The Global Warming Debate

Global warming is the increase in the average temperature of the earth. Scientists believe that it started in the mid 20th century.
The green house effect is the scientific belief that the earth is slowly getting hotter. Most scientists believe that this is due to the fact we have been polluting the atmosphere with damaging gases such as carbon dioxide, sulphur and methane. These gases have been building up in our atmosphere. When the sun shines on the earth its rays normally hit our planet and reflect back into space, however the gases we have polluted into our atmosphere often reflect the rays of light back onto the planet – thus heating it.
If the world temperature rose by a mere degree Celsius hundreds of cities across the world would flood. Part of the ice-caps would melt meaning the water-level would rise by at least 10 metres and animals that rely on the ice as a habitat (such as the polar bear) would become extinct.
Some scientists disagree with the theory of global warming as the temperature of the earth has been like this before humans polluted the atmosphere, in fact the temperature of the earth has been in a pattern over the past 300 million years. The pattern has been in an up and down wave, currently we are at the peak of a high in the average temperature of the planet.

An ice-age is periods of time were the average earth temperature falls which results in the ice-caps expanding out further south/north (depending on the poles). According to this definition we are still technically in an ice age as the Greenland and Antarctic sheets are still present.
Many scientists believe that greenhouse gases such as methane and carbon dioxide are responsible for global warming. These gases are formed when we burn fossil fuels (such as coal and petrol).
To protect our planets future we can help the atmosphere in many ways; we can