If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm.
|Journal reference:||Open Atmos. Sci. J. (2008), vol. 2, pp. 217-231|
The alarmist organisation 350.org led by Bill McKibbin says:
Right now we're at 400 ppm, and we're adding 2 ppm of carbon dioxide to the atmosphere every year. Unless we are able to rapidly turn that around and return to below 350 ppm this century, we risk triggering tipping points and irreversible impacts that could send climate change spinning truly beyond our control.
|Source : Nature Communications|
To find appropriate species, we choose two regions with similar climate, one from a simulation
with today’s climatic and CO2forcing and another from an Ordovician simulation with a
high atmospheric CO2 value of 24 PAL.
concentration was 2240ppm and perhaps 6720ppm (24 PAL) as in above diagram.