►Supreme Court accepts Environment Ministry’s new definition: Only hills that are 100 m above local relief qualify as Aravalli.
►This change could exclude over 90% of the Aravalli hills from protection.
►Environmentalists warn this could open the ancient range to mining, real estate, and construction, worsening dust pollution and water scarcity.
The Supreme Court’s decision to adopt a new definition of the Aravalli Hills, based on a minimum height of 100 meters above local terrain, has triggered widespread concern from environmentalists, citizens, and political leaders.
The new definition was recommended by a Union Environment Ministry panel and accepted by the apex court on November 20.
According to a report in The Indian Express, internal documents of the Forest Survey of India (FSI) warn that this criterion will exclude over 90% of the Aravalli hills from legal protection.
The FSI found that in Rajasthan alone, only 1,048 of 12,081 hills measuring 20 metres or more in height qualify under the 100 m rule, just 8.7% of the landscape.
FSI warned that protecting only the tallest hills would be like safeguarding “a few guard posts while surrendering the fences below,” potentially exposing vast areas to dust and sand storms moving from the Thar Desert to the Indo-Gangetic plains.
Former Environment Minister Jairam Ramesh and several ecologists have criticised the judgment, calling it “bizarre” and “regressive.”
Where Are the Aravallis and Why Are They Crucial?
The Aravalli Range spans nearly 700 km from eastern Gujarat to southern Haryana and parts of Delhi.
It is one of the oldest fold-mountain systems in the world, formed 3–4 billion years ago, far older than the Himalayas.
The Range Supports a Mosaic of Ecosystems:
-Dry deciduous forests like those in the Sariska Tiger Reserve.
– Tropical thorn forests in the Delhi Ridge.
– Wetlands such as Rajasthan’s Sambhar Lake, home to thousands of birds.
The hills act as a natural barrier against desertification, stopping sand and dust from the Thar Desert, while also recharging aquifers and stabilising the region’s microclimate.
The FSI notes that even hills as low as 20 metres play a critical role as wind barriers. This protective function is crucial for the Delhi-NCR region, which already suffers from severe air pollution.
How the New Definition Endangers the Hills
Environmentalists warn that redefining the Aravalli hills purely on height, instead of ecological function, could open massive portions of the range to mining and construction.
A technical committee in 2024 had earlier suggested a more practical requirement: Hills with a minimum slope of 4.57° and a height of 30 metres, which would still include about 40% of the range. However, an unsigned ministry report submitted to the Supreme Court replaced this with the 100 m criterion.
The new definition also cites the presence of strategic minerals such as gold, tungsten, lithium, and rare earth elements as reasons for enabling “sustainable mining.”
Experts Argue This Could Worsen:
– Dust pollution in Delhi and NCR.
– Water scarcity, as the Aravalli rocks recharge 2 million litres of groundwater per hectare.
– Loss of biodiversity.
– Agricultural decline from dust deposition on crops.
– Human–wildlife conflict due to shrinking habitats.
Medical professionals also warn that increased dust could worsen asthma, bronchitis, and other respiratory illnesses.
Citizens Mobilise: Petitions Seek Recall of Judgment
On December 5, citizen groups, including People for Aravallis and Save Sariska, launched an online petition urging the Supreme Court to recall the judgment. The petition argues that the 100 m definition places the ancient hill range in an “existential crisis” and threatens communities across northwest India.
Citizens recently gathered in Gurgaon carrying posters that read: “Do you want to breathe? Do you want to drink water? Then save the Aravallis.”
Activists demand that the entire Aravalli landscape across Gujarat, Rajasthan, Haryana, and Delhi be declared a Critical Ecological Zone and that mining near settlements, farmland, and water bodies be stopped.