UPSC Mains 2019 GS Paper 3 Q17: model answer

In the summer of 2018, Shimla ran out of water, and residents told tourists to stay away. The town had been built for about 25,000 people in British times; it now held lakhs of residents and visitors. Shimla had crossed its carrying capacity.

The concept

• Carrying capacity is the largest population, or level of activity, that an environment can support indefinitely without being damaged.
• It is set by limiting factors: water, food, space, energy and the ability to absorb waste.
• For humans, it changes with technology and consumption: the same valley supports more people with efficient use, fewer with wasteful use.

Its parts

• Ecological: what nature can supply and absorb.
• Physical: land, slopes and infrastructure.
• Social: what local communities will tolerate.

Why it matters in planning

• Prevents overshoot, which leads to water shortages, pollution and disasters.
• Guides limits on construction, tourism and industry.
• Reveals cumulative impacts that single-project EIAs miss.
• Protects future generations, the heart of sustainable development.

Indian cases

• Joshimath (2023): land subsidence worsened by heavy construction on unstable slopes.
• Himalayan towns: in 2024 the Supreme Court asked for carrying capacity studies of hill states.
• Tourism caps: permits in Ladakh and Sikkim, and limits on visitors to some Himalayan shrines.
• Goa and Kerala's coasts face pressure from tourism and construction.

How to apply it

• Carrying capacity studies before master plans and tourism plans.
• Water budgets for towns and river basins.
• Zoning of fragile areas and building height limits.
• Regional, cumulative EIA instead of project-by-project clearance.
• Use of technology to raise capacity: rainwater harvesting, waste recycling, public transport.
• Local participation in setting limits.

Development that ignores carrying capacity borrows from nature, and nature always collects.