OFF HAY POINT, Australia — The traffic is thick out here on a calm Coral Sea and, very soon, it may get worse. Much worse.

The horizon is marked by two dozen ship hulls, freighters that wait for days to pick up coal at the looming Hay Point terminal. Just beyond are the invisible southern limits of the Great Barrier Reef marine preserve, among the seven natural wonders of the world.

As much of a warming world considers alternatives to burning coal for energy, Australia embarked last year on one of the largest expansions of the industry in a generation. The Indian conglomerate Adani received approval to tap one of the world’s largest reserves of thermal coal, the kind that when burned in power plants releases carbon dioxide, which is linked to climate change.

But something has shifted over the past several months.

Wildfires that have scorched an area larger than Portugal — and are still burning — have been made more devastating by climate change, scientists say.

That’s forced many here to confront the global impact of the Australian coal industry and, along with it, the future of a national economy built in large part on briquettes.

Environmental activists are preparing an “autumn rebellion” of civil disobedience focused on Adani and its Carmichael Mine, as the project is called. Even those who have relied for years on coal revenue for their livelihoods are noticing with increasing alarm its harmful effects on their own, smaller worlds.

“When we started out on the tugs, we’d fish right off the marina while we waited,” said Jim Forrest, a tug captain for 41 years in these now-opaque waters. “Now there is nothing at all.”

The politics of coal

In Australia’s commodity-driven economy, coal has been either king or crown prince for generations. And it enjoyed the political support that comes with that status, more or less unquestioned, amid the rising global debate over the Earth’s warming.

But ominous signs over the past three years have shaken the rock-solid support among Australians for their country’s leading export. The introspection has come with new international criticism over Australia’s role as one of the world’s main suppliers of coal, including to China and India — where greenhouse-gas emissions have been increasing.

In 2016 and 2017, a number of scientific reports showed that bleaching across the 1,400-mile Great Barrier Reef system had been far more extensive in recent years than previously thought. Then, last year, a study published in the journal Nature reported a nearly 90 percent collapse in new coral formation on the reef since the bleaching began.

The coral die-off is caused by rising ocean temperatures, themselves a consequence of atmospheric warming.

The Nature report’s author, Terry Hughes, who is the director of James Cook University’s ARC Center of Excellence for Coral Reef Studies, has framed the debate over the Carmichael Mine as a national choice between a future with coal and the Great Barrier Reef. He has said, in essence, that the country cannot have both.

“The extent to which the Great Barrier Reef will be able to recover . . . remains uncertain, given the projected increased frequency of extreme climate events over the next two decades,” Hughes wrote.

Australians, though, narrowly chose Scott Morrison again as prime minister last year in what was called the climate election. Morrison once famously carried a chunk of coal into the Australian Parliament to call out the “coalophobia” he said plagued the rival Labor Party, which he criticized for having an “ideological, pathological fear of coal.”

Six months after the election, Australia’s wildfires began — and they continue. Scientists here have called the fires a second sign, after the Great Barrier Reef’s bleaching, that a “tipping point” has been reached in the continent’s climate.

The public appears to agree. A poll released in November, as the fires began, found that 60 percent of Australians think the government is not doing enough to address climate change; that percentage was up by nearly double digits from just eight months earlier.

“These forests burning are experiencing record high temperatures and record low moisture,” said Will Steffen, a emeritus professor at the Australian National University in Canberra. “The heating of the planet is pushing the tropics farther from the equator, and for us that means our rains are pushing toward the poles. Many fronts just don’t reach us anymore.”

The same warming affecting Australia’s reefs and forests is posing an even more dire threat to some of the country’s smaller island neighbors.

At a regional conference last year, Fiji’s prime minister, Frank Bainimarama, implored Australia, which is among the world’s five leading coal producers, to make “a rapid transition from coal to energy sources that do not contribute to climate change.”

“That transition,” he said, is essential to help Pacific nations that “face an existential threat that you don’t face and challenges we expect your governments and people to more fully appreciate.”

A new focus of opposition

Adani received permission last June, a month after Morrison’s reelection, to proceed with the Carmichael project.

Covering more than 10 square miles, the mine is set in Queensland’s remote Galilee Basin, several hundred miles northwest of this coal-shipping hub. The project has become shorthand internationally for what environmentalists see as Australia’s misguided relationship with coal.

Adani, which declined a Washington Post request to visit the site, plans to begin extracting an initial 10 million tons of coal annually from the mine as early as next year.

The company says the project will add and support hundreds of jobs in Queensland, where mining employment has stagnated in recent years, and grow to produce 60 million tons annually.

That is twice the present capacity of Australia’s largest mine.

When it reaches that peak, the new business would add at least 500 transits by coal ships through the Great Barrier Reef World Heritage Area each year of the project’s six-decade life. The coal will be shipped mostly from the company’s Abbot Point terminal, 130 miles north of here on the Queensland coast. The reef lies roughly 30 miles offshore from the terminal.

