Sectoral Approach

    India is more vulnerable to effect of climate change due to its high dependence on climate sensitive sectors like agriculture and forestry, and its low financial adaptive capacity. Apart from these two sectors the water sector and health are also facing adverse impact under changing climatic condition. How these sectors are affected by climate change is discussed under following sections. In addition we take a look at the energy sector, which is at the very heart of the climate change challenge. If we are to effectively tackle climate change it is imperative that we solve the problem of emissions from the energy sector.

    Climate Change & Agriculture

    Among India’s population of more than one billion people, about 68% are directly or indirectly involved in the agricultural sector. In India, climate change could represent an additional stress on ecological and socioeconomic systems that are already facing tremendous pressures due to rapid urbanization, industrialization and economic development. Agricultural activities are very sensitive to changing climate and weather conditions, including multiple years of low and erratic rainfall. Climate change affects agriculture and agriculture contributes to climate change. The relative confidence in the elements of climate change implies different effects on agriculture. Increased CO2 concentrations are mostly beneficial, whereas temperature and precipitation effects can be both beneficial and detrimental. Changes in climate could also bring an increase in climatic extremes, warming in the high latitudes, advance or delayed of the monsoon rainfall, and reduced soil water availability. The major impacts of climate change will be on rain fed or un-irrigated crops, which is cultivated in nearly 60% of cropland area. In India it is the poorest, most vulnerable farmers who practice rainfed agriculture.

    Predicted Climatic Impact on Agriculture

    Assessment of Vulnerability of Agriculture to Climate Change

    Assessment of Vulnerability of Agriculture to Climate Change

    Agricultural activities are very sensitive to climate and weather conditions. An agricultural decision-maker can either be at the mercy of these natural factors or try to benefit from them. Climate change affects agriculture and agriculture contributes to climate change. The relative confidence in the elements of climate change implies different effects on agriculture. Increased CO2 concentrations are mostly beneficial, whereas temperature and precipitation effects can be both beneficial and detrimental.

    Agricultural productivity can be affected by climate change in two ways: first, directly, due to changes in temperature, precipitation and/or CO2 levels and second, indirectly, through changes in soil, distribution and frequency of infestation by pests, insects, diseases or weeds. Acute water shortage conditions, combined with thermal stress, could adversely affect wheat and, more severely, rice productivity in India even under the positive effects of elevated CO2 in the future. The predicted changes to agriculture vary greatly by region and crop.

    Temperature Increase

    Crop growth is often limited by temperature. The current scientific consensus is that temperatures are expected to increase more in the higher latitudes where vegetational shifts will be greater. According to IPCC fourth assessment report the earth temperature has increased by 0.74 degree C between 1906 and 2005 due to increase in anthropogenic emissions of greenhouse gases. It is estimated that Due to this increase in temperature, 10-40% decrease in crop production is possible by 2100 AD despite the beneficial effects of higher CO2 on crop growth [1] .

    The mean temperature in India is projected to increase by 0.10 C to 0.30C in kharif (summer) and 0.30C to 0.70C in rabi (winter) by 2010 and to 0.40C to 2.00C in kharif and 1.10C to 4.50C in rabi by 2070 [2]. Mean rainfall is projected not to change by 2010 but may increase by 10% during rabi by 2070. At the same time, there is an increased possibility of climate extremes, such as the timing of onset of monsoon and intensities and frequencies of droughts and floods [3].

    Moisture Availability

    Moisture and water availability will be affected by a temperature increase, regardless of any change in precipitation. Based on global warming of 1.4-5.8OC over the next 100 years, climate models project that both evaporation and precipitation will increase, as will the frequency of intense rainfalls. While some regions may become wetter, in others the net effect of an intensified hydrological cycle will be a loss of soil moisture and increased erosion. Some regions that are already drought-prone may suffer longer and more severe dry spells. Higher temperatures increase the evaporation rate, thus reducing the level of moisture available for plant growth, although other climatic variables are involved. A very large decrease in moisture availability in the dryer regions would be of great concern to the subsistence farmers that farm these lands. Reduced moisture availability would only exacerbate the existing problems of infertile soils, soil erosion and poor crop yields. In the extreme case, a reduction in moisture could lead to desertification.

