India is already experiencing a warming climate.

Unusual and unprecedented spells of hot weather are expected to occur far more frequently and cover much larger areas.

Under 4°C warming, the west coast and southern India are projected to shift to new, high-temperature climatic regimes with significant impacts on agriculture.

With built-up urban areas rapidly becoming “heat-islands”, urban planners will need to adopt measures to counteract this effect.

A decline in monsoon rainfall since the 1950s has already been observed. The frequency of heavy rainfall events has also increased.

A 2°C rise in the world’s average temperatures will make India’s summer monsoon highly unpredictable.

At 4°C warming, an extremely wet monsoon that currently has a chance of occurring only once in 100 years is projected to occur every 10 years by the end of the century.

An abrupt change in the monsoon could precipitate a major crisis, triggering more frequent droughts as well as greater flooding in large parts of India.

India’s northwest coast to the south eastern coastal region could see higher than average rainfall.

Dry years are expected to be drier and wet years wetter.

Improvements in hydro-meteorological systems for weather forecasting and the installation of flood warning systems can help people move out of harm’s way before a weather-related disaster strikes.

Building codes will need to be enforced to ensure that homes and infrastructure are not at risk.

Evidence indicates that parts of South Asia have become drier since the 1970s with an increase in the number of droughts.

Droughts have major consequences. In 1987 and 2002-2003, droughts affected more than half of India’s crop area and led to a huge fall in crop production.

Droughts are expected to be more frequent in some areas, especially in north-western India, Jharkhand, Orissa and Chhattisgarh.

Crop yields are expected to fall significantly because of extreme heat by the 2040s.

Investments in R&D for the development of drought-resistant crops can help reduce some of the negative impacts.

More than 60% of India’s agriculture is rain-fed, making the country highly dependent on groundwater.

Even without climate change, 15% of India’s groundwater resources are overexploited.

Although it is difficult to predict future ground water levels, falling water tables  can be expected to reduce further on account of increasing demand for water from a growing population, more affluent life styles, as well as from the services sector and industry.

The efficient use of ground water resources will need to be incentivized.

Glaciers in the northwestern Himalayas and in the Karakoram range – where westerly winter winds are the major source of moisture – have remained stable or even advanced.

On the other hand, most Himalayan glaciers – where a substantial part of the moisture is supplied by the summer monsoon – have been retreating over the past century.

At 2.5°C warming, melting glaciers and the loss of snow cover over the Himalayas are expected to threaten the stability and reliability of northern India’s primarily glacier-fed rivers, particularly the Indus and the Brahmaputra.  The Ganges will be less dependent on melt water due to high annual rainfall downstream during the monsoon season.

The Indus and Brahmaputra are expected to see increased flows in spring when the snows melt, with flows reducing subsequently in late spring and summer.

Alterations in the flows of the Indus, Ganges, and Brahmaputra rivers could significantly impact irrigation, affecting the amount of food that can be produced in their basins as well as the livelihoods of millions of people (209 million in the Indus basin, 478 million in the Ganges basin, and 62 million in the Brahmaputra basin in the year 2005).

Major investments in water storage capacity would be needed to benefit from increased river flows in spring and compensate for lower flows later on.

Mumbai has the world’s largest population exposed to coastal flooding, with large parts of the city built on reclaimed land, below the high-tide mark.  Rapid and unplanned urbanization further increases the risks of sea water intrusion.

With India close to the equator, the sub-continent would see much higher rises in sea levels than higher latitudes.

Sea-level rise and storm surges would lead to saltwater intrusion in the coastal areas, impacting agriculture, degrading groundwater quality, contaminating drinking water, and possibly causing a rise in diarrhea cases and cholera outbreaks, as the cholera bacterium survives longer in saline water.

Kolkata and Mumbai, both densely populated cities, are particularly vulnerable to the impacts of sea-level rise, tropical cyclones, and riverine flooding.

Building codes will need to be strictly enforced and urban planning will need to prepare for climate-related disasters.

Coastal embankments will need to be built where necessary and Coastal Regulation Zone codes enforced strictly.

Even without climate change, world food prices are expected to increase due to growing populations and rising incomes, as well as a greater demand for biofuels. 

 Rice: While overall rice yields have increased, rising temperatures with lower rainfall at the end of the growing season have caused a significant loss in India’s rice production. Without climate change, average rice yields could have been almost 6% higher (75 million tons in absolute terms).

Wheat: Recent studies shows that wheat yields peaked in India and Bangladesh around 2001 and have not increased since despite increasing fertilizer applications. Observations show that extremely high temperatures in northern India – above 34°C – have had a substantial negative effect on wheat yields, and rising temperatures can only aggravate the situation.

Seasonal water scarcity, rising temperatures, and intrusion of sea water would threaten crop yields, jeopardizing the country’s food security.

Should current trends persist, substantial yield reductions in both rice and wheat can be expected in the near and medium term.

Under 2°C warming by the 2050s, the country may need to import more than twice the amount of food-grain than would be required without climate change.

Crop diversification, more efficient water use, and improved soil management practices, together with the development of drought-resistant crops can help reduce some of the negative impacts.

Climate-related impacts on water resources can undermine the two dominant forms of power generation in India – hydropower and thermal power generation – both of which depend on adequate water supplies to function effectively.

To function at full efficiency, thermal power plants need a constant supply of fresh cool water to maintain their cooling systems.

The increasing variability and long-term decreases in river flows can pose a major challenge to hydropower plants and increase the risk of physical damage from landslides, flash floods, glacial lake outbursts, and other climate-related natural disasters.

Decreases in the availability of water and increases in temperature will pose major risk factors to thermal power generation.

Projects will need to be planed taking into account climatic risks.

Many parts of India are already experiencing water stress. Even without climate change, satisfying future demand for water will be a major challenge.

Urbanization, population growth, economic development, and increasing demand for water from agriculture and industry are likely to aggravate the situation further.

An increase in variability of monsoon rainfall is expected to increase water shortages in some areas.

Studies have found that the threat to water security is very high over central India, along the mountain ranges of the Western Ghats, and in India’s northeastern states.

Improvements in irrigation systems, water harvesting techniques, and more-efficient agricultural water management can offset some of these risks.

Climate change is expected to have major health impacts in India- increasing malnutrition and related health disorders such as child stunting – with the poor likely to be affected most severely. Child stunting is projected to increase by 35% by 2050 compared to a scenario without climate change.

Malaria and other vector-borne diseases, along with and diarrheal infections which are a major cause of child mortality, are likely to spread into areas where colder temperatures had previously limited transmission.

Heat waves are likely to result in a very substantial rise in mortality and death, and injuries from extreme weather events are likely to increase.

Health systems will need to be strengthened in identified hotspots.

Improvements in hydro-meteorological systems for weather forecasting and the installation of flood warning systems can help people move out of harm’s way before a weather-related disaster strikes.

Building codes will need to be enforced to ensure that homes and infrastructure are not at risk.

South Asia is a hotspot for the migration of people from disaster-affected or degraded areas to other national and international regions.

The Indus and the Ganges-Brahmaputra-Meghna Basins are major trans boundary rivers, and increasing demand for water is already leading to tensions among countries over water sharing.

Climate change impacts on agriculture and livelihoods can increase the number of climate refugees.

Regional cooperation on water issues will be needed.