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Interesting Facts About Coal: From Ancient Times to the Present Day

Coal's history from 3,600-year-old Bronze Age hearths to today's power grid, plus how it forms, its types, mining dangers, and where it's heading.

By Written Facts StaffJune 7, 2023Updated October 17, 20267 min read

When you flip on a light or plug in your phone, there is a fair chance some of that power came from coal. In 2025 coal still generated about a third of the world's electricity. That coal began as swamp plants that died around 300 million years ago, and people have been burning it for at least 3,600 years. Here is how coal formed, how its types differ, how people have used it from the Bronze Age to now, what it costs the miners who dig it, and where it may go next.

It Started in Ancient Swamps

Much of the world's coal dates to the Carboniferous period, roughly 359 to 299 million years ago. Huge swamp forests covered large areas then. When the plants died, they fell into waterlogged ground with little oxygen, so they did not fully rot. Instead they piled up as peat. Over millions of years, buried under more layers, that peat slowly turned into the major coal deposits mined around the world today.

Not All Coal Is the Same

Geologists sort coal into four ranks by how much carbon it holds. The U.S. Energy Information Administration gives these ranges:

Anthracite: 86% to 97% carbon
Bituminous: 45% to 86% carbon
Subbituminous: 35% to 45% carbon
Lignite: 25% to 35% carbon

Anthracite is the highest rank and gives off the most heat when burned. It is also rare in the United States, and it is used mostly in metal industries rather than power plants. At the other end, lignite, often called brown coal, holds the most moisture and the least energy. Because it carries so little energy for its weight, it is burned almost entirely in power plants built near the mines.

People Have Burned Coal for Thousands of Years

The oldest firm evidence of people using coal as a regular fuel comes from China. At the Jirentaigoukou site in the Ili Valley of Xinjiang, archaeologists found coal burned in hearths and smelting furnaces about 3,600 years ago, during the Bronze Age.

Coal also has a long history in Britain. After the Romans invaded in 43 CE, Roman forts, country villas and metal workshops drew on local coalfields in Yorkshire, Lancashire, Northumberland and Somerset.

Coal Moved One of London's Most Famous Landmarks

Many centuries later, coal powered Britain's industrial age, and one famous example still stands over the Thames. When Tower Bridge opened in 1894, its roadway was raised by hydraulic machinery driven by coal-fired steam engines. To keep the hydraulic pressure up, stokers shoveled more than 20 tonnes of coal a week. The bridge kept running on coal until it switched to electricity in 1976.

How Much Coal the World Digs Today

Coal is far from a thing of the past. Global production hit a record of more than 9 billion tonnes in 2024, and China alone produced about half of it.

In the United States, Wyoming has been the top coal-producing state since 1988. In 2024 it produced about 190.7 million short tons, roughly 37% of the country's total. Most of that comes from the Powder River Basin, home to the North Antelope Rochelle Mine. Run by Peabody Energy, it is one of the largest coal mines in the world. It holds more than 1.7 billion tonnes of recoverable coal and has produced more than 100 million tons in a single year.

The Human Cost of Mining

Digging up that much coal has always been dangerous. One of the worst recent disasters happened on May 8 and 9, 2010, at the Raspadskaya mine in Mezhdurechensk, in Russia's Kemerovo region. Two methane explosions killed 91 miners and rescue workers.

Most of the harm to miners comes slowly, from the dust they breathe. Long exposure to coal mine dust causes pneumoconiosis, better known as black lung. In the United States, the Black Lung Benefits Act gives disabled miners a path to monthly payments. The Department of Labor's Division of Coal Mine Workers' Compensation runs the program. If a miner has at least 15 years of coal mining work, the law presumes they are totally disabled by the disease. Miners apply with Form CM-911 through the department's online C.O.A.L. Mine portal, and the program also pays for lung exams.

Rules on dust exposure have been in flux. In April 2024, the Mine Safety and Health Administration cut the legal limit for respirable crystalline silica to 50 micrograms per cubic meter of air, averaged over an 8-hour shift. In April 2025, a federal appeals court paused the rule's compliance deadlines while lawsuits play out. In April 2026, MSHA put enforcement of the rule's changes on hold indefinitely.

Coal's Shrinking Share of Electricity

Once the coal is out of the ground, most of it is burned to make electricity, though its share is falling. According to the International Energy Agency, coal produced about 36% of the world's electricity in 2023, 35% in 2024, and about 33% in 2025, as solar and wind grew.

The drop has been steeper in the United States. Coal supplied about 16.2% of the country's utility-scale electricity in 2023 and 15.1% in 2024. That 15.1% equals 652,156 gigawatt-hours out of 4,308,634.

A Back-and-Forth Over Carbon

Coal plants also release carbon dioxide, and U.S. rules for that pollution have changed twice in two years. On April 25, 2024, the Environmental Protection Agency finalized standards that would have required existing coal plants planning to run long-term to capture 90% of their carbon by 2032. On September 14, 2026, the EPA finalized a partial repeal of those standards. It said the technology requirements conflicted with the Supreme Court's ruling in West Virginia v. EPA.

Coal Without the Fire

As power plants burn less coal, researchers are looking for other ways to use it. Projects funded by the Department of Energy and its National Energy Technology Laboratory turn coal pitch into fibers, which can then be made into strong carbon fiber for aircraft, cars and wind turbine parts. The lab has also worked with the University of Illinois Urbana-Champaign to turn coal into tiny particles called carbon nanodots. These have been used as insulating layers in experimental electronic parts built from a very thin material called molybdenum disulfide.

From Bronze Age hearths and Roman workshops to Tower Bridge and today's power grid, coal has run through human history for thousands of years. Coal still makes a third of the world's electricity, but its share is shrinking, and its next chapter may be in materials rather than fire.

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