Download Natural Disasters and Climate Change

Fact Sheet 3.5
SUSTAINABLE COMMUNITIES
2
ENVIRONMENT ISSUES: Natural Disasters and Climate Change
A natural disaster is the effect of a naturally occurring hazard (such as an earthquake) taking place in a
populated area and resulting in severe damage to the environment and often loss of life. These types of
events have environmental, social and economic consequences.
Hurricanes, earthquakes, tsunamis, floods and droughts are all examples of natural hazards. Although experts
(such as meteorologists also known as ‘weatherman’) can sometimes predict them, natural disasters are often
totally unexpected. (See also fact sheet 3.5 Environment Issues - Natural Disasters for ages 12-14.)
Environmental factors and changes in the global temperature (caused by global warming, see fact sheet
3.4 Environment Issues - Climate Change) are largely agreed to cause more natural disasters such as
earthquakes, volcanoes and flooding. Melting polar ice caps for example increase sea levels and affect the
amount of pressure being placed on the tectonic rock plates under the Earth’s crust. Increased temperatures
also cause heavier rainfall in some regions causing flooding.
Hurricane
A hurricane is a severe tropical thunderstorm with strong
winds reaching 74mph or more. They form when a storm
travels over warm water (80°F/26.6°C or more) causing
the surface temperature of the ocean to begin to rise
creating what is called ‘low pressure’ on the surface of the
water. The winds blowing in different directions cause the
storm to start spinning.
Hurricane Katrina was one of the worst natural disasters
to hit the United States of America. It struck New Orleans
in the summer of 2005, killing more than 1,800 people.
Earthquake
An earthquake is caused by the movement of rocks called ‘tectonic plates’
under the Earth’s surface. The ‘fault line’ which marks the gap between
each plate is affected by the movement causing pressure to build and
a ‘shock wave’ to be sent out. Earthquakes are measured on a ‘Richter
scale’ with zero being a minor tremor (shake) and nine being a large
vibration.
On the 11th March 2011, an earthquake measuring nine on the Richter
scale occurred off the coast of Japan. What devastated the country more
than the quake, however, was the tsunami (see next page) caused by it,
which has destroyed entire areas of the coastline and islands.
Cont’d
Sustainable Living
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SUSTAINABLE COMMUNITIES
Fact Sheet 3.5
2
ENVIRONMENT ISSUES: Natural Disasters and Climate Change cont'd
Tsunami (tidal wave)
A tsunami (from the Japanese word meaning ‘harbour-wave’) is caused by underwater movements such as
earthquakes, landslides and submarine (underwater) volcanoes. These cause large waves of water to form on
the surface travelling vast distances across the ocean before eventually dissipating (losing momentum
and coming to an end).
The waves slow down once they hit land but the wave height increases which causes more destruction,
whereas in deep water the waves are very small. Japan has a number of tsunami prevention measures such
as large walls surrounding coastal towns; however there is evidence suggesting trees form a much better,
natural barrier to tsunamis.
Asian tsunami (2004)
On the 26th December 2004, an earthquake
measuring nine on the Richter scale (and triggering
quakes across the world) occurred underwater in the
Indian Ocean causing a tsunami in Asia. The wave
that hit the Indian Ocean coast was over 30 foot high
devastating coastal areas of Indonesia,
Sri-Lanka, India and Thailand. It is the deadliest
tsunami ever known with over 300,000 killed and the
effects felt as far away as Somalia in Africa!
Flooding and droughts
One of the most common forms of natural hazard is flooding, which occurs when areas of water (lakes, rivers,
reservoirs etc.) receive more water than they can contain, flooding the surrounding land areas. Heavy rainfall
is the most common cause of floods and they occur across the world, even in the United Kingdom.
Droughts, on the other hand, occur when there is not enough rainfall in a region (usually if there is less than a
third of average rainfall for that time period it is classified as a drought) causing plants and wildlife (and human
inhabitants) to die. They commonly happen in hot, dry areas such as Africa where there can be minimal rainfall
but droughts have been known to occur in parts of the United Kingdom. In June 2007 bad flooding affected
much of the UK, particularly parts of Northern Ireland, Yorkshire and the Midlands. In 2003 Europe, particularly
France, experienced an extremely hot summer heat wave, almost 2,000 people in the
UK died from the extreme weather.
?? ?
Did you know?
During the 2003 European heat
wave almost 15,000 people died
in France.
Sustainable Living
Provided by Nationwide - available on www.NationwideEducation.co.uk