A 10 per cent rule for sustainable development

Recent estimates place the economic cost of environmental degradation in India at around 9-11 per cent of GDP. A precautionary approach would be to treat this as an ecological threshold

India’s development trajectory is entering a decisive phase. Infrastructure expansion, renewable energy transitions and economic growth are accelerating, often in the  landscapes that underpin the country’s ecological security. Forested regions, many overlapping with tiger habitats and wildlife corridors, are increasingly at the centre of this transformation. This raises a difficult question: How much ecological cost is too much?

For decades, India has relied on regulatory instruments such as Environmental Impact Assessments (EIA), forest clearances and compensatory afforestation to manage this balance. More recently, the idea of Green GDP — adjusting economic output to reflect environmental loss — has gained attention. Yet these approaches are often difficult to translate into clear decision thresholds. Policymakers need not merely more data but a simple, credible benchmark to recognise when economic activity begins to undermine its own ecological foundation. An answer may lie in a principle that governs all natural systems. In every ecosystem, energy flows through a hierarchy — from plants to herbivores to predators. At each step, most of the energy is lost, leaving only a small fraction available for the next level. This principle, described by Lindeman’s 10 per cent Law, explains why nature forms pyramids.

In much of India’s forests, the tiger is at the pyramid’s apex.  Its survival depends on a large and stable prey base, which in turn depends on healthy vegetation, water systems and minimal disturbance. Even small disruptions at the base can cascade upward, destabilising the system. This ecological reality offers an important economic insight: Systems can absorb only limited stress before they begin to degrade.

Recent estimates place the economic cost of environmental degradation in India at around 9-11 per cent of GDP. A precautionary approach would be to treat this as an ecological threshold — a point beyond which the economy is not operating sustainably and is  drawing down its natural capital. Development must pay a minimum ecological due.

This idea acquires particular urgency in tiger landscapes. India’s tiger reserves and corridors are embedded within  landscapes that support agriculture, infrastructure and local livelihoods. They also provide critical ecosystem services, including water regulation, carbon storage and biodiversity conservation. These systems also operate under tight ecological margins. Incremental pressures — linear infrastructure, mining, unsustainable extraction and land-use change — can accumulate rapidly. The consequences are already visible in many regions: Rising human-wildlife conflict, fragmentation of corridors and stress on prey populations.

In such contexts, a simple threshold can serve as an early warning. If the cumulative ecological cost of activities within a landscape begins to exceed a notional 10 per cent of its total economic or ecological value, it should trigger a policy pause — not to halt development, but to reassess its scale, location and design. In more fragile wildlife corridors, an even more conservative threshold of 5-8 per cent may be appropriate. Such an  approach can be incorporated into EIA processes, landscape-level planning in notified corridors, green accounting frameworks and infrastructure design.

In nature, as in economics, systems that consume their foundations do not collapse immediately. But they do, eventually — and often without warning.

The writer is secretary general,  Global Tiger Forum