The Causes of Climate Change
Climate change is primarily attributable to an increase in trace gases – carbon dioxide, methane and nitrous oxide, also called greenhouse gases (GHGs) that warm the atmosphere by trapping heat radiating from the earth. Human activities resulting in constantly escalating use of energy ‘subsidies’ in the form of fossil fuels and also through more economically ‘productive’ land use changes are the primary reasons for increased GHGs. These gases cause aberrations in the global carbon cycle involving interaction among the atmosphere, oceans, soils and vegetation and fossil fuel deposits.
Magnitude of Global Warming
The increasing GHGs resulted in global warming by a modest 0.74°C over the past 100 years although 11 of the 12 warmest years occurred after 1995. The Intergovernmental Panel for Climate Change (IPCC) on temperature predicts an increase between 1.8 and 4°C from the current levels by the end of this century with a projection of about 0.2°C per decade for the next two decades. Even with all future emissions stopped, a further warming of about 0.1°C per decade is expected. Also, hot extremes, heat waves and heavy precipitation may become more frequent.
Impact on India
Although micro regions are likely to be affected differently in India, some generalisations may be attempted to understand the impacts of climate change. An annual mean surface temperature rise by the end of century, from 3 to 5°C under an extreme scenario and 2.5 to 4°C under a moderate scenario, with warming more pronounced in the northern parts of India is envisaged. Also some parts of northwest and southern India are predicted to turn somewhat cooler. A substantial rise in all India summer monsoon rainfall over all states is calculated except Punjab, Rajasthan and Tamil Nadu, where a slight decrease has been estimated. Rising extremes in maximum and minimum temperatures with substantial increases in precipitation over the west coast of India and west central India as well as the severity of droughts and intensity of floods in various parts of India is anticipated by climate change experts. Notwithstanding some disagreements on the exact nature of climatic changes in different parts of India, the available literature is unambiguous about extreme climatic events, spread across larger areas in the country.
Climate Change and Agriculture
Scholars broadly agree that global warming is likely to favour agricultural production in temperate regions (largely northern Europe, North America) and negatively impact tropical crop production (South Asia, Africa). The net effect of climate change would depend upon the relative strengths of the positive and the negative changes. In an optimistic scenario – increased CO2 would have positive physiological effects because of increased photosynthesis. Also, as the ratio of carbon to nitrogen is a constant, a doubling of carbon would imply a higher storage of nitrogen in soils as nitrates providing better yields. Thus quality of crops such as rice will become firmer under elevated CO2 environment.
On the downside global shortages of food grains are predicted in the first half of this decade as temperature increases and drought conditions prevail. Shorter growing cycles of crops will lead to reduced yield levels – recent IPCC report and other global studies indicate a probability of 10 to 40 per cent loss in crop production in India with increases in temperature by 2080-2100. Vulnerability of farmland in semi arid tropics of developing countries already suffering low levels of productivity will increase, with the warming projected to push even more farmland into this zone. There is a sizeable concern that small scale farmers with little capital will be unable to pursue the new strategies that are required to adapt to climate change. Also, small changes in temperature and rainfall would have a significant effect on quality of fruits, aromatic and medicinal plants impacting their prices and trade. Moreover, change in temperature and humidity may change population dynamics of pathogens and insect populations resulting in yield loss.
Impact on India’s Agriculture
Region specific studies in India related to climate change and agriculture, although few, generally endorse a decline in agricultural output. Recent studies at the Indian Agricultural Research Institute indicate the possibility of future loss of 4 to 5 million tons in wheat production with every 1oC rise of temperature throughout the growing period (but no adaptation benefits). Losses for other crops are expected to be relatively smaller, especially for the kharif crops. Rapidly melting glaciers in Himalayas may affect irrigation in the Indo Gangetic plains, negatively impacting food production. Although CO2 effects of climate change may lead to productivity increases for some irrigated crops, major agricultural production areas, particularly water stressed, are likely to be adversely affected.
Even as a global phenomenon, the ‘polluters’ in terms of quantum of emissions of GHGs are highly skewed. The share of developed countries because of their per capita high use of fossil fuels far exceeds the share of the developing countries. For example, the USA was responsible for around 25 per cent of the CO2 emissions while India with a population more than 3 times of the USA accounted for a little over 4 per cent in 2003 as per the Department of Energy, Government of United States of America. There is a concern that fast growing economies of India and China also register high rates of growth of carbon emissions. However, with technologies available to the developing countries, carbon emission control by these countries would be at the cost of their development whereas the developed countries have ‘free-ridden’ on the global climate change till very recently to achieve the current status of their development. India, in the recent negotiations of (United Nations Framework for Convention of Climate Change) UNFCCC has suggested that the ‘right’ to pollute the atmosphere be proportionate to countries’ population. Through carbon trading, India and China could then ‘sell’ some of the ‘rights’ to the industrialised countries as their current greenhouse gas emissions are less than the proposed allocation. Although unsustainable in the long term, the proposal certainly takes the North South debate on climate change to a level playing field.
Despite uneven contribution towards climate change – both in absolute and relative terms – topical regions face a more severe negative impact on agriculture making them address issues of mitigation of and adaptation to climate change. Mitigation measures in India and China include energy efficiency and conservation, promotion of renewable energy and fuel substitution, abatement of air pollution, afforestation and development of wasteland etc. However, the resources available with India are limited and it is debatable whether we would be in a position to divert developmental resources internal to the country into such mitigation measures – although interventions related to development of wasteland could serve both purposes and can be prioritised accordingly.
Creating an enabling environment towards adaptation to climate change is imperative to buttress the farmers’ livelihood with governmental support – despite arguments that propose that tillers have an intrinsic ability to adjust to the effects of change. Efficient infrastructure such as rural roads, electrification, irrigation facilities etc. give them the flexibility to adapt, state scholars. Reduced public capital formation in agriculture in the post reform period needs to be reversed to serve this purpose. Increased interest in agriculture to develop a variety of crops suitable for higher temperatures is urgently sought as India currently invests only 0.5 per cent as compared to an investment of 0.7 per cent in developing countries as a whole and 2 – 3 per cent in developed nations.
Without doubt the water stressed tropics would be the hardest hit. For the last fifteen years national and state agricultural policies in India have emphasised decentralised and participatory natural resource management, particularly for watershed development directed primarily towards the semi arid tropics with substantially increased financial allocations. Implementation of these programmes have to now fill the gaps of treating the commons, and spreading the benefits to the smaller holders, whose livelihoods are likely to be the severely marginalised with climate change.