Global records show that the temperature of the earth’s surface has increased by 1º C on average since the 1800s. This rising trend is called global warming, and it crossed the 1.5º C mark partially in 2016, 2017, 2019, and 2023. The latest measurements from the Mauna Loa Observatory in Hawaii, which maintains the world’s longest record of measurements of atmospheric carbon dioxide, reveal a continuous rise in carbon emissions.
The daily average atmospheric concentration of carbon dioxide was found to have exceeded 430 parts per million (ppm) twice in early March this year. The long-term shift in the earth’s average temperatures and its consequences on climatic patterns at global and local levels are evident from the retreat of ice sheets and rising sea levels. Many projections suggest that by 2050, in many parts of the world including India, the surface temperature will surpass 2° C — a level considered dangerous by the UN Intergovernmental Panel on Climate Change (IPCC), not least because it threatens survivability limits.
India is currently the world’s fourth-most emitter of greenhouse gases. But while its per capita emission increased steadily between 1970 and 2022 — from 0.39 to 1.91 metric tonnes — it is significantly below the global average of 4.55 metric tonnes. Among the countries most affected by climate change, India is placed seventh.
Climate-related impacts, amplified by unregulated human interference that alters natural systems, are steadily transforming India’s socioeconomic and environmental landscape for the worse. The increasing frequency of natural disasters like landslides, forest fires, flash floods, and cyclonic storms has resulted in large-scale human and economic losses.
The land plays an important, sometimes essential, role in mediating their consequences. Climate change and deleterious anthropogenic activities work like a double whammy, posing a significant threat to India’s four major biodiversity hotspots: the Himalayas, the Western Ghats, the Sundaland (which includes the Nicobar Islands), and the Indo-Burma region. The country’s vulnerability to slow-onset events like retreating glaciers, rising sea levels, declining river flow and depleting groundwater is also becoming more evident.
Mountains under stress
The Himalayas are known as the ‘Third Pole’ because they contain the world’s largest quantity of freshwater after the two poles. The Himalayan region is key to the way India experiences climate change due to its role as a water tower: it influences the availability of water as well as patterns of the all-important monsoon.
Rising temperatures are causing Himalayan glaciers to retreat, threatening the flow rate of the Indus, Ganga, Brahmaputra, and Yamuna rivers, among others. Many of these rivers are also already stressed in other ways. For example, experts have said that a new dam being built by China will reduce the flow of the Brahmaputra in India’s northeast. For another, India recently suspended the Indus Waters Treaty with Pakistan, threatening a water crisis in the region. The natural flow of rivers has also been significantly altered by human-made structures like dams and is further endangered by deforestation and unsustainable withdrawal of water and sand.
It is also widely reported in the scientific literature that the frequency and intensity of extreme rainfall and temperature events have both increased thanks to changes in atmospheric circulation patterns that will affect the Indian monsoon as well as Western disturbances. A particularly visible consequence of these changes is glacial lake outburst floods (GLOF) like the one South Lhonak Lake in Sikkim suffered in 2023. The frequency of cloudbursts and forest fires has also been predicted to increase.
The complexity of the alteration of the Himalayan climate is related to factors like snow albedo, black carbon, and other suspended particulates. Aside from contributing to warming the atmosphere, black carbon (a.k.a. soot) also settles on snow-covered surfaces, absorbs more solar radiation, heats up, and causes the snow to melt faster.
The construction of the Char Dham road, which connects four major Hindu pilgrimage centres in the Uttarakhand Himalaya, has led to a significant rise in vehicular traffic. Black carbon is a well-known product of the combustion of fossil fuels, and the increasing spiritual tourism in the region is causing ice sheets to melt faster. Because of the presence of black carbon and aerosols — some of which also absorb sunlight — the higher Himalayas have become more sensitive to a rise in temperature during the winter compared to the foothills.
