Natural disasters have caused more than $7 trillion (6.2 trillion euros) in economic damage worldwide since 1900, with floods and storms accounting for nearly 60 percent of the total, researchers said Monday.

The death toll from such natural calamities -- which also include earthquakes, volcanoes, droughts, heatwaves and wildfires -- topped eight million from 1900 to 2015, according to findings presented at a meeting of the European Geosciences Union in Vienna.

More than a third -- 38.5 percent -- of the economic damage, and just over half the loss of life was the result of flooding, according to James Daniell, an Australian risk engineer at the Karlsruhe Institute of Technology in Germany.

"Flooding is the key driver" for economic loss and death, said Daniell, who has catalogued 35,000 disasters over 115 years, the largest such database in existence.

Since about 1960, storms and storm surges -- the exceptional waves they cause -- have replaced flooding as the most destructive forces, battering buildings and infrastructure.

Whether this shift was due to climate change was impossible to say, he told AFP.

"When we go back in time, the record is not complete," he said on the sidelines of the annual gathering of about 13,000 Earth and space scientists.

"We probably have floods and storms from the 1930s or 1940s, for example, that never came into the database."

The frequency of other natural disasters -- notably earthquakes, which accounted for 26 percent of losses, and volcanoes, which caused one percent -- remained fairly constant over time.

Earthquakes accounted for nearly 30 percent of deaths, some 2.3 million people over the 115-year period.

Of those fatalities, nearly 60 percent died when buildings collapsed, while about 28 percent perished in a tsunami or landslide.

Overall, the annual cost of economic losses due to natural disaster has increased progressively over time, the study found.

But as a percentage of the rising value of all infrastructure on the ground -- currently estimated at some $300 trillion -- losses have actually declined, Daniell said.