What is the worst damage that increased Carbon Dioxide could possibly cause on earth?The answer is surprisingly little (ignoring hypothetical ‘feedbacks’) !
So now let’s imagine the most extreme case possible. What if CO2 levels were somehow to rise 300 times higher than current levels reaching crazy levels like 10%? Just how hot would the earth then get ?
So really not so bad after all! The maximum possible CO2 greenhouse effect on earth is about 13 deg. C.
These calculations are based on a line by line ‘radiative transfer’ code covering the dominant 15 micron absorption band described here.
So what is the problem of anthropogenic global warming – if any?
For 99.9% of earth’s 4 billion year climate history CO2 never has been a problem. On the contrary CO2 has helped to keep the earth’s temperature just right for life to flourish. In reality CO2 is a wonderful stabilising feedback that counteracts external ‘dangerous’ forcings on climate, and will allways to do so as long as life continues to flourish.
CO2 levels in the earth’s atmosphere normally react to changes in climate. They naturally regulate atmospheric CO2 by responding to changes in ocean temperature. It is basically only now that CO2 levels have increased before temperature, with the possible exception of the Paleocene–Eocene Thermal Maximum (PETM) event 50 million years ago. Anthropogenic CO2 ‘climate change’ is less than a blink in the eye.
Geological evidence shows that during the PETM, CO2 levels rose by about 3 times more than the most pessimistic levels imaginable today, even if humans were to burn all available fossil fuels on earth. Yet during PETM temperatures only rose by just 5C. Furthermore it is entirely possible that the PETM excursion in CO2 levels was not due to some volcanic belch of CO2, but instead was also the result of some external astronomical forcing such as a supernova, which CO2 levels then reacted to as a response.
So we need to keep things in perspective regarding (catastrophic) anthropogenic climate change. Yes human activity will most likely result in some small warming but its effect will naturally be rather limited.
It may even turn out to be a blessing in disguise because increased CO2 levels now may likely delay the onset of the next ice age which otherwise is due to start around now. Another ice age would be orders of magnitude more catastrophic.