Brussels, 31 Jul 2003
Scientists from the UK meteorological office have found new evidence to suggest that humans are to blame for climate warming, not only at global level, but over individual continents such as Europe.
By comparing temperature rises since the beginning of the last century in six continents, using simulations from climate models, scientists found that the global average temperatures have risen by between 0.6 and 0.7 degrees centigrade.
While identifying the effect of human activity on the global scale is difficult due to the 'noise' of natural climate variability, which is even greater at continental level, scientists believe that the rise in temperature is due to human-made greenhouse gases.
As Peter Stott, who leads the team at the Met office's Hadley Centre, explained: 'The continental warming of the past few decades cannot be explained by natural factors such as solar changes, volcanoes or natural variability. But once we factor in the effects of human activity, we find we can explain the warming that is observed.'
Dr Stott says that the effect of these emissions can be seen over the past few decades in every continent, including Europe, but is especially clear over North America, South America and Africa.
'It is generally accepted that global-scale warming of the past few decades is largely due to emissions of greenhouse gases such as carbon dioxide. But now we have gone a step further and shown that the same thing is happening on the scale of continents,' he added.
To support this theory, Dr Stott used a climate model, together with advanced 'optimal detection' analysis, to show that the effects of greenhouse gases from human activity, such as carbon dioxide (CO2) from fossil fuel burning, can be detected.