bodyType

customContents

entityId

entityUuid

articlePageQuery

filter

article

articleBaseAdvertisingInfoArticle

articleListArticle

articleSeoArticle

helpersCheckIsPostiesArticle

hooksArticleAcknowledgementGateOverlayArticle

hooksTrackPageViewArticle

hooksContentInterestArticle

articleLinkingDataContent

articleSchemaContent

liveArticle

advertZone

sentiment

contentLock

topics

types

sections

moreOnThisArticles

urlAlias

commentCount

sponsorType

authorLocations

authors

paywallTypes

corrections

displaySlideShow

multimediaEmbed

printHeadline

seriesContainer

socialHeadline

headline

flag

firstTopic

glossary

flattenTypeIds

publishedDate

additionalInfoBoxes

images

image

relatedLinks

relatedNewsletters

__typename

createdDate

sponsor

factSheets

series

disableOffPlatformContent

published

updatedDate

summary

subHeadline

body

keywords

copyrighted

customTimezone

liveContents

Chris King

Deep underground
If you follow the news, you will know that coal mining accidents happen regularly on the mainland. This is because there is more demand for coal than the people digging it up can provide. About 70 per cent of the mainland's energy comes from burning coal.
Coal is usually 300 to 360 million years old. This time was during the Carboniferous period. Carboniferous means ?coal bearing?.
During this period, there were a lot of swamps. Ferns and trees in these swamps decomposed. Dirt, rocks and water covered them. Over millions of years, these plants became hard. This was coal.
Coal is called a ?fossil fuel?. It is actually fossilised plant life.
Burn it
Coal today is still the No 1 source of energy. What's more, humans have used it for longer than any other kind of energy. Even cavemen used coal to warm up their caves. When the Romans occupied cold England, they burned coal to heat their buildings. Even the native Americans used coal fires to cook and make pottery.
But the big breakthrough was the Industrial Revolution. By the early 1700s, coalpowered steam engines were used in Britain, but they were not very powerful. In the 1760s and 1770s, inventor James Watt made improvements to the engines so they could be used in factories. Suddenly, the demand for coal grew.
Turn off the lights
Today, we mostly use oil to power our engines - of our cars, that is. But coal is still king because it provides so much of our electricity. The mainland relies on it more than most countries. But India is not far behind, using coal for about two-thirds of its electricity. More than half of the electricity used in the United States comes from burning coal. In Hong Kong, more than half our energy is provided by coal.
The downside of coal is not only the terrible accidents that can happen to miners - like the one on the mainland recently - but also that coal is a dirty fuel. It causes air pollution - a serious problem here in Hong Kong. It also emits substances that are poisonous, such as sulphur dioxide and even mercury.
now do this
1 Most coal was formed ?
a. 100-150 million years ago
b. 300-360 million years ago
c. 250-300 million years ago
2 The mainland relies on coal for ? of its energy needs.
a. about two-thirds
b. half
c. 90 per cent
3 A breakthrough in the development of ? made coal the king of fuel.
a. steam engines
b. coal-fired electricity plants
c. tunnel-digging machines
Answers:
April 14 



Coal still king in the power stakes