The Effects of the Population Explosion
- There are increaing numbers of people on the planet.
- Many people want and demand a better standard of living.
- We are using up raw materials and thoses that are non-renewable cannot be replaced.
- We are producing more waste and the pollution that goes with it.
- We are also using land that animals and plants need to live on. It's being used for buildings, quarrying, farming and dumping waste.
- the water with sewage, fertilliser, and toxic chemicals.
- the air with gasses such as sulfur dioxide and smoke.
- the land with pesticides and herbicides and these can then be washed into water.
- Burning fuels can produce sulfur dioxide (and nitrogen oxides.)
- These dissolve in water in the air forming acidic solutions.
- The solutions then fall as acid rain - sometimes a long way away from where the acids were produced.
- Acid rain kills organisms. Enzymes, which control reactions, are very senstive to pH (acidity or alkalinity.) So acids stop enzymes working correctly, killing the organism.
- Burning fuels (combustion) releases carbon dioxide.
- Cows and rice fields release methane gases.
- Both of these gases are greenhouse gases. As these gases increase in the atmosphere, it retains more heat from the Sun. The Earth is therefore warming up.
- This warming may cause a number of changes in the Earths climate and cause sea levels to rise.
- We are cutting down forrests (deforrestation). This is making the problem worse because trees take up carbon dioxide (during photosynthesis). When the tree dies, they release this carbon back into the atmosphere.
As our population rises, we use up more of the Earths resourses. There are many example, eg land, fossil fuels and minerals.
Substainable development means finding ways of reducing this need for more resources.
This may mean finding alternatives to some resources, for example:
- Fuels for cars.
- Recycling what we already have, eg plastics, aluminium in cans.
- Using land that has already been previously used, brownfield sites.
Planning for the Future
- Lichens indicate the level of pollution in the air. The more species of lichen growing the cleaner the air is. Fresh water invertebrates indicate the level of water pollution in the same way. The wider the range of these invertebrates the cleaner the water in the stream, river or pond. Some fresh water invertebrates only live in polluted water.
- The world population is growing and needs sutible housing. It is important not to use up green areas of the country side too much but to use areas that have already bee built upon, brownfield sites. Many countries put aside areas of land which are important to widelife and will not allow development on them.