GENEVA (AFP) – Flooding in the world's major port cities caused by melting icecaps could cause up to $28 trillion in damage in 2050, environmental group WWF said in a report Monday.

"If the temperature rises between 0.5 and 2 degrees (Celsius) between now and 2050, it's possible that the sea level would progress by half a meter (nearly two feet) bringing major financial damage," Ulrike Saul, in charge of climate and energy for WWF Switzerland, told AFP.

Such a rise in the sea level would cause up to $28 trillion in damage in the world's 136 biggest port cities, according to the study in which German insurance company Allianz took part.

Saul warned: "If the current climate protection policies do not change, it is more probable that we will register a rise of 2 degrees in 2050."

The northeast coast of the United States could see a rise in sea levels 15 centimeters higher than the world average, the study said.