    Projected Facts

    • The wheat, which is generally grown in the winter, is more likely to be affected than rice.
    • Reductions in wheat production as a result of climate change are predicted to be more pronounced for rain fed crops (as opposed to irrigated crops)and under limited water supply situations because there are no coping mechanisms for rainfall variability.
    • The difference in yield is influenced by baseline climate. In sub tropical environments the decrease in potential wheat yields ranged from 1.5 to 5.8%, while in tropical areas the decrease was relatively higher, suggesting that warmer regions can expect greater crop losses.
    • The increases in temperature (by about 2ºC) reduced potential grain yields of wheat in most places in India.
    • Reductions in yields as a result of climate change are predicted to be more pronounced for rain fed crops (as opposed to irrigated crops)and under limited water supply situations because there are no coping mechanisms for rainfall variability.
    • Overall, temperature increases are predicted to reduce rice yields. An increase of 2-4ºC is predicted to result in a reduction in yields.
    • Eastern regions are predicted to be most impacted by increased temperatures and decreased radiation, resulting in relatively fewer grains and shorter grain filling durations.
    • By contrast, potential reductions in yields due to increased temperatures in Northern India are predicted to be offset by higher radiation, lessening the impacts of climate change.
    • Although additional CO2 can benefit crops, this effect was nullified by an increase of temperature.

    Additional Reading:

    DEFRA Climate Key Sheet 6: Impacts of Climate Change on Agriculture

    Climate Change and Forest

    Climate Change the potential to adversely impact forest ecosystems. Probably it is the most important deter¬minant of vegetation patterns and has a significant influence on forest distribution, species dominance, plant productivity and, in general, ecology of forests. Plant communities are associated with certain climate regimes. Thus, it is logical to as¬sume that a change in climate is likely to alter forest vegetation.

    India is a mega-biodiversity country where forests account for about 20% (64 million ha) of the geographical area with nearly 200,000 forest villages. Any adverse impact of Climate Change on forest ecosystem will also affect communities of these forest villages because they are largely dependent on forest resources. According to Third Assessment Report of IPCC forest ecosystems could be seriously impacted by future climate change. Even with global warming of 1-2°C, much less than the most recent projections of warming during this century [4], most ecosystems and landscapes will be impacted through changes in species composition, productivity and biodiversity [5].

    Climate Change Impact on Forest

    According to IPCC Third Assessment Report apart from other threats and pressures climate change constitutes an additional pressure that could change or endanger the forest ecosystem. Though there are uncertainties with respect to projections of climate change on forest ecosystem, evidence is growing to show that climate change coupled with socioeconomic and land use pressures is likely to adversely impact forest biodiversity, biomass productivity, carbon sink and/or carbon uptake rates.

    Projected shift in Forest Type

    An assessment of the impact of climate change projections on forest ecosystems for the two green¬house gas emission scenarios for 2085, showed that 68 per cent and 77 per cent of forested grid are likely to experience shifts in forest vegetation type [6]. Notably, the country’s dominant forest cover, characterised by Moist Savanna (32.5%) and Dry Savanna (33%) is projected to change, such that Tropical Dry Forest (37.2%) and Tropical Seasonal Forest (28.4%) become dominant (fig 2).

    Figure 2.

    Climate Change impact on forest biome (B2 Scenario)

    There may not be a total replacement of one forest type by another under the projected climate change scenarios, due to differing climate toler¬ance of the various plant species in a forest. How¬ever, large-scale mortality of tree species is likely under the changed climatic conditions.

    Impact on Forest Health

    Climate change could have both negative and positive effect on forest health and susceptibility to pest and diseases. Increase temperatures could increase the rate of multiplication of insect pest, thus increasing their destructive potential.

    It has been projected that part of future climate change includes increased climatic anomalies such as higher incident of droughts, storms or period of excess rainfall. These will put additional stresses on trees and forests making them more susceptible to attack by pest and disease. A combination of greater sensitivity to pests and disease and air pollutants could cause forest dieback.

