Greenhouse!!!!!
What's that?
The greenhouse effect is a term that describes how natural gases in the earth's atmosphere reduce the amount of heat escaping from the earth into the atmosphere. The more of these gases there are, the more the earth heats up.
The greenhouse effect is a term that describes how natural gases in the earth's atmosphere reduce the amount of heat escaping from the earth into the atmosphere. The more of these gases there are, the more the earth heats up.
These gases act like a blanket around the earth - they allow the sun's rays in to warm the earth's surface, but they also prevent much of the heat escaping. It is a bit like car windows on a sunny day - they allow the sun's rays in to heat up the car, but prevent much of the heat escaping. That is why the inside of your car is warmer than the outside air on sunny days.
Greenhouse gases are a natural part of the atmosphere. They trap the sun's warmth, and maintain the earth's surface temperature at a level necessary to support life. The problem we now face is that human actions - particularly the burning of fossil fuels (coal, oil and natural gas) and land clearing - are increasing the concentrations of these gases, creating the prospect of global climate change. This is called the enhanced greenhouse effect.
Greenhouse gases are a natural part of the atmosphere. They trap the sun's warmth, and maintain the earth's surface temperature at a level necessary to support life. The problem we now face is that human actions - particularly the burning of fossil fuels (coal, oil and natural gas) and land clearing - are increasing the concentrations of these gases, creating the prospect of global climate change. This is called the enhanced greenhouse effect.
Increases in the earth's temperature can occur naturally as a result of climatic fluctuations caused, for example, by solar cycles and changes in the sun's radiation. Human activity such as burning of fossil fuels (coal, oil and natural gas) and land clearing, however, are increasing the concentration of greenhouse gases in the atmosphere. These additional gases are like additional blankets around the earth. They allow the sun's energy to reach the earth's surface, but they prevent more heat escaping. This means that the earth slowly heats up. This is called the enhanced greenhouse effect - it causes global warming and it is changing our climate. Greenhouse gases are a natural part of the atmosphere. It is the increase in the amounts of these gases through human activity that causes global warming. Human activity such as land clearing and burning fossil fuels have increased the concentration of these gases. Humans have had most impact on the enhanced greenhouse effect through increases in the amounts of carbon dioxide, methane and nitrous oxide.
Water vapour: Water vapour is the most important greenhouse gas, but human activity has little direct impact on the amount in the atmosphere.
Carbon dioxide (CO2): The amount of carbon dioxide in the atmosphere is about 30% higher now than 200 years ago. The main causes of this increase are the burning of fossil fuels such as oil, coal and natural gas to create energy to make electricity and to produce fuel for transport, and the clearing and burning of vegetation. This gas is the biggest contributor to the enhanced greenhouse effect (about 70%).
Methane (CH4): The amount of methane in the atmosphere is about 145% higher now than 200 years ago. The main causes of this increase are:
- digestive processes of cattle and sheep (ie their burps!)
- cultivation of rice
- escape of natural gas
- decomposing waste in garbage dumps or landfills
This gas is the second biggest contributor to the enhanced greenhouse effect (about 20%)
Nitrous oxide (N2O): The amount of nitrous oxide in the atmosphere is about 15% higher now than 200 years ago. The main causes of this increase are:
- burning of vegetation
- emissions from industries
- the effects of agriculture on the soil (using nitrogenous fertilisers)
- Halocarbons
Carbon dioxide (CO2): The amount of carbon dioxide in the atmosphere is about 30% higher now than 200 years ago. The main causes of this increase are the burning of fossil fuels such as oil, coal and natural gas to create energy to make electricity and to produce fuel for transport, and the clearing and burning of vegetation. This gas is the biggest contributor to the enhanced greenhouse effect (about 70%).
Methane (CH4): The amount of methane in the atmosphere is about 145% higher now than 200 years ago. The main causes of this increase are:
- digestive processes of cattle and sheep (ie their burps!)
- cultivation of rice
- escape of natural gas
- decomposing waste in garbage dumps or landfills
This gas is the second biggest contributor to the enhanced greenhouse effect (about 20%)
Nitrous oxide (N2O): The amount of nitrous oxide in the atmosphere is about 15% higher now than 200 years ago. The main causes of this increase are:
- burning of vegetation
- emissions from industries
- the effects of agriculture on the soil (using nitrogenous fertilisers)
- Halocarbons
These greenhouse gases have been reduced since the phasing out of chlorofluorocarbons (CFCs) to protect the ozone layer. However, other halocarbons effecting the atmosphere include perfluorocarbons (PFCs) emitted during aluminium production.
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