Climate change is generally used to describe climatic variation over the past 100 years or so. There is increasing scientific consensus that these changes, and those predicted for the rest of the 21st Century, are largely the consequence of human activity, rather than due to natural changes in the atmosphere.

The overwhelming majority of scientists believe it is the extra greenhouse gases that humans have released that are the greatest threat to the climate. The main sources of man-made greenhouse gases are:

• burning of fossil fuels in electricity generation, transport, industry and households,
• agriculture and land use changes like deforestation,
• land filling of waste,
• use of industrial fluorinated gases.

Since the late 1990s, the EU has played a global leadership role in the fight against climate change. Statistics show that currently the EU is struggling to meet the climate change targets it has committed to.

In the context of the Kyoto Protocol, the EU-15 is committed to reducing its greenhouse gas emissions to 8% below "base year" 1990 levels before 2012. Through an internal EU agreement some EU member states are allowed increases in emissions, while others should decrease emissions. Most new member states have targets of – 6 to – 8 % from their base years (mostly 1990).

In January 2008, the Commission proposed a major package of climate and energy-related legislative proposals to implement these commitments and targets. The proposals are now being discussed by the European Parliament and the Council of the EU. It is hoped that agreement will be reached on the package before the end of 2008. The 10% biofuels target of the EU was seen as increasingly controversial in 2008, as concerns grew about hiking food prices and environmental degradation, particularly in the developing world. 

In June 2009, the European Council agreed that all developed countries should help fund the fight against climate change in the world’s poorest countries. In early September 2009, the Commission said it would channel up to €24 billion annually to developing countries. Within days, this figure was scaled back to between €2 and €15 billion. According to the Commission report, most “long term low cost efficiency measures… should be financed domestically” so just “10 to 20%, would need to be funded by international public support by 2020”.

At the COP15 UN summit in December 2010, the states responsible for around 80% of emissions made pledges to cut emissions. However they failed to produce a full and binding global agreement for tackling climate change.

Despite this major setback, Climate Action Commissioner Connie Hedegaard presented a Communication to other EU institutions in May 2010, detailing her plan to go beyond 20% greenhouse gas emission reductions, aiming instead for “30%, as part of a genuine global effort”.