The greenhouse effect and global warming

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The greenhouse effect and global warming

• What are they?
• The causes, effects, impacts and responses

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THE NATURAL GREENHOUSE EFFECT

• The atmosphere has a number of gases, often in
  tiny amounts, which trap the heat given out by
  the Earth.
• To make sure that the Earth's temperature remains
  constant, the balance of these gases in the
  atmosphere must not be upset.

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The GREENHOUSE GASES are very important and are
mainly

• water vapouroccurs naturally in the atmosphere.
• carbon dioxideproduced naturally when people and
  animals breathe. Plants and trees absorb carbon
  dioxide to live. Volcanoes also produce this gas.
  Carbon dioxide is not the same as carbon monoxide
  
• methanecomes from cattle as they digest their
  food. The gas also comes from fields where rice
  is grown in paddy fields.
• nitrous oxidewhen plants die and rot, nitrous
  oxide is produced.
• ozoneoccurs naturally in the atmosphere.

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THE ENHANCED GREENHOUSE EFFECT

• Because there are more and more greenhouse gases
  in the atmosphere, more heat is trapped which
  makes the Earth warmer. This is known as global
  warming.
• A lot of scientists agree that man's activities
  are making the natural greenhouse effect
  stronger. If we carry on polluting the atmosphere
  with greenhouse gases, it will have very
  dangerous effects on the Earth.

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What are the causes of rises in Greenhouse gases
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THE ENHANCED GREENHOUSE EFFECT

• Some of the activities of man also produce
  greenhouse gases. These gases keep increasing in
  the atmosphere. The balance of the greenhouse
  gases changes and this has effects on the whole
  of the planet.
• Burning fossil fuels - coal, oil and natural gas
  - releases carbon dioxide into the atmosphere.
  Cutting down and burning trees also produces a
  lot of carbon dioxide.
• A group of greenhouse gases called the
  chlorofluorocarbons, - which are usually called
  CFCs, because the other word is much too long! -
  have been used in aerosols, such as hairspray
  cans, fridges and in making foam plastics. They
  are found in small amounts in the atmosphere.
  They are dangerous greenhouse gases because small
  amounts can trap large amounts of heat.

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Some greenhouse gases
Methane is x 30 more effective than CO2 Where
does methane come from? (3 places)
X 300 more effect on global warming than CO2
Man-made sources of nitrous oxide include nylon
and nitric acid production, the use of
fertilisers in agriculture, cars with catalytic
converters and the burning of organic matter.
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CO2 and temperature rise
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Two ways of looking at causes
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• The effects

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Global Warming some effects

• Since 1970, rise in Decrease in
• Global surface temperatures NH Snow extent
• Tropospheric temperatures Arctic sea ice
• Global Sea Surface Temperatures Glaciers
• Global sea level Cold temperatures
• Water vapor
• Rainfall intensity
• Precipitation extratropics
• Hurricane intensity
• Drought
• Extreme high temperatures
• Heat waves

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Global mean temperatures are rising faster with
time
Warmest 12 years 1998,2005,2003,2002,2004,2006,20
01,1997,1995,1999,1990,2000
Period Rate Years ?/decade
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Global mean temperatures are rising faster with
time
Period Rate Years ?/decade
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Global mean temperatures are rising faster with
time
Period Rate Years ?/decade
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Land surface temperatures are rising faster than
SSTs
Sea Surface T Land
Annual anomalies of global average SST and land
surface air temperature
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Land precipitation is changing significantly over
broad areas
Smoothed annual anomalies for precipitation ()
over land from 1900 to 2005 other regions are
dominated by variability.
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Proportion of heavy rainfalls increasing in most
land areas
Regions of disproportionate changes in heavy
(95th) and very heavy (99th) precipitation
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Projected Patterns of Precipitation
Change 2090-2100
Precipitation increases very likely in high
latitudes Decreases likely in most subtropical
land regions This continues the observed patterns
in recent trends
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Sea level is rising from ocean expansion and
melting glaciers

• Since 1993
• Global sea level
• has risen 41 mm
• (1.6 inches)
• 60 from
• expansion as ocean temperatures rise,
• 40 from melting glaciers
• Steve Nerem

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Evidence for reality of climate change
Glaciers melting
Muir Glacier, Alaska
1909 Toboggan Glacier Alaska 2000
1900 2003 Alpine glacier, Austria
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Global mean temperatures are rising faster with
time
Period Rate Years ?/decade
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The impacts
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Impacts on living things

• If the sea-levels are rising then what might
  the effects be? And on people and the ecosystems?
• If there are more climatic hazards what might
  they be? What is the impact? Where might be
  affected the most?
• Changes in rainfall what might be the effects
  on the earth? On the human welfare?
• Rises in temperature what would be the effects?
  What are the impacts on the different groups?
  That is the sea as well? Warming seas with more
  CO2 in ( that is an acid by the way)?

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Impacts on living things

• Ecosystem changes
• which would be most affected?
• What would be the impacts on the world as a
  whole?
• On people?
• On ecosystem populations?
• Agricultural production all bad or maybe some
  good?

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One of the impacts is on human health why?
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Responses to climate change
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On an international level

• Countries get involved in UN inspired activities
  (more about them next term)
• KYOTO
• IPCC
• Copenhagen
• They sign up to the agreements made there
  unlike the USA and Australia which did not sign
  up to KYOTO
• Individual countries make international
  agreements to mitigate against increased
  greenhouse gas emissions

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Norway Offer Brazil 1 Billion to Save the Amazon

• by Alan Harten September 17, 2008
• The prime minister of Norway, Jens Stoltenberg,
  has announced a donation of 1 Billion by 2015 to
  the International Fund for the preservation of
  the Amazon, created in August by Brazilian
  President da Silva.
• The Norwegian government has decided to
  contribute 1 Billion to the Amazon Fund, over
  the next few years, and payments will begin this
  year, explained the Norwegian prime minister.
• Successive contributions will depend on results
  in reducing Amazon deforestation. One
  pre-condition is that will be able to see clearly
  documented evidence that deforestation is
  actually being reduced.
• Norway and the UK have also promised 50 million
  a-piece to the Congo for a similar project with
  similar rules they are using satellite tracking
  to ensure their investment is well-spent

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National activities

• As a result of Kyoto, many MEDCs (excluding USA
  and Australia) have committed to reducing
  emission by increasing the efficiency of the use
  of fossil fuels in vehicles and changing the fuel
  source for energy generation either by
  renewables and/or nuclear power, that some say
  must form an essential element if they are to
  succeed in making the cuts.
• They are also committed to improving the
  standards of house building to reduce heat loss,
  and paying a feed-in tariff for smaller
  providers of renewable energy.

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National activities

• Car emissions are reduced by legislation and
  clean electric cars get a variety of good
  deals.
• Congestion charging started in London is also
  seen as a green initiative. If a city is clogged
  with slow moving petrol/devisal cars stuck
  interminably in low gear, the emissions are much
  more concentrated and more damaging. Get people
  on the buses and the damage is far less.

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Local activities

• Too much international trade involves boats and
  planes, when the goods could be produced locally.
  Buy locally, you support your local community and
  the food or goods have not travelled so far
  fewer emissions! Farmers markets are gaining in
  popularity all over the world.
• Farmers are increasing getting a premium both in
  terms of the value of their goods that result
  from greener production methods and grants from
  the EU/government to maintain the biodiversity
  and reduce inputs in terms of fertilizers and
  pesticides.