Climate change could threaten to challenge the downward trend of large-scale fatal disasters in New Zealand.

A University of Otago study in Wellington analysed events in New Zealand causing at least 10 deaths.

It found a sharp drop in the number of fatal large-scale events, from 21 between 1900-1919, to just three between 2000-2015.

Public health researcher Professor Nick Wilson said people have found much safer ways of getting around.

"They were largely driven by the reduction in transport related events."

"So, ships sinking, trains crashing, aircraft crashing."

But he said the downward trend may not last forever.

"In the future, it's still uncertain, because climate change does seem to be happening rapidly."

"So there could even be those sort of risks that New Zealand has to think about in the future."

Across the Tasman, Australia has seen an increasing incidence of disasters since the 1980s, which peaked between 2005-2009.