    In contrast to above mentioned negative effects of climate change on forest health some positive effects are also possible. The higher growth rates under elevated CO2 and temperatures could allow forest to sustain higher levels of pest and disease damage without reductions in growth and yield.

    Adaptation to climate impacts in forest sector

    To develop adaptation strategies good understanding about climate change impacts are necessary. But due to uncertainties involved in projections of climate change parameters , particularly at regional level and responses of forest vegetation it is difficult to suggest effective adaptation strategies. The climate impact assessment made for Indian forest sector using different climate models indicates that, over half of the vegetation is likely to find itself less optimally adapted to its existing location, making it vulnerable to adverse climatic conditions and to biotic stresses [7].

    The regional climates, as well as vegetation response models, are being continuously modified, improving the reliability of projections. However, current knowledge of the impacts of climate change may not be adequate for micro-level decision-making on forest manage¬ment at forest division or range level in India.

    Additional Reading:

    DEFRA Climate Key Sheet 7: Impacts of Climate Change on Forests

    Impact of Climate Change on Forests in India – N. H. Ravindranath, N. V. Joshi, R. Sukumar and A. Saxena

    Climate Change and Water Resources

    The main climate change consequences related to water resources are increases in temperature, shifts in precipitation patterns and snow cover, an increase in the frequency of flooding and droughts, and a wide range of other geophysical effects [8]. These changes will also have many secondary impacts on freshwater resources, altering both the demand and supply of water, and changing its quality.

    Of the many social, economic and environmental impacts and vulnerabilities to climate change, the projected effects on the qualitative and quantitative status of India’s water resources is a critical area for people’s lives and the economy. While India has about 16% of the global population, it only has 4% of total water resources, and many parts of India already face water scarcity.

    Figure 3

    Per capita water availability (Table 1) decreases from 5410 m3 in 1951 to 1451 m3 (low population growth scenario) in 2050 (Projected). The availability of water in India shows wide spatial and temporal variations. Also, there are very large inter annual variations. Hence, the general situation of availability of per capita availability is much more alarming than what is depicted by the average figures [9].

    Table 1: Per capita per year availability of surface water in India (in m3)
    Year Population (Million) Water Availability (Per Capita)
    1951 361 5410
    1955 395 4944
    1991 846 2309
    2001 1027 1902
    2025 (Projected) 1286 (low growth) 1519
    1333 (high growth) 1465
    2050 (Projected) 1346 (low growth) 1451
    1581 (high growth) 1235
    Table 2: Estimated annual requirement of water in India by different users (Billion Cubic Meters BMC)
    Source: Central Water Commission 2000
    Sector Year
    2000 2025 2050
    Domestic 42 73 102
    Irrigation 541 910 1072
    Industry 08 23 63
    Energy 02 15 130
    Other 41 72 80
    Total 634 1093 1447

    Future Climate Change Impacts on Water in India

    The most dominant climatic drivers for water availability are precipitation, temperature, and evaporative demand (determined by net radiation at ground level, atmospheric humidity, wind speed, and temperature). Temperature is particularly important in snow-dominated basins. Climate change can affect the quantitative and qualitative status of water resources by altering hydrological cycles and systems, which, in turn affect different variables at local level including:

    • Surface and ground water availability and demand.
    • Water quality including temperature and nutrient content.
    • Intensity and frequency of floods and droughts.

    Changes in these variables lead to impacts on all the socio-economic and environmental goods and services that depend on these variables directly or indirectly. Furthermore, the impacts vary in time and space. Some impacts are on daily/local scale (e.g. lower oxygen content), others are at longer/larger scales (e.g. changes in algal blooms over weeks or months, groundwater level variations and alterations to groundwater flow directions).The hydrological cycle includes processes such as evaporation and precipitation that are predicted to shift with climate change, and can have important implications for fresh water supply for drinking water, rain-fed agriculture, groundwater supply, forestry, biodiversity, and sea level. The hydrological cycle is predicted to be more intense, with higher annual average rainfall as well increased drought.

