The number of people who die during heat waves is expected to double by 2040 due to climate change, according to a government report Tuesday.

According to the 2014 climate change assessment report drafted by the Ministry of Environment and Korea Meteorological Administration, seven people per 1 million died in Seoul annually between 2001 and 2010, but by 2040, the number could reach 15.

The assessment is the result of collaboration among 155 experts who analyzed more than 2,500 studies done in Korea and abroad.

Between 1954 and 1999, Korea experienced the temperature increase by 0.23 degrees Celsius, and 0.5 degrees between 2001 and 2010. The report said the temperature will increase 4 degrees by 2040 if nothing is done now. Even if drastic measures are taken, the temperature will increase 2 degrees by that year, the report said.

It also said the sea water temperature near Korea is rising quicker than the global average, and that could bring about a faster rise in coastal sea levels.