The Aravalli Hills, nearly two billion years old, are India’s oldest mountain range and serve as a vital ecological shield for North India. Protecting this 700 km range is critical for regional climate stability and water security.

Aravalli Hills Ecological Importance

● Barrier Against Desertification: The Aravallis act as a natural wall, preventing the Thar Desert from expanding into the fertile Indo-Gangetic plains.

● Water Security: The range’s fractured rocky terrain allows rainwater to percolate into deep aquifers, serving as a massive groundwater recharge zone for the water-stressed National Capital Region (NCR).

● Air Quality Buffer: The hills trap dust and fine pollutants from western India, acting as a “green lung” for cities like Delhi, Gurugram, and Jaipur.

● Biodiversity Hub: The hills provide critical wildlife corridors for leopards, hyenas, and endangered flora, connecting sanctuaries like Sariska and Ranthambore.

Recent Legal Challenges (2025 Updates)

In late 2025, a landmark Supreme Court ruling accepted a new, narrower definition of the Aravallis that defines an “Aravalli Hill” as a landform with an elevation of at least 100 meters above local relief.

●Threat to 90% of the Range: Experts warn that this “100-meter rule” could exclude over 90% of the existing Aravalli hills from legal protection, potentially opening them to mining and construction.

● Interim Protections: While the court accepted the definition, it also issued a complete moratorium on all fresh mining leases and renewals across Delhi, Haryana, Rajasthan, and Gujarat until a comprehensive “Management Plan for Sustainable Mining” (MPSM) is finalized.

The “Aravalli Green Wall” Initiative

To restore degraded areas, the government has launched the Aravalli Green Wall Project, aiming to create a 5 km green buffer around the range. In June 2025, Prime Minister Modi kick-started the first phase of this regreening effort to rehabilitate forest cover by replacing invasive species with native plants.

Why do we need to save The Aravalli?

We need to save the Aravalli range because it is an ecological lifeline for North India, acting as a natural shield against the expansion of the Thar Desert, a critical groundwater recharge zone, and a crucial regulator of the region’s climate and air quality. Its preservation is vital for the survival of millions of people and a rich diversity of wildlife.

Key Reasons to Protect the Aravallis

● Halts Desertification: The Aravallis form a natural barrier that prevents the eastward spread of sand and dust from the Thar Desert into the fertile Indo-Gangetic plains, including Delhi-NCR. Degradation of the hills would allow dust storms to occur more frequently and intensely, accelerating desertification.

● Groundwater Security: The range is a primary water recharge zone for states like Rajasthan, Haryana, and Delhi. Rainwater percolates through its fractured rocks and fissures, replenishing vital underground aquifers that are a lifeline for the water-stressed region.

● Climate & Air Quality Regulation: The hills influence regional weather patterns, help in regulating local temperatures, and act as “green lungs” by filtering air pollution. They shield the plains from cold westerly winds in winter and help guide monsoon clouds eastward towards the Himalayas, thus impacting rainfall in the northern plains.

● Biodiversity Conservation: The Aravallis are a significant biodiversity hotspot, providing essential habitats and wildlife corridors for numerous species, including leopards, hyenas, jackals, and hundreds of bird species. Destruction of their habitat increases human-wildlife conflict.

● River Systems: Several important rivers, such as the Sabarmati, Luni, and Chambal, originate from or are supported by the Aravalli system. Preserving the range is crucial for maintaining the flow of these rivers and supporting downstream ecosystems and agriculture.

● Cultural & Historical Heritage: The ancient, billion-year-old range holds significant historical and cultural importance, with sites of archaeological interest, forts, and temples that are integral to the region’s heritage.

Degradation due to unchecked mining, urban expansion, and deforestation has already led to water scarcity, increased pollution, and ecological imbalance in the region. Saving the Aravallis is essential for safeguarding North India’s environmental stability and ensuring a sustainable future for its population.

Why is the Aravalli in the target?

In November 2025, a landmark decision by the Supreme Court of India officially accepted a new, standardized definition of the “Aravalli Hills” proposed by the Ministry of Environment, Forest and Climate Change (MoEFCC). While the government has presented this as a move toward administrative clarity and curbing illegal activities, the ruling has sparked intense controversy.

