The technical paper of IPCC on climate change and water clearly shows that water resources especially fresh water resources are vulnerable and have the potential to be strongly impacted by climate change. The observational records and climate projects indicate that the impact will have wide-ranging consequences for human societies and ecosystems. The impacts such as increased in intensity and variability of precipitation is projected to aggravate the risks for flooding and drought in many areas, which in turn is likely to affect water quality and exacerbate many forms of water pollution.
The impacts of climate change will affect the livelihood of people globally. It will induce risks and vulnerabilities in the water using and influencing sectors. It will distress the sectors like health, agriculture and food security, energy, transport, water supply and sanitation, industry, mining, etc. Global environment changes observed throughout the previous decade can be credited to anthropogenically boosted climate change and the changes related to water include: sea level rise; melting of snow and ice; changes in the frequency and/or intensity of extreme weather events; changes to ecosystems and biodiversity patterns. Changes due to climate change are expected to further aggravate water-related hazards and water scarcity, increasing the vulnerability of socio-ecological systems.
The impact of climate change on water resources will be high and substantial in under-developed and developing countries of Africa and Asia compared to developed countries. Most of the people of Africa and Asia are engaged in agriculture and livestock and impact on water availability and quality will have significant impact in these sectors. This will reduce production significantly and aggravate the food insufficiency on the people residing in these areas. These regions will be incapable to adapt climate change due to very limited resources compared to wealthier nations who can import water if required. A rise of one degree Celsius would threaten water supplies for 50 million people in these areas and a rise of five degrees Celsius could cause in the disappearance of large glaciers in the Himalayas which would affect one quarter of China’s population and millions of India population.