Are the Aravalli Hills Facing a Crisis? Supreme Court's New Definition Sparks Concerns

The recent Supreme Court ruling defining Aravalli Hills only as those over 100 meters tall has raised significant concerns among environmentalists. Experts warn that this could lead to the loss of 90% of the mountain range, jeopardizing biodiversity and worsening air quality in regions like Delhi. The ruling has sparked political debate, with calls for the government to reconsider its amendments to environmental laws. As the national capital grapples with severe pollution, the fate of the Aravalli Hills remains critical for the ecological health of North India.

By Narendra Chaudhary Dec 5, 2025, 16:16 IST

The Aravalli Hills: A Natural Shield Under Threat

New Delhi: The Aravalli Hills, recognized as one of the planet's oldest mountain ranges stretching around 700 kilometers, have historically acted as a natural barrier against sand and dust from the Thar Desert. They play a crucial role in groundwater replenishment and support diverse ecosystems across several states, including the Delhi-NCR area.

However, a recent ruling by the Supreme Court, which adopts a new government definition stating that only hills exceeding 100 meters in height will be classified as Aravallis, has raised alarms among experts. They caution that this change could leave many ecologically significant areas unprotected, potentially exposing regions like Delhi to more severe weather and drought.

"Limiting the definition to hills taller than 100 meters disregards the landscape that is vital for North India's ecological balance and groundwater supply. While it may appear as 'sustainable mining' and 'development' on paper, the reality involves destructive activities like road construction and mining that disrupt wildlife corridors and the last green spaces of Delhi-NCR," remarked Harjeet Singh, founding director of the Satat Sampada Climate Foundation.

"This narrowed definition could legally erase 90% of the 700-km mountain range, leading to a gradual loss of not just biodiversity but also the essential water and climate stability it provides. This is not merely about losing a geological feature; it threatens the region's critical water recharge areas, resulting in increased dust storms, declining groundwater levels, and a significant rise in air pollution affecting millions," Singh added.

Environmentalist Vimlendu Jha expressed similar concerns, stating, "The Supreme Court's ruling puts not just Delhi but the entire Aravalli region at risk of pollution and degradation. The term 'Aravalli Hill' will now refer to any landform in designated districts that is at least 100 meters above local relief, while an 'Aravalli Range' will consist of two or more such hills within 500 meters of each other."

The Supreme Court has instructed authorities to identify areas suitable for mining and those that are ecologically sensitive, where mining should be strictly limited or allowed only under exceptional circumstances. However, Jha warns that this decision could lead to the near-total disappearance of the Aravallis.

"Allowing any form of mining or development effectively means that up to 90% of the Aravalli hills could be lost. This decision, made in the context of rising air pollution, undermines the very natural protections that need safeguarding," Jha stated, emphasizing the ecological importance of the region.

The Aravalli range is the source of significant rivers, including the Chambal, Sabarmati, and Luni, and its diverse ecosystems support endangered species. Yet, issues like deforestation, mining, and human encroachment are exacerbating desertification, harming aquifers, and diminishing the range's capacity to support wildlife.

In March 2023, the government initiated the Aravalli Green Wall project aimed at addressing these challenges. This initiative seeks to create a five-kilometer-wide green belt covering 6.45 million hectares across Gujarat, Rajasthan, Haryana, and Delhi.

Anumita Roy Chowdhury, Executive Director of the Centre for Science and Environment, pointed out that the underlying causes of wind-blown dust affecting the NCR and surrounding states are not being adequately addressed. She emphasized the critical role of the Aravallis and the green belt in maintaining air quality, stating, "This natural barrier is essential for protecting air quality, as it not only shields us from desert dust but also provides the necessary green cover to trap pollution and absorb toxic emissions."

The air quality in the national capital remains a pressing issue, with recent reports indicating that it has fallen into the 'very poor' category again. Thirty monitoring stations across the city recorded 'very poor' levels, with Bawana registering the highest AQI at 373. The AQI fluctuated throughout the week, indicating a persistent air quality crisis.

Bharati Chaturvedi, an environmentalist, described the Aravalli hills as one of the last defenses against dust storms, warning that the new government definition could severely impact vulnerable populations, including children, the elderly, and outdoor workers. She urged for a reconsideration of this decision, stating, "This could render Delhi unlivable. No amount of urban planting can replace the Aravallis."

The implications of pollution and the Supreme Court's ruling on the Aravalli have sparked discussions in Parliament, with Congress parliamentary party chairperson Sonia Gandhi accusing the government of effectively signing a 'death warrant' for the hills. She called for the withdrawal of amendments made to the Forest (Conservation) Act, 1980, and the Forest Conservation Rules (2022).

Congress leader Priyanka Gandhi Vadra also demanded a parliamentary debate on air pollution, labeling it a significant public concern that requires urgent attention. She highlighted the worsening pollution crisis in India and called for decisive government action, asserting that environmental protection should transcend political boundaries.