aravalli Crucial In Fight Against Air Pollution; Know How Much Of The Ancient Hills Has Delhi-NCR Lost

mog Stories: The issue of Aravalli hills' definition has created massive outrage with several environmentalists and residents in Rajasthan and Delhi-NCR staging protests. The row was triggered after the Supreme Court accepted a government-led committee's suggestion to define the Aravalli hills as landforms with elevations above 100 metres from ground level. The ruling came in November, but when it came to the public domain, it created an unprecedented furore amid choking conditions in the region due to the deteriorating air quality. The protests prompted the top court to put a stay on its own order on Monday (December 30).

The Aravalli issue gained significance in the backdrop of rising air pollution in Delhi-NCR, which continues to gasp for clean air. In the last couple of weeks, the air quality in the region remained a matter of concern. Delhi recorded its worst air quality for December this year since 2018, with an average AQI of 349. In December 2018, the capital logged an average Air Quality Index (AQI) of 360.

The December average stood at 294 in 2024, 348 in 2023, 319 in 2022, 336 in 2021, 332 in 2020, 337 in 2019, and 301 in 2015, Central Pollution Control Board (CPCB) data showed. This month, the city recorded 'severe' air quality on five days. Last year, Delhi saw six such days in December.

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The daily mean data generated by the Decision Support System (DSS) of IITM Pune under the Ministry of Earth Sciences shows a steady decline in the contribution of stubble burning to PM2.5 levels during the October-December period over the years. The share of stubble burning stood at 13 per cent in 2020 and 2021, fell to 9 per cent in 2022, rose marginally to 11 per cent in 2023, and was 10.6 per cent in 2024 before dropping to 3.5 per cent in 2025.

Why Is Aravalli Known As A Wall Against Dust Particles?

The Aravalli mountain range in and around Delhi (also known as the Delhi Ridge) is significant for dust barriers, water recharge, and biodiversity. It acts as a barrier against the Thar Desert sands, recharges groundwater, and helps keep air clean, but over years, India's oldest mountain range has suffered significant damage, primarily due to illegal mining, urbanisation, deforestation, and waste dumping. Though mining is banned in the capital region, the authorities overlook Aravalli's importance for the infrastructure projects. The mountain are severely affected across their entire range in Delhi-NCR.

Alarming Reports

The study published in Science Earth Informatics in 2023 flagged that nearly 8% of the Aravalli range flattened (around 5772.7 sq km) between 1975-2019, and it may lose 22% by 2059. The Central University of Rajasthan (CURaj)'s study on the land-use and land-cover (LULC) dynamics, highlighted that the degradation over decades due to human activities like mining, urbanisation, and deforestation. The Delhi Ridge is threatened by illegal mining, construction, and invasive species (such as Prosopis juliflora). The gaps in the mountain range are increasing dust storms, which can worsen Delhi's AQI by 4-6 times.

What Environmentalist Said

Speaking to The Daily Jagran, Kaleshwar Mishra, co-founder, Green India Foundation and environmentalist, flagged tampering with ecology around the Aravalli range could cause irreparable damage.

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"As someone who has followed the Aravalli crisis for years, I see Delhi-NCR’s treatment of this ancient range as a case study in self-sabotage. Decades of quarrying, road building, luxury townships, farmhouses, and resorts have literally cut through the hills. Official assessments have already recorded that dozens of identified Aravalli hill features have disappeared or been fatally fragmented. That isn’t just a loss of scenery; it is the dismantling of a living barrier that once filtered dust, blocked hot desert winds, slowed desertification, recharged groundwater and helped keep local temperatures and pollution in check," Mishra explained.

Delhi Government's Efforts In Fight Against Air Pollution

In a democratic setup, a government cannot afford to ignore such a big issue, which is linked to people's health. The city government keeps launching green projects and other initiatives to make the air breathable. The Centre also took several steps aiming restoration of the Aravalli hills.

Here Are Major Initiatives

- Under the Air Pollution Mitigation Plan 2025 Cloud Seeding Pilot Project, the government targets reducing pollution through artificial rain.

- Large-scale deployment of anti-smog guns and mist sprayers.

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- Strict vehicle emission norms such as strict PUC enforcement on out-of-state vehicles from November 2025.

- Dust control, waste management, and public awareness.

- Ek Ped Maa Ke Naam: Large-scale tree plantation, under which the government targets planting 7 million saplings in 2025.

- Electric Vehicle (EV) Promotion: Under the expansion of EV policy or preparation of a new EV Policy 2.0, the government is increasing EV charging infrastructure.

(This article is part of the series 'Smog Stories'. To read more articles in the series, click here.)