    Many north Indian rivers such as the Ganga, Yamuna have shown a sharp decline in the summer discharge in the recent past, possibly due to shrinking of the Himalayan glaciers that feed them. During the past 40 years an estimated reduction of 40% in the Himalayan ice volume has occurred [10].

    Impact assessment of climate change on three major river basins of India [11] the Krishna, the Ganga,and the Godavari indicates that

    1. Figure 4There is a predicted increase in extreme rainfall and rainfall intensity in all three river basins towards the end of the 21st century (Table 3). The Godavari basin is projected to have higher precipitation than the other two.
    2. The intensity of daily rainfall is also predicted to increase.
    3. Changes in the number of rainy days were also examined, with results indicating decreases in the western parts of the Ganga basin, but with increases over most parts of the Godavari and Krishna basins.
    4. Thus surface water availability showed a general increase over all 3 basins (though future populations projections would need to be considered to project per capita water availability.
    Table 3
    River Basin Baseline (1961-1990) Future (2071-2100)
    Annual Rainfall (cm) Annual Flow (km3) Annual Rainfall (cm) Annual Flow (km3)
    Ganga 134 482 150 543
    Godavari 166 98 201 116
    Krishna 91 60 112 67

    Climate Change Impacts on water quality

    Higher water temperature and variations in runoff are likely to produce adverse changes in water quality affecting human health, ecosystems, and water use. Climate change could also result in significant changes in the variables that affect the quality of water. These impacts come from a variety of alterations to the hydrology of water bodies, their physico-chemical and biological attributes, and changes in anthropogenic pressures. Climate change impacts are not limited to changes in precipitation but also include other factors. Higher air temperatures lead to higher water temperatures.

    The temperature changes that are projected to result from climate change could result in:

    • Reduced oxygen content. Increases in water temperature in streams and rivers reduce oxygen content and increase biological respiration rates and thus may result in lower dissolved oxygen concentrations, particularly in summer low-flow periods.
    • Alterations to habitats and distribution of aquatic organisms. For example, a number of aquatic organisms conform to temperature preferences, which determine their spatial distribution. Higher water temperatures lead to changes in distribution and may even lead to extinction of some aquatic species.
    • Alterations to thermal stratification and mixing of water in lakes.
    • Changed nutrient cycling in aquatic systems and algal blooms.
    • As temperatures increase, bacterial populations that control nitrogen mineralisation and nitrification processes in the soils also increase [12].

    Additional Reading:

    Water Resources in India and Impact of Climate Change – R. K. Mall

    DEFRA Climate Key Sheet 5: Impacts of Climate Change on Water Resources

    Climate Change and Human Health

    Climate change poses substantial risks to human health in Asia. Among vector-borne diseases in India, malaria is of considerable concern. Periodic epidemics of malaria occur every five to seven years, and the World Bank estimates that about 577,000 DALYs (disability-adjusted life years) were lost due to malaria in India in 1998. Climate change could increase the incidence of malaria in areas that are already malaria-prone, and also introduce malaria into new areas.

    Predicted changes in Malaria incidence due to climate change

    Transmission windows (TWs) for malaria are predicted to increase with climate change (Figure 1). For most vectors of malaria, the temperature range of 20ºC – 30ºC is optimal for development and transmission. A relative humidity higher than 55% is optimal for vector longevity, enabling the successful completion of sporogeny. Analysis of average temperature, humidity, precipitation and incidences indicate that the maximum incidence occurs in the months of June, July and August when the relative humidity is in the range of >60% and <80%, at temperatures ranging between 25ºC to 30ºC. This window shifts from state to state depending on the arrival of the monsoon [13].

