External Causes of Climate Change - THEN
Orbital Geometry - the earth's orbit changes every 95000 years from elliptical to circular. when the orbit is elliptical then we experience warm periods whereas in circular orbits we experience cold, glacial periods. Also, the angle of the earths tilt changes every 41000 years from 21.5 - 24.5 degrees. when the angle of tilt is greatest the climate gets warmer.
Solar Output - the energy provided by the sun is not always constant. In the past a decrease in sunspot activity may have resulted in the Little Ice Age in the 16-17th Century. If the solar output changes by 1% then global temperatures can change by 0.5-1 degrees.
Internal Causes of Climate Change - THEN
Change in Atmospheric gases - CO2 is the main contributor to the greenhouse effect and there is a clear link between CO2 level and global temperatures. Greenhouse gases like CO2 trap long wave radiation from the sun in our atmosphere which causes Earth to warm. A bit of this is good, if we didnt have the grenhouse effect the average global temperature will be -18 rather than 15 degrees.
Volcanic Activity - volcanoes release SO2 and ash which acts as a cloak and prevents the suns energy reaching earth, this means the earth cools. in 1815 mt tambora erupted, the following year was unusually cold and was called the 'year without a summer'
Tectonic activity - the changing shape of the earth can alter oceanic and atmospheric currents.HOwever, this is thought to be too slow to have affected the climate in the past 10000 years.
Surface Reflection - ice and snow reflect some of the suns energy back into space, however because the ice caps are melting there are larger bodies of water available to absorb the heat. This means the planet warms and even more snow and ice melt!!
Causes of Climate Change - NOW
Burning fossil fuels - releases 25% of all CO2 emissions and we know this is one of the main greenhouse gases. the demand for energy from fossil fuels has increased (75% of chinas energy is from coal) because of higher demand for a better quality of life in developing countries and increases numbers of cars. This increased demand has meant that tonnes and tonnes of CO2 and other greenhouse gases have been emitted which is warming our planet!
Methane - there are a number of sources of methane; paddy fields, cows, landfill sites, wetlands, fossil methane and rotting vegetation. The amount of methane has increased because: increasing populations in rice growing countries; more people eating a western style diet; higher temperatures mean bacteria emissions in wetlands and landfill sites are increasing; the increased mining for fossil fuels has meant more fossil methane is being released from the ground. Methane contributes to climate change because it is a greenhouse gas - it is x20 more potent than CO2, therefore the more there is in our atmosphere the greater the greenhouse effect.
Negative Effects of Climate Change - Crop Yields
Changing patterns of crop yields -
Countries close to the equator will suffer the most because the increased number of droughts and hotter and drier conditions will mean shorter growing seasons.
Tanzania will lose a third of its maize crop due to droughts.
India will lose 50% of its land available for growing wheat due to hotter and drier conditions.
Kenya will experience droughts every 3 years rather than 10 which. In 2006 tey had the worst drought in 60 years and they lost many of their cattle.
Negative effects of Climate Change -rising sea lev
Rising Sea Levels -
The oceans are expanding naturally due to the hotter temperatures but also as many ice caps are melting they are increasing the volume of water on our earth.
The Hadley Centre in Exeter predicts a 88mm rise by the end of the century.
Low-lying countries will be directly affected.
2 of the Kiribati islands are already under water.
75 people move per year from the Tuvalu islands to New zealand because of rising sea levels.
If the sea levels rise by 1m Bangladesh will lose 17.5% of its land - they may suffer food shortages.
The great barrier reef may 'drown' because it is too far below the surface to get sufficient sunlight. greenpeace predicts it will be dead in 30 years.
Negative effects of Climate Change - melting glaci
Melting glaciers -
the warmer temperatures of our planet are causing many problems for people and animals.
90% of the glaciers in antarctica are melting, including ones such as the Sheldon glacier.
In 30 years all of Montanas glaciers will be gone - there were 150 in 1810.
The melting ice in the north may cause the Gulf Stream to divert south, this may mean northern europe will have temperatures similar to those in Labrador, where it only reaches 8-10 degrees in summer.
The polar bears of wrangel island are suffering because they cannot travel overland to catch prey because the ice is melting and unstable to walk across.
Local responses to Climate change
LiveSimply Campaign - set up in 2007 to try and encourage schools to get their student aware of climate change, sustainability and to challenge the way they live their lives.
They encourage children to walk to school because this reduced fossil fuel usage and lowers carbon emissions. Also schools are encouraged to install wind turbines so they can cut their electricity consumption so less demand is put on the burning of fossil fuels which adds to global warming. they provide schools with resources to help inform the children and parents.
Manchester is my planet Campaign - ran in 2005 to get people to reduce their carbon emissions and get involved with green energy projects. 20 000 people pledged to a low carbon future.
one of their initiatives was the green badge parking permit. this encouraged people to buy low carbon cars because then they would get a 25% discount on thier parkng permit in greater manchester. this helped reduce the carbon emissions in the city.
