The Earth's climate has been changing throughout the history, but the current warming trend of the earth is of significant concern to the world because it is induced by humans at an unprecedented rate in the past 1300 years (IPCC Fourth Assessment Report, 2007). A number of evidences are produced by the scientists to show that the average temperature of earth is rising along with the rising sea-level. According to the CSIRO (2008) report, the global sea level rose to about 17 centimetres (6.7 inches) in the last century. However, the rate in the last decade is nearly double than that of last century. It is also seen that most of the warming has occurred since 1970s, with the 20 warmest years having occurred since 1981 and with all 10 of the warmest years occurring in the past 12 years (Peterson et.al, 2009). The recent report from Intergovernmental Panel on Climate Change (2007), estimates that the global average land and sea surface temperature has increased by 0.6 ±0.2 C since the middle of 19th century, with most of the change occurring since 1976.
Scientists have proved that one of the main causes for the current global climate change situation is attributed to the human expansion of the "green house effects"- the warming that results when the atmosphere traps the heat radiating from the Earth toward space. In the IPCC Fourth assessment report 2007, a group of 1,300 independent scientific experts from countries all over the world working under United Nations, concluded that there is more than 90% probability that human activities over the past 250 years have warmed the planet. The panel also found out that the industrial activities of modern civilization have raised the atmospheric carbon dioxide levels from 280 parts per million to 379 parts per million in the last 150 years. They concluded that the human produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in Earth's temperature over past 50 years. The IPCC also warned that if the introduction of these greenhouse gases is continued at the same rate, global temperature could rise up by 2.40°C to 6.40°C by the end of the century and thus will cause a major impact on global climate change. Global warming can have a disturbing effect on the human, animal and plant life. Thus it is a major threat to all the nations of the world (IPCC, 2007).
Global climate change: India's perspective
India is a developing country with a population of more than 1 billion people. It has close economic ties to the natural resources and climate-sensitive sectors such as agriculture, fishing, water and forestry. India has seen a rapid rise in the use of energy resources and greenhouse gases emission in the past 50 years due to structural changes in the Indian economy by moving from agricultural base to industrial base. According to DOE (2000), the carbon dioxide emission for India in the year 2000 was about 250 million metric tons of carbon equivalents, and these emissions are expected to grow in the future with the growth in economy. As it is a developing country the energy needs of nearly 700 million people of rural areas are various rural industries are met by biomass. However, it is noticed that the growth of biomass energy has been stagnated because of the growth in the fossil fuel consumption. Most of the carbon emissions arise from the use of coal in the electric power and industry sectors, the agriculture and livestock sectors emit substantial amounts of methane (Shukla et.al, 2003). However in per capita terms, the difference between emission of carbon by India and other developed nations like United States of America is reasonably high. For example, an Indian citizen emits less than 0.25 tonnes of Carbon per year whereas a citizen of the USA emits almost more than 5.5 tonnes (Parikh et.al, 1991).
How will the global climate change affect India?
The Government of India's National Communications (NATCOM) in 2004, identified the future impacts of climate in India which includes:
Erratic monsoon with serious effects on rain-fed agriculture, peninsular rivers, water and power supply
Decreased snow covers resulting in melting of glacial systems such as the Himalayas from where big rivers such as Ganges and Brahmaputra originates. 70% of the summer flow of the Ganges comes from melt-water
Rising sea levels causing displacement along the densely populated cost lines like Mumbai, Chennai and Gujarat.
Drop in the agriculture production, where it is projected that the wheat production will drop by 4-5 million tonnes, with even 1°C rise in temperature
Increased frequency and intensity of floods as well as droughts
Increase in the occurrence of vector borne diseases like malaria, dengue, chikungunya and filariasis.
Impact of Global Climate Change on Water Availability and Water Resources of India
In India, several studies have been conducted which found that there is increasing trend in surface temperature and no significant decreasing/ increasing trends in rainfall (Kothwale and Kumar R., 2005; Mall et.al, 2006). Several studies have been reported in order to assess the impact of climate change situation on hydrology of various basins and regions. However, few studies are conducted for the hydrological impacts of possible climate change for an Indian region/basin (Chattopadhyay and Hulme, 1997 ; Gosain and Rao, 2003). The demand for water has already increased in India due to rapid urbanization, agriculture expansion, industrialization and economic development.
