The Supreme Court on Monday put on hold its recent acceptance of a new definition of the Aravalli Hills, saying key environmental clarifications were still required. Activists and political leaders welcomed it but the Opposition warned that the battle for saving the ancient mountain range was far from over.
The top court said an expert committee must first examine the environmental impact of the recommendations made by an earlier panel that had proposed redefining the Aravalli range.
That committee had suggested classifying only landforms rising more than 100 metres above the surrounding terrain as part of the Aravallis — a move that critics say could strip environmental safeguards including against mining from large swathes of the 700-km mountain system.
A bench headed by Chief Justice of India Surya Kant along with Justice J.K. Maheshwari and Justice Augustine George Masih passed the order while hearing a suo motu case on issues relating to the definition of the Aravallis.
The matter was taken up amid widespread protests and mounting concern that the redefinition could open ecologically sensitive areas to mining and construction.
Congress leader Jairam Ramesh welcomed the judgment but warned that the battle was not over.
“The definition issue is to be re-examined. Forest Survey of India was against it. The Central Empowered Committee of the Supreme Court was against it. So it's a welcome sign, but the struggle is long because we have to put an end to this. It's an interim victory for the environment. It's not a victory for any political party or any individual. It's a victory for saving India's environment for the ease of breathing…”, he posted on X.
Experts say the episode has exposed a deeper fault line in how India defines and protects the Aravallis. They warn that the change could expose vast stretches of the 700-km-long system, running from Gujarat to Delhi, to mining and construction, with consequences that may unfold slowly but irreversibly.
“What we are seeing is largely a geomorphological categorisation. From an ecological perspective, this approach has significant limitations,” Dr Dibyadeep Chatterjee, a conservation ecologist, told The Telegraph Online.
“The Aravallis are not just a set of hills that can be measured by height. They perform critical ecological functions, such as temperature moderation, groundwater recharge, soil retention, and seed dispersal, that do not conform to a simple elevation threshold.
“Many inter-hill corridors, lower slopes, and seasonal stream systems do not rise above 100 metres. Excluding these areas based solely on elevation risks overlooking components that are functionally critical to the integrity of the ecosystem,” Chatterjee said.
The stakes extend far beyond geology.
“The Aravallis function as an ecological mosaic,” Chatterjee explained. “Fragmentation of any kind – whether through mining, construction, or selective protection – has non-linear consequences. Even minor disruptions can sharply reduce aquifer resilience and accelerate desertification. Ecological research consistently shows that threshold-based exclusions can lead to disproportionate and often difficult-to-reverse impacts on ecosystem function.
“These are very old mountains with shallow and fragile hydrological systems. They demand precaution, not simplification,” he added. “Disturbance of lower slopes and connected landforms can significantly impair groundwater recharge processes over time, which in turn increases the risk of desertification.”
Environmental activist Vimlendu Jha described the court’s earlier decision of accepting the redefinition as one that “exposes not just Delhi but the entire region that covers the Aravalli hills to contamination and pollution”.
“The top court permitting any form of mining or other 'developmental' activities effectively means that up to 90 per cent of the Aravalli hills could vanish. In the context of rising air pollution, this decision, while the Supreme Court simultaneously speaks of taking long-term measures, ends up exploiting the very natural safeguards that should be protected,” Jha told PTI, calling the range “an ecological treasure”.
The Aravallis are the source of rivers such as the Chambal, Sabarmati and Luni, and their forests, grasslands and wetlands support endangered plants and animals.
Many of these species depend not on the highest ridges but on the lower hills and valleys now at risk.
“A large number of species are not found at higher elevations at all,” Chatterjee told The Telegraph Online. “They depend on the lower hills, slopes, and corridors for movement, breeding, and survival. When such areas are opened up, biodiversity loss can occur rapidly, and recovery is often slow and uncertain.”
The government insists that safeguards remain in place. On Wednesday, the Union environment ministry had issued directions to Delhi, Gujarat, Haryana and Rajasthan to impose a complete ban on the grant of any new mining leases in the Aravallis.
Critics remain unconvinced.
Ramesh had also written to Yadav raising four specific questions, pointing to earlier definitions based on a 2010 Forest Survey of India (FSI) report that included areas with slopes of three degrees or more, along with buffers and associated valleys.
He also cited a September 2025 communication from the FSI stating that smaller hill formations act as effective barriers against desertification, noting that even hills of 10 to 30 metres can serve as strong windbreaks.
The FSI has pushed back against claims that it concluded 90 per cent of the Aravallis would be left unprotected, saying on X that it had carried out no such study.
For conservation scientists, the argument is less about percentages and more about processes. Chatterjee warned that ideas such as “sustainable mining” are often misunderstood in fragile landscapes.
“Sustainable mining, in practice, requires compensating for ecological loss. However, trees planted as offsets take decades to begin functioning like mature ecosystems, if they do so at all, and this time lag becomes critical in fragile landscapes such as the Aravallis,” he said.
“The impact does not stop at forests. Soil quality is affected, cropping patterns change, and food security is impacted.
“Over time, these ecological changes can also have social and livelihood implications, particularly for agrarian and pastoral communities that depend directly on these landscapes,” he added.
“These systems cannot be altered overnight and repaired later. The impacts unfold slowly, but cumulatively across ecology. Once certain ecological thresholds are crossed, recovery becomes increasingly uncertain and difficult to manage.”