Whole communities have risen up out of that dark soil. The industry now directly employs around 14,000 people in the NSW region, with flow-on profits supporting hundreds of other businesses.

"You know, my business is so strong because of mining bringing people to the town," Muswellbrook realtor Jay Shepherdson said.

"The rents are so good because we have such a big workforce and that brings investors to the town. That all leads back to the coal mining industry and the power stations and the railway infrastructure."

But experts say the days of coal as a driver of the region's economy are numbered.

If the change does come, Jay is concerned about what the future of Muswellbrook - a town in the Upper Hunter - would look like. Although he doesn't think coal is going anyway any time soon.

"If coal mining pulled out of Muswellbrook, which won't happen, but if it did, then it would be a big problem for the town and for my business," he said.

"Liddell [coal-fired power station] will close in the foreseeable future and they may replace it with something else. But at this point in time, we don't have any other industries that can generate the power that we supply from the coal."

While mining is as widespread in the Hunter as ever - coal prices are at record highs, and the Australian government has forecast exports to South East Asia and India to grow over the next two years - coal is gradually being phased out of the global economy.

The coal mining industry could have decades left in the Hunter, but there's every possibility changes in government policy, combined with action from the private sector, could kill the industry a lot sooner than expected.

Origin Energy has announced intentions to close NSW's largest coal-fired power station, Eraring, which sits on the edge of Lake Macquarie, by 2025 - seven years ahead of schedule.

On top of this, Liddell and Bayswater power stations - located about a 15 minute drive south east of Muswellbrook and representing about 8 per cent of generation in the national electricity market - will both close in the foreseeable future.

Liddell is scheduled to begin a year-long decommissioning process in April this year with Bayswater following suit no later than 2033.

General manager of both the Lidell and Bayswater power stations, Len McLachlan, said as "more and more renewables come around" employees are beginning to see the change ahead.

"You can see a shift in the employees starting to say 'actually you know what, this is going to happen'," he said.

"I think that once we start getting into some of those new types of plants, even though the the amount of employees per plant is less, we'll be able to then shift 20 to 30 per cent of our employees to those plants and also participate in any other renewable investment that's taking place in the valley.

"Seeing that continue to grow over the next 20 years would be fantastic."

A consortium, which includes Australian tech billionaire Mike Cannon-Brookes, is looking to buy AGL, with plans to transform the company into a green energy provider.

Even if the buy-up doesn't go ahead, AGL already intends to establish a range of green industries such as solar, hydrogen and battery technologies on the Liddell and Bayswater sites, as part of their Hunter Energy Park concept.

Nathan Clements is an electrical fitter employed directly downstream of coal mining in the Hunter. He is only 26 and having worked in the industry for 7 years, is preparing for employment away from coal.

"What is my potential future? Is it safe? How financially stable is it?" Nathan asks.

It's why he's studying Commerce, part-time, at the University of Newcastle.

Nathan said he wants to avoid being left with no options when coal mining does wind down. But he's worried about what his colleagues are going to do.

"It has me concerned in a sense about what the future holds. Where are my co workers going to work in 20 years time, will there be enough work to keep them in their current jobs?"

He argues that until there are viable alternatives to employment in the mining industry, there's unlikely to be much movement from workers.

"Part of the conundrum is that you have people working in a coal mine looking at $120,000 a year plus and you're asking them to change to a job in the renewable energy sector for $80,000 - based on climate morality," he said.

"When petrol is nearing two dollars a litre and houses are almost completely unaffordable."

Executive director at the Ethics Centre, Dr Simon Longstaff AO, co-authored an eight point blueprint in 2016 outlining a transition away from fossil fuel.

Titled Our Energy Future, the plan was presented to government as a way forward for Australia.

'Action Five' of the plan, which was Dr Longstaff's focus, outlines the need for a "just and orderly transition" for people like Nathan and his colleagues.

"It's about looking at what are the essential requirements of a community and whether they're being satisfied in the circumstances before change commences," Dr Longstaff said.

"It's about the access to basic goods, the bread and butter things that people worry about. You know, 'will my children have a job in the future? Can I afford health care? What about the cost of living?'."

Dr Longstaff said the needs of communities like the Hunter are often misunderstood and, at times, taken advantage of.

"It's not so much the opportunity to go into the pit every day. What they want is the opportunity to make provision for their families to be able to live reasonably decent lives where they've got an opportunity to deal with those bread and butter issues," he said.

"So when people prey on fear of loss and don't actually provide any reasonable prospect of an alternative, I think they're actually manipulating people in a relatively vulnerable position."

One organisation which is presenting an alternative for the future is progressive think tank Beyond Zero Emissions (BZE).

As part of their Millions Jobs Plan, BZE has proposed a Renewable Energy Industrial Precinct for the Hunter.

"It is a cluster of manufacturers powered by 100% renewable energy," BZE Hunter Engagement Leader Samantha Mella said.

"They're located either within our renewable energy zone or connected to a renewable energy zone through high voltage transmission lines that have access to clean heat and renewable hydrogen production and infrastructure."

A Renewable Energy Zone (REZ) is an initiative lead by State Government. NSW treasurer, Matt Kean, has announced 87 expressions of interest in the project worth about $100 billion.

The investments are in renewable energy generation - including solar, wind, and battery projects - making the Hunter an "energy powerhouse of NSW" according to Mr Kean.

By manufacturing zero emissions products alongside the REZ, Sam Mella believes the Hunter can become the "electric motor of the global economy."

"Why we're focusing on manufacturing is because it accounts for 21 per cent of Australia's emissions. But also it's an opportunity to boost and future proof our economy," she said.

Nathan might be preparing for an alternate career but he's not convinced that the renewables industry is quite there yet when it comes to employment conditions.

"The coal mines have been around for so long, [they're] heavily unionised, they have fought, taken action, achieved the conditions and wages that they're on," Nathan said.

"The renewable energy sector hasn't had that chance yet. It's so new and it's so far lacking. And so to ask coal miners to do that, right now, today, there's not going to be many yeses."

Listen to the full story on the podcast search Voice of Real Australia, on Apple Podcasts, Spotify or your preferred platform. You can also listen on the web player above.