Groundwater has been the main source of water for domestic needs of more than 80% of rural and 50% of urban population in India. Besides this it is also noted that 70-80% of the value of irrigated production in India comes from the groundwater irrigation. Thus around two-fifth of India's agriculture output is contributed by groundwater irrigation. It has also been estimated that ground water contributes around 9% to the Gross Domestic Product (GDP) of India (Mall et.al, 2006). Climate change will result in the shortage of water resources due to increasing pressure in the Indian subcontinent. Currently, more than 45% of the average annual rainfall, including the snowfall is wasted by natural run off to the ocean. However, the Government of India has introduced many rain water harvesting schemes by building the check dams around various small rivers in order to increase the ground level water (Burjia J. and Romani S., 2003).
The hydrolytic cycle will be accelerated by warmer climate thus altering rainfalls, magnitude and timing of run-off. Warm air holds more moisture in the atmosphere and increase evaporation of surface moisture. Thus with more moisture in the atmosphere rainfall and snowfall events will be more intense, increasing the potential for floods. However, if there is very less or no moisture in soil to evaporate, the incident solar radiation goes into raising the temperature, which can contribute to more longer and severe drought. A number of studies have been reported to access the climate change scenarios on hydrology of various basins and regions and it is found that increasing temperature and decline in rainfall may reduce net recharge and affect groundwater levels (Mirza et.al., 2003).Therefore, climate change will affect the soil moisture, groundwater recharge and frequency of flood and drought and finally groundwater levels in different areas of country (Trenberth, 1999).
How climate change can influence the moisture content in atmosphere and alter the rainfall can be shown by following figure:
Figure 1: Conceptual framework of effect of green house gases and global warming on the hydrolytic cycle and phenomenon associated with climate extreme events (Adapted from- Trenberth, 1999)
Linkage of rainfall with population, food and fresh water needs of India
The average long-term annual rainfall in India is about 117 cm; however, this rainfall varies according to time. Almost 75% (88cm ± 10 SD) of the long-term average rainfall comes in four months i.e. June-September (southwest monsoon season). The northeast region of India, situated along the west coast of peninsular India, receives heavy rainfall of around 200-400 cm every year. The average rainfall over the northern part of India running parallel to the foothills of the Himalayas varies from about 150 cm in the east to 50 cm in the west. Over the central part of India it varies from 150 cm in the eastern half to about 50 cm on Western Ghats side. In the southern part of Indian peninsula, the average rainfall varies from 100 to 75 cm from east to west. While on the other hand some regions such as western Rajasthan receive very less annual rainfall of mere 15cm or even less. Along with this there are considerable intra-seasonal and inter- seasonal variations as well. The year-to-year variation in monsoon causes extreme hydrological events resulting in the lowering of agricultural output and affecting the national economy. Climate change and global warming have enhanced the variation in monsoon rainfall in India and it leads to extreme events like floods and draught in the country (Mall et.al, 2006).
The current population of India is around 1.18 billion which accounts for almost 17.31% of world population (Indian Population Department, 2010). A major part of India's population around 1027 million with decadal growth from 21.34% from 1991 to 2001 is rural and agriculture oriented and mainly survive on the rivers and ground water for water resources. According to the United Nations, the world population grew at the rate of 1.4% during 1990-2000, while for India it was almost 1.9% during the 1991-2001 decade period. Thus due to the high rise in population the country is facing acute shortage of fresh water in some parts of states like Rajasthan, North Gujarat, Punjab and major cities like Mumbai and Delhi.
The average food consumption in India at present is about 550g per capita per day, whereas for China and USA it is around 980 and 2850 g respectively. The present annual requirement based on the consumption level of 550 g is about 210 million tonnes (mt) which is almost equal to the current production. The food grain production was very impressive in 1999-2000, which was more than four times the production of 50.82 mt in 1950-51. But however the country faces major challenges to increase the food production by 300 mt by 2020 in order to meet the ever- growing population need, that is likely to reach 1.30 billion by 2020. Thus in order to meet this demand for food with increasing population the farmers of India need to produce 50% more grain by the year 2020(Agriculture statistics at glance, 2003, http://agricoop.nic.in/statatglance2003.htm). Hence it is feared that the increasing demand for food in the future two or three decades could be very challenging looking at the current serious problems of soil degradation and climate change (Mall et.al., 2006).
