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20 October 2014
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    The Environment
    The Basics | More Information | Web Links
    Environmental disasters

    Environmental disasters can be caused by the natural cycles of the earth. Others are the result of human activity.

    Floods

    • A flood occurs when a body of water - usually a lake, sea or river - overflows onto normally dry land when the land becomes saturated.

    • Some research suggests that the number of floods throughout the world is increasing due to climate change and practices like chopping down the trees which protect the earth.

    • In 2002 one third of the 526 natural catastrophes on earth were floods.

    • Floods killed more people and cost far more than earthquakes or other natural disasters. Floods in Europe alone killed more than 100 people.

    Drought

    • Drought is the result of a prolonged period of abnormally dry weather which causes an imbalance in the climate.

    • Sometimes drought is caused by human activity - changing the natural course of rivers, for example. Drought conditions are usually hot and often result in crop failure and, in extreme cases, famine.

    • Some scientists believe that droughts will increase as a result of climate change.

    Water Shortages

    • In 1999, the United Nations Environment Programme identified water shortage as the second most worrying problem of the new millennium, after climate change.

    • Usable water is essential for our food and health. But supplies are limited, and some estimates say humanity will want to increase its consumption by 40% over the next two decades. This increase could mean a shortfall of 17% in the amount needed for agriculture.

    • The current picture on the health front is that one person in five has no access to safe drinking water, and about half lack sanitation.

    • There are many causes for the crisis - among them population growth, the drive to improve living standards, the inefficiency of the way water is often used (e.g. in irrigation) and the effects of pollution and climate change.

    • Apart from the impact on development prospects, water scarcity is also a potentially serious source of conflict in several areas.

    Hurricanes
    • A hurricane is a fierce storm that forms over tropical oceans.

    • Hurricanes cause big waves, strong winds and driving rain. A typical hurricane lasts nine days. Hurricanes are the most powerful type of storm on the Earth.

    • They are always given names. In September 2003, Hurricane Isabel produced 160 mph winds, killing 28 people, and devastating parts of the US.

    Fires
    • Wild fires are a natural part of a forest's regeneration process. They occur every now and then, often sparked by lightning. The fires clean up the debris of dead vegetation on the forest floors, thus preventing more serious fires.

    • Some plants must have fire in order to reproduce. Many kinds of pines have cones that only fire can pop open, releasing the seeds inside.

    • But fires can be damaging. As well as destroying land and property, the smoke causes pollution. In 1997, Indonesia was blanketed by a choking, thick brown haze. Hundreds of fires, many deliberately lit to clear land, burnt for months.

    • Combined with industrial emissions and car fumes, the smoke from the fires covered large areas of Indonesia as well as neighbouring Malaysia, Singapore and Brunei causing widespread respiratory problems.


    Industrial accidents

    Industrial accidents can take many forms and have a variety of causes.

    One devastating accident was at Bhopal in India in 1984 when a gas leak from a chemical factory owned by Union Carbide killed nearly 4,000 people. Thousands of others suffered permanent disability.

    In 1986 the Chernobyl Nuclear plant in Ukraine exploded, initially killing thirty people. No-one knows the long-term effects on the environment but most people agree that there has been a big rise in the cases of cancer in the area.

    In 1989 the Exxon Valdez oil tanker ran aground off the coast of Alaska. About eleven million gallons of oil leaked from the ship - that's about 125 Olympic-sized swimming pools' worth.

    The spill is thought to be the most damaging to the environment ever. About 1,300 miles of shoreline were affected.

    No-one knows how much wildlife was destroyed, but some estimates are: 250,000 seabirds, 2,800 sea otters, 300 seals, 250 bald eagles, up to 22 killer whales, and billions of salmon and herring eggs.


    Other natural environmental disasters

    Earthquakes can be devastating. They remind us that the earth is constantly moving. They are caused by the motion of 'tectonic plates' - individual sections that make up the Earth's surface like panels on a football. Immense strain accumulates along 'fault lines' where adjacent plates meet. When the rock separating the plates give way, sudden 'seismic' ground-shaking movement occurs.

    In 2001 an earthquake devastated much of Gujarat state in north-western India, killing an estimated 30,000 people and making more than a million homeless.

    Volcanoes are explosions of molten rock which comes from deep in the earth. It's estimated that one in ten of the world's population lives within 'danger range' of volcanoes. In 2002 Goma, in the Democratic Republic of Congo, was engulfed by lava from a volcano, forcing hundreds of thousands of people to flee.

    Tsunami are giant waves which travel up to 500km/hour. They are caused by underwater shocks, such as earthquakes or volcanoes. Following the world's biggest earthquake off the coast of Chile in 1960, a series of waves created havoc around the Pacific Rim. It caused 56 deaths in Hawaii, 32 deaths in the Philippines, and 138 deaths in Japan - 10,000 miles away.

    Tornado. A tornado is a violent whirling wind. A tornado can travel at 300 miles per hour causing a great deal of damage. Heavy objects, like cars and cows, can be sucked up and flung around. The United Kingdom is actually the world's most tornado-prone nation.

    Landslides are caused by instability on a slope - often made worse by rain and deforestation.




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