With approvals in place, Adani faces only one remaining challenge: building a roughly 120-mile rail line linking the mine to an existing rail system that reaches the coast. It has become the focus of environmentalists opposed to the mine, being the last real chance they have of preventing the operation from starting.

The German engineering and electronics giant Siemens has the contract to supply the signaling system along the rail line. As a result, the company has become a target for environmental activists here and beyond Australia.

Last year, a member of the group Extinction Rebellion glued himself to the window of the Siemens lobby in Melbourne, prompting similar acts at Siemens offices in Germany and other countries. Then, last month, the teenage climate activist Greta Thunberg called on Siemens to drop the rail contract.

The company, which has pledged to become carbon-neutral over the next decade, issued a statement two days later declaring its intention to proceed with a contract that only a small number of companies can fulfill.

Joe Kaeser, the company’s chief executive, wrote that “even though we do not have clear evidence that the wildfires and this project are directly connected, I feel empathy for all those who spoke up and warned about worsening conditions.”

“While I do have a lot of empathy for environmental matters, I do need to balance different interests of different stakeholders, as long as they have lawful legitimation for what they do,” he continued. “Only being a credible partner whose word counts also ensures that we can remain an effective partner for a greener future.”

A camp and a plan

Camp Binbee uses a word in its name that means “happy place,” and if Ken Kesey and his Merry Pranksters were alive and Australian, they might well be living along the hard dirt track in the middle of Queensland where the complex sits behind a gate secured with a bike lock.

This is the forward operating base of the resistance to the Adani project, the come-and-go-as-you-like camp of the group Frontline Action on Coal. There are a few cattle and a lot of brush, handmade signs, seashells and painted banners, and the occasional koala.

There is not much else.

With dreadlocks and green-painted toenails, David Anderson is the group’s leader and, on the eve of a week of civil-disobedience training, he worked on plans for a season of direct action against Adani, Siemens and the mine.

“It’s always been a passion to smash these multinationals, who pay nothing in taxes and contribute next to nothing to society,” said Anderson, who is 49 and once sang to the region’s miners with his band the Traveling Agitations.

The group is part of a broader climate movement in Australia that has used novel, direct action as protest, exemplified by the Siemens lobby escapade. That was carried out by a Queensland native named Dan Bleakley, who grew up near the mine site.

The political climate has turned more amenable to the activists’ tactics. Anderson’s chief role is to train those interested in taking part and to help stage what in the coming months will be demonstrations around the country employing what he said will be “nonviolent direct action.”

What’s at stake here on Birri land, the name of its aboriginal tribe, is an already thin water supply threatened by the mine project, which will draw on groundwater across much of central Queensland, where both camp and mine are located. Among the many banners that hang around the 100-acre site is one with a simple message: “Defend Our Water.”

“We had been concerned about Adani for some time, but we didn’t know this place existed,” said Ben Winch, who, with his wife, Ciannait, and twin 14-year-old sons, arrived at the training camp from their home on Byron Bay.

“We just wanted to show them some hope,” he said of the boys. “And now I also feel like we all have some skills and some material to share.”

Summer is the offseason for protest in Queensland, which heats to kiln-hot during the day and discourages those from Australia’s more temperate climates from coming. But a few gathered ahead of training week.

The camp’s residents live in their own tents. There is a tented central meeting place, an open-air kitchen and a collection of garishly painted tables, which serve as the cafeteria. Despite the long odds facing its Don Quixotes, this is a hot and happy spot.

“It’s people power,” said Margid Bryn-Burns, the 79-year-old former head of New Zealand’s social workers union, who arrived a few days ahead of training.

“If I’m doing this for my grandchildren, what is Scott Morrison doing for his?” Bryn-Burns said of her first visit to Binbee. “They are always my reason.”

Concern and profit

The Pioneer River flows out of the valley named for it near the port of Mackay, bringing runoff from the hills, including coal dust generated by the hundreds of nearby mines, into the Sandringham and Dalrymple bays and beyond.

Dozens of coal ships swing on their anchor chains in the distance. Helicopters from Hay Point shuttle ship pilots from shore to deck. The pilots have expert knowledge of the local waters and guide the freighters through the Torres Straits or the reef at Blossom Banks.

The debate here and across the continent between business interests and the “greenies,” as the environmental lobby is often derisively called, has gone more often than not the way of business. The Adani decision followed that pattern.

“We have a stable political situation right now,” said Forrest, the retired tug captain, who also used to run tourist excursions out to the Great Barrier Reef. “I think [the reef] is okay right now. And at any rate, it does recover.”

But Forrest and others who support the industry do so increasingly with a note of concern. It is getting bigger and, along with it, so are the quantities of ballast water discharged from coal ships, the choking coal dust and a more in-your-face opposition.

For now, though, the rule that has long guided the Australian economy and much of its political leadership remains in place.

“Coal makes money,” Forrest said. “And they don’t want to waste that.”