The primary reasons cited for these orders include:

● Administrative Clarity: Historically, different states (Delhi, Haryana, Rajasthan, and Gujarat) used inconsistent criteria to define the Aravallis, leading to legal loopholes and difficulty in enforcement. The new order establishes that a landform must rise 100 meters or more above the local terrain to be legally classified and protected as an “Aravalli Hill”.

● Facilitating “Sustainable Mining”: The government argued for a “calibrated approach” that balances conservation with the need for strategic minerals like graphite, lithium, and granite. The court ordered the creation of a Management Plan for Sustainable Mining (MPSM) to identify “no-go” zones versus areas where regulated mining can occur.

● Curbing Illegal Mafias: The Court noted that total bans on mining often lead to the rise of unregulated illegal mining syndicates and sand mafias. By allowing strictly regulated legal mining, the government aims to maintain order and professional oversight.

● Economic Interests: Government lawyers argued that a total ban would have a “cascading effect” on the livelihoods of millions of laborers and the construction industry’s need for materials.

Environmental Backlash and Concerns

Environmentalists have criticized this “technical redefinition,” calling it a “death warrant” for the range for the following reasons:

● Massive De-classification: Experts warn that over 90% of the Aravalli hills fall below the 100-meter height threshold. These lower-lying ridges—which act as crucial barriers against the Thar Desert and recharge groundwater—could now lose legal protection and be opened to mining and real estate.

● “Surrendering the Fences”: The Forest Survey of India (FSI) previously warned that protecting only the highest peaks is like “guarding posts while surrendering the fences below,” leaving the region vulnerable to dust storms and ecological collapse.

● Threat to Delhi-NCR: Removing protection from these “non-hills” may accelerate desertification, deplete groundwater aquifers, and worsen the already hazardous air quality in the National Capital Region.

What happens when The Aravalli is completely injured?

As of late 2025, environmental experts and climate scientists warn that if the Aravalli range is “completely injured” or destroyed—a risk heightened by recent legal redefinitions that may leave up to 90% of the range unprotected—it would lead to an irreversible ecological and humanitarian crisis in North India.

The catastrophic consequences of losing this “ecological lifeline” include:

Accelerated Desertification

The Aravallis serve as the “Great Green Wall” that blocks hot, dust-laden winds from the Thar Desert.

● Desert Advancement: Without this barrier, sand and dust storms would sweep unimpeded into the Indo-Gangetic plains, including Delhi, Haryana, and Uttar Pradesh.

● Loss of Farmland: Massive dust deposition would destroy soil fertility, turning fertile agricultural land into semi-desert within decades.

Collapse of Water Security

The range is a primary groundwater recharge zone for the water-stressed National Capital Region (NCR) and surrounding states.

● Drying Aquifers: The hills act like a sponge, allowing rainwater to percolate into deep, interconnected aquifers. Destroying them would lead to a permanent collapse of the regional water table, which has already dropped to 1,000–2,000 feet in some degraded areas.

● Death of Rivers: Key rivers such as the Banas, Luni, and Sahibi, which originate from the Aravallis, would permanently disappear, exacerbating water insecurity for millions.

Toxic Air Quality and Extreme Heat

The Aravallis are the “green lungs” of North India, filtering pollutants and regulating local weather.

● Air Toxicity: Loss of the range would lead to an unprecedented increase in particulate matter (PM10), making the air in cities like Delhi lethally toxic for months.

● Temperature Spikes: The destruction of hills and forest cover would worsen the urban heat island effect, potentially raising local temperatures by 3–4°C and increasing the frequency of severe heatwaves.

Ecological and Biodiversity Loss

● Wildlife Conflict: The range is a critical corridor for species like leopards, hyenas, and jackals. Habitat destruction would force these animals into human settlements, causing a sharp rise in human-wildlife conflict.

● Extinction of Native Species: Hundreds of bird species and native plants unique to this ancient ecosystem would be permanently lost.

Public Health Crisis

The combined effect of water scarcity, dust pollution, and extreme heat would trigger a surge in respiratory diseases, heat-related illnesses, and socioeconomic displacement, making the region increasingly uninhabitable.