Figure 2: Shows the observed and projected decline in per capita average annual fresh water availability and growth of population from 1951 to 2050.
Source- (Mall R., et.al, 2006)
This figure clearly indicates that the demand for fresh water is increasing with the increase in the population which will result in faster withdrawal of water from ground which in turn will reduce the recharging time of the water-tables. As a result, the availability of water will reach a critical level sooner or later till the end of 2035. Climate change will result in the unpredictable monsoon rainfall which in turn will lead to extreme events like droughts/floods and cause a catastrophic effect on population.
Water resources in India
India has various water resources and is gifted with several rivers. As many as 12 rivers among them are classified as major rivers, with catchment area of 252.8 mha and average annual potential in rivers is 1570.98 b.cu.m. While another 48 rivers are classified as medium rivers with total catchment area of 24.9 mha (Water and Related Statistics p.479, 2002).the total annual discharge of water by these rivers amounts to almost 1869 km³. Few rivers are seasonal while many rivers like Ganges, Brahmaputra and Cauvery are perennial. However the amount of water in these rivers is not always the same it depends on the monsoon season and varies during the months from June to September. These rivers however, remain at the high state throughout the monsoon season. The heavy rains develop large run-off in the catchments which may last for several hours to few days (Kale V.S., 1998).
The average water yield per unit area of the rivers originating from the Himalayan Rivers is almost double than that of south peninsular river systems this shows the importance of snow and glacier melt contribution from high mountains. Average intensity of mountain glaciations varies from 3.4% for Indus, 3.2% for Ganges and 1.3% for Brahmaputra. Apart from the monsoon rains the Himalayan mountain glaciers contribute a lot to the development of water resources for the north-east region of India. Global warming has caused a significant impact on the hydrological cycle and many hydrological events have occurred due to extreme weather conditions in this region of Indian subcontinent (Ives and Messerli, 1989). Frequent hydrological disasters like enhanced variability in rainfall and run-off, extensive reservoir sedimentation and pollution of lakes have been caused recently as a result of the climate change (Ramakrishnan P.S., 1999)
Scientists from NASA have identified that the groundwater in north-western India is being depleted at an average rate of 4 cm a year equivalent height of water. It was determined using the GRACE (Gravity Recovery and Climate Experiment) satellites. This amounts to about 18 cubic km of water per year. The researchers also examined that the water table is declining at a rate of one metre every three years, averaged over the Indian states of Rajasthan, Punjab, and Haryana. This figure by the researchers of 18 cubic km a year of groundwater depletion is roughly 5 cubic km higher than the Indian ministry of Water Resources. It was found that around 114 million people live in the region where around 95% of groundwater withdrawals are for the irrigation of crops such as rice, wheat and barley. This enhances the depletion rate of groundwater; it can only be lessen by implementing more efficient irrigation methods and asking farmers to shift away from water-intensive crops such as rice. Indeed the Indian government has started to propose the regulation to reduce the consumption of groundwater after the publication of such research work which clearly indicated shortage of groundwater (Kalaugher, 2009)
Projected climate change during the next century over India
Region
All -India
All- India
All- India
Temperature
Increase in winter temperature by 1-4°C with increased CO2
Average temperature change is predicted
to be in the range of 2.33 to 4.78°C,
with a doubling in CO2 concentration
A general increase in minimum
temperature up to 4°C all over the
country
Rainfall
Precipitation increase of approximately 20%.Increase in heavy rainfall days during the summer monsoon period and an increased inter-annual variability.
Increase in frequency of heavy rainfall events.
Increase in rainy days intensity by 1-4 mm/day, except for small areas in
northwest India, where rainfall intensities may decrease by 1 mm/day
Sources- ( Bhaskaran B., et al., 1995 ; Lonergan S., 1998 ; Lal, M et al., 2001 ; Rupakumar, K. et al., 2003)
The climate change will not only have its impact on groundwater but it will severely affect the rain-fed (non-irrigated) agriculture, which is practised by small and marginal farmers who will suffer the most. The most vulnerable crops include the pulses and oilseeds which are already in short supply and are consequently high-priced. It was found that nearly 80 million hectares, out of country's total sown are of around 143 million hectares, lack the basic irrigation facilities and thus have to rely fully upon the rainwater for crop growth. Nearly 65% of cotton seed, 75% of oilseeds and over 85% of pulses and coarse cereals are produced from such lands. The crop yields are quite low. Most of the rain-fed agriculture land is situated in the arid or semi arid region where the average annual rainfall is meagre and prolonged dry spells along with drought are quite usual even during the monsoon season.
