Global Warming and Climate Change
What is Global Warming?
Global warming is the term given to an average increase in the
earth's temperature, which in turn causes changes to the climate
all over the world. A warmer earth may lead to a rise in sea level,
changes in rainfall patterns and impact upon plants, wildlife, and
humans. When scientists talk about the issue of climate change,
their concern is about global warming caused by human activities
Changes are happening all over the world from the Arctic sea ice
melting earlier and forming later to glaciers disappearing. Heat
waves, storms and floods are becoming more extreme. Insects are emerging sooner and
flowers are blooming earlier. In some places, birds are laying eggs before they’re expected
and bears have stopped hibernating.
So what’s going on? Our planet is getting warmer, even a small increase in temperature
can change our climate. And when our climate changes, we are all affected.
What changes are we seeing on land as a result of global warming?
Every second, a large section of forest the size of a football
field is cut down or burned somewhere in the world. Alongside
deforestation, glaciers are melting, deserts are growing
(which can’t support farming), there are more wildfires and
longer periods of drought.
A bear with her cubs in
Pyrenees, when they should be
hibernating Photo: EuroPics
The effects of global warming for living things are
even worse, causing huge changes and disruptions.
Plants and insects are moving upward (north) and
causing distress to the natural, original ecosystems
of those areas. Birds are also moving further north
and some are even laying their eggs earlier, which can
be a problem when it’s out of synchronisation with
insect hatchings (since birds are insects’ main
predators). The winter of 2006 was so warm that
mountain bears in Spain decided not to hibernate
(sleep for the winter).
How has global warming affected humans?
As a species, humans needs fresh water to survive. However, changing rainfall patterns and
melting glaciers cause severe droughts, during which crops fail, causing huge food
shortages. In 2003, Europe experienced such an extreme spell of hot weather that more
than 20,000 people died as a direct result of the heat. Also, mass extinction of many other
species we depend on for survival will mean big trouble for humanity.
Global warming is caused by a phenomenon known as the greenhouse effect. A greenhouse
(or glasshouse) is good for growing things because it traps heat inside and stays hotter
than the atmosphere around it.
What is the Greenhouse Effect?
The greenhouse effect is the rise in
temperature which the earth experiences
because certain gases in the atmosphere like
water vapour, carbon dioxide, nitrous oxide,
and methane trap energy from the sun.
Without these gases, heat would escape into
space and earth’s average temperature would
be about 60ºF colder and would not be warm
enough for humans to live. But if the
greenhouse effect becomes stronger, it
could make the earth warmer than usual.
The Greenhouse Effect
The highest impact of global warming has been seen in the Earth’s coldest places, like the
Arctic, Antarctica, Alaska and parts of Canada, Scandinavia and Russia.
Polar Bear on floating ice
Arctic temperatures are rising twice as fast as
anywhere else on earth. There has been a huge
amount of ice loss in the last 20-30 years. While
some is natural, global warming seems to be the
main culprit. Ice shelves which have been around
for tens of thousands of years have collapsed due
to lower temperatures, which causes sea levels to
rise. Permafrost (soil which has been frozen for
at least 2 years) has started to melt, which
results in forests and even towns and cities to
crumble as the ground beneath them thaws.
Because the far north and south have very fragile ecosystems, when one part of the chain
breaks the effects can be seen almost immediately. As the ice disappears, so are tiny sea
creatures called krill are dying – and so are the many fish, birds and whales that eat them.
Polar bears spend most of their time on sea ice hunting seals and other sea animals. As the
ice melts, the bears’ hunting season is shortened and female bears, with lowered body
weights, can’t seem to produce cubs. Warmer summers also mean certain pests’ life cycles
are longer than before. For example, the spruce bark beetle, which is only supposed to live
for one summer, is now surviving for two. This tiny bug destroys an unimaginable number
of trees in Arctic forests – and now it can do it for two years in a row instead of just one.
How do humans affect global warming?
Since the 18th century, when coal-burning
steam engines were first used on a large
scale, humans have been using energy in far
greater quantities. For example, car engines
work by burning petrol with oxygen from the
air to make heat (combustion). This not only
makes the car work, but also creates a gas
called carbon dioxide (the same gas our
bodies breathe out). Power plants also use
combustion to make our electricity which
Carbon dioxide and other gases from
again, produces more carbon dioxide. Even
cars and factories trap extra heat
burning fuels like coal, gas, and oil also give
off carbon dioxide too. Most of the energy people use is made by burning these so-called
fossil fuels, but this produces huge clouds of carbon dioxide. The carbon dioxide drifts up
into the atmosphere and makes earth's greenhouse gas just a little thicker. This is called
the enhanced greenhouse effect. As a result, more of the Sun's heat gets trapped inside
the atmosphere and the planet warms up.
How does global warming affect climate change?
Climate is the pattern of weather in a
particular place over a long period of time:
how much sunlight and rainfall it gets, how
windy it is, and so on. The world's weather is
entirely powered by the Sun. Scientists
believe that greater amounts of carbon
dioxide in the atmosphere, and hotter
temperatures on earth, will significantly
change the climate across the whole planet.
This climate change is already beginning to
happen in parts of the world. Some places will
be hotter some of the time, but most places
will simply see more erratic and extreme
weather. That could mean heavier rainfall on
occasions, more snow in some places, longer
Questions about global warming and
periods of drought, more storms and
climate change.
hurricanes, and more frequent heatwaves.
Governments across the world have been tasked with reducing their countries carbon
footprint. A carbon footprint is created when people use energy sources called fossil fuels
which produce carbon dioxide, (we now know this is a type of greenhouse gas). The main
two causes of a large carbon footprint are electricity and gas heating.
Now you need to find out what you can do to reduce your carbon footprint!
Information sourced from: http://www.weatherwizkids.com/weather-climate.htm
http://www.kidzworld.com/article/17859-the-kids-guide-to-global-warming