Global Warming skeptics Q#1: Why is CO2 at the highest level in 20 million years?
The current level of CO2 in the atmosphere is 383 ppmv, higher than at any time in the last 20 million years. Are human activities responsible for this, or have we seen an amazing rise in volcanic activity? What is the theoretical effect of adding this much CO2 to the atmosphere?
No best answer will be awarded to anyone who cites anything other than peer-reviewed science.
CO2 was high just 140,000 years ago and there were no SUV's back then.
Historically, there is no evidence that CO2 drives temperature change. Also, NASA proved that an increase in CO2 happens after an increase in temperature. Also, the oceans releases huge amounts of CO2 when temperatures increase. Also, melting ice and melting permafrost both release CO2.
If you step back and think about the amount of biomass that has been concentrated into crude oil and coal - millions of years of pulling CO2 from the atmosphere and replacing it with 02 through photosynthesis, making our atmosphere hospitable for mammals - is it any wonder why CO2 levels are so high? We probably release millions of years of carbon sequestration in a decade, and at the same time, we are destroying the very mechanism that balances this flow of CO2, the plants and trees. The theoretical affects are unclear, since climate is so complicated, and our trends of our effects are not fixed, but basically increased temperature will accelerate the evaporation mill that runs the global weather system. Increased clouds may reflect radiation back into space, but we're also melting the ice that currently serves this purpose, so the positive/negative feedback loops of this system are not certain.
People who are sceptical say that co2 has little influence on temperatures. So even if your stats are true, they are meaningless.
In a new scientific paper in the journal Energy and Environment, German researcher Ernst-Georg Beck, shows that the pre-industrial level is some 50 ppm higher than the level used by computer models that produce all future climate predictions. Completely at odds with the smoothly increasing levels found in the ice core records, Beck concludes, "Since 1812, the CO2 concentration in northern hemispheric air has fluctuated, exhibiting three high level maxima around 1825, 1857 and 1942, the latter showing more than 400 ppm."
In a paper submitted to US Senate Committee hearings, Polish Professor Zbigniew Jaworowski, a veteran mountaineer who has excavated ice from 17 glaciers on six continents, stated bluntly, "The basis of most of the IPCC conclusions on anthropogenic [human] causes and on projections of climatic change is the assumption of low level of CO2 in the pre-industrial atmosphere. This assumption, based on glaciological studies, is false."
Sequences of annual tree rings going back thousands of years have now been analyzed for their 13C/12C ratios. Because the age of each ring is precisely known we can make a graph of the atmospheric 13C/12C ratio vs. time. What is found is at no time in the last 10,000 years are the 13C/12C ratios in the atmosphere as low as they are today. Furthermore, the 13C/12C ratios begin to decline dramatically just as the CO2 starts to increase -- around 1850 AD. This is exactly what we expect if the increased CO2 is in fact due to fossil fuel burning. Furthermore, we can trace the absorption of CO2 into the ocean by measuring the 13C/12C ratio of surface ocean waters.
Tree ring and ice core data both show that the total change in the 13C/12C ratio of the atmosphere since 1850 is about 0.15%. This sounds very small but is actually very large relative to natural variability. The results show that the full glacial-to-interglacial change in 13C/12C of the atmosphere -- which took many thousand years -- was about 0.03%, or about 5 times less than that observed in the last 150 years.