No clear message on photosynthesis products
A new study has confirmed previous estimates that the average appropriation of what is known as 'net primary productivity' is about 32 per cent. At the same time, however, the authors say that there is considerable uncertainty in this figure, which could be as low as 10 per cent or as high as 52 per cent.
Writing in the journal Science, they say that this broad range "reflects uncertainty in key parameters and makes it difficult to ascertain whether we are approaching crisis levels in our use of the planet's resources." They also state that improved estimates will require high-resolution global measures within agricultural land and forests.
Reference: Science 294, 2490-91 (2001)