Global warming and climate change could affect India’s growth story unless a range of steps are taken to address the effects of increased surface temperature and its effect on monsoon pattern and river flows.
There is a wealth of evidence quantifying the economic costs of climate change in India. Experts from the University of Reading have estimated that mean summer rainfall in India will increase by 10% — along with rainfall intensity — and this will be accompanied by more regional variations. This is likely to affect agriculture and, therefore, GDP growth.
The review identifies three elements of policy required for an effective response: carbon pricing, through tax, trading or regulation, so that people pay the full social cost of their actions; policy to support innovation and deployment of low-carbon technologies and removal of barriers to energy efficiency and measures to inform, educate and persuade.
Some of the key predictions, according to the Stern report, of changes over the next 100 years:
• Regional climate models suggest 2.5-5 degrees Celsius rise in mean surface temperature. Regionally within India, northern India will be warmer.
• 20% rise in summer monsoon rainfall. Extreme temperatures and precipitations are expected to increase.
• All states will have increased rainfall except Punjab, Rajasthan, Tamil Nadu where it will decrease. Extreme precipitation will increase, particularly along the western coast and west central India.
• Hydrological cycle is likely to be altered. Drought and flood intensity will increase. Krishna, Narmada, Cauvery, Tapi river basins will experience severe water stress and drought condition and Mahanadi, Godavari, Brahmani will experience enhanced flood.
• Crop yield decrease with temperature and rise with precipitation. Prediction of loss of wheat is more. Rabi crops will be worse hit which threatens food security.
• Economic loss due to temperature rise estimated between 9-25%. GDP loss may be to the tune of 0.67%. Coastal agriculture suffers most (Gujarat, Maharashtra, Karnataka), Punjab, Haryana, Western UP will face reduction in yield; West Bengal, Orissa, Andhra Pradesh will gain marginally.
• 100-cm sea level rise can lead to welfare loss of $1259 million in India equivalent to 0.36% of GNP.
• Frequencies and intensities of tropical cyclones in Bay of Bengal will increase particularly in the post-monsoon period and flooding will increase in low-lying coastal areas.
• Malaria will continue to be endemic in current malaria-prone states (Orissa, West Bengal and southern parts of Assam north of West Bengal). It may shift from the central Indian region to the south-western coastal states of Maharashtra, Karnataka, Kerala. New regions (Himachal Pradesh, Arunachal Pradesh, Nagaland, Manipur and Mizoram) will become malaria prone and transmission duration window will widen in northern and western states and shorten in southern states.