    Transmission Window of Malaria in Different States of India (a) for base case and (b) under projected climate change scenario

    Transmission Window of Malaria in Different States of India (a) for base case and (b) under projected climate change scenario

    Health concerns and vulnerabilities due to climate change (Source: Ref. 13)
    Health Concern Vulnerabilities due to climate change
    Temperature related morbidity:
    • Heat and cold related illness
    • Cardio vascular illnesses
    Vector borne diseases
    • Changed patterns of diseases by region and by climate parameter
    • Malaria, Filaria, Kala-azar, Japanese Encephalitis, and Dengue caused by bacteria, viruses and other pathogens carried by
      mosquitoes, ticks, and other vectors.
    Health effects of extreme weather
    • Diarrhoea, Cholera and intoxication caused by biological and chemical contaminants in water
    • Damaged public health infrastructure due to cyclones / floods
    • Injuries and illness
    • Social and mental health stress due to disasters and displacement
    Health effects due to insecurity
    • Malnutrition, hunger, particularly in children

    Global burden (mortality and morbidity) of climate-change attributable diarrhea and malnutrition are already the largest in South-East Asian countries including India, Bangladesh, Bhutan, Maldives, Myanmar and Nepal in 2000, and the relative risks for these conditions for 2030 is expected to be also the largest [14] , although in some areas, such as southern states in India, there will be a reduction in the transmission season by 2080 [15]. An empirical model projected that the population at risk of dengue fever (the estimated risk of dengue transmission is greater than 50%) will be larger in India [16] and excess mortality due to heat stress is also projected to be very high [17], although this projection did not take into account possible adaptation and population change. There is already evidence of widespread damage to human health by urban air quality and enhanced climate variability in India.

    Additional Reading:

    DEFRA Climate Key Sheet 9: Impacts of Climate Change on Human Health

    Malaria and Climate Change – Richard Tren

    Climate Change and Energy

    Worldwide, the energy sector is responsible for the largest contribution to green house gas emissions. As can be seen in the chart below energy (constituting transportation, electricity and heat, other fuel consumption, fugitive emissions and industrial use of energy) accounts for over 60% of CO2e (carbon dioxide equivalent) emissions globally. This is largely due to the over reliance on fossil fuel to meet energy needs.

    CO2e Emissions by Sector based on data from World Resource Institute, 2000

    CO2e Emissions by Sector based on data from World Resource Institute, 2000

    (((( FIGURE 2 IS MISSING ))))

    The above chart shows that fossil fuel based sources are by far the largest source of energy the world over, accounting for more than 80% of world energy production.

    GHG Emissions by Sector-India: Source PEW Centre International Brief 2: ‘Climate Change Mitigation Measures in India’, September, 2008

    GHG Emissions by Sector-India: Source PEW Centre International Brief 2: ‘Climate Change Mitigation Measures in India’, September, 2008

    This is the as true if not more, of developing countries like India. The chart below shows that the energy sector and especially electricity and heat are responsible for the majority of greenhouse gas emissions from India.

    Again, this is due to India’s high reliance on fossil fuel to meet its energy demands. The following chart shows that coal constitutes just over half of energy supply, while oil is 36% and gas 9%. Thus over 90% of India’s energy sources are fossil fuel based. This dependency is only set to rise as India pursues its legitimate quest for development. Coal in particular will be important as India has large reserve of this fossil fuel.

    The Government of India has committed itself to vastly improving the country’s human development indices by 2031-2032. In order to do so, the country must average economic growth of at least 8 percent per annum for the next twenty-five years. According to a report released by the Planning Commission of India, if India is to sustain an 8 percent level of growth, then it will need to increase its primary energy supply by at least 3 or 4 times and its electricity supply by a factor of 5 to 7 by 2031-2032. Likewise, power generation capacity will have to increase from 120,000 MW to 780,000 MW [18].

    India’s composition of energy sources and usage

    India’s composition of energy sources and usage

    Figure 9In addition The Government of India has undertaken to completely meet India’s growing electricity needs by 2012 so that shortage of energy supply does not impair the growth and development needs of our booming economy and industry, as well as to electrify all villages in India under a time bound programme. Seeing that there are still over 1lakh villages without electricity and only about 55% of households in India have electricity, this is a significant undertaking, which will necessitate more energy production. As currently renewable and alternate energy sources are not mainstream sources, the government aims to achieve its goal through major investment in thermal and hydro-electric power (50,000 MW Hydro and 1,00,000 MW Thermal projects have been planned) [19].

