In 1997, Britain and other industrialised countries came together to draw up the Kyoto Protocol - a treaty that would require countries across the world to tackle the causes of climate change.
Ratified (made official or law) on 16 February 2005, it called for a total reduction in carbon dioxide emissions, which contribute to the greenhouse effect, by 5% below 1990 levels.
Each country agreed to their own specific target depending on their income levels and existing greenhouse gas emissions. Countries were given a decade to meet their targets, and in 2012 the treaty would expire.
Poor countries did not have to sign because they contribute least to climate change. China and India were not given specific targets, since at that time, their emissions were still relatively low.
But even the United States, then the largest emitter of greenhouse gases, did not ratify the treaty. The USA pulled out of the international agreement in 2001 when US President George W Bush said implementing Kyoto would gravely damage the US economy.
This decision provoked anger and resentment from many other countries around the world.
Canada withdrew from the treaty in 2011.
As a rich, industrialised nation, Britain agreed to cut emissions by 12.5% of its 1990 levels. By investing in clean and renewable energy, and efficiency incentives, the UK achieved a 24% decrease in emissions from 1990 to 2010.
And it’s not the only country succeeding - overall, EU member states committed to a 8% reduction in emissions and reported a 11% reduction from 1990 to 2010.
That’s a good beginning, but climate scientists say more action is desperately needed.
The Stern report was produced for the UK government in 2006. It was the first major report on climate change written by an economist, rather than a scientist.
The report countered fears that reducing carbon dioxide emissions would stop economic growth. Stern recommended that 1% of GDP (Gross Domestic Product) should be spent on reducing carbon dioxide emissions – this figure was later revised to 2%. However, if action is not taken then climate change could cost 5% of GDP each year. In the worst case scenario this figure could rise to 20%.
Stern’s conclusion was that early action on climate change is crucial, and that the costs are very small compared to the cost of doing nothing.
At the 2012 UN climate conference in Doha, Qatar, a deal was agreed by nearly 200 nations to extend the Kyoto Protocol to 2020. However, the nations that have taken on targets are responsible for less than 15% of global emissions.
To stop the most serious consequences of global warming, carbon emissions need to be cut by 70% across the world, according to the Colorado-based National Centre for Atmospheric Research.
Any future treaty must include China and also India, which have rapidly rising emissions as their economies grow and develop. In 2009, China was producing 7.7 billion metric tons of carbon dioxide from burning fossil fuels per year, more than any other country in the world, although this is still far less per person than many other countries.
Future UN climate change negotiations will focus on developing a new legally-binding agreement that will apply to all countries. The intention is that this would be signed in 2015 and come into effect in 2020.