Greenhouse gases

Carbon Dioxide levels in the Earth's atmosphere have increased by 30% in the last 200 years alone.

Concentrations of greenhouse gases in the atmosphere are currently at their highest for 800,000 years.

Temperatures

Global temperatures have risen by over 0.7C since the 1700s with 0.5C of this warming occurring during the past 100 years.

The warmest decade of the last millennium was the 1990s with four out of five of the warmest years ever recorded occurring during the decade. 1998 was the warmest year globally since records began in 1861.

1999 was the warmest year on record in the UK.

Water

Average global sea levels have increased by between 0.1 and 0.2 metres over the last 100 years as a result of heavier rainfall, melting artic ice sheets and water expanding due to warmer temperatures.

The frequency and severity of drought conditions has increased in Asia and Africa in the past few decades.

Predictions

The Intergovernmental Panel on Climate Change (IPCC) predicts a probable global temperature rise of between 1.8C and 4C (3.2-7.2F) by the end of the century if current levels of greenhouse gas emissions continue.

The IPCC states that possible global temperature changes by the end of the century could be as high as 6.4C.

Sea levels around the world are likely to rise by 28-43cm by the end of the century.

Arctic summer sea ice is likely to disappear in second half of century

An increase in the number of heatwaves and tropical storms are expected in parts of the world.

Human activities

The world population has grown by more than 2.5 times in the past 55 years from 2.5 billion in 1950 to 6.45billion in 2005.

Global energy demands are projected to rise by as much as 60% in the next 20 years as a result of continued population growth and economical, commercial and social development.