One of the big stumbling blocks for Adani's proposed Carmichael coal mine in Queensland has been securing finance from lenders to build the project.

Now, opponents of the mine are at it again—this time pressuring insurance firms not to provide cover.

So far, 10 major insurance companies have said they do not intend to do so, with a number categorically ruling it out.

Sorry, this video has expired Adani protests, December 2018

Since Adani announced last month it would self-fund its long-planned Carmichael coal mine, activists have written to 30 major firms making their case, on the grounds it would accelerate climate change.

Julien Vincent, executive director of Market Forces, one of the groups behind that letter, said some of the world's biggest insurers were among those that had pledged support.

"So far about 10 of them have got back to us, including QBE, Suncorp from Australia, including some of the world's biggest insurance and re-insurance companies like Allianz and Munich Re and Swiss Re — all of them committing to not providing insurance for this project," Mr Vincent said.

"So, it's not just financially uninvestable; for a lot of insurance companies it's not something they're able to touch either."

Even though only a third of the insurance companies approached have said they did not plan to cover Adani's mine, Mr Vincent said it was a serious indication that insurance would be hard to come by.

"Ten out of 30 for a first stab at this is a pretty massive response, to be honest," he told the ABC's AM program.

"A lot of insurance, especially for major projects, they're done largely in syndicates, so it's not just going to be one insurance company providing coverage.

Sorry, this audio has expired Listen to Angela Lavoipierre's report on AM.

"It will have to be most likely half-a-dozen to a dozen would need to come together.

"And so when you start taking away big chunks of the pie like that, it really does make a dint in the prospects of Adani [to find insurance]."

'Most likely they will find an insurer'

Mr Vincent said there was no way of knowing for sure whether Adani had secured insurance.

But energy market analyst Tim Buckley said it was becoming much harder for carbon-emitting projects like this one to attract insurers.

He said part of the reason is that climate change represents a serious existential threat to the insurance industry, because of its link to extreme weather events.

"The risk for financial institutions is rising; the regulatory risk, the fiduciary risk for directors is clear.

"And so ultimately, I think you will find—like tobacco, like asbestos—thermal coal will become totally uninsurable."

Mr Buckley believes that, one way or another, Adani will eventually secure cover for its mine, even if it does mean the company providing it will become a target for activists.

"It's most likely that they will find an insurer," he said.

"We've seen seven of the biggest European insurers rule out thermal coal insurance work, but Americans are laggards, so they are most likely going to find an insurer in America who is still willing to do it."

It is also possible that Adani will self-insure the mine.

In a statement to AM, Adani said its insurance arrangements were commercial-in-confidence.

"Like any other Australian organisation, Adani Australia ensures we have the insurance necessary to cover our various business activities," the statement said.