ABOUT THE ARAVALLI

The Aravalli Range (also spelled Aravali) is a mountain range in north-western India, running approximately 670 km (420 mi) in a south-west direction, starting near Delhi, passing through southern Haryana and Rajasthan, and ending in Ahmedabad, Gujarat. The highest peak is Guru Shikhar in Mount Abu, Rajasthan at 1,722 m (5,650 ft). The Aravalli range is the oldest fold-mountain belt in India, dating back to the Paleoproterozoic era.

History of The Aravalli

The Aravalli Range stands as one of the oldest geological features on Earth, with a history that stretches back approximately 1.5 to 2.5 billion years to the Proterozoic eon. Predating even the mighty Himalayas, these mountains emerged through a series of massive tectonic upheavals known as the Aravalli-Delhi Orogenic cycle. In their youth, the Aravallis were likely as high as the modern Himalayas, but hundreds of millions of years of erosion have worn them down into the weathered ridges and rolling hills seen today. This ancient fold mountain system once spanned from the coast of Gujarat all the way to the outskirts of modern-day Delhi, serving as a silent witness to the drift of the Indian plate and the shifting of the Earth’s crust.

Human history in the Aravallis is equally profound, dating back to the Stone Age. Archaeological evidence from sites like the Banas River valley reveals that the range supported the Ahar-Banas culture, a contemporary of the Indus Valley Civilization. These early inhabitants utilized the mountains’ rich mineral deposits, particularly copper, which fueled ancient trade networks and metallurgical advancement. As the centuries progressed, the Aravallis became the strategic backbone of medieval India. Their rugged terrain provided a natural fortress for the Rajput clans, most notably the Mewar dynasty. The hills are crowned with legendary forts such as Chittorgarh and Kumbhalgarh, which were designed to be impenetrable. The range acted as a vital defensive wall that protected Rajasthan from repeated invasions, allowing a unique culture of valor, art, and architecture to flourish in its valleys.

Beyond warfare, the Aravallis have historically served as a critical ecological regulator. For millennia, they have dictated the climate of North India by shielding the Indo-Gangetic plains from the expansion of the Thar Desert. The range channeled monsoon winds and gave birth to numerous rivers that sustained civilizations. The ancient city of Indraprastha, and later the various cities of Delhi, were founded at the northern tip of the Aravalli ridges because the hills provided elevated, defensible ground and reliable water sources.

In the modern era, the history of the Aravallis has transitioned from a story of protection to one of peril. The 20th and 21st centuries have seen the range suffer from unprecedented human intervention. Massive mining for stone, marble, and minerals, alongside rapid urban expansion, has scarred the landscape. By late 2025, the historical significance of the range is being weighed against industrial demands, leading to controversial legal battles over its very definition. What was once an eternal barrier and a cradle of civilizations is now a fragile ecosystem. The history of the Aravallis is the history of the Indian subcontinent itself—a testament to resilience that now faces its greatest challenge as it struggles to survive in a rapidly developing world.

Etymology of The Aravalli

The term Aravalli is a composite Sanskrit word derived from the roots “ara” and “vali”, which literally translates to “line of peaks”.

Etymological Breakdown

● Ara (Sanskrit): Some interpretations suggest this root refers to a “point” or something “awl-shaped,” describing the sharp, jagged nature of the mountain summits. Another historical interpretation from regional records suggests ara can mean “enemy,” implying the range’s role as a protective barrier.

● Vali (Sanskrit): This root means a “line,” “row,” or “series. Together, the name aptly describes the range’s physical appearance—a continuous, jagged row of peaks stretching across the landscape.

Historical and Alternative Names

● Arbuda Mountains: The southern section of the range, particularly the area around Mount Abu, is historically known in ancient texts as the Arbuda Mountains.

●Aravāḷī / Ārāvali: Variant spellings found in ancient Sanskrit literature.

The Ridge: In the National Capital Region (NCR), the northernmost extensions of the Aravallis are colloquially and legally referred to as “The Ridge”.

●Lifeline of Rajasthan: Due to its critical role in regulating the local climate and providing water, it is frequently referred to as the “Ecological Spine” or “Lifeline” of the region.

Human history of The Aravalli

The human history of the Aravalli Range spans hundreds of thousands of years, evolving from a prehistoric cradle for early humans to a strategic stronghold for powerful medieval empires.

