The Earth’s atmosphere comprises four key gases vital to human life: nitrogen, carbon dioxide, oxygen, and water vapour.
Greenhouse gases are essential to the survival of all living things on Earth. They help keep the planet 16°C warmer. Without greenhouse gases, the earth would be a frozen, harsh environment.
The Greenhouse Effect
The greenhouse effect keeps the Earth warm, trapping heat from the sun in its atmosphere while also allowing some heat back into space. The earth remains at a temperature that allows plants and animals to inhabit it, just like a glass greenhouse you may have in your garden.
The Enhanced Greenhouse Effect
While carbon dioxide is essential in maintaining the greenhouse effect, human actions are responsible for the enhanced greenhouse effect. These human actions include:
| Greenhouse Gas | % of greenhouse gas produced | Sources | Warming power compared to CO₂ | % increase since 1850 |
|---|---|---|---|---|
| Carbon Dioxide | 89% | Burning of fossil fuels such as oil, gas & coal. Deforestation also causes the release of CO₂. | 1 | +30% |
| Methane | 7% | Rice production in paddy fields, cattle farming and gas leaks. | 21x more powerful | +250% |
| Nitrous Oxide | 3% | Produced by cars and lorries, jet engines and fertilisers and sewage farms. | 250x more powerful | +16% |
| Halocarbons | 1% | Can be found in industry, solvents and cooling equipment such as refrigerators. | 3000x more powerful | Not Natural |
The industrialised world is responsible for the majority of carbon dioxide production, with people producing on average 10-25 tonnes of carbon per year, compared to just 1-3 tonnes in the developing world.
There is a lot of pressure on developed countries to reduce carbon dioxide production. The biggest producers are the EU, USA, and Japan, which produce 33%, closely followed by China, which produces 29%, and Russia and India, which produce 5% each.
By increasing the amount of greenhouse gases in the atmosphere, the earth is warming at an increased rate, which is causing a range of climate-related hazards. These will be covered in the next section.