The vanishing waterworld
Since the Green Revolution in the 1960s, groundwater has been a major source of irrigation water to feed water-hungry crops, especially rice. But reaping this agricultural bounty also meant the overuse of fertilisers and the exploitation of groundwater.
For this reason alone, the aquifer level in the country’s Gangetic plains has been dropping by about 4 cm per year. Taken together with erratic weather that has been known to dump too much or too little rainfall in areas that used to receive a consistent amount, productivity and income from agricultural lands are dropping.
Outside the Gangetic plains, Rajasthan is facing an acute water shortage because of frequent droughts, the extraction of groundwater, as well as the long-standing natural paucity of groundwater in that region.
According to official data, India’s groundwater utilisation has increased from 10-20 km3 to 240-260 km3 in the last 50 years. In a performance audit conducted by the Comptroller and Auditor General in 2015-2016, 14 of 24 States were found to have subpar water management practices. These underforming States were concentrated across the populous agricultural belts of north and east India, plus the northeastern and Himalayan states. A 2019 report drafted by NITI Aayog stated that 40% of Indians, or about 500 million people, will have “no access to drinking water” by 2030 and that several major cities already run the risk of dry aquifers.
Along with the dwindling groundwater sources, its contamination has reached alarming proportions in several parts of the country. Large-scale pumping transfers the arsenic present in deeper reaches to shallower depths, and the pumped water consequently contaminates the soil and accumulates in paddy grains. One global water quality index thus ranks India 120th among 122 countries.
The country-wide depletion of aquifers has resulted in many perennial rivers of central and southern India becoming seasonal. Rivulets and streams across the country have also been reduced to drains or sewers thanks to the expansion of the built environment onto riverbeds and the dumping of waste, especially of the untreated variety.
The only way the plan to interlinking the country’s major rivers (in the form of inter-basin water transfers) in order to move “extra water” from a “water-surplus” area to a “water-deficient” area can surmount the water crisis is also by junking all the best scientific and ecological research. As The Hindu wrote in an editorial in December 2024 about the Ken-Betwa interlink, work on which Prime Minister Narendra Modi has flagged off:
“That a river interlink will water fields and quench thirst is irrefutable, but for how long? Various studies have asserted that the Ken and the Betwa basins suffer floods and droughts together, that the subcontinent’s rainfall and sedimentation patterns stand to be altered, and that the Betwa basin can be replenished more affordably by maintaining environmental flows and bolstering natural storage. The government’s principal claim is that the Ken and the Betwa basins are respectively water-surplus and water-deficient. This is disingenuous: the Betwa basin is water-deficient strictly because it hosts several lakh hectares of irrigated cropland. Should the demand in the Ken basin increase, both areas will suffer.”
As increasing temperatures and environmental degradation threaten to reduce farm productivity, the transformative potential of the methods of the Green Revolution hinges on introducing green technologies, including new high-yielding seed varieties that respond better to water stress. Farmers will also gain if they follow practices like zero-tillage and minimal soil disturbance, so that the soil can develop a permanent cover of organic material derived from crop residues; and diversify the crops they sow.
In light of these facts, India must develop a national water policy to manage aquifers effectively, in particular regulating the use of natural water resources and improving its reuse.
The sea thirsts for the land
Sea levels are rising around the world thanks in most part to two factors related to global warming: the water added to the seas from melting ice sheets and glaciers and the expansion of sea water as it warms. Data from tide gauges in the water as well as satellites in earth orbit have shown that the global average rise over the last decade has been 3.6 mm per year. If greenhouse gases are allowed to accumulate at their current rate in the atmosphere, projections indicate that sea levels may rise by at least 0.4-0.8 m by 2100. This could be terrible for major coastal cities in India like Mumbai, Chennai, and Kolkata. Some scientific studies have found that Mumbai will probably be the worst-hit and that it already experienced a sea-level rise of 4.44 cm between 1987 and 2021.
