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Climate change since last ice age.
- -Temperature since the last ice age raised to 6 DC
- -After the last ice age the temperature rose rapidly for the following 2000
- -Between 4,000-8,000 years ago there were two warm periods interrupted by a
- colder spell
- -Medieval warm period- Warm spell between AD800 and AD 1200.
- -There then was a little ice age where temperatures were below long term average
- for 600 years.
- -In the past 100 years the temperature has begun to rise steadily with greater
- increases since the 1960s.
- -The temperature is projected to increase much more in the coming years, being 5
- DC warmer in 2100 than it is now.
FACTORS WITH AFFECT CLIMATE CHANGE
- Solar Output – Energy that comes from the sun.
- -Energy that comes from the sun changes overtime.
- -Measurements 1980s- Total amount of solar energy reach Earth decreases by 0.1%.
- -If continued for 100 years it could influence global climate.
- -Predicted if solar output changes by 1% it could make temp. Rise or fall by
- between 0.5-1.0 DC
- -Activity of sunspots on Sun’s surface affects solar output.
- -Period of drastically reduced sunspot activity between 1645 and 1715- might
- have been a cause of the little ice age.
- Orbital geometry- Orbital characteristics that are possible for past and future
- climate changes include:
- 1) Shape of Earth’s orbit around sun varies from circular to elliptical and
- back to circular every 95,000 years.
- Circular orbit- Cold glacial periods
- Elliptical orbit- Warm periods
- 2) Tilt of Earth’s axis varies over time from 21.5 D to 24.5 D – Occurs over
- 41,000 year time span
- Greater angel of tilt- Hotter summers colder winters and warmer periods.
FACTORS WHICH AFFECT CLIMATE CHANGE
- Volcanic activity- Release large amounts of sulphur dioxide and ash into atmosphere- Acts as cloak and reduce amount of solar energy
- reaching the Earth’s surface.
- -1815- Mount Tambora erupted. Following year unusually cold over much of the
- world and Europe having heavy snowfalls and frost throughout the summer; 1816-‘the
- year without summer’
- Surface reflection- Cooler periods when snow and frost on Earth, global temp. Will
- drop due to snow and ice reflecting sunlight back to space. If planet warms up,
- snow and ice will diminish and Earth will get warmer.
- Change in atmospheric gas- Clear relationship between amount of CO2 in
- atmosphere and temperature variations.
- Greenhouse effect keeps heat within Earth’s atmosphere by absorbing long wave
- radiation. Without this the average temp. will be -18 DC rather than present 5
- Tectonic activity- Movement of continents cause by plate tectonics affects
- global pattern of atmospheric and ocean circulation; and the changing shape of
- the Earth’s surface causes winds an ocean currents to change.
- -Process is too slow to have much effect on climate over the relatively short
- geological time span of 10,000 years.
Causes of current climate changes on a local and global scale
- - Climate change has a lot of different causes, burning fossil fuels and an increase of methane in the atmosphere
- -Fossil fuels- Fuels produced for coal, oil or gas.
- -They are used to produce energy in power stations and fuel for vehicles.
- - Two gases are Carbon dioxide and Methane.
- - Methane makes 20% of greenhouse gases and 20 times more potent than carbon
- -Comes from dead organisms and those alive today.
- - It was formed underground many years ago and comes to the surface when fossil
- fuels are mined.
Modern methane comes from:
- -Wetlands including marshes and swamps
- - Growing of rice plants
- - Burning vegetation
- - Bowels of animals
Methane rises by 1.5% a year for the past decade, Due to:
- -An increase in the mining of fossil fuels
- - Rising temperature, which causes an increase in bacteria emissions from
- - Increase in ride production due to growing population.
- - Increase in the number of cattle and sheep for meat reflecting an increase in
- Western style diets.
Negative effects of climate change (Global scale):
- Changing pattern of crop yields- Countries closer to the
- equator are like to suffer most as their crop yields decrease. In Africa,
- countries such as Tanzania and Mozambique will have longer periods of drought
- and short growing seasons. The could lose 1/3 of their maize crop. India there
- will be a 50% decrease in the amount of land available to grow wheat This is
- due to hotter and drier weather.
