GLOBAL CLIMATE

CHANGE
OBJECTIVES
1. Describe the greenhouse effect (insolation, radiation).
2. Describe the ways in which human activities influence climate change
( deforestation, carbon dioxide emissions, other greenhouse gases)
3. Explain the consequences of climate change in the Caribbean and either
USA or UK (impacts of sea level rise, changes in weather patterns).
4. Discuss the impacts of climate change on either USA or UK.
5. Suggest possible measures to combat climate change (reduced emissions,
sustainable forestry, education) in Caribbean and either USA or UK.
6. Analyse graphs and charts of global climate change.

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FACTS

• The earth is getting warmer.

• In the 20th century, average global
temperatures rose by 0.6 °C.
• Most increase in the last 40 years.
• By 2100, average global temperatures
could be between 1.6 °C and 4.2 °C
higher than it is today.

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Key terms
• Insolation is the solar radiation that reaches the earth's surface. It
DOES NOT HEAT THE AIR.
• Solar radiation is radiant energy emitted by the sun, particularly
electromagnetic energy.
• Global warming is a term used to describe the rise in the average
global temperatures caused by a man-made increase in the level of
greenhouse gases”.
• It also describes the increase in the average global temperatures that
has taken place in the last few decades”.

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EVIDENCE OF CLIMATE CHANGE
Global temperature trends
• Intergovernmental panel on climate change (IPCC) has combined all of the
land, surface, air and sea surface temperatures from 1861 to 1998.
• Instrument readings – direct measurements of temperature using
thermometers have recorded a clear upward trend in increase in global
temperatures.
• Between1961–1990, there has been a sharp warming from the start of the
1980’s onwards.
• Studies have shown that increased levels of greenhouse gases (due to
human activity) being pumped into the atmosphere and industrial
processes is increasing the global earth surface.
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 EVIDENCE OF CLIMATE CHANGE
• Ice cores – water molecules and air bubbles become trapped when
snow turns to ice and provide a frozen record of the earth’s climate at
the time when the snow fell.
• Analysis of deep ice cores in Antartica and Greenland suggest a
steady rise in temperature over the last few years.

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EVIDENCE OF CLIMATE CHANGE
• Arctic ice cover – the Arctic ice has thinned to almost half of its
earlier thickness in the last 30 years..

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EVIDENCE OF CLIMATE CHANGE
• Glacier retreat – considerable photographic evidence of rapid glacier
retreat across the world. The World Glacier Monitoring Service
estimates that up to 25% of global mountain glaciers could have
disappeared by 2050.

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GREENHOUSE EFFECT
• Greenhouse gases are transparent to shortwave but absorb
longwave radiation.  Thus, the atmosphere stores energy.
• The sun’s energy enters the atmosphere and passes through
greenhouse gases as short-wave radiation. 
• The earth’s surface emits energy, mainly as long-wave radiation.
• Greenhouse gases trap some of the long-wave radiation/energy. 
This helps to warm the atmosphere. As a result, the Earth’s surface is
~33 degrees Celsius warmer than it would be without an
atmosphere.
• See video: https://www.youtube.com/watch?v=SN5-DnOHQmE
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 Human activities that contribute to global warming and
influence climate change

The increased concentration of greenhouse gases in the atmosphere has resulted in more heat from the Earth being absorbed,
thereby increasing the greenhouse effect. Many scientists believe that this ‘enhanced greenhouse effect’ resulting from
human activities accounts for the recent rise in global temperatures.
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Emissions of carbon dioxide

• Carbon dioxide (CO2)

• Source: fossil fuel burning in industry and
power stations to produce electricity, car
exhausts, deforestation and burning wood
• Global concentration of carbon dioxide has
increased by 30% since 1850.
• Average atmospheric residence time: 500
years

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Emissions of other GREENHOUSE GAS
• Methane (CH4) is very effective in absorbing heat.
• Source: Rice cultivation, cattle & sheep ranching, decay from landfills and
compost tips, mining, burning biomass for energy
• Accounts for 20% of the ‘enhanced’ greenhouse effect
• Average atmospheric residence time: 7-10 years
• Nitrous oxides – very small concentrations in atmosphere
• Source: agriculture (fertilizers), car exhausts, sewage treatment, power stations
producing electricity
• Up to 300 times more effective at capturing heat than carbon dioxide
• Average atmospheric residence time: 140-190 years

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Deforestation

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 CONSEQUENCES OF
CLIMATE CHANGE
(Rising sea levels and
Changes in weather patterns
and their impacts)
  Global sea levels are expected to rise
by 18-59cm by 2100, putting low-lying
SEA LEVEL RISE islands and deltas at risk from flooding.

 Coastal cities and settlements will also

become flooded.
 Such areas include Netherlands,
Bangladesh, the Maldives and the
Cayman Islands, the Bahamas, and
Turks and Caicos in the Caribbean.
 Coral reefs, coastal mangroves and
wetlands will suffer from increasing
depth.
 Melting glaciers in the Himalayas may
increase flooding in Nepal, India and
China.
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 Examples of consequences of climate change in the Caribbean 9p.
122-123)

• SEA LEVEL RISE IN THE CARIBBEAN CAN CAUSE:

• Increased incidence of coastal flooding
• Most Caribbean cities and smaller settlements are built
on coastal or low-lying land and are at risk from coastal
flooding. Rising sea levels could flood low-level islands
like the Bahamas and Cayman Islands and capitals such
as Belize City and Georgetown.
• Important industrial estates on low-lying land like Point
Lisas in Trinidad could be vulnerable.
• Hotels and roads built close to the beach could be
flooded easily e.g. the road from Norman Manley
Airport in Jamaica.
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 Sea level rise can cause:
• Impacts on coral reefs, coastal wetlands and
settlements
• Coastal wetlands and other low-lying
wildlife habitats are also at risk from
flooding.
• Increased rates of coastal erosion could
threaten beaches and coastal ecosystems,
which could negatively impact tourism.
With deeper water offshore, waves
approach the coast with more force and the
rate of erosion increases.

