Man has however had an effect which has degraded the environment and is affecting his own Health.

Climate

The major way in which we are having an impact on the climate is through adding greenhouse gases to the atmosphere.

The greenhouse effect is a natural phenomenon, keeping the Earth warm and helping to support life. But we are adding greenhouse gases such as Carbon dioxide released when fossil fuels are burnt for energy, Methane (formed when plant and animal remains rot without oxygen being present in rice fields, the stomachs of cows, rubbish dumps etc);Water vapour, Chloroflourocarbons(CFCs), Halogenated flourocarbons (HFCs) and other ‘halogenated’ gases (used as solvents, in dry cleaning, as refrigerants, in car air conditioning systems, as insulators in electrical applications), Nitrous oxide (also formed when fossil fuels are burnt, e.g. by cars), Ground-level ozone (a by-product formed when other types of air pollution react with sunlight).

This has resulted in more heat being trapped and the warming of the Earth. As well as adding more greenhouse gases to the atmosphere, we are making it harder for nature’s cycles to remove them.

Carbon dioxide is used by plants and when the plants die and decompose, it can be stored in the soil. Forests are being cut down and soils farmed so hard that they cannot store as much carbon.

This is leading to a wide variety of changes in the climate, including more extreme weather like droughts, floods, and severe storms. We are also impacting on the climate by cutting down forests which changes the pattern of rainfall.

Essential Climatic Terms

Global warming

The increased ‘greenhouse gases’ in the atmosphere, causes more heat being trapped on the Earth. This is causing overall temperatures to rise. The average surface temperature has increased by between 0.3 and 0.7 ºC over the last century.

The Earth is warming faster than at any time in the past 10,000 years resulting in Snow cover, glaciers and ice sheets being in retreat, a 40% drop in the amount of Arctic ice since the 1970s and the whole western Siberian sub-Arctic region has started to thaw for the first time since its formation, 11,000 years ago.

Climate change

The Earth is warming, and as a result the climate and sea levels are changing. What the weather will be like in the future is hard to predict, but it is likely to be more extreme (with more frequent severe storms, flash floods, heat waves and droughts, Tsunamis, reactivation of volcanos).

The pattern of temperature and rain around the world will shift and people will need to adapt to different agriculture, and different ways of living their lives. Plants and animals will also be affected, migrating at different times of the year, to places which no longer have the same weather they would have expected.

Protection from radiation

The ozone layer has been damaged and has got very thin over some parts of the planet.

The cause is the release of man-made chemicals like Chloro-Flouro-Carbons(CFCs), Halogenated Flouro Carbons (HFCs) and other ‘halogenated’ chemicals, which drift up to the upper atmosphere and destroy the ozone layer.

Fresh water

Man is polluting lakes, rivers and the underground natural reservoirs known as ‘ground water’. Once polluted, it is extremely hard to clean up. Secondly, we are diverting and using water often in a very wasteful way making it unavailable downstream, where it would otherwise have been expected.

Thirdly, we are draining marshes, cutting down forests and stopping rivers from using natural flood plains. This means that water passes through an area much faster than it would have done previously, rather than being stored up and gradually emerging later in the season.

Breathable air

Man is polluting the air and making pollutants which do not occur naturally. In cities, levels of air pollution often go above safe levels.

Even in the countryside, where there is less pollution, pollutants created from things like traffic, high levels of pollution can be found as pollution is carried by the wind.

Food webs

We put many pressures on food webs (and the habitats and ecosystems of which they are a part). Pollution can harm living things and prevent them from reproducing.

The physical destruction of habitats (forests, lakes and so on) means that other creatures which depend on those habitats for food or shelter can die out.

As such creatures which depend on them for food suffer. Logging, draining, building, mining, quarrying and ploughing up for farming are some of the ways that we disrupt food webs.

Fertile soils

By taking away the covering and protection provided by plants, soil is left uncovered and can be washed or blown away.

If the plants which grow in an area are removed each year, then the soil can become poor and thin, as the nutrients and organic matter are not replaced.

The microscopic life of the soil is reduced, and the soil becomes less fertile and more easily eroded.

Food

Although 7,000 species have been used for food by humans over our history, today we use fewer than 20 species for most of our food.

This makes our own food supplies very vulnerable to changes – because of the lack of variety if there is a big problem with one source of food, we don’t have a lot to fall back on.

On the other hand, rural communities in more than 60 countries get much of their protein from wild animal meat and fish. This makes them vulnerable if that source of protein shrinks, because of any of the reasons above.

The most important wild source of protein, globally, is fish. Nearly 70% of the world’s fish stocks are fished at dangerously high levels that is, more fish are taken out each year than are replaced by natural reproduction and growth, and fish are increasingly being caught before they are mature, so stocks are even lower in future years.

Fuel

When people depend on wood, use it at a faster rate than it can re-grow, and in a way which damages the forest as a whole, it means that the supply of fuel gets smaller over time.

Raw materials

When plants and animals are used at a faster rate than they can reproduce, then the overall stock of materials goes down.

In addition, the ecosystems (food webs and habitats) which they are part of get damaged. We have a tendency to use minerals and metals very wastefully throwing them away into rubbish dumps, rather than reusing, repairing or recycling.

Medicines

We get a lot of our medicines from plants and animals. We might be missing out on more, for example by destroying rainforests and the plants and animals which live there, before we fully understand what other useful medicines we might get from them.

Man’s Effect on His Environment