Local councils influence homeowners therefore their aim since April 2008 has been to reduce carbon emissions to help UK reach its target of 20% less emissions by 2020. they can provide energy saving light bulbs or something as advanced as Woking Boroughs CHP system. This is a very efficient method because it supplys power over a small area so less enrgy is lost during transfer.
NGO responses to climate change
Greenpeace is a non-government organisation that is tackling climate change by targeting the use of fossil fuels. They are trying to influence governments to produce energy in a more sustainable way
Their research has shown that 22% of carbon emissions come from transport. therefore they are encouraging more low carbon cars to be produced and also make public transport more efficient so people are moer likely to use that. They have said that air traffic causes more pollution than cars so to reduce these emissions they are saying governments should deny any more airports to be built and to increase the taxes on flights so they are more expensive and people are less likely to fly as often.
Furthermore, the production of energy is very inefficient, 2/3s is lost as waste energy in cooling towers. Greenpeace are suggesting that is this energy were to be captured and used then the demand for fossil fuels would reduce. Things like Combined heat and power systems that produce energy for a small area are much more efficient.
Since 2005, industry has been required to lower their carbon emissions or buy carbon credits from other companies if they go over their limit - this is as a reuslt of greenpeace's work.
Global Responses to Climate change
In 1988, the UN set up a panel on climate change. this panel organised the Earth Summit meeting in Rio de Janiero in 1992.
At the meeting important decisions were discussed about tackling climate change. the meeting resulted in the first international envirnmental treaty aiming to stabilise greenhouse gas emissions.
In 1997 in Kyoto, the Kyoto Protocol was signed and ratified by many countries (not the USA). Countries that signed promised to reduce carbon emissions by 5.2% compared to global averages in 1990. Each country was set their own limit (Europe - 6%). If they went over they were able to buy carbon credits from others countries who had not.
In 2005 the Kyoto protocol came into force.
By 2008 181 countries had signed.
In 1980 the united nations defined sustainable development in the Brundtland Report as "development that meets the need of the present generation without compromising the ability of future generations to meet their own needs".
The definition is open to different interpretations by different countries and organisations. In the UK sustainable development has been split into four key areas:
Climate change and energy (including greenhouse gases)
Sustainable consumption and production
Congestion charging is a sustainable transport scheme that makes motorists pay to enter large urban areas at times of heaviest use.
The aim of this scheme is to lower congestion and pollution emissions and hopefully lead to the greater use of sustainable transport, eg buses and bicycles, by the public.
London implemented this scheme in 2003 and by 2008 saw many good effects:
21% reduction in traffic levels. 65 000 fewer cars
12% increases in cycle journeys into the zone
12% reduction in nitrous oxide and particulate emissions
29 000 extra bus passengers.
This shows that congestion charging is an effective way of buiding a more sustainable community because less fossil fuels are being consumed during commutes to work. Also less emissions mean the impact on th greenhouse effect is less :)
Park and Ride
Park and ride is a sustainable transport scheme that involves people parking for free on the outskirts of a city and then catching a bus into the centre. 87 towns and cities are using this because it is very effective for lowering congestion, pollution, encouraging sustainable transport and making cities dafer because there are less vehicles.
Cambridge has five P and R sites that cover all the main routes into the city so people have easy access therefore are more likely to use them. The trumpington and madingly sites cover the M11 and the newmarket and milton sites cover the A14.
The buses run frequently(10 mins) which is an incentive to use them because there is not much waiting. They carry 70 people which significantly reduces carbon emissions. they only cost £2.20 which means people are more likely to use it because it is cheap.
The parking sites have 4500 parking spaces. They are well lit, have lots of facilities (waiting rooms etc.) and have security systems so people feel safe using them.
Sustainabilty in large organisations
Large organisation can become more sustainable in one of four ways:
1)During the manufacture of products. 2)Recycling of packaging materials. 3)Encouraging customers to recycle products. 4)Encouraging employees to work in a more sustainable way.
ASDA - recycles its plastic packaging using a company called Mil-tek. They installed a baler so the plastic is compressed to 10% of its original size meaning it only needs to be collected once a week - saving fossil fuels. Mil-tek recycles the plastic into bin liners etc. ASDA is paid for its plastic.
NOKIA - encourages customers to recycle old phones. 100% recycable. 240000 tonnes of raw materials could be saved! information is given on webistes etc.
GENERAL ELECTRIC - understands the importance of water so are trying to cut their frsh water usage by 20% by 2012 - saving 3000 olympic sized swimming pools! Most of their water in their boilers and cooling towers will be recycled.
WAYS EMPLOYEES CAN BE SUSTAINABLE - video conferencing, emailing (becoming paperless), push taps, automatic lights, signs to turn things off, waste and recycling bins, computers on an automatic timer to be turned on and off etc.