Impact of Climate change on Water Resources

Introduction:

No one can deny the effect of climate change as a phenomenon, which is increasingly becoming evident to affect the food, water and energy security worldwide. With increase in temperature, there has been a significant impact on the fresh water supplies. Rise in temperature results in increase in evaporation, which could result in droughts. This could also result in melting of glaciers, thus resulting in disappearance of one of the important sources of fresh water. Snow and ice in the high altitudes and Polar Regions store water in the form of glaciers that gets released slowly when they melt during the warmer seasons.More than 50% of the world’s freshwater comes from the mountain runoff and snow melts. But increased melting of glaciers and reduction of precipitation in the form of snow, results in water shortages as water runoff happens more quickly.

Heavy precipitation events will become more frequent over most regions in the 21st century, resulting in increased risk of flash flooding and urban flooding (IPCC, 2007). This increased run off also means that there will be reduced groundwater recharges and decreased levels of soil moisture, which can result in reduced agricultural productivity as well.

There are more concerns that climate change raises with respect to it’s impact on water resources. Large amounts of energy are required to find water supplies and to treat them, which also contributes to the climate change. The filtering units, bottled water also contribute to greenhouse gas emissions with the increased energy requirements to produce them as well as to transport.

IPCC (2007) during their studies had observed the following changes specific to water resources due to climate change in last two centuries all around the world(IPCC, 2007):

Situation in India:

Climate change is expected to result in intensification on global hydrological cycle and with respect to India, this will have a severe impact on per capita availability of water as well. Just by taking into consideration the population as per the 2001 census, the per capita availability is calculated as:

Thus at a macro level, clearly India is in a water stressed state. In local/regional level it could be even starker, considering the high variations in water availability across the country. When we apply the impact of climate change, the per capita availability is bound to decrease further more in futur