    The inset table compares the likely utilization of different fuel sources in 2031-32 with those presently as conceived by the Planning Commission of India. A great increase in fossil fuel use would lead to substantial increase in emissions and further worsen the already serious climate problem.

    Hence, a growth strategy based on increasing dependence of fossil fuels is unsustainable and there is an urgent need for the Government to aggressively purse policies that encourage greater share of renewable and alternate sources of energy in India’s energy mix.

    Additional Reading:

    World Energy Outlook – IEA

    India Energy Outlook – KPMG

    Energy And Climate Change: Focus On India – Kapil Mohan

    Inida: Adressing Energy Security and Climate Change – Government of India

    Indian Biofuel Scenario: An Assessment Of Science and Policy – Vijai Pratap Singh

    WWF Climate Scorecards – Assessment of the climate performance of the G8 plus 5 countries

    FOOTNOTES

    • 1. Agarwal P K (2008) Global climate change and Indian agriculture: Impacts, adaptation and mitigation, Indian Journal of Agricultural Sciences Vol: 78 Issue: 10 pp: 911-919
    • 2. IPCC 1996
    • 3. NATCOM, 2004: India’s Initial National Communication to the UN Framework Convention on Climate Change, Ministry of the Environment and Forest, New Delhi.
    • 4. Climate Change 2001: The Scientific Basis, Summary for Policy Makers and Technical Summary of the Working Group I Report, Intergovernmental Panel on Climate Change, Geneva, Switzerland, 2001b.
    • 5. Leemans, R. and Eickhout, B., Another reason for concern: regional and global impacts on ecosystems for different levels of climate change. Global Environ. Change, 2004, 14, 219-228.
    • 6. Ravindranath N. H. Climate Change Impacts on Forestry in India, Key sheet 7
    • 7. Ravindranath N. H., N. V. Joshi1, R. Sukumar and A. Saxena (2006) Impact of climate change on forests in India Current Science, VOL. 90, NO. 3, pp 354-361
    • 8. IPCC 2007
    • 9. Rakesh Kumar, R. D. Singh and K. D. Sharma (2005) Water resources of India, Current Science, VOL. 89, NO. 5, pp 794-811
    • 10. Gosain, A. K. and Sandhya Rao, Climate Change and India, VulnerabilityAssessment and Adaptation (eds Shukla, P. R. et al.), Universities Press, Hyderabad, 2003, pp. 159-192.
    • 11. Pant G. B. Climate Change Impacts on Water Resources in India, Key sheet 5, DEFRA
    • 12. Whitehead, P. G.; Wilby, R. L.; Butterfield, D. and Wade, A. J., (2006). Impacts of climate change on nitrogen in a lowland chalk stream: An appraisal of adaptation strategies. Science of the Total Environment, 365, 260-273.
    • 13. Mitra A. P. DEFRA report
    • 14. McMichael, A.J., D.H. Campbell-Lendrum, C.F. Corvalan, K.L. Ebi, A.K. Githeko, J.D. Scheraga and A. Woodward, Eds., 2003: Climate Change and Human Health – Risks and Responses,World Health Organization, Geneva, 333 pp.
    • 15. Mitra,A., S. Bhattacharya, R.C. Dhiman, K.K. Kumar and C. Sharma, 2004: Impact of climate change on health: a case study of malaria in India. Climate Change and India: Vulnerability Assessment and Adaptation, P.R. Shukla, S.K. Sharma, N.H. Ravindranath,A. Garg and S. Bhattacharya, Eds., Orient Longman Private, Hyderbad, 360-388.
    • 16. Hales, S, N., de Wet, J. Maindonald and A. Woodward, 2002: Potential effect of population and climate changes on global distribution of dengue fever: an empirical model. Lancet, 360, 830-834.
    • 17. Takahashi, K., Y. Honda and S. Emori, 2007: Estimation of changes in mortality due to heat stress under changed climate. Risk Res., 10, 339-354.
    • 18. Draft Report of the Expert Committee on Integrated Energy Policy, Planning Commission, Government of India, December 2005.
    • 19. India 2008: A Reference Annual, page 255