QUESTION 2 - CLIMATE CHANGE

QUESTION 2 - CLIMATE CHANGE

Key areas of study for this question:

  • Greenhouse effect / Carbon cycle
  • Causes of climate change
  • Evidence of climate change
  • Climate change around the world
  • Case study - Arctic
  • Case study - Africa
  • Case study - UK
  • Managing climate change - Kyoto Protocol
  • Local ways of managing climate change e.g. BedZED community.

DEFINITIONS

Global Warming - An overall warming of the planet, based on average temperature over the entire surface.

Climate Change - Changes in regional climate characteristics, including temperature, humidity, rainfall, wind, and severe weather events.

 

Climate change is considered by many to be the world’s greatest problem, and a large-scale threat to people. Uncertainty about its impact is inevitable as scientists struggle to make firm predictions. It is an unfair world in which the wealthiest countries have emitted most of the greenhouse gases and the poorest ones are most vulnerable to their impacts.

 

 

GREENHOUSE EFFECT / CARBON CYCLE

 
WHAT IS THE GREENHOUSE EFFECT? - The Earth is wrapped in a blanket of air called the atmosphere which is made up of several layers of gases. The sun is much hotter than the Earth and it gives off rays of heat (radiation) that travel through the atmosphere and reach the Earth. The rays of the sun warm the Earth, and heat from the Earth then travels back into the atmosphere. The gases in the atmosphere stop some of the heat from escaping into space. These gases are called greenhouse gases and the natural process between the sun, the atmosphere and the Earth is called the 'Greenhouse Effect', because it works the same way as a greenhouse.
 
greenhouseeffectdiagram.jpg
 
WHAT IS 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, 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.
 
greenhouseeffect.jpg
 
 
 
WHAT IS THE CARBON CYCLE?
Carbon is one of the most common elements in the environment. It is present in:
  • All organic substances i.e. all living things
  • Simple compounds such as CO2, which exists as a gas in the atmosphere and is dissolved in the oceans.
  • Complex compounds, for example hydrocarbons found in fossil fuels such as oil, gas and coal.

Carbon is able to transfer from one part of the environment to another through a series of biological processes, such as respiration, and chemical processes such as solution. These transfers take place between parts of the environment that release carbon, known as sources, and parts of the environment that absorb the carbon over long periods of time, known as carbon sinks. The transfer between sources and sinks is shown in the carbon cycle diagram below.

carbon-cycle.jpg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  1. At night photosynthesis stops. The tree continues to respire and it emits more CO2 than it absorbs.
  2. Solar energy is absorbed.
  3. Whilst the tree is alive it absorbs more CO2 from the atmosphere than it emits.
  4. During the day the tree uses sunlight to convert carbon dioxide to plant sugars. This is photosynthesis.
  5. Organisms such as beetles and earthworms may digest the plant tissue. Their respiration adds CO2 to the air in the soil.
  6. Rainwater dissolves some of the carbon dioxide that has come from soil organisms. This water may carry the dissolved CO2 into a river and eventually to the sea.
  7. When branches or leaves fall they transfer the carbon that is locked in the plant tissue into the soil.

KEELING CURVE

The Keeling Curve is a graph which plots the ongoing change in concentration of carbon dioxide in Earth's atmosphere since 1958. It is based on continuous measurements taken at the Mauna Loa Observatory in Hawaii. Keeling's measurements showed the first significant evidence of rapidly increasing carbon dioxide levels in the atmosphere. Many scientists credit Keeling's graph with first bringing the world's attention to the current increase of carbon dioxide in the atmosphere.

keelingcurve.gifThe regular annual wiggles in the graph reflect seasonal changes; as plants in the Northern Hemisphere, which has far more land area, begin to grow each spring, they remove some CO2 from the air via photosynthesis, causing the graph to dip slightly. The opposite effect appears during each Northern Hemisphere autumn.

ICE CORE EVIDENCE

Ice cores are cylinders of ice drilled out of an ice sheet or glacier. Most ice core records come from Antarctica and Greenland, and the longest ice cores extend to 3km in depth.

The oldest continuous ice core records to date extend 123,000 years in Greenland and 800,000 years in Antarctica. Ice cores contain information about past temperature, and about many other aspects of the environment.

Crucially, the ice encloses small bubbles of air that contain a sample of the atmosphere - from these it is possible to measure directly the past concentration of gases (including carbon dioxide and methane) in the atmosphere.

 

lesson-2-evidence.ppt lesson-2-evidence.ppt

CLIMATE CHANGE AROUND THE WORLD

Scientists from around the world with the Intergovernmental Panel on Climate Change (IPCC) tell us that during the past 100 years, the world's surface air temperature increased an average of 0.6° C. This may not sound like very much change, but even 1 degree can affect the Earth.