Effects of global climate change on Health in India
It has been known since many years, that the climate change has wide ranging impacts on health. Health researchers have started showing interest in assessing the potential mechanisms by which changes in climate could influence health. This whole mechanism can be explained by the flow chart given below.
Source Adapted from- (Haines A. et.al, The Lancet, 2006, vol.367, p 2102)
The climate change can affect health by several mechanisms. Events of extremes of temperature and rainfall- e.g. the heat waves, droughts and floods have direct immediate effects on mortality as well as several long term effects. Change in temperature and rainfall may also lead to the distribution of vector borne diseases like malaria, dengue and chikungunya (Haines et al, 2006). Climate change has caused a lot of impacts on health of people in India. Current population of India is around 1.2 billion, out of which 42% people of country fall below the international poverty line and live on around $1.25 a day. The climate change is widening health and social inequalities, particularly at a time when the country is focusing on an ambitious range of programmes to improve the lives of people below the poverty line. The poor population of country stays mostly in the rural areas and depend upon climate-sensitive activities such as agriculture and fishing for the livelihood, so they are at the highest risk of impacts of climate change on health (Rao, 2010).
The evidence of impacts of climate change on health in India can be seen by the burden of diseases due to climate related problems, for example, eighteen heat waves were reported in India between 1980 and 1998, and many more since then, which caused death especially among the rural population, the elderly and the outdoor workers. India has seen many extreme weather events such as tropical cyclones in Andhra Pradesh, floods in Mumbai (2005), Surat and Barmer (Rajasthan) in 2006 which resulted in spread of various vector borne diseases like malaria, dengue and chikungunya and mental distress (Confaloneri et.al., 2007). India's food security is closely linked to amount of rainfall in the country. Climate change can result in the decline of crop yields due to unpredictability of the patterns of the monsoon and rainfall thus resulting in the shortage of food. It has been reported in the last few years that the farmers in some states of India like Andhra Pradesh, Orissa and West Bengal are committing suicide because of the drought condition in the country and increasing debts.
Climate change is also altering the patterns of vector borne disease like malaria in India. Malaria is sensitive to temperature change. Increase in the temperature shows increase in feeding and egg laying capacity of vector. The amount of precipitation affects the amount of surface water within which the malaria vector can breed. The central and the eastern region of India currently experience the highest endemic level for malaria with around 1.48 million cases and 1173 deaths in2007. Climate change in future may shift it to the south western coastal states with several northern states that were previously malaria free is becoming malaria prone (Bhattacharya et.al, 2006). The increase in the urban population is also resulting in the pollution rise due to vehicles and industry, with negative effects on the health of population. This rapid migration to the urban cities results in grater demand for water sanitation and housing which has bad impacts on health like respiratory and cardiovascular disease, and water and vector-borne disease. This exacerbates the burden of disease among the urban poor staying in slums (IPCC, 2007). Other vector-borne diseases such as Schistosomiasis, Sleeping sickness, Chagas disease, River blindness and several strains of encephalitis could change their ranges and patterns of infection due to climate change. Increase in temperature also leads to increase in micro-organisms for waterborne diseases such as Vibrio Cholera bacterium, causing Cholera. The rise in temperature, changing patterns of rainfall and extreme events such as floods and droughts are expected to decrease the crop yield in many developing countries causing the shortage of food supplies. This can lead to severe malnutrition among children in developing country like India where majority of population depends upon rain-fed farming.
Major climate sensitive health outcomes in recent years in India
Temperature increase to about 50°C in the North-west part of India in 2004.
Malaria epidemic in Surat (Gujarat) following the heavy rainfall same year.
Flood in Mumbai on July 25 and 26, 2005 due to heavy rainfall of about 944 mms which resulted in more than 1000 deaths.
Death due to heat strokes and cold waves reported every year in states like Uttar Pradesh, Haryana and Rajasthan.
Consecutive droughts in 2000 and 2002 in Orissa which affected 11 million people.
Tsunami in 2004 which resulted in more than 10,000 deaths along the coast lines
(Oxfam international, 2008).
