Climate change scenario prevalent in India
Many studies have pointed to the nation’s vulnerability to climate change. With changes in key climate variables, namely temperature, rainfall and humidity, crucial sectors like agriculture and rural development are likely to be affected in a major way.
Impacts are already being seen in unprecedented heat waves, cyclones, floods, droughts, salinisation of the coastline and effects on agriculture, fisheries and health.India is home to a third of the world’s poor, and climate change will hit this section of society the hardest. India, set to be the most populous nation in the world, overtaking China by 2045, the economic, social and ecological price of climate change payable by her citizens will be tremendous. The future impacts of climate change include:
· Decreased snow cover, affecting snow-fed and glacial systems such as the Ganges and Bramhaputra. Notably, 70% of the summer flow of the Ganges comes from melt-water.
· Drop in wheat production by 4-5 million tones, with even a 1ºC rise in temperature.
· Rising sea levels causing displacement along one of the most densely populated coastlines in the world, threatening freshwater sources and mangrove ecosystems like the Sunderbans.
· The various studies conducted in the country have shown that the surface air temperatures in India are going up at the rate of 0.4 ºC per hundred years, particularly during the post-monsoon and winter season. Using models, they predict that mean winter temperatures will increase by as much as 3.2 ºC in the 2050s and 4.5 ºC by 2080s, due to Greenhouse gases. Summer temperatures will increase by 2.2 ºC in the 2050s and 3.2 ºC in the 2080s.
· Extreme temperatures and heat spells have already become common over Northern India, often causing loss of human life. In 1998 alone, 650 deaths occurred in Orissa due to heat waves.
· Climate change has had an effect on the monsoons too. India is heavily dependent on the monsoon to meet its agricultural and water needs, and also for protecting and propagating its rich biodiversity. Subtle changes have already been noted in the monsoon rain patterns by scientists at IIT, Delhi. They also warn that India will experience a decline in summer rainfall by the 2050s, summer rainfall accounts for almost 70% of the total annual rainfall over India and is crucial to Indian agriculture.
· Apart from monsoon rains, India uses perennial rivers, which originate and depend on glacial melt-water in the Hindukush and Himalayan ranges. Since the melting season coincides with the summer monsoon season, any intensification of the monsoon is likely to contribute to flood disasters in the Himalayan catchment. Rising temperatures will also contribute to the raising of snowline, reducing the capacity of this natural reservoir, and increasing the risk of flash floods during the wet season.
· Increased temperatures will impact agricultural production. Higher temperatures reduce the total duration of a crop cycle by inducing early flowering, thus shortening the `grain fill’ period. The shorter the crop cycle, the lower the yield per unit area.
· A trend of sea level rise of 1 cm per decade has been recorded along the Indian coast. Sea level rise due to thermal expansion of sea water in the Indian Ocean is expected to be about 25-40 cm by 2050. This could inundate low lying areas, down coastal marshes and wetlands, erode beaches, exacerbate flooding and increase the salinity of rivers, bays and aquifers.
· Deltas will be threatened by flooding, erosion and salination. Loss of coastal mangroves will have an impact on fisheries. The major delta area of the Ganga, Brahmaputra and Indus rivers, which have large populations reliant on riverine resources will be affected by changes in water flow, salt water intrusions and land loss.
· Increase in temperature will result in shifts of lower altitude tropical and subtropical forests to higher altitude temperate forest regions, resulting in the extinction of some temperate vegetation types. Decrease in rainfall and the resultant soil moisture stress could result in drier teak dominated forests replacing sal trees in central India. Increased dry spells could also place dry and moist deciduous forests at increased risk from forest fires.
· Medical Science suggests that the rise in temperature and change in humidity will adversely affect human health in India. Heat stress could result in heat exhaustion, heat stroke, and damage physiological functions, metabolic processes and immune systems. Increased temperatures can increase the range of vector borne diseases such as malaria, particularly in regions where minimum temperatures currently limited pathogen and vector development.
Mitigating Climate Change
While knowledge about the impact of climate change on current water and crop production is still nascent, mitigating and bringing a halt to climate change is not within the capability of one country alone. Hence adaptation strategies by Indian government are more likely to save livelihoods and ensure food security rather than be wholesome mitigation strategies.
At the outset we need to maintain the sustainability of water-based ecosystems by ensuring adequate water supplies to meet the food and non-food needs of a growing population. As agriculture is the largest user of water in India (using more than 80 percent of usable freshwater) and a large proportion of the population derives its livelihood directly or indirectly from it, we need to build efficient irrigation systems and adopt water conservation strategies. This we need to do more in semiarid regions through combined use of surface and groundwater in India.
The main thrust of the program to combat the impact of climate change in the rainfed areas should be on activities relating to rainwater harvesting, soil conservation, land shaping, vegetative bunding and water resources conservation on the basis of the entire compact micro-watershed which would include both cultivated and uncultivated lands. In the preparation of the watershed development plans, for which the National Rural Employment Guarantee Scheme (NREGS) funds can also be used, user groups and other people depending directly on the watershed should be actively involved. However, there are strong social and political constraints leading to modest success.
Although the Government have been implementing watershed projects for more than a decade, evaluation reports show that these projects cannot succeed without full participation of project beneficiaries and careful attention to issues of social organization and motivation. This is because success depends on consensus among a large number of stakeholders. Further, the costs and benefits of watershed interventions are location specific and unevenly distributed among the affected people. Unfortunately, most projects have become unsustainable because of the extremely limited success of government agencies to involve the people and build their social capital. Finally, there is political reluctance to control water hungry crops in low rainfall regions, such as sugarcane in Maharashtra and paddy in Punjab. One would need stricter implementation of environmentally sound cropping patterns and regulation of use of groundwater. Incentives should be given to cultivators to move away from crops that tempt them to ‘rob’ water from their neighbours.
In view of the impending threats caused by climate change, regulating the unrestrained exploitation of groundwater and aggressive pursuit of water conservation should become a national priority. Drip irrigation and water sprinkler approach, mulching and bed plantation, construction of tanks and “Hapa”s should be promoted for water harvesting and conservation. Its impact is visible in blocks of Bankura , Purulia where there has been a large scale digging of Hapa/ Jaladhar models and 30-40 models for water and soil conservation.
Forest is a natural carbon absorber. A programme for massive tree plantation and control on open grazing will help in the regeneration of forests and slow down the process of desertification. Agro-forestry can be the answer. For instance, trees may fertilise the soil for agricultural crops or may provide shade from sun or shelter from wind. Complementary relationship between trees and crops may also be in labour use, especially when the two outputs draw labour resources at different time of a year.
With unpredictable weather in future, farmers will have to change crop management practices, grow tougher plant varieties and be prepared for constant innovation in the way they operate. In some areas one may consider developing strategies for crop substitution that is to replace wheat with millets, tubers like potato, yams and cassava.
As occurrence of flood is likely to increase in many parts of India, one needs better systems for detection and forecasting of floods and popularise rainfall tolerant and short duration varieties or shift cropping pattern to the rabi (winter crop) season by increasing access to irrigation in those months. Income diversification provides a robust way of mitigating flood risks. In coastal areas aquaculture holds considerable potential if the supply chain and marketing are improved.
