Download Theme 2 – Climate Change

Climate Change
Climate change
• Climate change is a natural
phenomenon
• In the past the world climate
has fluctuated over millions of
years.
• We have had warmer periods
called inter-glacial (like the
current warm period we are in)
• And cool periods called glacial
(known as ice ages)
• These changes are thought to
be due to changes in the
output of solar radiation
Global warming
• Global warming is the recent warming that
is occurring in our atmosphere as a result
of human activities.
• Global warming is a result of the
‘enhanced greenhouse effect.’
The Greenhouse Effect
1. The sun releases radiation (short
wave) that travels across space to
earth
2. Some of the suns radiation enters
the earths atmosphere some is
reflected by the atmosphere back
into space.
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4
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5
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3. As the earth is warmed up by the
solar radiation from the sun, it also
released radiation (infrared radiation
– long wave)
4. Some of the infrared radiation
escapes the earths atmosphere back
into space
5. The rest of the infrared radiation is
trapped by greenhouse gases in the
atmosphere, this causes earth to
warm.
The Greenhouse Effect
• The greenhouse effect is natural and keeps our
planet warm.
• without it life would not have formed on earth.
• However humans are enhancing the
greenhouse effect by adding greenhouse gases
to the atmosphere which cause the earth to
warm even more!!
• This is called the Enhanced Greenhouse
Effect
The Greenhouse Effect
Click on the link to watch the video on YouTube.
It is a short clip from the ‘Inconvenient Truth’
explaining the greenhouse effect
Click on the link to watch the video on the
‘Greenhouse effect’
Greenhouse Gases
Water Vapour
Carbon Dioxide
Burning fossil fuels
(coal, oil and gas)
Deforestation and
burning of trees.
Occurs naturally
and not influence by
human activities
Greenhouse gases
Methane
Gas pipeline leaks,
farming rice in
paddy fields, cattle
farming.
Halocarbons
Does not occur naturally. It
is the most powerful green
house gas. Produced in
Industry
Nitrous Oxide
Jet aircraft engines,
cars and lorries,
fertilisers and
sewage farms.
Human activities
• Cars and transportation – increased car ownership and
increases in air travel all contribute. Both burn fuel that
releases co2 into the atmosphere.
• Deforestation – trees take in co2 and store it. When
trees are cut down/burnt co2 is released back into the
atmosphere.
• Electricity – 76% of our electricity comes from burning
fossil fuels which release co2 into the atmosphere
• Technology – Increases in technology often require
more electricity. E.g. mobile phones, computers etc.
• Increased population – mean more electricity is used,
more cars are driven and more tress are cut down.
Evidence for global warming
• Average world temperatures have risen by 0.6
degrees Celsius
Graph showing
global average
changes.
Evidence for global warming
• Evidence of glaciers and ice sheets melting (e.g.
Rhone glacier in Switzerland has retreated by
2.5 km over the last 150 years)
The Rhone Glacier – the
white lines show that the
glacier used to be further
down the valley
Evidence for global warming
• Ice cores from the Antarctic ice sheet show that
amounts of carbon dioxide and methane in the
atmosphere have increased as a result of
human activity.
Ice cores
Graphs – CO2 levels
Evidence for global warming
• Increases in extreme weather events such as
tropical storms and drought. Some of the
biggest hurricanes have occurred in the past 10
years
• Birds, insects and fish species that are found in
Africa are spreading north
Impacts of Global Warming
• There are both positive and negative
impacts of global warming.
Click on the link to watch the video by
National Geographic on ‘Global Warming’
Click on the link to watch the video by
National Geographic on ‘6 degrees could
change the World’
Positive Impacts
Agriculture
• New agricultural regions will be created in areas such as northern
Canada
• UK will have a longer growing season and may be able to grow crop
like oranges that currently grow in southern parts of Europe.
Tourism
• As temperatures increase tourist hotspots will move north in Europe.
E.g. beaches in Scandinavia could become the new Costa del sol.
• Warmer temperatures could also increase tourism to British beach
resorts E.g. Brighton.
