Clean coal is coal that does not release carbon dioxide into the atmosphere.
Coal was made from the deposited layers of forests and organic matter that have held the carbon under the earth over millions of years. We are now digging it up and burning it. This releases all that carbon dioxide which is a major greenhouse gas. So burning coal and other fossil fuels contributes to global warming.
Coal is still plentiful. It is reasonably easy to dig up and burn. If scientists can discover a way to capture the carbon dioxide as the coal is burned, and store it, sequester it, somewhere safe. This process is called carbon sequestration. Nobody has managed to do it successfully on a large scale yet. There are trial projects going on around the world.
Advantages: If it works:
- we can keep using coal to produce electricity for hundreds of years more because we are putting all that old carbon back under the ground where it came from.
- we won't have to spend so much money on new renewable technologies like solar, wind and water power.
- the coal miners can keep their jobs.
Disadvantages: If it works:
- There will still be the other pollution emitted by coal fired power stations, like selenium and arsenic, both harmful to human health and the environment.
- Other pollutants include nitrogen, nitrous oxides, sulfur dioxide, fly ash and mercury as well as the waste ash.
- Governments will be reluctant to spend money on research into renewable technologies like solar, wind and water power.
Many scientists and environmentalists are not confident that carbon sequestration will work successfully. They fear the stored carbon will escape into the atmosphere and the vast amounts of money being spent to try and find this solution would be better spent on developing better ways of harnessing solar, wind and water power.