No matter what President Trump says, coal in America isn’t coming back — and it’s bringing other industries down with it.

Driving the news: Coal demand for electricity is likely to drop by more than 50% in 11 years, according to a report by the rating agency Moody's. In turn, revenue from transporting that coal around the country via trains is expected to drop $5 billion by 2030, or 5.5% of the railroad industry’s 2018 revenue.

The big picture: Coal’s dramatic decline is fueled by several factors: cheaper natural gas and renewable electricity, tougher environmental regulations in the Obama administration and the global shift to cleaner sources of energy in the face of climate change.

One level deeper: Because of the industry's outsized dependence on coal, the fossil fuel’s decline is hitting railroads especially hard. Coal makes up 13% of total freight volume, which is the largest single freight commodity moved by rail.

4 railway companies, led by CSX and Burlington Northern Sante Fe (BNSF), get more than 10% of their revenue from coal and are thus most at risk for revenue hits.

CSX gets nearly 20% of its revenue from coal, while BNSF gets nearly 17%.

Moody’s says credit effects for U.S. railroad companies "are likely manageable if the [coal] decline remains gradual."

Go deeper: Moody's developing new rating system to assess companies' "carbon risks"