India has reason to be concerned about the effects of climate change2. Across its geography, India shows a wide range of climatic conditions – from the high altitude Himalayas to the marine climates of the coastline and islands; from the arid deserts of the north-west to the tropical forests of the north-east. Owing to this complex geography, the consequences of changes in climate would vary greatly across the different climatic zones of the country.
Much of the climate and a large proportion of the economy depend on the South West Monsoon – the short three-month period over which nearly all the rainfall occurs over the subcontinent. Any changes in the monsoon will further stress water availability and distribution across the subcontinent.
Regional climate model simulations for India indicate that a 0.4 °C rise in annual air surface temperature has already taken place2. Predicted increases in maximum and minimum temperatures and increased frequency and intensity of floods and drought are likely to adversely affect agriculture, ecosystems, coastal zones, health and infrastructure.
Projections of rainfall vary from model to model, but it is projected climate change will affect water balance in various parts of the country, and alter the quality of ground water.
Reduced water availability – owing to glacier retreat and decreased rainfall will increase water stress. These and other impacts become significant in light of projected water demands from a growing population: estimated to rise to 980 billion cubic metres by 2050.
River basins of west-flowing Mahi, Pennar, Sabarmati and Tapati are likely to experience constant water scarcities, while the river basins of the Cauvery, Ganga, Narmada and Krishna are likely to experience seasonal or regular water-stressed conditions.
Agriculture
Sixty-eight percent of agriculture in India is rain-fed, and depends heavily on the quantity and distribution of rainfall2. Predicted effects include a drop in wheat production if the effects of climate change are ‘pessimistic’ – i.e, higher temperature increase.
Ecosystems
Regional climate model predictions indicate shifts in forest boundary, changes in species assemblages, and 70 percent of forest vegetation likely to be less optimally adapted to their existing locations. These are long-term and irreversible impacts, for which long-term adaptation strategies need to be developed. Mangroves submergence and increased wetland salinity are likely to occur with sea level rise, as also bleaching of degraded coral reefs that are typical to South Asia.
Coastal Areas
India’s coastline is densely populated – with an average population density of 455 persons per km2 as opposed to the national average is 324. Adverse effects are likely to be worsening of existing coastal zone problems such as erosion, flooding, and the submergence and deterioration of coastal ecosystems.
A one-meter sea level rise could displace about 7.1 million people, and result in the loss of 5674 sq. km of land, damage coastal infrastructure and result in the salinisation of fertile agricultural soils.
Health
Similar to other tropical countries, India is predicted to have increased susceptibility to vector-borne diseases such as malaria – projected to move to higher latitudes and altitudes, covering ten percent more area in 2080 than it did in 2000.
References
- Amarasinghe et al. India’s water supply and demand from 2025-2050: Business as Usual Scenario and Issues. IWMI
- India National Communications. 2004
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