- Rising sea levels- 2007- Hadley centre- Showed between 1993 and 2006 sea levels
- rose 3.3mm a year. This will lead to an 88cm rise in sea levels by the end of
- the century. This rise will threaten low lying coastal land including major
- cities such as London, New York and Tokyo. 2 of the Kiribati islands are now
- covered in water.
- Retreating glaciers- Vast majority of the worlds glaciers are retreating due to
- greenhouse effect. Research shown that 90% of the glaciers in Antarctica are
- retreating. Melting of glaciers at the pole can also affect ocean water
- movement. It will cause Gulf stream to be diverted further south, which will
- lead to colder temperatures in western Europe, matching temperature across the
- Atlantic. Temperatures are frequently below 0 DC in the winter with averages of
- 8-10 DC in July, which is 10 DC cooler than the average UK summer temperature.
Responses to climate change
- -June 1992 Rio de Janeiro- Earth Summit, Number of decisions were made by most
- powerful countries about their response to climate change
- -Results- First international environmental treaty which aimed to stabilise
- greenhouse gas emissions which lead to
- Kyoto protocol which was signed at the Kyoto conference in December 1997 and
- into force in February 2005.
- -Agreement was to cut greenhouse gas emissions by 5.2% compared with 1990
- levels globally.
- - Each country agreed to a national limit on emissions which ranged from 8% for
- EU, 7% for USA, 6% for Japan and 0% for Russia. Allowed increases of 10% for
- Iceland and 8% for Australia because they were not using all of their carbon
- -Countries could either cut their emissions or trade with other countries in
- carbon. Means that a country could buy carbon credits from another country
- -2008 181 countries signed Kyoto protocol
- - December 2007 conference took place in Bali, Indonesia were representatives
- of more than 180 countries were present
- - Result- Bali roadmap- Initiatives were agreed to try to reach a secure future
Actions of non-governmental organisations
- Greenpeace- against climate change on use of fossil fuels.
- - Trying to get governments to change
- their policies so that energy is produced in a more sustainable way.
- * A lot of energy is wasted when being produced in inefficient power stations; approx.
- 2/3 is lost in waste heat in cooling towers. If captured amount of fuel needed
- to produce energy will be reduced. One way to do this is to use combined heat
- and power systems. – produce energy for a small area therefore less energy
- wasted. If energy was based on renewable sources this will also reduce the use
- of fossil fuels.
- * Transport produces 22% of the UK’s carbon emissions. Low carbon cars need to
- be produced and public transport more efficient. Air traffic also produces a
- lot of carbon. If government did not allow anymore airports to be built and
- raised taxes to make flights expensive this will reduce the amount of carbon
- * 2005- Industry has been required to reduce its emissions or buy carbon
- credits from other companies if they exceed their limit.
Local scale responses
- By school- ‘Livesimply’-2007- Initiated by Catholic church to encourage students
- to consider how they make choice in life. Provided a number of resources for
- schools to make students aware about their impact on the world and
- sustainability. Introduced energy efficient water and central heating systems
- run from renewable sources such as wind turbines an solar panels. They have
- walk to school and put up notices to switch of lights
- Local councils- UK’s target is to cut down carbon emissions to 15% below 1990
- levels by 2010 and 20% by 2020. Government believes that local councils are
- important to reduce carbon emissions as they have an influence on local home
- owners- 15% of UK’s carbon emissions are produced by houses. April 2008 local
- councils success in cutting carbon emissions has been one of their targets. To
- help them government has given them £4million. Idea is for those local councils
- that have already introduced ideas to cut carbon emissions to help those that haven’t.
- Ideas- Giving away free low energy light bulbs or working heat and power
- Local interest groups- ‘Manchester is my planet’ encourage individuals to
- reduce their carbon footprint and become involved in a number of green energy
- projects. Started in 2005 and works with local council. Now more than 20,000
- individuals who have pledged to work towards a low carbon future. Green Badge
- parking permit- People who own cards which have been recognised as having low
- carbon emissions can apply for a green badge parking permit which allows car
- owners to buy an annual parking permit for NCP car parks within Greater Manchester
- at a 25% discount- Valid for 12 months.