“Carbon dioxide has been suspected as an important factor in ending the last Ice Age, but its exact role has always been unclear because rising temperatures reflected in Antarctic ice cores came before rising levels of CO2,” said Shakun, who is a National Oceanic and Atmospheric Administration (NOAA) Post-doctoral Fellow at Harvard University and Columbia University.
“But if you reconstruct temperatures on a global scale – and not just examine Antarctic temperatures – it becomes apparent that the CO2 change slightly preceded much of the global warming, and this means the global greenhouse effect had an important role in driving up global temperatures and bringing the planet out of the last Ice Age,” Shakun added.http://oregonstate.edu/ua/ncs/archives/ ... glaciation
Keep in mind that a lot of the data skeptics use is somewhat dated and more recent work is more supportive of co2 nudging temperature.
We could have an endless debate over which studies are valid and which are not, who here is really able to make those judgment calls?
Scientist are skeptics by nature which is a point that the lay population does not fully appreciate when reviewing the debate from the outside. It is easy to get lost in the details of just how much of the current warming can be attributed to anthropomorphic forcing. What no one debates is that co2 is a greenhouse gas and even if the majority of the warming was due to natural causes the fact that the planet is warming is not in debate. Evidence suggest that in periods of climate instability even a small amount of forcing can tip the positive feed back scales. So even if as little as 15 percent of the forcing is anthropomorphic if could be critical.
If climate patterns repeat in a predictable way then we are about to fall off the warming cliff into another ice age some time in the next thousand years but that does not mean that we can just wait for it to start cooling. Human population growth means that there is very little margin of error in terms of food supply before we have mass starvation. Keeping these facts in mind my choice would be to immediately intervene to slow warming even if co2 emissions cannot be reduced. Reducing co2 is not the only thing we can do to slow warming, land use, aerosols, and other steps can be taken many of which have side benefits that significantly offset the cost and are easily reversible. Cooling such as another little ice age even over a period of two years would be far worse than the predicted warming in terms of it's effect on food supply so putting all our eggs in one basket seems unnecessarily fatalistic and that is my issue with environmentalist. While it is true that intervention could do more harm than good the same could be said about bypass surgery but often the natural remedies are insufficient and drastic steps are justified.
What is the debate really over anyway, fossil fuels pollute, oil imports destabilize the world economically and politically, desertification needs addressed, low till agriculture works, shore lines benefit from plantings, carbon is a valuable resource worth conserving, quality of life is less dependent on material wealth than attitude, population density has made the current transportation system impractical, non point source pollution is now a bigger issue than industrial pollution, fossil fuels are non renewable, population growth is out of control, technology to control climate must be developed to prevent the next ice age, human impact on the environment is often worse with low tech solutions, why are we waiting for the debate over Climate Change to be conclusive?