Herctorus Rex
Not sure where I implied that your facts were inaccurate? If I did, my apologies. Not my intention.
With regard to biological productivity - yes, it is a little reported by-product of CO2 elevations that biological productivity increases - off the top of my head it has been estimated that increased CO2 has been responsible for a 4% increase in crop yields in temperate areas?
However, it is undeniable that increased productivity is not compensating adequately for increased CO2 production - otherwise levels wouldn't be rising. The fact is that this increase is tiny compared with the growth in world population, and certainly is not the answer to those problems. Add to that the poitential loss of productivity to aridity if, as predicted, climate zones move.
Some calculations have been done of the amount of increased tree planting that would be needed to compensate for the emissions from humans. Generally, the figures come out as follows (from Goreau 1992):
'A major part of global warming could be averted if the addition of CO2 to the atmosphere were accompanied by equal removal. Emitters could pay for planting, growing, and sustaining enough biomass and storage to remove excess carbon permanently. It would require trees that consume 10 tonnes of carbon per ha per year on 4 million km2 of land, to ensure removal of the current carbon increase. The area could be as low as 2 million km2 in the humid tropics, if reforestation stopped, or as high as 8 million km2 if areas with long dry seasons or colder temperatures were planted.'
(I haven't checked these numbers though).
Weather is a chaotic system, but as with many non-linear systems order emerges (that is climate). We are getting better and better at modelling this ordered behaviour from the non-linearity. Of course temperature fluctuations have occurred previously (and my very first post in this thread demonstrated that explicitly). The fact remains that, except during extinction events, the rapid changes in global temperature that we are currently measuring do not appear to occur in the geological record, and that our observations of increased atmospheric temperature are consistent with the results from Global Climate Models when increased CO2 levels are input. Add to that the clear linkage between palaeo levels of atmospheric CO2 and temperature (with the rider that cause and effect are hard to interpret as per bluskis post), and the argument becomes reasonably strong.
DrDave