If global warming continues at the present rate and the world warms up by 4 degrees Celsius over the next 100 years, there is a chance of cities in north India becoming so hot that outdoor activities will become impossible for some months in the year.

A recent study by research bodies in the US, China, UK and India have flagged alarming prospects for India owing to climate change.

The report – Climate Change: A Risk Assessment – simultaneously launched in London and Mumbai on Monday, claimed flooding in the Ganges basin could be six times more frequent, becoming a one-in-a-five-year event, over the course of the century because of high emissions.

“In a year’s time, when important climate negotiations are scheduled, this global risk assessment report hopes to inform a wide audience about the risks for which human societies need to prepare,” said Dr Arunabha Ghosh, co-author of the report and chief executive officer, Council on Energy, Environment and Water (CEEW), a not-for-profit policy research institution that collaborated with universities such as Harvard, Cambridge and Tsinghua to establish the report.

Commissioned by the UK’s foreign and commonwealth office, the report considers three key areas to communicate the risk of climate change – how emissions will rise, the direct risks – on health, crop output, coastal flooding, shortage of water – and the risks to human systems – conflict, international security concerns, migration and state failure.

Coastal flooding is another alarming projection. “With one metre of global sea level rise, the probability of what is now a 100-year flood event, becomes 1,000 times more likely in Kolkata, 40 times in Shanghai and 200 times in New York,” read the report.

“In India, we could expect a population shift from rural to urban areas, increasing demographic pressure on cities,” said Pradeep Chauhan, former chief of Western Naval Command and a speakers at the event. He said coastal cities such as Mumbai, will be vulnerable to flooding both from the rise in sea level, and intense rainfall.

Future tense

The five urban areas that will see the highest increases in heat-related deaths are Mumbai (15,300 deaths), Delhi (15,200), Ahmedabad (17,600), Bangalore (14,900) and Kolkata (9,400), revealed a study by the Council on Energy, Environment and Water, IIT Gandhinagar and IIM Ahmedabad

By 2050, nearly 750 million people in South Asia will face extreme water shortage