Negative Impacts
Sea Level Rise
• 3.8 billion people (60% of worlds population ) live 60km away from
the coast. This is likely to rise to 75% by 2030
• Between 1900 and 2000 world sea levels rose by 2mm per year
• This would impact upon people living on the coast e.g. Holderness,
UK.
• If all ice was to melt sea levels would rise by 65m – whole countries
would disappear (e.g. Maldives, Bangladesh) and cities (e.g.
Venice, Miami, New York, London)
Agriculture
• Main agricultural regions will shift north. With some areas turning
into deserts. One area to be affected is south east of USA (cereal
grains)
• Reduction of crops produced in sub-Saharan Africa is likely to result
in severe famine.
Negative Impacts
Extreme weather events
• Tropical storms (hurricane) will become more common and those
that do occur will be stronger.
• Increased number of storms will also affect the UK. The Thames
barrier has had to be used more in recent years to protect against
storm surges which cause flooding. (1983 only closed once, 2007
closed 11 times)
• Heat waves like the one that hit Europe in 2003, where 35,000
people died, will be far more common.
• Countries in sub-Saharan Africa are more likely to suffer from
drought.
Diseases
• Tropical diseases such as Malaria could spread further. Many
diseases are only found in areas where there are tropical climates, if
temperature rises there could be more areas that will have tropical
climates.
Negative Impacts
Fauna and Flora
• Many plants and animals will go extinct as the climate changes and
they are unable to adapt to the new climatic conditions.
• Polar bear numbers have already been affected. Many polar bears
hunt on the sea ice in the Arctic Ocean. As this sea ice is melting
earlier every year, the time they have to hunt is also decreasing.
Tourism
• Ski resorts such as those in the Alps will disappear. Having a major
impact on the economy of these areas.
• As temperatures increase tourist hotspots like the Costa del Sol may
lose tourist as they decide to holiday further north.
Reducing Global Warming
• To reduce global warming we need to reduce
the amount of greenhouses gases (e.g. CO2)
that are being released into the atmosphere.
• The next few slides give different ways we can
do this.
Reducing Global Warming
Deforestation/ Afforestation
• Trees play an important role in regulating the gases in our
atmosphere.
• The breath in carbon dioxide and breath out oxygen.
• Therefore it is important that we protect the remaining forests we
have.
• Afforestation is occurring in many areas where forest have been lost
and can help reduce the amount of CO2 in the atmosphere.
Reducing Global Warming
Renewable Energy
• Renewable energy sources e.g. solar energy, wind
energy
• We need to create electricity using renewable energy
sources that do not release greenhouse gases into our
atmosphere.
• Currently only 15% of our electricity comes from
renewable sources.
Reducing Global Warming
Energy Conservation and efficiency
• We need to change our lifestyles so that we reduce our
carbon emissions.
• For example people can reduce their energy
consumption by insulating their homes, using energy low
appliances, using public transport more and taking fewer
flights.
Reducing Global Warming
Carbon Capture and storage
• Carbon dioxide can be captured
from fossil fuel power stations.
• it is possible then to convert this
gas into a liquid where it can be
stored under ground in the rocks.
• This would reduce the carbon
dioxide going into our atmosphere.
• However this would be expensive
to setup.
Reducing Global Warming
Bio fuels
• There are a number of crops that produce oil that can be processed
to make fuel for cars and aircraft.
• These biofuels could reduce poverty in developing countries by
creating jobs and wealth for farmers.
• Also people in developing countries could use their cars and take
flights without worrying about carbon emissions and fossil fuels
running out .
Reducing Global Warming
Governments
Governments have been working together to
reduce global warming. One way they have
done this is by the creation of the Kyoto
protocol
Reducing the Impact of
Global Warming
• Defend low lying coastal areas from flooding
• Improve water supplies in areas that suffer from drought
(e.g. putting wells with hand pumps into villages)
• Encourage research into crops that can withstand
drought and disease.
• Develop more efficient way to predict and prepare for
extreme weather events such as tropical storms.