Mumbai and Kolkata will be the worst sufferer among Indian cities with flash rains, floods and fall in water tables as well as water conservation potential, says an international report on climate change.
According to the fourth assessment report by the Intergovernmental Panel on Climate Change (IPCC), the rise in sea level and flooding of villages would become a regular affair in the near future.
"Since Mumbai has reclaimed ocean land substantially, they are going to have a tough time. Though the average rainfall would reduce, yet flash rains will be the major cause of worry for urban populace in Mumbai," IPCC chairman R.K. Pachauri told IANS.
"Intense rain occurring over fewer days, which implies increased frequency of floods during the monsoon, will also result in loss of the rainwater. The direct runoff of water would reduce the groundwater recharging potential," he added.
Pachauri said like 2005, flooding would be a common scene in Mumbai and expose the drainage system.
The report said the projected sea level rise could flood the residences of millions living in the low lying areas of South, Southeast and East Asia such as Vietnam, Bangladesh, India and China.
"Even during the most conservative scenario, sea level will be about 40 cm higher than today by the end of 21st century. It is projected to increase the annual number of people flooded in coastal population from 13 million to 94 million (worldwide).
"Almost 60 percent of this increase will occur in South Asia (along the costs from Pakistan, India, Sri Lanka, Bangladesh to Burma," the chairman said.
He said vector borne disease like dengue and malaria would also increase in these cities. "I think mosquitoes would be healthier than human being. Diarrhea would be another concern point.
"An empirical model projected that population at risk of dengue fever would be increased by almost 50 percent in India and China. In both countries, the excess mortality due to heat stress is projected to be very high.
"Due to flooding villages in low line areas of both the cities would migrate to the city and thus create a survival problem both in terms of food and housing," Pachauri added.
In West Bengal, the Sunderban has started showing the result of global warming and in next few years Kolkata would witness unprecedented heat wave, he explained.
The report, "Climate Change 2007: Impact, Adaptation and Vulnerability", was unveiled in Brussels on April 6.