While the burning of coal has sustained production since the
industrial revolution, it has also produced damaging side effects.
For one thing, coal is not pure. It contains sulfur, which makes up
only 1 percent of the total content but will turn into sulfur
dioxide during combustion. Additionally, when coal is burning, the
high temperature will lead to a combination of oxygen and nitrogen
gas in the air. The two will react with each other and form nitric
gases.
As a result, when we consume coal, harmful acidic gases are
released into the air. They remain there until the moisture absorbs
them and carries them down to the earth in the form of acid rain.
When conditions permit, these gases can also fall down in the form
of acid snow or fog.
In 1872, a British scientist discovered that the rain in London
was acidic and the term “acid rain” was first used. At present,
Europe, North America, and China are generally recognized as areas
suffering most from acid rain.
Also called the “tears of paradise,” acid rain is believed to
have a critical impact on our surroundings. It increases the
acidity of soil, thus leading to the death of agricultural products
in large quantity. It damages the ecosystem of forests, where trees
grow more slowly and die more quickly. It kills microorganisms in
polluted rivers and lakes, which consequently kills the fish and
shrimp living on the microorganisms. Moreover, it seeps into the
earth and makes ground water undrinkable.
According to the statistics available, acid rain has led to the
death of 1 million hectares of forest in middle Europe and some
9,000 in northern Italy. In Sweden, more than 20,000 lakes are void
of aquatic life and in Norway, fish and shrimp no longer exist in
some 260 lakes. In 1980, 8,500 Canadian and at least 1,200 American
lakes were measured as acidified and thus became “dead lakes” where
no life prevailed.
Acid rain can also severely erode the surface of architecture,
vessels, vehicles, power transmission lines, railway rails, and
electromechanical equipment. Some specialists hold the opinion that
the weathering of ancient Greek and Roman relics is getting worse
with each passing day, largely because of acid rain. In eastern
America, some 3,500 historic buildings and 10,000 monuments have
been affected.
Acid rain and acid fog in particular put human health at risk.
They can seep deep into our lungs and lead to pulmonary edema,
pulmonary sclerosing hemangioma, and even lung cancer. According to
an investigation in 1980, 1,500 people in the UK and Canada died of
such diseases.
With regard to China, the country’s development relies heavily
on the consumption of coal. Every year, sulfur dioxide is
discharged in large quantities and many areas are troubled with
acid rain. At present, acid rain is mainly observed in areas to the
south of the Yangtze River, such as the Sichuan Basin, Guizhou,
Hunan, Hubei, and Jiangxi, and costal areas, such as Fujian and
Guangdong. All together, they account for 30 percent of China’s
total territory. What is more, a large area in the country is now
stricken by severe acid rain. All of these phenomena tell us that
the pollution of acid rain in China is much heavier than that in
Europe and North America.
As estimated by environmental protection specialists in 1995,
damages caused by acid rain and sulfur dioxide in areas under
special control totaled 110 billion yuan, accounting for 2 percent
of total annual GDP. In 1998, southwestern China saw a sharp
decline in forest output. A total of 6.3 million cubic meters of
timber were lost, equivalent to a financial loss of 3 billion yuan.
In Guangdong, the annual loss caused by acid rain amounts to 4
billion yuan.
Since the 1990s, China has made Herculean efforts to treat acid
rain and curb emissions of sulfur dioxide. Thanks to this
unremitting effort, the total area suffering from acid rain extend
is no longer increasing. With the gradual reduction of sulfur
dioxide emissions, officials are optimistic that acid rain could be
completely eliminated in China.
(China.org.cn September 12, 2007)
