GLOBAL WARMING

Global warming is caused by the greenhouse effect.

Global Warming

Global warming refers to an average increase in the Earth's temperature, which in turn, causes climate change. A warmer earth may lead to changes in rainfall patterns, a rise in sea level and a huge impact on plants, wildlife and humans. Climate change usually refers to global warming that is the result of human activities.

The Greenhouse Effect

The greenhouse effect is a natural process that keeps the Earth warm. It is caused by a layer of gases that traps heat energy from the Sun. This layer of gases is made up of water vapour, carbon dioxide, nitrous oxide and methane, which are called the greenhouse gases.

As heat energy reaches the Earth, some of it is absorbed, and some of it is reflected into space. However, some of the reflected heat is trapped in the atmosphere by the blanket of greenhouse gases.

Diagram courtesy of the EPA

The greenhouse effect is vital for the survival of humans. Without the greenhouse effect, temperatures on Earth could drop by about 33 degrees Celcius/60 degrees Fahrenheit. However. if the greenhouse effect becomes stronger, it could make the Earth hotter than usual. This extra warming may cause climate change, which would be a great problem for humans, animals and plants.

Scientists have deduced that human activities in the main reason why there is an increase in global temperature. Industries, vehicles, farms and dumps are all sources of greenhouse gases. These activities are known to produce a lot of carbon dioxide, methane and nitrous oxides. These gases intensify the greenhouse effect and result in a warmer Earth.

What are the effects of global warming?

Scientists do not know for sure what the effects of global warming are, but there are a few possibilities.

Firstly, there might be more cases of heat stress and other heat related problems, caused by very warm temperatures and high humidity.

Climate change may also alter the world's habitats and ecosystems, which depend on a delicate balance of rainfall, temperature and soil type. A rapid change in climate would upset this balance and there would not be enough time for plants and animals to adapt and survive.

Humans would be greatly affected by this, as humans depend very much on the animals and plants for food. If they die, humans would definitely die, too.

Another popular prediction is that sea levels would rise globally. This is based on the belief that the ice near the Poles would melt and add more water to the oceans. Water would also expand and take up more space, due to more heat. Altogether, these would cause sea levels to rise. The rise in sea level would cause coastal flooding and beach erosion.