Introduction
The natural environment includes the air, land and water that provide the basis of all life on Earth. Air, land and water are affected by sunlight, climate, altitude, latitude, natural disasters and the interactions among all living organisms, including people. Environments vary from the frozen poles to tropical jungles, from the sandy deserts to coral reefs, from the fertile plains to snowy mountains. Each is populated by a diversity of microorganisms, plants and animals which have taken millions of years to adapt to their particular environment.
Sustainable development
As the world’s population grows, more and more pressure is placed on the environment to produce enough food and energy without people consuming the resources faster than they can be replaced. This is known as sustainable development. Current levels of consumption are likely to lead to an environmental crisis that affects everyone, although it is the richer countries that have the greatest levels of consumption. The poor, who consume only about 20% of the resources, have the least ability to adjust.
Climate change
Climate change refers to significant and long-term changes in the climate, such as temperature, rainfall, sea levels and wind. Whether caused directly or indirectly by human activity, climate change is a major challenge. Changes affect food production and the frequency and severity of weather events such as drought, flooding and bushfires.
Land degradation, desertification and urbanisation
Soil degradation and desertification are caused by over-cultivation, over-grazing, deforestation, poor water management, overuse of fertilisers and pesticides and poor waste disposal.
As cities grow, what was productive farming land is covered by houses and roads and the remaining land has to produce more food to support even more people. Well-planned, densely populated settlements can reduce the need for land conversion, provide opportunities for energy savings and make recycling more cost-effective.
Pollution
Contamination of air, water and soil can have serious effects on people’s health and ability to grow food. Identifying and managing the use of harmful chemicals and other substances to prevent pollution is vital, as is removing hazardous materials from use and finding alternatives.
Marine and coastal degradation
Disposal of wastes, particularly sewage, directly into oceans has a major effect on marine and coastal areas. Growth in population, urbanisation, industrialisation and tourism is increasing the extent of coastal degradation. Protecting marine and coastal areas from environmental damage is important not only for ecosystems but also for people living in coastal communities whose livelihoods depend on a healthy environment.