Impacts include:

  • Ice caps / glaciers melting
  • Sea level rise
  • Sea temperature warming - death of the coral reefs
  • Extreme weather - heavier rainfall, leading to flooding
  • More frequent heatwaves / extreme drought - leading to crop failure
  • Ecosystems change

CLICK ON THE WEBLINK BELOW TO SEE SPECIFIC IMPACTS.

http://news.bbc.co.uk/1/hi/6528979.stm 

CASE STUDY - THE ARCTIC

Climate change is faster and more severe in the Arctic than in most of the rest of the world. The Arctic is warming at a rate of almost twice the global average. Why? Shiny ice and snow reflect a high proportion of the sun's energy into space. As the Arctic loses snow and ice, bare rock and water absorb more and more of the sun’s energy, making it ever warmer. This is called the ALBEDO EFFECT.

arctic-impacts-1.pdf arctic-impacts-1.pdf

 

 

CASE STUDY - AFRICA

 

The African continent has warmed about half a degree over the last century and the average annual temperature is likely to rise an average of 1.5-4°C by 2099, according to the most recent estimates from the International Panel on Climate Change (IPCC).

Africa is becoming the most exposed region in the world to the impacts of climate change. In Sub-Saharan Africa extreme weather will cause dry areas to become drier and wet areas wetter; agriculture yields will suffer from crop failures; and diseases will spread to new altitudes.

By 2030 it is expected that 90 million more people in Africa will be exposed to malaria, already the biggest killer in Sub-Saharan Africa (malaria is a mosquito related disease - mosquito's increase in numbers when the temperature rises).

africa-impacts.pdf africa-impacts.pdf

 

 

 

CASE STUDY - UK

The main effects in the UK will be related to increases in global temperatures. This adds more energy to the atmosphere and so results in more extremes of weather. In general, there may be more winter rainfall. Increases in sudden, heavy rains will make flash floods more likely.

uk-climate-change.pdf uk-climate-change.pdf

the-united-kingdom-and-climate-change.doc the-united-kingdom-and-climate-change.doc

MANAGING CLIMATE CHANGE - THE KYOTO PROTOCOL

 
The Kyoto Protocol is an international agreement setting targets for industrialised countries to cut their greenhouse gas emissions. 140 countries signed the Kyoto Protocol and it went into action in February 2005. Industrialised countries have committed to cut their combined emissions to 5% below 1990 levels by 2008 – 2012.
 
 
 
 

LOCAL WAYS OF MANAGING CLIMATE CHANGE - BedZED COMMUNITY

Beddington Zero Energy Development (BedZED) is an environmentally friendly housing development in Hackbridge, London. It was designed by the architect Bill Dunster to support a more sustainable lifestyle. The 82 homes were built in 2000–2002.

Principles of the BedZED community:

  • Zero energy - The project is designed to use only energy from renewable sources generated on site. There are 777 m² of solar panels. Tree waste fuels the development's cogeneration plant (downdraft gasifier) to provide district heating and electricity.
  • High quality - The apartments are finished to a high standard to attract the urban professional.
  • Energy efficient - The houses face south to take advantage of solar energy, are triple glazed, and have high thermal insulation.
  • Water efficient - Most rain water falling on the site is collected and reused. Appliances are chosen to be water-efficient and use recycled water when possible.
  • Low-impact materials - Building materials were selected from renewable or recycled sources within 35 miles of the site, to minimize the energy required for transportation.
  • Waste recycling - Refuse-collection facilities are designed to support recycling.
  • Transport - The development works in partnership with the United Kingdom's leading car-sharing operator, City Car Club. Residents are encouraged to use this environmentally friendly alternative to car ownership; an on-site selection of vehicles are available for use.
  • Encourage eco-friendly transport - Electric and liquefied-petroleum-gas cars have priority over cars that burn petrol and diesel, and electricity is provided in parking spaces for charging electric cars.

vmqk-leonardoenergy-org-bedzed1.jpg

 

 

MANAGING CLIMATE CHANGE LOCALLY

Park and ride schemes - encouraging people to park their cars outside of towns/cities and take a bus ride into the town/city.

Use of renewable energy - use less fossil fuels and invest in renewable energy e.g. solar panels, wind turbines, tidal energy and Hydroelctric power (HEP).

Save hot water - Keep showers as short as possible to save both water and the energy needed to heat the water.

Switch off lights when they are not in use - Saving electricity is a great way to help prevent climate change.

Help sort out your recycling at home - Recycling stops re-usable items from ending up in landfill and therefore decreases greenhouse gas emissions.

Plant trees (afforestation) -  Trees absorb carbon dioxide and help to reduce greenhouse gases in the atmosphere.

Buy energy efficient appliances - When buying a new electrical appliance, look for ones with higher energy efficiency ratings - they'll reduce bills and carbon pollution.

Take public transport, ride or walk whenever possible - Catching the bus or train, riding bikes or walking is better for the environment than travelling by car, especially for short journeys.

Save energy - Hang washing on the line instead of putting it in the dryer, so the sun and wind can dry it naturally.

Turn off appliances at the plug - Save power by turning off electrical appliances at the plug, before leaving the house or when they are not being used.

 

 

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