The Actuaries Institute’s new Climate Index won’t cause insurance premiums to rocket up, Finity Principal Tim Andrews says.

The first index, which measures how climate change is affecting weather extremes and sea levels, was launched last week.

The frequency of extreme weather conditions in autumn this year exceeded historical trends, with risks linked to higher temperatures and rising sea levels.

But Mr Andrews told insuranceNEWS.com.au he does not foresee a dramatic impact on premiums.

“The impact to general insurance pricing will be gradual over many years,” he said. “We will see effects, but not in big steps. There are more extreme temperature events, that is clear, and sea levels are rising.

“But with wind and rain the index wobbles about a bit more and doesn’t shift much from the long-term average.”

The institute expects the index will help insurers assess risks by determining if their frequency is changing. Its baseline period covers 1981-2010, and it will be updated quarterly as new data becomes available.

It follows similar tools introduced in the US and Canada, and took 15 months to develop using Bureau of Meteorology data.