Syllabus: GS: II & V: Judiciary

Why in the news?

In November 2025, the Supreme Court of India redefined the Aravalli Hills for regulatory purposes, limiting the legal meaning of “hills” to landforms rising at least 100 metres above local relief. Though framed as a clarification, the ruling has sparked concern over its wider implications for environmental governance—especially in hill-dominated regions like Assam and the Northeast.

What did the Aravalli judgment say?

• The Court adopted a numerical, elevation-based definition of hills.
• Only landforms meeting the 100-metre local relief threshold qualify as “Aravalli hills” for environmental regulation.
• Areas below this threshold, even if geologically or ecologically connected, fall outside hill protection regimes.

This marks a shift from an ecosystem-based understanding of hills to a threshold-based legal test.

Why is this a conceptual shift?

Earlier, hills were treated as integrated landscapes—including ridges, slopes, foothills, plateaus, and rocky outcrops. Environmental safeguards such as mining bans and land-use controls applied to the entire hill system, not just its tallest parts.

The new approach:

• Reduces landscapes to measurable height.
• Risks ignoring ecological functions like water regulation, biodiversity support, and soil stability.
• Signals a move away from holistic environmental protection.

Why should Assam and the Northeast be concerned?

The Northeast is a hill-dominated region, but not defined by sharp peaks alone.

• Karbi Anglong, Dima Hasao, the Barail Range, and the Cachar Hills consist largely of rolling hills, plateaus, and gentle slopes.
• Their ecological value lies in forests, watersheds, wildlife corridors, and climate regulation—not elevation alone.
• Applying a rigid height criterion could reclassify ecologically sensitive hills as non-hill land, weakening environmental safeguards.

This could accelerate:

• Mining and infrastructure pressures
• Deforestation and habitat fragmentation
• Increased floods and landslides in plains

Social and constitutional implications

• Hills in Assam and the Northeast are inhabited landscapes, home to indigenous communities.
• Customary land use, community forests, shifting cultivation, and sacred groves are deeply tied to hill ecology.
• Reducing hills to numerical metrics risks erasing lived relationships with land from legal consideration.

This raises concerns under:

• Fifth and Sixth Schedule protections
• Principles of environmental justice and federalism

Key terms explained

• Local Relief: Height difference between a landform and its immediate surroundings.
• Ecosystem-based approach: Protecting nature as interconnected systems rather than isolated features.
• Threshold-based regulation: Legal protection triggered only when a fixed numerical limit is crossed.
• Cumulative degradation: Gradual environmental damage from multiple small interventions.
• Ecological corridors: Natural pathways enabling wildlife movement and genetic flow.

The larger governance question

Judicial definitions often travel beyond their original context—entering policy, administration, and expert committees. What begins as an exception can become a national template.

The core issue is philosophical:

• When does a hill stop being a hill?
• Is it when it fails a height test, or when it stops performing its ecological role?

Ancient hill systems like the Aravallis or the Barails are not failed mountains. They are geological elders, quietly sustaining life.

Exam Hook

Key Takeaways

• Environmental protection depends as much on how nature is defined as on laws themselves.
• Threshold-based definitions risk undermining ecosystem integrity, especially in the Northeast.
• Sustainable development requires recognising ecological limits first, not redefining them away.

Mains Question
Critically examine how the Supreme Court’s redefinition of the Aravalli Hills could influence environmental governance in the hill regions of Northeast India.

SOURCE