See also: The Carbon Cycle, Greenhouse Effect

Deforestation
Vegetation, in particular trees, absorb carbon, in the form of carbon dioxide throughout their lives by the process of photosynthesis. This carbon is stored in the carbohydrates produced. Although some of this is used up quickly in respiration, which returns the carbon dioxide to the atmosphere, some is changed to fats and proteins.

As man has evolved, however, he has slowly overrun the forests. Some figures say that at the moment, and area of woodland the size of Wales is destroyed every week. This causes several problems:

• Less carbon dioxide is absorbed form the atmosphere
• When trees are burnt or decay through the action of microbes, this carbon and methane is released
• More carbon is being released than is being absorbed

So the amount of carbon in the atmosphere has increased. So what? Well, it is thought by many scientists that this increase in the percentage of carbon dioxide could enhance the Greenhouse effect.

On a smaller scale, the destruction of trees destroys habitats and can lead to the expansion of deserts as the nutrient rich soil around the trees is held together by the tree roots. Without these, the soil is erroded away.

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See also: The Carbon Cycle, Greenhouse effect, Eutrophication, Acid rain

Pollution
There are 3 types of pollution:

• Air
• Water
• Land

Air

Whenever we burn anything, we produce gases. Fossil fuels such as coal, oil and gas contain sulphur which becomes sulphur dioxide, carbon which becomes carbon dioxide, and nitrogen which also oxidises.

• Sulphur dioxide and nitrogen oxides dissolve in rainwater to become acid rain
• Carbon dioxide could be causing an enhanced Greenhouse Effect

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Water

We are polluting the water with sewage, fertiliser and toxic chemicals.

As we use more land for farming therefore using more fertilisers, more of it ends up in the water, be that in ponds, lakes or rivers. This can cause eutrophication.

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Land

Land can be polluted in two main ways:

• With toxic chemicals, fertiliser and herbicides
• With building, quarrying, and dumping waste
• By using up non-renewable resources

Chemical pollution impacts the environment by simple poisoning of plants and animals or by eutrophication.

As we as humans use more land for building, quarrying and dumping waste, we impede on habitats, and slowly are reducing the plant and animal population.

In addition, waste we dump, and land we use for cattle, produces huge amounts of methane, which may be contributing to an enhanced Greenhouse Effect.

We very much rely on fossil fuels. As well as the air pollution caused, these resources will run out, and in the places where coal in particular has been extracted, huge slagheaps are left.

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