The greenhouse effect and global warming What are they? The causes, effects, impacts and responses.

The greenhouse effect The greenhouse effect and global warmingand global warming

What are they?The causes, effects,

impacts and responses

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THE NATURAL GREENHOUSE THE NATURAL GREENHOUSE EFFECTEFFECT

•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 The GREENHOUSE GASES are very important and are mainly: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 THE ENHANCED GREENHOUSE EFFECTEFFECT

• 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.

What are the causes of What are the causes of rises in Greenhouse rises in Greenhouse

gasesgases

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THE ENHANCED GREENHOUSE THE ENHANCED GREENHOUSE EFFECTEFFECT

• 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 Some greenhouse greenhouse

gasesgasesX 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.

Methane is x 30 more effective than CO2 Where does methane come

from? (3 places)

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COCO22 and temperature rise and temperature rise

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Two ways of looking at causesTwo ways of looking at causes

The effects

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Global Warming – some Global Warming – some effectseffects

Global Warming – some Global Warming – some effectseffects

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

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 timeGlobal mean temperatures are rising faster with time

150 0.0450.012

Period Rate

Years /decade

Warmest 12 years: 1998,2005,2003,2002,2004,2006,2001,1997,1995,1999,1990,2000

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Global mean temperatures are rising faster with timeGlobal mean temperatures are rising faster with time

150 0.0450.012100 0.0740.018

Period Rate

Years /decade

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Global mean temperatures are rising faster with timeGlobal mean temperatures are rising faster with time

150 0.0450.012100 0.0740.018

50 0.1280.026 25 0.1770.052

Period Rate

Years /decade

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Annual anomalies of global average SST and land surface air temperature

Sea Surface TLand

Land surface temperatures are rising faster than SSTsLand surface temperatures are rising faster than SSTs

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Smoothed annual anomalies for precipitation (%) over land from 1900 to 2005; other regions are dominated by variability.

Land precipitation is changing significantly over broad areasLand precipitation is changing significantly over broad areas

Increases

Decreases

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Regions of disproportionate changes in heavy (95th) and very heavy (99th) precipitation

Proportion of heavy rainfalls: increasing in most land areasProportion of heavy rainfalls: increasing in most land areas

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Projected Patterns of Precipitation Change2090-2100

Projected Patterns of Precipitation Change2090-2100

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

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

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 changeEvidence for reality of climate change

Glaciers meltingGlaciers melting

1900 2003 Alpine glacier, Austria

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TobogganGlacierAlaska

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Muir Glacier, Alaska

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Global mean temperatures are rising faster with timeGlobal mean temperatures are rising faster with time

150 0.0450.012100 0.0740.018

Period Rate

Years /decade

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The The impactsimpacts

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Impacts on living thingsImpacts 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 thingsImpacts 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 One of the impacts is on human health – why?health – why?

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Responses to climate changeResponses to climate change

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On an international levelOn 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 Norway Offer Brazil $1 Billion to Save the AmazonSave 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 activitiesNational 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 activitiesNational 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 activitiesLocal 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.