about co2 levels in the air..., page-61

bb, the question was because we have been regaled with guaranteed increases in life threatening weather events - the evidence of the last 90 years is that this is a load of rubbish. An equally valid scenario is to consider the potential for:

- warmer climate results in a slower rate of loss of biodiversity (most losses occur due to manmade intervention like forestry and farming, NOT GW);
- increased crop yields
- higher rainfall increasing water supplies
- increasing amounts of fish resulting from warmer oceans
- less extreme weather events (already strongly indicated)
- less droughts in some areas (Qld this year)
- less floods in some areas (Qld three years ago)

Tipping point? Co2 levels used to be nearly 20 times higher than today.

"there is evidence for very high CO2 volume concentrations between 200 and 150 Ma of over 3,000 ppm and between 600 and 400 Ma of over 6,000 ppm.[4] In more recent times, atmospheric CO2 concentration continued to fall after about 60 Ma. About 34 Ma, the time of the Eocene-Oligocene extinction event and when the Antarctic ice sheet started to take its current form, CO2 is found to have been about 760 ppm,[22] and there is geochemical evidence that volume concentrations were less than 300 ppm by about 20 Ma. Low CO2 concentrations may have been the stimulus that favored the evolution of C4 plants, which increased greatly in abundance between 7 and 5 Ma."

http://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth's_atmosphere