Mitigation strategies by India to combat the impact of Global Climate Change
The Prime Minister of India, Mr. Manmohan Singh released the National Action Plan on Climate change (NAPCC) on 30th June 2008. This plan was prepared by the members of Prime Minister's Council on Climate Change. This document was prepared to show the necessary plans taken by the government of India in order to combat the impacts of climate change. The very first line of the plan states "India is faced with the challenge of sustaining its rapid economic growth while dealing with global threat of climate change." In his speech regarding the NAPCC, the Prime Minister said "Without a careful long term strategy, climate change may undermine our development efforts, with adverse consequences across the board, on our people's livelihood, the environment in which they live and work and their personal health and welfare" (NAPCC, 2008, p.1). The NAPCC sets out eight "National Missions" as the core part of the plan. The main objectives of these missions are to "promote understanding of climate change, adaptation and mitigation, energy efficiency and natural resource conservation."
The missions are:
National Solar Mission
National Mission for Enhanced Energy Efficiency
National Mission on Sustainable Habitat
National Water Mission
National Mission for Sustaining the Himalayan Ecosystem
National Mission for Green India
National Mission for Sustainable Agriculture
National Mission on Strategic knowledge for Climate Change
Other Programs by NAPCC
Power Generation: The government is mandating the retirement of inefficient coal-fired power plants and supporting the research and development of IGCC and supercritical technologies.
Renewable Energy: Under the Electricity Act 2003 and the National Tariff Policy 2006, the central and the state electricity regulatory commissions must purchase a certain percentage of grid-based power from renewable sources.
Energy Efficiency: Under the Energy Conservation Act 2001, large energy-consuming industries are required to undertake energy audits and an energy labeling program for appliances has been introduced.
Each mission has been given a set of objectives for the remaining duration of the 11th and 12th plan period (till 2017). Ministries with lead responsibility for each of these missions are directed to develop objectives, implementation strategies, timelines, and monitoring and evaluation criteria, to be submitted to the Prime Minister's Council on Climate Change.
The Council is also responsible for periodically reviewing the progress of these missions (National Action Plan on Climate Change, 2008).
States like Gujarat have take initiatives to deal with the challenges of Climate Change, which includes
Narmada, Sujalam Sufalam and participatory check dam movement have led to recharge of depleted ground water resources.
A wide network of CNG operated transport system has been introduced to reduce air pollution.
A remarkable solar energy policy has been declared by the state government for development of green energy aimed at reducing the Green house gases emission.
Dependence of fossil fuel has been reduced by promoting usage of non- conventional and renewable energy sources. (Source- http://deshgujarat.com)
Conclusion
India is highly vulnerable to the climate change and it can cause severe impacts on population of the country. It is seen from many studies that the event of climate change is going to be dangerous for the water availability and health of India. The ground water level are depleting at very rate high rate in northern part of India while the sea level is rising as a result of global warming. India has close economic ties with many climate sensitive sectors like agriculture, water and forestry, thus the global climate change can be a major threat to the people of country. According to A.K. Singh, deputy-general of the Indian Council of Agricultural Research (ICAR), medium-term climate change predictions have projected the likely reduction in crop yields due to climate change at the rate between 4.5 to 9 per cent by the year 2039. However, the long term prediction shows a scary picture for the crop yield with fall by 25 per cent or more by 2099. Thus this can have damaging effects on the income and purchasing power of farmers and thus can decrease county's GDP by around 4-5 % (Indian Council of Agriculture Research, 2009). India has also seen many extreme events in this decade including the floods in North-East part of country like Assam, Bihar, Meghalaya, Tripura and Arunachal Pradesh in the year 2002. Floods also contributed to the outbreak of water-borne diseases like malaria which resulted in deaths of many people. On the other side, in the same year many North Indian states like Rajasthan, Gujarat, Madhya-Pradesh faced conditions of drought. This region also had events like heat waves where around 250 people died due to heat stroke (Greenpeace, 2003). Also the continuous melting of Himalayan Glaciers due to climate change is a serious issue. However, various initiatives have been by the government to tackle the situation of global warming in India. An Action Plan for mitigation policies on global climate change has been prepared and discussed but still it lacks detailed action plans for dealing with the situation. It also does not specify particular targets to complete within a fixed time period. Thus the issue of Impact of Global Climate Change on India should be taken seriously by the Prime Minister of country and the government should invest money in strategies which promote use of renewable sources of energy and decrease emission of carbon.