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 Examples of consequences of climate change
in the USA
• SEA LEVEL RISE
• Sea level rise in the USA could flood low-lying coastal areas like the
Gulf of Mexico and parts of Florida’s wetlands.

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Examples of consequences of climate change
in the UK (p. 128)
• SEA LEVEL RISE
• Coastal areas will be at increased risk of flooding and erosion. There
is a risk of flooding in London along the River Thames and at high
tide.

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CHANGES IN WEATHER PATTERNS AND THEIR IMPACTS IN
THE CARIBBEAN

• The warming of the tropical seas can cause harmful

bleaching of corals. In Belize Barrier reef an estimated
300 km was bleached between 2005 and 2015. with
global warming, bleaching can become more extensive,
threatening the tourism and fishing industry.
• Warmer ocean temperatures could result in more
intense hurricane activity, which could be very costly to
Caribbean economies.
• Erratic rainfall could affect crop yields, water supply and
irrigation, leading to poverty and migration.

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CHANGES IN WEATHER PATTERNS AND THEIR IMPACTS IN
USA

• Weather patterns could change significantly, bringing floods to some areas and
drought to others.
• Moderate warming may lead to increased crop production.
• Fragile mountain and arctic ecosystems may suffer habitat loss and some
species may become extinct.
• Tropical diseases could spread more widely, threatening human health.
• Warming will increase electricity demand e.g. for air conditioning.

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CHANGES IN WEATHER PATTERNS AND THEIR IMPACTS IN UK
(p.128-129)

• Warmer summers with less rain.

• More intense rainfall in the winter, which will bring more frequent flooding.
• Lack of rainfall and increased evaporation in summer months will lead to water
supply problems for agriculture, households and businesses.
• Threats to wildlife – tree species like birch at risk from drought in southern
England.
• Possible benefits:
• Less need for winter heating and deaths from the cold.
• Many people will enjoy the warmer summer weather
• Crops like wheat and grapes will grow more productively
• Tourism will also benefit from warmer climate.
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IMPACT OF CLIMATE CHANGE ON HUMAN
HEALTH

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 REDUCING THE
IMPACT OF CLIMATE
CHANGE
(REDUCED EMISSIONS, SUSTAINABLE FORESTRY, EDUCATION)
 Reduced emissions in Caribbean (p. 124 -
127)
Reduce the use of fossil fuels – coal, oil and natural gas by:
• Ending subsidies for gasoline and electricity generation – this
makes fuel more expensive and people will lower their
consumption to avoid paying high prices.
• Increased efficiency and fuel consumption - using technology and
introducing strict regulations to reduce emissions from power
stations and car exhausts.

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 Reduced emissions (p. 124 -127)
Reduce the use of fossil fuels – coal, oil and natural gas by:
• Simple measures at home like drying clothes in sun instead of
in dryer, e.g. conserving energy at home by using low-energy
light bulbs, switching off electrical appliances when not in use;
walking, cycling or using public transport to reduce vehicle
emissions.
• Use of alternative sources of energy - encouraging renewable
energy production, such as wind, solar and hydro-electricity,
by providing grants and tax incentives. Hydroelectric power in
Belize, biomass energy in Guyana and Belize, wind energy in
Jamaica, solar energy in most Caribbean islands and
geothermal power in Dominica.
• Providing grants for people to insulate their homes to reduce
energy consumption.
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REDUCED EMISSIONS in UK(p. 130-131)
Mitigation strategies include:
Individual responses
• Reducing energy consumption/ energy conservation
• Recycling
• Carbon offset payments
• Growth of the ‘green movement

Government responses
• Developing alterative sources of energy (renewable, nuclear)
• Reducing vehicle emissions
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Reduced emissions – Government actions
• Setting targets for reduction in emissions
• Encouraging renewable energy production
• Encouraging persons to recycle and reduce waste
• Encouraging development of public transportation.

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Reduced emissions – International actions
• Kyoto protocol became
international law in 2005
• The 37 industrialised countries
that have signed the agreement
must reduce their carbon
emissions by 5.2% below their
1990 levels by 2012.
• USA and Australia have refused
to sign this treaty. USA claims
that the costs of reducing
carbon emissions would harm
its economy and are unhappy
that the treaty only applies to
industrialised countries.
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• Carbon trading – if a country or organisation
within a country has cut its carbon emissions
to a level tht is below its target, it has “spare”
carbon. These carbon credits can then be
traded (carbon trading) with a country or
organisation that has not been able to cut its
emissions. Tree planting programmes are also
used to “buy” carbon credits.
• Climate protection payments – establishes a
value for an area of forest and pays
governments not to carry out deforestation. In
this way emissions can be reduced and
important natural habitats protected.

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 Sustainable forestry

Encouraging people to recycle

and reduce waste.

Encouraging reforestation and

Re-afforestation (carbon
sequestration).
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