More than 20% of India’s population — about 250 million people — lives within 50 km of the sea and the country’s 7,500-km-long coastline is already considered to be among the world’s most vulnerable to the consequences of climate change. Sea-level rise also poses a significant threat to coastal ecosystems like mangrove forests, coral reefs, estuaries, and wetlands, which are habitats for diverse species and serve as natural barriers against cyclones, storm surges, and erosion. Sea-level rise is also exposing many coastal communities to salinisation, which will destroy crops, degrade fish stock, and ultimately further strain the strained lives of marginalised people that depend on these resources.
Long-term strategies to counter this threat include creating buffer zones along the coast to forestall sea water while creating social safety nets that keep any water-related consequences on the people from pushing them into poverty or debt. In fact, finding alternative sources of income for these people as well as facilitating community-based decision-making is essential to build resilience against the rising seas. Restoring degraded coastal ecosystems can also confer natural protections against the effects of extreme weather.
In sum, our efforts to adapt to sea-level rise must include better flood-defence infrastructure that protects coastal cities, early-warning systems for climate-induced disasters that help people move to safety and reduce loss of lives and property, and the restoration of ecosystems like mangrove forests. Just last month, it was reported that the residents of a hamlet named Rejosari Senik in Indonesia, where water levels have risen so much in the last 50 years that its houses stand on stilts and people use boats rather than bicycles to travel, have been planting 15,000 mangrove trees a year for two decades even as “Indonesia plans to build a 700-km-long sea wall to keep sea-level rise at bay”.
The climate-resilient society
Climate reports prepared by the IPCC define ‘vulnerability’ as the propensity to be adversely affected by climate change. It applies to humans as well as to ecosystems. According to one World Bank estimate, the climate crisis could cost India 6.4% to more than 10% of its national income by 2100 and push 50 million people into poverty. The Government of India also said in its most recent Economic Survey that “developing countries such as India need to undertake climate adaptation on an urgent footing as this has a direct impact on lives, livelihoods and the economy”.
Considering the crucial role the land and its attendant ecosystems play in determining how Indians experience climate change, the importance of land-use policies should be at par with policies to ensure carbon neutrality. If India is serious about the commitments it has made in international climate-related fora, its land-use policies should have sustainability at their collective heart.
Unfortunately, reality is more dire: the country’s push to expand public infrastructure is fuelling deforestation en masse in many parts of the country. While such infrastructure is important, the realities of climate change are such that if the government sidesteps good-faith environmental governance and allows resource extraction and construction at the expense of sustainability, the infrastructure will have no net benefits.
An example of a particularly concerning project in this vein is the Indian government’s plan to build a large transshipment port in Great Nicobar. The island is a biodiversity hotspot, yet the project proponents plan to clear about 130 sq. km of forests and displace tribal communities. The Ken-Betwa river interlinking project, with a sanctioned cost of ₹44,605 crore, has also been controversial because the government signed off on it even though it doesn’t have all the requisite green clearances.
Another area of concern is the future trajectory of India’s urban landscape. The expansion of built-up areas in big cities at the cost of blue and green spaces has led to profound urban heat-island effects. People with ramshackle living arrangements — particularly in urban slums and tenements built to accommodate a high density of people but without sufficient ventilation, both of which are also far removed from green spaces — are especially vulnerable to heat stress as a result.
National housing-related missions will be well-served if they adopt design and construction practices that keep the amelioration of heat stress in mind at every decision point. The new crop of ‘smart buildings’ around the country shows one way to do this, but they are also part of gentrified localities and thus unaffordable to most people. Increasing the coverage and quality of urban green spaces and permeable surfaces will also enhance floodwater control and groundwater recharge.
C.P. Rajendran is an adjunct professor at the National Institute of Advanced Studies, Bengaluru. This article benefited from ideas in the paper ‘Navigating the impact of climate change in India: a perspective on climate action (SDG13) and sustainable cities and communities (SDG11)’, Frontiers in Sustainable Cities 2024, and the book ‘A Better Planet: Forty Big Ideas for a Sustainable Future’, Yale University Press 2019.