1. Prehistoric Beginnings (Stone Age)

The Aravallis are home to some of India’s earliest human activity. Recent archaeological discoveries in the Mangar Bani region (Haryana) revealed Acheulian stone tools, such as handaxes and cleavers, dating back between 200,000 and 500,000 years. These findings establish the range as a vital habitat for Lower Palaeolithic hunter-gatherer societies who relied on the hills’ flat tops and raw materials for tool-making.

2. Early Civilizations (Copper & Bronze Ages)

The range was central to the development of early urban cultures due to its rich mineral wealth :

● Indus Valley & Regional Cultures: Settlements like Kalibangan (Rajasthan) and Kunal (Haryana) thrived along the Aravalli foothills, utilizing its fertile land and water sources.

● Ahar-Banas Culture: Approximately 4,000 years ago, the Ahar culture developed in the Banas River valley, specializing in copper smelting.

● Ganeshwar-Jodhpura Culture: This 2,800-year-old civilization was a primary supplier of copper to the Harappans, mining the extensive deposits found in the Aravalli-Delhi orogenic belt.

3. Medieval Strategic Stronghold (Rajput Era)

For over a millennium, the Aravallis served as the natural defensive backbone of the Rajput kingdoms.

● Impregnable Forts: The rugged terrain allowed for the construction of massive hilltop citadels, including Chittorgarh, Amer, and Kumbhalgarh. Kumbhalgarh is world-renowned for its 36-kilometer-long wall, often called the “Great Wall of India”.

● Natural Barrier: The range acted as a shield for northwestern India, frequently halting invasions from Central Asian and Mughal forces.

4. Spiritual and Cultural Significance

The Aravallis have been a center of religious life for centuries:

● Sacred Sites: The range hosts the Dilwara Temples at Mount Abu, celebrated for their intricate 11th–13th century marble architecture.

● Sacred Groves: In regions like Alwar, local communities have preserved nearly 100 “Orans” or “Devbanis”—sacred groves protected by spiritual beliefs that maintain local biodiversity and water levels.

5. Modern Era

Industrial Transition. In the last century, the human relationship with the Aravallis shifted from strategic protection and reverence to industrial extraction. Massive mining for marble, copper, and building materials fueled India’s urban growth but has left the range—once considered an eternal protector—ecologically scarred and physically diminished.

Environment and Ecology of The Aravalli

The environment and ecology of the Aravalli Range are defined by its status as one of the world’s oldest mountain systems, serving as the “ecological spine” of northwestern India. Spanning nearly 700 km across Delhi, Haryana, Rajasthan, and Gujarat, the range acts as a critical natural barrier and resource provider.

1. Crucial Ecosystem Services

● Barrier Against Desertification: The Aravallis prevent the eastward expansion of the Thar Desert into the fertile Indo-Gangetic plains. They block hot, dust-laden winds and help stabilize regional soil.

● Groundwater Recharge: The weathered and fractured rock formations act as massive recharge systems, replenishing aquifers that provide water for millions. It is estimated that one hectare of the Aravalli landscape can recharge up to 2 million liters of groundwater.

● Climate Regulation: The range moderates local temperatures, influences wind patterns, and regulates rainfall in the semi-arid region.

● Freshwater Source: Several key rivers, including the Chambal, Sabarmati, and Luni, originate from or are sustained by this system.

2. Biodiversity and Flora

The Aravallis feature diverse ecosystems ranging from tropical dry deciduous forests to thorn forests.

● Dominant Species: Native trees include Dhok (Anogeissus pendula), Khejri, Neem, and Salai.

● Wildlife Hotspot: The range provides critical habitat for over 200 bird species and mammals such as:

▪︎ Leopards and Striped Hyenas

▪︎ Golden Jackals, Nilgai, Honey Badgers, and Jungle Cats

▪︎ Porcupines, Palm Civets, and Rhesus Macaques.

3. Current Ecological Status (2025 Updates)

The region is currently facing severe environmental pressure due to recent administrative changes and industrial activity:

● New “100-Meter” Definition: In late 2025, the Supreme Court accepted a new definition where only landforms rising 100 meters or more above local relief are legally classified as “Aravalli Hills”. Experts warn this may leave up to 90% of the range—specifically, lower ridges and slopes—without legal protection.

