Down To Earth(July1-15 2023)

Population and its impacts on environment

Context: Population per se is not the determinant of environmental problems; it is their consumption pattern that leads to environmental degradation.


A smaller population could still be more destructive:

  • Countries like the USA, Australia and or European nations with smaller populations have emitted huge amounts of carbon dioxide into the atmosphere, adding to our common jeopardy.
  • So, population per se is not the determinant of environ­mental problems, but it is their consumption pattern that leads to environmental degradation as they overexploit land, water, forests and other resources, but exter­nalise the source.
  • On the other hand, the poor and developing countries have intensive use of their local environment. They depend on native forests, land and water bodies with visible destruction like resource depletion and pollution, but their combined impact on the environment is less than developed countries with smaller populations.

Countries with its population and environmental footprint:

  • Countries like the USA with 336 million people or Australia with 26 million people have much greater environmental footprints than that of India with more than 1400 million people.
  • The ‘Earth Overshoot Day’ estimates that if everyone lived like an American, then five Earths needed; as an Australian, 4.5 Earths needed and as an Indian, only 0.8 of an Earth needed.
  • The Indian popula­tion has a smaller environmental footprint because it is poor. It is poverty that makes us frugal.
  • There is no doubt that more people will need more resources to survive. But it cannot be argued that population growth is an indicator of the resultant environmental degradation.

Human Population and resources availability:

  • The ‘carrying capacity of the earth’ is the total number of people who can live on Earth sustainably.
  • In  the book ‘The Population Bomb’ by Paul Ehrlich advocated for immediate action to limit population growth on a finite planet.
  • It was reiterated later by the Club of Rome in 1972 by a report ‘The Limits to Growth’ that aptly demonstrated the dynamic relationship between increasing consumption and the idea of ‘planetary boundaries’ which cannot be crossed without risking severe environmental change.
  • There are three multi-pronged approaches to keep balance between population and resources:
    • India is already seeing a decline in its Total Fertility Rate (TFR), which has dropped below the replacement level, i.e. 2.1, which represents the level at which a population exactly replaces itself from one generation to the next, resulting in zero population growth.

Fertility: an indicator of progress

  • The latest National Family Health Survey reveals that Bihar, Jharkhand, Manipur, Meghalaya and Uttar Pradesh are the only outliers, with fertility levels above the average of the country.
  • Fertility is not about population control but about women’s right over reproductive decisions. It is an indicator of progress.


  • It is well known that fertility declines only when girls are educated, women are empowered and they have health and economic security.

Negative impacts of low TFR:

  • As already being experienced by developed countries, a low TFR comes with its own set of problems, for example, a skewed workforce – to – population ratio results in a high tax burden on those who are employed and a significantly lesser number of young people to take care of the elderly.
  • Utilising the population dividend by education and skilling. Every human being is a wonderful creature and an asset. There is a need to make sure that as our population grows, we do not end up being in the self-destructive mode as the rest of the world.
  • There is a need to fix the environment question without compromising the aspira­tional idea of a global middle class. The lifestyle of the global consuming class is about market forces and the economics that drives wealth creation.

There is a need to reduce the population by orders of magnitude, because humans are no longer a direct part of the natural food chain. For this, we have to focus on popula­tion regulation.

Third pole melting away


  • Himalayan glaciers have been disappearing 65% faster since 2010 which could drastically reduce water flows in the Indus, Ganga and Brahmaputra.


  • Latest assessment from the International Centre for Integrated Mountain Development (ICIMOD), an intergovernmental institute serving the eight Himalayan countries, pointed that the regions of the Hindu Kush Himalayas are seeing an increase in mean temperature, with an average observed trend of 0.28°C per decade from 1951 to 2020.
  • This is likely to impact the cryosphere, and in particular glacial melt, which is a major contributor of water for Himalayan rivers like the Ganga, the Brahmaputra and the Indus.

About Cryosphere:

  • It is the part of the Earth's climate system that includes solid precipitation, snow, sea ice, lake and river ice, icebergs, glaciers and ice caps, ice sheets, ice shelves, permafrost, and seasonally frozen ground.
  • The term “cryosphere” traces its origins to the Greek word 'kryos' for frost or ice cold.


Why Himalayan Glaciers are more vulnerable?

According to the ICIMOD:

  • Already, mass loss of glaciers has accelerated in the first two decades of this century.
  • One reason for the rapid ice loss is that the Tibetan plateau, like the other two poles, is warming at a rate up to three times as fast as the global average, by 0.3°C per decade.
  • The average elevation of the region is too high which favours absorbing energy from rising, warm, moisture – laden air.

What are the consequences?

  • If average global temperatures stay below 1.5°C, the region will experience more than 2°C of warming which can cause to lose 30 to 50 percent of Himalayan glaciers by 2100, and if emissions are not reduced, the rise will be 5°C.
  • Peak water in most basins will be reached around mid century, and water availability will decline by 2100.
  • The Hindu Kush Himalayas will also see a decline in snowfall of 30 to 50 per cent in the Indus basin; 50 to 60 percent in the Ganga basin; and 50 to 70 percent in the Brahmaputra basin between 2070 and 2100, as against the average from 1971 to 2000.
  • The ICIMOD noted an increase in disasters like landslides, avalanches and glacial lake outburst floods (GLOFs) in recent years. Warming may lead to an increase in snow avalanches, while glacial retreat will result in a rise in GLOFs, especially by the mid century.

About GLOF:

A glacial lake is formed as the ice in a glacier melts and water fills up the space between the glacier and the moraine – the wall of debris – in front of the glacier. As the pressure of water increases – due to melting or a trigger such as a large ice avalanche into the lake – the lake may breach the containing moraine walls, potentially driving millions of tonnes of water, boulders and debris before it.

  • For biodiversity, the report highlights range shifts, ecosystem degradation, species decline and extinction. By 2100, Indian Himalayas may see nearly a quarter of its endemic species wiped out, it says with medium confidence.

High stakes involved

  • About 60% of the Himalayan region features seasonal cryosphere (snow, glaciers, permafrost and glacial lakes), a major source of water and ecosystem services, which is vulnerable.
  • Two thirds of permafrost on the Tibetan Plateau will be degraded by 2071– 2099 under high emissions scenarios. Between 2002 – 2004 and 2018 – 2020, western Himalayas lost 8,340 sq km of permafrost area, while Uttarakhand Himalayas lost 965 sq km between 1970 – 2000 and 2001 – 2017.
  • Glaciers are time capsules. And when they melt, they release the elements of that recorded air back into circulation. As the frozen reserves of fresh water make their way down to the oceans, they are contributing to sea-level rise that is already making life difficult in the heavily populated low-lying deltas and bays.
  • The most detailed survey of the cryosphere in the Hindu Kush Himalayan region as part of the Hindu Kush Himalayan Monitoring and Assessment Programme conducted by the ICIMOD, highlighted the three key policy recommendations:
    • The world must focus on lowering carbon emissions. The challenges of managing the cryosphere will only increase if the world warms at a faster rate.
    • The expansion of observation networks and data-sharing agreements across the extended HKH region.
    • Improvements in research and observation should be used to anticipate disasters such as GLOFs and avalanches, and put processes in place to minimise their impacts.

Groundwater Extraction and Associated Issues


  • Excessive groundwater extraction is triggering land subsidence in the Indo – Gangetic plain.


  • Groundwater generally resides in pores or aquifers within the soil. When large amounts of groundwater are extracted year after year, a void is created in the pores. This causes collapse or compaction of the soil, leading to land subsidence.
  • The Indo – Gangetic plain, which has stratified layers of sand and clay, is highly prone to subsidence.