Whether global warming is real, and if mankind is having a direct impact on climate change is often the first question raised by the sceptic. After all, it’s true to say that climate change has always existed, in that Earth’s climate is always changing.

Natural causes have and will continue to effect the climate of course, but when we talk about climate change today, the general consensus is that we are referring more particularly to those changes in our recent history (the last 100 years or so), changes that are thought by many to be the result of human behaviour rather than natural changes in the atmosphere.

There exists very compelling data and scientific consensus that global warming is occurring on an unprecedented scale. In recent years many of these dramatic changes can only be explained if greenhouse gas emissions are responsible.

The greenhouse effect is central to the climate change debate, so it’s worth taking a few moments to describe what it is. Solar rays from the sun heat up the Earth. As the Earth warms it radiates its own infrared heat rays which rise.

Those that don’t leave the atmosphere are absorbed by greenhouse gases. These greenhouse gases warm the Earth. This is a naturally occurring process and without it the Earth would be much colder (about 30c), making life on Earth entirely different to what we know.

The problem is that we are producing too many greenhouse gases. Our consumption of fossil fuels, natural gas and oil produce Carbon Dioxide as does the chopping down and burning of trees. Carbon Dioxide is one of the main greenhouse gases and with so much of it being produced by mankind, there is simply too much in the atmosphere, overloading the natural production of greenhouse gases which is causing the Earth to warm abnormally.

Scientists the world over are examining the evidence to try and predict the potential changes to our environment if greenhouse gas emissions were continue at current levels. These scenarios predict the effect of changes in sea levels, animal habitats, deforestation, and extreme weather conditions to demonstrate how seriously this issue should be taken.

Rising Sea Levels
As temperatures increase, the sea absorbs the additional heat from the atmosphere, causing it to expand and therefore rise. In addition to this, glaciers are melting faster than the snow can replace them. In a recent Report the IPCC predict a sea level rise of 0.18 – 0.38m increase by 2100 in the most optimistic scenario and 0.26 – 0.59m in the most pessimistic.

Threats to Other Species

Milder winters with less snow, more winter rain and warmer temperatures in summer will affect all types of wildlife. In fact, it’s estimated that 20 to 30% of plant and animal species will be at increased risk of extinction if temperatures rise by more than 1.5 to 2.5C.

Many species are already at risk, mainly those that rely on colder environments for their survival. Species like the Polar Bear, Snow Leopards, Emperor Penguins and others are under considerable threat already and organisations like the World Wildlife Fund (WWF) are already campaigning for help in these areas.

Deforestation

The world’s forests absorb Carbon Dioxide by photosynthesis, which is a naturally occurring process in plants and trees. We continue to destroy huge areas of forest every day, so deforestation remains one of the major causes of the escalation of the greenhouse effect. In fact, tropical deforestation is responsible for approximately 20% of world greenhouse gas emissions.

The more forest we destroy, the greater the impact is on the escalation of the greenhouse effect.

Increases in Extreme Weather

Increasing temperatures mean that we’re more likely to see increased rainfall, more Hurricanes (due to increased rain and intense winds), greater risks of drought in continental areas, and more heat waves.

All this means an increased likelihood of floods, wildfires, droughts, Hurricanes and other forms of extreme weather events.

The Kyoto treaty was drawn up in 1997 to consider what could be done to reduce the impact of Global warming. The treaty was established by the United Nations Framework Convention on Climate Change (UNFCCC) and included most world countries, with the notable exception of the United States of America (responsible for around 36% of 1990 emission levels). At time of writing 184 countries have signed and ratified the Kyoto Protocol.

Under the Protocol, 37 industrialised nations committed to reduce levels of four greenhouse gases (GHG) (carbon dioxide, methane, nitrous oxide, sulphur hexafluoride) and two groups of gases (hydro fluorocarbons and per fluorocarbons) produced by them, and all member countries give general commitments.

After much debate in the intervening years the Kyoto Protocol came into force in 2005. In December of that year the Kyoto signatories agree to discuss emissions targets for a second compliance period beyond 2012, while countries without targets, including the US and China, agree to a "non-binding dialogue" on their future roles in curbing emissions.

In 2006 the UK government commissioned Stern Report, argues that the costs of coping with climate change will be greater than the costs of preventing it. Meanwhile, the US Environmental Protection Agency is taken to the Supreme Court over its refusal to regulate CO2 emissions. US agencies, including NASA, are accused of trying to censor climate experts.

At the 2008 G8 summit in Tokyo, Japan leaders agreed a statement on climate change which referred to ‘the vision’ of achieving at least a 50% reduction in greenhouse gas emissions in 2050.

At time of writing Governments, including the US, prepare to negotiate a successor to the Kyoto Protocol at a conference in December 2009.