Australia’s largest private health insurer, Medibank, will shed tens of millions of dollars in fossil-fuel investments because of the effects of climate change on human health.

In a statement to the Australian Stock Exchange before its annual general meeting in Melbourne on Monday, its chair, Elizabeth Alexander, said the company would move to low-carbon investments “in line with our commitment to the health and wellbeing of our customers”.

“We understand that the health of the environment has an impact on the health of the community,” she said. “Medibank acknowledges the science of climate change and the impacts on human health.”

The company would move to low carbon investments in its international investment portfolio “within the next 12 months”.

Medibank is Australia’s largest private health insurer with more than 3.8 million members and annual revenue of more than $6bn. The divestment announcement follows similar decisions by other private insurers, such as HCF and NIB.

Major health and medical bodies such as the Australian Medical Association have warned of the effects climate change will have on human health.

The World Health Organisation has estimated that climate change will kill 250,000 people a year between 2030 and 2050 by increasing the rates of malnutrition, malaria, diarrhoea and heat stress.

Alexander said Medibank did not “directly invest in fossil fuels”, but had exposure through high-carbon investment.

“Overall, high-carbon-emitting companies make up less than 0.5% of our investment assets,” she said.

“To offset this we have invested $25m in green bonds to support carbon-reducing and environmentally responsible projects.

“As the global economy makes the transition to low-carbon-emitting energy we believe it is important that our investment portfolio reflects this.”

Pablo Brait, from campaign group Market Forces, said: “It’s extremely positive that Medibank has ended its unhealthy addiction to fossil fuels.

“The medical profession has long understood that climate change has a devastating effect on people’s health, so it stands to reason medical insurers should not be invested in the industries which drive it.”

At its last AGM in 2016 shareholders asked about the health impacts of fossil-fuel companies that it was investing in.

At the time the company’s non-executive director, Peter Hodgett, said the company had divested from tobacco and would consider further divestments.

Alexander said the company had made a commitment to “carbon neutrality within our direct emissions and energy consumption by the end of 2018”.

“Our commitment also extends to our investments and we have reduced our exposure to investments that have the ability to adversely impact the health of our customers and the community,” she said.