The issue of global warming is a hot topic at present, with massive debate as to what is happening, why it happening and what we should be doing about it. Global warming is a term used to describe the increase in temperatures across the world, which in turn leads to climate change. The terms ???global warming??™ and ???climate change??™ are often used as if they mean the same thing but they are quite different; global warming is the measurable increase in temperature, whereas climate change refers to ???any change in the state of the climate that can be identified by changes in the average and/or the variability of its properties (e.g., temperature, precipitation), and that persists for an extended period, typically decades or longer??™ (Nodvin, 2010)
Evidence shows that global temperatures have been rising steadily over the last few decades (Nodvin, 2010), and that this has had an effect on the natural climate and topology of our world. Global warming is a result of the greenhouse effect. Our earth is naturally surrounded by a layer of insulating greenhouse gases which help to retain energy within the earths??™ atmosphere. Increase in the levels of greenhouse gases – such as carbon dioxide (CO2), water vapour and methane – results in an increase of the heat trapped, boosting the global temperature. Higher temperatures lead to shifts in climatic patterns across the world; the weather becomes more erratic, rainfall increases and changes in distribution and sea-levels rise. Human activity is seen as the biggest factor in this climate change. Global warming is accepted as fact by the large majority of climactic scientists (The Royal Society 2004), yet there is a small group of dissidents who debate its cause, or even its very existence. These sceptics suggest that global warming is part of a natural cycle of the Earth, or that the effects of global warming do not result in climate change.

The increase in CO2 production is one of the most significant causes of the increase in greenhouse gases. Carbon compounds are found in every living thing on Earth; human, animal or plant (CarbonInfo, 2010). Without human interference, the amount of carbon in the atmosphere is regulated naturally. Humans, animals and the decay of biomass, or plant life, all produce carbon, but the Earth is equipped with natural ???carbon sinks??™, or consumers of carbon. These include rainforests, oceans and rocks, which use carbon as part of their natural processes. However, human activity has resulted in a massive increase in the amount of carbon dioxide in the atmosphere, through the burning of fossil fuels and the clearing and burning of rainforests, resulting in a much higher level of CO2 than the earth is naturally able to cope with .Carbon dioxide levels are now higher than they have ever been in the last million years (Shukman, 2006), mainly due to human industrialisation.
Changing weather patterns are often cited as further proof of climate change. According to the National Academies (2008), average temperatures have risen twice as fast in the last decade as in the previous decade, eleven of the last twelve years are the warmest on record and the years from 2000??“2100 are predicted to be the hottest in the last 10,000 years. It??™s not just about the temperature; the heat causes oceans to expand, leading to rising sea levels and increased rainfall. Furthermore, it is not simply the case that everywhere will get hotter at the same rate; climactic patterns are expected to radically shift, resulting in a knock-on effect to agriculture and natural migratory patterns, and threats to human and animal habitats (Huntley, B., 1991). Evidence of extreme weather is easy to find; in the past year alone there has been massive flooding in parts of Asia, extreme heat waves in Moscow, Russia and the calving of the biggest chunk of ice from the Greenland ice sheet since monitoring began 50 years ago (World Meteorological Organization, 2010).
The effects of climate change are already visible in our world. Research from National Geographic (2010) shows that glaciers and ice sheets are melting, coastlines are receding and animals??™ migratory patterns are changing. Further suggestions are made as to the future ??“ less fresh water is predicted to be available, storms and drought will increase, and whole inhabited islands will disappear as sea levels rise. A report released in 2004 by the Parliamentary Office for Science and Technology (POST) outlines a number of health impacts of climate change on the UK; it is predicted that extremes of temperature could lead to more heat-related deaths, increased UV radiation levels could lead to more skin cancer and cataracts in human individuals and the incidence of both insect- and water-borne diseases may increase.
Despite the overwhelming evidence, there are some small communities who deny the existence of global warming. More commonly, there are also groups who concede global warming, but deny that global warming is effecting climate change. Furthermore, there are groups who allow that both global warming and climate change are indeed real phenomena, but reject the idea that human activity is to blame.

Nodvin, S., 2010. Global Warming, Encyclopedia of Earth, [online] Available at: Accessed 11/11/2010
The Royal Society, 2004. The costs of Kyoto for the US economy. The Energy Journal, volume 25,
pages 53-71.
Carbon-Info, 2010. Global Warming ??“ The Science Explained, Carbon-Info, [online] Available at: Accessed 11/11/2010
Shukman, D., 2006. Sharp rise in CO2 levels recorded, BBC News Science/Nature, [online] Available at: < http://news.bbc.co.uk/1/hi/sci/tech/4803460.stm> Accessed 11/11/2010
National Academies, 2008. Understanding and responding to climate change, National Academiesof Sciences, Engineering and Medicine, [online] Available at: < http://dels.nas.edu/resources/static-assets/materials-based-on-reports/booklets/climate_change_2008_final.pdf > Accessed 11/11/2010