Trees absorbing less CO2 as world warms, study finds

· Shorter winters weaken forest 'carbon sinks'
· Data analysis reverses scientists' expectations

The ability of forests to soak up man-made carbon dioxide is weakening, according to an analysis of two decades of data from more than 30 sites in the frozen north.

The finding published today is crucial, because it means that more of the CO2 we release will end up affecting the climate in the atmosphere rather than being safely locked away in trees or soil.