The largest coalmine ever built in Australia, and one of the biggest in the world, received final approval from the federal environment minister Greg Hunt on July 28.

The Carmichael coalmine in central Queensland, owned by Indian company Adani, is forecast to produce 60 million tonnes of coal a year over the next 60 years. This dwarfs Australia’s current largest mine, which produces 20 million tonnes a year.

Approval for the mine was given even after global banks like Deutsche Bank and HSBC refused to fund the expansion of the coal ports associated with the project. They cited concerns by UNESCO that the Great Barrier Reef was at risk from mining development.

An independent Commonwealth committee, the Independent Expert Scientific Committee on coal seam gas and large mining developments, also raised serious concerns about the impact the mine would have on water resources.

But the Queensland and federal governments ignored these concerns.

This is just one of nine mega-coalmines that have been proposed in Queensland’s Galilee Basin. Environmentalists say if the mines go ahead, it will be game over for the climate.

Two years ago, Greenpeace produced a major report about the impact these mines would have on climate change, saying: “If the Galilee Basin were a country, the carbon dioxide produced from using this coal would make it the seventh dirtiest fossil fuel burner on the planet.”

It is not just the climate that will suffer if this project goes ahead. Environmentalists have warned it could also have a devastating impact on the Great Barrier Reef Marine Park.

The mine will comprise six open-cut pits and five underground mines, and stretch over 200 square kilometres. The coal will be transported along a railway line hundreds of kilometres long to link up to the Abbot Point and Hay Point coal ports near Rockhampton.

From there, the coal will be shipped through the Great Barrier Reef for export to India.

Felicity Wishart, from the Australian Marine Conservation Society, said the mine would need huge port development, including millions of tonnes of dredging and dumping, in the reef’s World Heritage Area.

“Approval of the Carmichael coalmine is another step along the way to seeing Indian company Adani develop port expansion at Abbot Point. If this mine goes ahead, at full capacity there would be another 450 ships crossing the reef every year.

“There is growing scientific evidence of the impacts of dredging and dumping, shipping and coal dust on the reef’s health – increased coral disease, reduced water quality and ship strikes on whales. This means impacts on the industries that rely on a healthy reef like tourism and fishing.

“With mining you can only dig it up once, but the reef and the industries it supports should be forever.”

Last year, UNESCO warned the Australian government that development along the reef was putting it in serious danger. It threatened to place the Great Barrier Reef on its “World Heritage in danger” list.

One delegate said: “We are concerned that not only [is] Canberra handing over environmental approval powers to the Queensland state government on a matter of such high national and international relevance, but also other measures that have been taken that can deteriorate the health of the reef even more.”

All available evidence says these coalmines and coal ports will be disastrous for the climate and the reef. It has led some people to scratch their heads about how such an environmentally destructive project could be given the green light.

Greenpeace campaigns director Ben Pearson described Hunt as “a decent bloke who cares about the environment”, who, on the basis of the evidence in front of him, could have easily rejected this proposal but “for whatever reason, [he] couldn’t do it.”

If you believe Hunt’s role is to make a decision only after rationally weighing up the evidence in front of him, you would be right to be confused about why he decided to approve the mine.

The truth is, he ignored all advice and approved the mine because he is a minister in a government that believes corporations should be free to invest their money where they want, and governments should get out of the way.

The logic of the market allows companies to invest where they think they can make a profit, no matter the risk to people or the environment.

Queensland premier Campbell Newman has repeatedly said the state is “open for business”, and their business is coal. So it is no surprise the state and federal governments are enthusiastic about a coalmine of this size.

But even though final approval has been given, there is still a long way to go before the mine is built. Last year, huge rallies were held around the country calling on the federal government to do more to protect the reef from industrialisation.

This public pressure could hurt Adani’s attempts to secure financing for the project. Greenpeace has said it will run a campaign targeting Australian banks and calling on them not to loan money for the mine. Banks are becoming more wary of loaning money to risky projects, particularly those that do not have the support of the public, because of the harm it does to their brand.

Like similar environmentally destructive projects that have been defeated in the past, such as the coal seam gas project at Bentley, or the gas hub at James Price Point in the Kimberley, people power can defeat this mine too.

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