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, the high-riding 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 coal, 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 linked to climate change.

But something has shifted over the last several months. Wildfires that have consumed 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.”