External factors which affect climate change
Energy that comes from the Sun. The energy that comes from the Sun changes over time. Measurements made in the 1980s show that the anount of solar energy reaching the Earth has decreased by 0.1%. Although this is not much, if the trend continued for 100 tears ut could influence global climate.
Orbital characteristics that are responisble for past and possible future climatic changes include:
- The shape of the Earth's orbit around the Sun varies from nearly circular to eliptical and back to circular agin every 95 000 years. Cold, glacial periods have occured when the Earth's orbit is circular and warmer periods when it is more eliptical.
- The tilt of the Earth's axis varies over time from 21.5 degrees to 24.6 degrees. This variation occurs over a 41 000 time span. The greater the angle of the tilt, the hotter the si,,ers are and the colder the winters are.
Internal factors which affect climate change
Volcanic eruptions release large amounts of sulphur dioxide and ash into the atmospher. These act as a cloak and reduce the amount of solar energy reaching the Earth's surface. In 1815 Mount Tambora erupted. The following year was unusually cold over much of the world.
During cooler periods when there is a larger amount of snow and ice on the Earth, global temperatures will drop due to the snow and ice reflecting sunlight back to space. If the planet warms up, snow and ice will diminish, and the Earth will continue to get warmer.
Change in atmospheric gas
There is a clear relationship between the amount of carbon dioxide in the atmosphere and temperature variations. Carbon dioxide is one of the most important gases responsible for the greenhouse effect. The greenhouse effect keeps heat within the Earth's atmosphere by absorbing longwave radiation. Without the greenhouse effect, the average global temperature would be -18 degrees c instead of 15 degrees c.
The cause of climate change on a local and global
Current climate change has a number of different causes these are: Burning of fossil fuels and increase of methane in the atmosphere.
Fossil fuels are used to prodce energy in power stations + fuel in cars. In China 75% of energy is produced from coal. When the fossil fuesls are burnt gases are released e.g. carbon dioxide which build up in the atmosphere. The genreation of power, accounts for 25% of global carbon dioxide emissions.
Methane is a greenhouse gas; this means that it can trap heat within the Earth's atmosphere. It makes up 20% of the greenhouse gases in the atmosphere and is 20 times more potent than carbon dioxide. Methane comes from recently dead rotting organisms and people alive today. Modern methane comes from a variety of sources:
- The growing of rice
- Landfills which contain rotting vegetable matter
- Burning of vegetation
The levels of methane in the atmosphere have been rising by 1.5 % a year due to an increase in the mining of fossil fuels. An increase in the number of cattle and sheep for meat. An increase in rice production
The negative effects of climate change
Changing pattern of crop yields
Countries closest tot he equator are likely to suffer the most as their crop yields will decrease. In Tanzania and Mozabique there will be longer periods of drought and shorter growing seasons. They could lose almost a third of their maize crop. It is forecase that in India there will be a 50% decrease in the amount of land available to grow wheat due to hotter drier weather.Rising sea levels
Research published in 2007 by The Hadley Centre in Exeter showed that beetween 1993 and 2006 sea levels rose 3.3mm a year. THis will lead to an 88 cm rise in sea levels by the end of the century. This rise will threaten large area of low lyingcoastal land including major world cities like London, Tokyo and New York.
The cast majority of the world's glaciers are retreating( melting) quite quickly.This is thought to be because of the increase in temperatures. The melting of the glaciers at the poles could affect the oceanwater movement. It is believed that melting ice in the Arctic could cause the Gulf Stream to be diverted further South. This will lead to colder temps in western Europe. This would mean temperatures would be 8 dc in July 10 dc cooler than average temp for UK in July.
Global response to climate change
June 1992 UN meeting about the response to climate change. The result of the meeting was the first international environment treaty which aimed to stabilise greenhouse gas emissions. The treaty led to the Kyoto proctocol which was signed at the Kyoto conference in December 1997 and came into force in February 2005. Countries that signed the protocol agreed to cut greenhouse gas emissions by 5.2% compared with 1990 levels globally. Each country agreed to a national limit on emissions which ranged from 8% for the EU to 0% for Russia.
The actions of NGOS
NGOs like Greenpeace are focusing their campaign against climate change on the use of fossil fuels. They are trying to get the Uk government, to change their policies so tht energy is produced in a more sustainble way. They have a number of solutions e.g.:
- Transport produces 22% of the UKs carbon emissions. Low carbon cars need to be produced and public transport made more efficient. Air traffic produd an even larger amount of our carbon emissions than cars. If the government did not allow any more airports to be built and raised taxes on flights this would reduce the cabron emissions.
- Two thirds of energy is lost in waste heat in cooling towers. If this waste head was captured the amount of fuel needed to produce energy would be reduced. One way to do this is to use combined heat and power systems.
