If a population grows too fast, it creates severe difficulties. However, it’s a very hard problem to control, and it’s getting worse!
As these poor countries gradually become more industrialised and with rapidly growing populations, the demand on the limited sources of the Earth and increasing sharply.
Pollution levels are increasing, as they burn wood and fossil fuels to power growing economies, and use up their mineral reserves to create material comforts. And deforestation is as rampant as ever, to make more room for people and their farming. The great rainforests of the world are being destroyed at and alarming rate by the countries which contain them, in order to make room for cattle rearing and their out-of-control human populations.
When fossil fuels are burned they release mostly carbon dioxide, which is causing the Greenhouse Effect. They are release two other harmful gases:
- Sulphur Dioxide
- Various Nitrogen Oxides
When these mix with clouds they form acids. This then falls as acid rain. Car and power stations are the min causes of acid rain.
Acid rain causes lakes to become acidic which has a severe effect on its ecosystems. They way this happens is that the acid causes aluminium salts to dissolve into the water. The resulting aluminium ions are poisonous to many fish and birds. Acid rain also kills trees. It also damages limestone buildings and ruin stone statues.
Cleaning up emissions can prevent acid rain. Power stations now have Acid Gas Scrubbers to take the harmful gases out before they release their fumes into the atmosphere. Cars are now being fitted with catalytic converters to clean up their exhaust fumes. And the other way of reducing acid rain is simply to reduce our usage of fossil fuels.
The three main sources of atmospheric pollution are burning fossil fuels, CFC’s and lead used in petrol. Coal oil and natural gases, these are known as fossil fuels. The main culprits who burn these fossil fuels are cars and power stations. They release mostly carbon dioxide, which is causing the greenhouse effect. But they also release sulphur dioxide and oxides of nitrogen, whish are causing acid rain.
CFC’s are also known as Chlorofluorocarbons. These are used in aerosols, fridges, air-conditioning units and polystyrene foam. They are causing a hole in the ozone layer. This allows harmful UV rays to read the Earth’s surface.
Lead is used in petrol. “Old-fashioned” leaded (4 star) petrol contains lead, which polluted the air. The lead is breathed in and causes damage to the nervous system. Breathing in the lead in petrol can also cause severe damage to young children’s brains.
CFC’s are causing the hole in the ozone layer. The ozone is made up of molecules, three oxygen atoms, O3. There is a layer of ozone high up in the atmosphere. The ozone absorbs harmful UV rays from the sun. However, CFC gases react with the ozone molecules and break them up. This thinning of the ozone layer allows harmful UV rays to reach the surface of the Earth. This is making it dangerous to go out in the sun in many parts of the world due to the increased risk of skin cancer from the harmful UV rays. Other gases are replacing CFCs now, but the harmful effects of the CFCs already released may continue for centuries to come.
