Evidence is gathering that human activities are changing the climate. This 'climate change' could have a huge impact on our lives. The following tutorial will tell you the facts about climate change, and what effects a change in climate will have on our lives.
Alternatively, you can click here to see the tutorial on 'Factors Affecting Climate'.
Would you like to look at : What has already happened?
Global temperatures have risen by 0.6 degrees Celsius in the last 130 years. This rise in global temperatures leads to huge impacts on a wide range of climate related factors. The graph below shows the rise of global temperatures since 1860.
Global Temperature Since 1860
http://news.bbc.co.uk/hi/english/special_report/sci/tech/global_warming
Levels of carbon dioxide, methane and nitrous oxide gases are rising, mainly as a result of human activities. Carbon dioxide is being dumped in the atmosphere at an alarming rate. Since the Industrial Revolution, humans have been pumping out huge quantities of carbon dioxide, raising carbon dioxide concentrations by 30%. The burning of fossil fuels is partly responsible for this huge increase. This graph shows carbon dioxide emissions increasing over the last 130 years.
Global Carbon Dioxide Emissions Since 1860
Source: Intergovernmental Panel on Climate Change, 1995
You can see that the rate of increase is huge. How many times greater are the carbon dioxide emissions now than 130 years ago?
Methane levels in the atmosphere have increased by 145% since the Industrial Revolution. This increase is a result of gas produced by livestock and paddy fields.
Do you want to look at the possible effects of climate change globally or within the UK?
You can also look at 'What we can do to stop the process of global warming.'
There are some uncertainties as to what effects a change in climate might have on the earth. To predict what might happen, we first need to start by understanding how the increase in gases such as carbon dioxide and methane affect our climate. The diagrams below show the effects of these gases on our atmosphere.
Sun and Earth
Under Normal Conditions |
Barrier Forming
in Atmosphere |
http://news.bbc.co.uk/hi/english/special_report/1997
The diagram above left shows the normal conditions of the sun heating the earth. The suns rays hit the earth and some are reflected back into space. However, gases in the atmosphere such as carbon dioxide and methane form a barrier for sunlight. This is shown in the diagram above right. The suns rays hit the earth, but when they are reflected back out into space, they are trapped in the atmosphere. The sun rays cannot escape from the earth's atmosphere, and the earth heats up. This is called the 'Greenhouse Effect'.
Below are some predictions of what might happen to the earth if subjected to a change in climate.
The changes may be:
The Earth Subjected to a Change in Climate
http://news.bbc.co.uk/hi/english/
We already know that a global temperature rise of 2.5 degrees Celsius will have a detrimental effect on the earth. One impact of climate change would be a rise in global sea levels. If the heat from the sun cannot escape through the earth's atmosphere then the ice at the north and south poles could melt. This could have a huge effect on the low lying areas of the world. Do you live in a low-lying area, maybe near the sea or in London?
In 1998, 46 million people live in areas at risk of flooding (BBC News, 1997). This amount could increase rapidly if sea levels rose. Scientists estimate that a sea rise of only 50 centimetres would increase the number of people at risk to 92 million. A sea level rise of 1 metre would put 118 million people at risk. Scientists believe that there will be a sea level rise of 50 centimetres over the next 40 to 100 years (BBC News, 1997).
The diagram below shows the effect of a rising sea level on the low lying area of the Nile Delta.
The Effect of a Rise in Sea Level on the Nile Delta
http://news.bbc.co.uk/hi/english/special_report/1997
This diagram show the amount of land that would be lost in the Nile Delta if the world's oceans rose by 1.5 metres. You can see the huge effect it would have on the area. The rise in sea level would also make millions of people homeless and ruin valuable farmland.
A change in climate would have an effect on the world's vegetation zones. We would see a change in the boundaries between grassland, forest and shrubland. This change in vegetation zones could cause famine in arid areas such as Africa that depends on a certain type of crop. The change in vegetation would cause mass movement of people away from arid regions. This could cause huge over-crowding in towns and cities.
The range of pests could also change if the vegetation changed. This could bring about an increase in disease levels.
The Malaria Carrying Mosquito
http://www.brown.edu
Scientist believe that if the temperature increased by 3-5 degrees Celsius, the number of people potentially exposed to malaria (caught from the mosquito) could increase from 45% to 60% of the world's population. This could lead to an extra 50-80 million cases of malaria a year (BBC News, 1997).
Ecosystems could be affected by a change in temperature. It has been predicted that an increase in temperature would affect species composition. Scientists also believe that up to two thirds of the world's forests would undergo major changes. Scientists believe that deserts would become hotter, and desertification would extend and become harder to reverse.
The UK will be affected by most of the expected global impacts of climate change. It is likely that there will be a northwards shift in natural habitats and agricultural zones of 50-80 km per decade (NERC, 1997). Scientists also believe that there will be significant impacts on soils, wildlife, water resources and agriculture in the south of England.
Detailed studies are undertaken in the UK to see how climate change is affecting humans, agriculture, vegetation, the ozone layer, hydrology, invertebrates, marine life, forests, birds, and the freshwater environment. You can click on the button below to see how these indicators are changing as the climate is changing.
What we can do to stop the process of global warming
All these changes could occur if we carry on polluting the atmosphere with gases. There are many things we as individuals can do to help slow down any increase in global temperatures.
Carbon Dioxide is a By-Product of Power Stations
http://news.bbc.co.uk/hi/english/special_report |
Carbon dioxide has an effective lifetime of about 100 years. This means that any changes in the atmosphere will take along time to develop. If we cut down on the amount of carbon dioxide we use, the rate of climate change will slow down. |
One way we can cut down on the amount of carbon dioxide we use is by making less car journeys. How often do you get a lift to school when you could easily have walked? Could you share a lift with a friend so only one car would need to be used? These small differences count.
We could also use less carbon dioxide by using better insulation in our homes. This would lessen the need to burn fossil fuels such as coal and oil that give off carbon dioxide. We could also switch to using renewable sources of energy such as wind or solar power.
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