Local scale responses
Livesimply campagn which ran throughout 2007. Encourages studentsto consider how they make choices in life. It provided a number of resources for schools which made students think about their impact on the world and sustainability. Many schools are introducing energy efficient water and cental heating stystems run from renewable sources such as wind turbines or solar panels
The UK's target is to cut carbon emissions to 15% below the 1990 levels by 2010 and 20 % by 2020. The government believes that the local councils are important in the reduction of cabron emissions as they have influnece on local home owners - 15% of the UK's carbon emissions are produced by houses. Since April 2008 local councils' success in cutting carbon emissions have been one of their targets to help them meet one of their targets the government has given them 4 mill. These councils have introduced schemes to help cut carbon emissions. The changes can be as simple as giving away free low energy light bulbs.
Local interest groups
"Manchester is my planet" have been running a pleduge campain to encourage individuals to reduce their carbon footpring. The group started in 2005 and works with the local council. There are now more than 20 000 inviduals who have pledged to work towards a low carbon future.
How companies have become more sustainable
Nokia are concerned that people do not recycle their old phones. This is a very serious sitiuation, as more than 50% of mobile phone users change their phone every year; 44% of these old phones are left in drawers at home and never used again. Nokia is trying to persudae people to hand in their old phones to recycling because 100% of the phone can be recycled. If every mobile phone user recycled one phone it would save 240 000 tonnes of raw material. Nokia are prmoting this campagh in stores which sell their phones.
This is a large TNC which operates in many different countries. The company has introduced many policies to make it operate in a more sustainable way. One of the pledges is that by 2012 they will reduced fresh water usage by 20%. This is expected to save 7.4 million cubic metres of water. This will be achivedby assesing their water usage and improving their water recycling. Much of the water in their boilers and cooling towers will be recycled water.
Sustainable transport schemes
Park and Ride - Allows commuters to leave their cars and transfer to bus. Happening in Cambridge. There are 4500 parking spaces available. Double decker buses carry up to 70 passengers leave the parks every ten minutes. It costs 2.20 per day to catch the bus. Economic benefits: people pay less to park there than at shopping centres. Saves money on petrol. Environmental benefits: less people driving so less pollutants released. Social benefits: avoids stress of driving/ facing scarce spensive city centre parking. Avoids congestion charge.
Barclays cycle hire
2010 made by Boris Johnosh. Social benefits Promotes exercise. Available 24/7Improved health Fun way to go around London
Economic People pay to use money goes to maintance of buses. Saves money in medical cost if there are fewer cases of obesity. Bike lanes are cheaper to build and maintain
Car sharing: If half of UK motorist recieved a lift one day a week, vehicle congestion and pollution would be reduced by 10% and traffic jams by 20%. Economic: Less cars used, less being spent on road expansion and parking infrastructure., Enviro: less petrol being used better air quality.
The effects of resource extraction
Tropical rainforests being destroyed at the rate of 32 000 hectares per day
Mining in Brazil
- The Caraja iron ore mining project uses wood from the forest to power its pig iron plants, resulting in annual deforestation of 6100 km2.
- Mercury is used in gold mining. The mercury is very toxic and is found in high concentration in fish. 90% of all fish caught in the gold mining region are contaminated with mercury. If eaten it causes cancer and high miscarriage rates among the local tribes people.
- In the state of Roraima there have been conflicts between gold prospectors and the indigenous people.
Oil extraction in Ecuador
- Toxic waste water mixed with crude oil seeps out of 600 unlined pits into the subsoil, polluting surrounding freshwater and farmland.
- Many plants sich as the periwinkle which can be used to cure childhood leukemia are now an endangered species.
- Stomach cancer is five times more frequent in oil exploitation areas and there are many more miscarriages amongst indigenous people such as the Huaorani.
Tropical rainforest management
In Madagascar in 2001. Givaudan a swiss company, sent a team to Madascar to survey for new fragrances. It developed 40 aromas which were then sold. The comany shared the profits with loval communities through conservation and development initiatives.
Costa rica is develping its rainforest in a sustainable way. One of the ways is through ecotourism/ Many areas of the country have developed tourist facilities such as zip wiring and trails through the forest which are very popular with the tourists. Anorher way that Costa Rica is sustainably developing its forest is through its plant species. The Costa Rican government has allowed the American company Merck to look for plants which can be used to make fragrances. The Costa Rican government will get a share of the profits.
Since 2008 the government of Venezuela has not issued any more permits to minegold or diamons in the Imataca Rainforest Reserve or anywhere else in the country. The country does not need to exploit the minerals for economic reaons, due to its oil reserves, therefore it can afford to conserve its forest area. The government will now protect both the biodiversity of the forest and the local people.