BBC NEWS | Science/Nature | Heatwave makes plants warm planet

BBC NEWS | Science/Nature | Heatwave makes plants warm planet: "The really surprising finding came with the calculation that during the heatwave, European plants and their ecosystems were putting more carbon dioxide into the air than they were absorbing.

'In the past we expected that climate change would benefit European ecosystems because growth tends to be limited by the short growing season,' said Andrew Friend, 'but this analysis hadn't taken into account the possibility of extreme events.

'The conclusion of our study is that this extreme event meant a loss of carbon across Europe - a loss which undoes many years of net uptake.'

Plants can absorb and emit carbon dioxide and oxygen; the process of respiration takes oxygen in and releases CO2, whereas in photosynthesis, the reverse happens.

Other parts of the ecosystem such as soil bacteria can also contribute to the overall flow of these gases to and from the atmosphere.

During an average year, the net effect is that European plants absorb around 125 million tonnes of carbon (MtC).

But in 2003, according to this analysis, they released 500 MtC to the atmosphere."