What does this imply? -- We are already at the CO2 levels of the Pliocene, when ocean levels were 80 ft higher than today. Rising at 4ppm per year, we will see 500 ppm by 2040, and 740 ppm by 2100. The Earth has not seen CO2 levels that high since the Cretaceious, when NO POLAR ICE EXISTED !!
Global Warming has just begun. As the CO2 levels accelerate, so too will the rate of Global Warming.
We must also ask ourselves "why is this occuring"? The worlds energy infrastrucure has not changed, and the world economy has not grown enough to get a human caused doubling of added CO2 levels. CO2 had been rising at about 2ppm for the last 15 years. Something has changed to cause a rise of 4ppm.
Possible causes of the 4ppm rise --
- The warming oceans are not absorbing as much CO2 as they have in the past. As the oceans warm, they lose ability to absorb CO2. Just as cold sodas hold CO2 better than warm sodas, so too, the oceans will hold less CO2 as they warm. So, maybe the increased CO2 levels is still coming from only human created CO2.
- On the other hand, maybe the added CO2 is coming from Nature. We see the heat islands over Siberia. Maybe melting permafrost is now adding CO2 in significant quantities. If so, we can only expect that to increase even more as the Earth warms. We could soon be seeing 5ppm, 7ppm, and 10ppm rises in atmospheric CO2 annually, if this is the case.
Personally, I feel that the second hypothesis is more likely the correct one. If so, it is bad news. It means that Nature has taken over the controls of GW. Mankind may no longer have the ability to stop it, or even slow it down, by merely switching to non-fossil fuel energy.