● Mining and Degradation: Unregulated mining for minerals like marble, granite, and copper has led to hill flattening, habitat fragmentation, and falling groundwater levels (reaching depths of 1,000–2,000 feet in some areas).

● The Aravalli Green Wall Project: To counter degradation, the government has launched a project to create a 5-km-wide green buffer across 29 districts, aiming to restore 26 million hectares of land by 2030 using native species.

Concerns

In late 2025, concerns regarding the Aravalli range reached a critical point following a landmark Supreme Court ruling that redefined what legally constitutes an “Aravalli Hill.” This decision, alongside decades of industrial pressure, has created a multifaceted environmental and socioeconomic crisis.

1. The “100-Metre” Definition Crisis

On November 20, 2025, the Supreme Court accepted a new, standardized definition: only landforms rising 100 metres or more above local relief are legally classified as Aravalli Hills.

● Massive De-protection: An internal Forest Survey of India (FSI) assessment revealed that this technical change could strip legal protection from over 90% of the range. Out of 12,081 mapped hills in Rajasthan, only 1,048 (approx. 8.7%) meet this new 100m threshold.

● Loss of “Natural Fences”: Experts argue that lower-lying ridges (between 20–100m) are the most critical “fences” that block dust storms and recharge groundwater. Redefining them out of existence may allow for unchecked mining and real estate development.

2. Escalating Industrial and Urban Pressure

● Mining Expansion: While the court paused new mining leases until a Management Plan for Sustainable Mining (MPSM) is finalized, existing legal mining continues. Critics fear the new definition provides a “legal loophole” for the construction industry to mine granite and other minerals in previously protected low-lying areas.

● Real Estate and Encroachment: The proximity to the Delhi-NCR region has led to “explosive” urbanization. Groups have raised alarms over corporate land acquisition and tourism projects that fragment wildlife habitats.

3. Immediate Ecological Threats

● Desertification “Time-Bomb”: The Aravallis are the primary barrier preventing the Thar Desert from expanding into North India. Scientists warn that breaches in this range have already allowed desert sand (loess) to reach as far as Mathura and Agra.

● Water Security Collapse: Groundwater levels in parts of the Aravalli belt have plummeted to 1,500–2,000 feet. Mining punctures deep aquifers, leading to the permanent drying of lakes like Badkhal.

● Toxic Air Quality: The destruction of these “green lungs” removes a vital filter for particulate matter, worsening the already lethal air pollution in the National Capital Region.

4. Policy and Implementation Challenges

● Aravalli Green Wall Project: Launched to restore 26 million hectares by 2030, this initiative faces hurdles like fragmented land holdings, water scarcity for irrigation, and continued illegal mining.

●Human-Wildlife Conflict: Shrinking habitats for leopards, hyenas, and over 200 bird species are forcing animals into human settlements, increasing dangerous encounters.

By late 2025, environmentalists and political figures have termed these developments a “death warrant” for the range, calling for an immediate review to prioritize ecological function over height-based metrics.

Summary

The Aravalli Range, one of the world’s oldest geological formations, serves as the critical ecological spine of North India, shielding the Indo-Gangetic plains from the expansion of the Thar Desert. Spanning nearly 700 kilometers across Delhi, Haryana, Rajasthan, and Gujarat, this billion-year-old mountain system acts as a natural barrier against dust storms and a vital groundwater recharge zone for the water-stressed National Capital Region.

Historically, the range provided the strategic foundation for the Rajput kingdoms, whose legendary forts still crown its peaks, and it remains a spiritual sanctuary home to ancient sacred groves and the Dilwara Temples. However, as of late 2025, the Aravallis face an existential crisis. A landmark Supreme Court ruling recently accepted a new technical definition that classifies only landforms rising 100 meters or more as protected hills.

Environmentalists warn this could strip legal protection from over 90% of the range, opening vast, lower-lying ridges to mining and real estate development. The continued degradation of these hills threatens to trigger irreversible desertification, deplete deep aquifers, and worsen the region’s already hazardous air quality.

Protecting the Aravallis is no longer just a matter of conservation but a necessity for the survival and climate security of millions in Northern India.