| TNN Jun 20, 2013, 05.48AM IST (A report commissioned by…) NEW DELHI: An expected 2°C rise in the world's average temperatures in the next decades will make India's monsoon highly unpredictable and by 2040, the country will witness a sharp reduction in crop yields due to extreme heat, a report commissioned by the World Bank cautioned on Wednesday. It said shifting rain patterns will leave some areas under water and others without enough water for power generation, irrigation or, in some cases, even drinking. The report titled 'Turn Down the Heat: Climate Extremes, Regional Impacts and the Case for Resilience', examines the likely impacts of 2°C and 4°C warming on farm production, water resources, coastal ecosystems and cities across South Asia, sub-Saharan Africa, and Southeast Asia. The new report warned that by the 2040s, reduced water availability due to changes in precipitation levels and falling groundwater tables are likely to aggravate the situation in India, where groundwater resources are already at a critical level and about 15% of the country's groundwater tables are overexploited. The report cited Kolkata and Mumbai along with Bangladesh as "potential impact hotspots" threatened by "extreme river floods, more intense tropical cyclones, rising sea levels and very high temperatures". With South Asia close to the equator, the sub-continent would see much higher rises in sea levels than higher latitudes, with the Maldives confronting the biggest increases of between 100-115 cm. "Melting glaciers and loss of snow also pose a significant risk to stable and reliable water resources. Major rivers such as the Ganges, Indus and Brahmaputra depend significantly on snow and glacial melt water, which makes them susceptible to climate change-induced glacier melt and reductions in snowfall," the report said. It projected a rapid increase in the frequency of low snow years in the future, well before 2°C warming takes place and said this could increase the risk of flooding, threatening agriculture. In India, more than 60% of the crop area is rain-fed, making it highly vulnerable to climate-induced changes in precipitation patterns. It is estimated that by the 2050s, with a temperature increase of 2°C-2.5°C compared to pre-industrial levels, water for agricultural production in the river basins of the Indus, Ganges and Brahmaputra will reduce further and may impact food adequacy for some 63 million people. The report, prepared for the World Bank by the Potsdam Institute for Climate Impact Research and Climate Analytics and peer reviewed by 25 scientists worldwide, said the consequences for South Asia of a warming climate were even worse if global temperatures increased by an average of 4°C by 2090. "In this scenario, seen as likely unless action is taken now to limit carbon emissions, South Asia would suffer more extreme droughts and floods, rising sea levels, melting glaciers, and declines in food production," the report said. "In India, for example, an extreme wet monsoon that currently has a chance of occurring only once in 100 years is projected to occur every 10 years by the end of the century," it added. The report also said many of the worst climate impacts could still be avoided by holding warming below 2°C, but the window for action was narrowing rapidly. "Urgent action is needed to build resilience through climate-smart agriculture, flood defences, drought and heat resistant crops, improved groundwater management, better coastal infrastructure, and human health," the report said.  via Science - Google News http://news.google.com/news/url?sa=t&fd=R&usg=AFQjCNEq2Jh9xwVR95dxzMuX1M7OzuvS3w&url=http://articles.timesofindia.indiatimes.com/2013-06-20/developmental-issues/40092643_1_water-resources-groundwater-south-asia | |||
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