Linking an ancient CO2 drop to the Antarctic Ice Sheet using algae as a proxy | Watts Up With That? Read the summary of the work, then the comments.
Without some clue as to what caused the big changes in CO2 concentrations, I still maintain that you cannot conclude that "...increasing global temperatures could drive an increase in CO2, not the other way around". (Italics mine) It seems to me that this is an entirely dynamic equation: Increased Global Temps Increased CO2 Levels
I don't think I made any conclusion, note the use of the word 'could'. Yes, if CO2 is responsible for increasing global temperature and if that triggers a release of more CO2 then it could result in a runaway effect, but it hasn't. CO2 levels have been significantly higher in the past and we have not had runaway global warming. If someting else is driving climate change (not CO2) then there would be a correlation between temperature and CO2 levels but CO2 would lag temperature, which is what is seen in this study. Note the conclusion made by the author This order of events is not what one would expect from the enhanced greenhouse effect.
Re-reading it ... no, it can be read that you were not drawing a conclusion. My bad. We have a good understanding, scientifically speaking, of what causes greenhouse effects, in terms of the gases involved. We have a good understanding of how global temperatures are affected by greenhouse gas concentrations, planetary albedo and such. What we don't know are what causes fluctuations in g/h gas concentrations - we haven't been around long enough, as scientists rather than as a species, to make sufficient observations to formulate convincing theories on the subject. It's all guesswork at this point.
Yes it is, assuming you belive it to be true and as simple as that, but it isn't. Take a look at the White Cliffs of Dover and the many carbonate rocks the world over, all of that carbon used to be free in the atmosphere (as CO2) until it was incorporated by plankton etc. Conditions for plankton growth vary enormously over geologic time.
That's the thing though, isn't it? "Geologic time". The changes we are seeing are in a handful of decades, not geologic time. That's what is so fishy about it and the thing that people seem so keen to willfully ignore. It's the blink of an eye in on normal non-human timescales as far as the earth is concerned. Point me at the precedents.
Plankton growth, sub-oceanic methane, all really big factors in the carbon cycle. Probably the biggest factors, short of a world-ending increase in volcanic activity. What I would be wary of is believing that only the biggest factors can be triggers for climate change. The oceans represent probably the largest source of not only (readily-accessible) greenhouse gases but also the biological processes for reducing CO2 - in effect, a dynamic equilbrium. Now consider an unprecedented (in human, not geological, history) increase in volcanic activity, releasing large quantities of CO2, etc. On their own, not a global climate changer, but if it's enough to type the balance in the oceans ... well, bad news. Some folks maintain that human activities are of sufficient impact to create runaway climate change - unlikely of itself, but again, maybe enough to shift the oceanic balance towards that end. I am unconvinced, but not wholly sceptical. The geological record over the past billion years and more shows a history of the sort of ice ages our early ancestors survived (with some difficulty). There were however some very serious ice ages, going back long before the dinosaurs, that were very bad news indeed, eliminating 95%+ of all species across the globe. Who knows what processes were involved in these cycles.
The predictions made by extrapolating the 'hockey stick' graph have simply not happened. It is also the case, as Loz suggests (I think), that natural change does not always occur over geological timescales, it can, and has, happened very quickly.
Have a look at this short talk on the excellent TED site. James Hansen: Why I must speak out about climate change | Video on TED.com Then it would be interesting for those who don't want to believe him to say why. May as well know what we are up against.
This debate, both on the forum and in the wider world, seems to me to be mainly about side-issues. The important point is that if the climate of the earth is changing substantially, and if the change is detrimental (i.e. the drawbacks outweigh the benefits), efforts should be focused on inventing technological ways and means of reversing the change. It does not ultimately matter whether carbon dioxide levels rising is a cause or a consequence, still less does it matter whether any change is man-made or caused by natural volcanic activities, solar activity, oceanic algae effects, etc etc. Little purpose is served by arguing about these side-issues. Even if it were proved conclusively that climate change is a natural or random process, and nothing to do with human activities, the problem would still exist and strategies for tackling it would still be required, and be just as important. Always assuming the phenomenon exists at all, of course, and actually is a problem....
We seem to be finally getting somewhere. Yes it's happening. (who cares how). Is it detrimental to many people's livelihoods and the whole current set-up? Yes. So let's stop arguing about it and do something. The strategy of those who wish to do nothing is to continually argue about whether or not it is happening (ignoring all the evidence that shows that it is), whether we are to blame (as Pete points out, a side issue) and then whether we care (which we clearly should). As I pointed out many posts ago (and probably on the electric bike thread), there is a clear PR strategy amongst those for whom any form of change of the status quo is detrimental to their current interests, to (a) sow DOUBT about whether it is happening, to sow DOUBT about whether we are to blame. There is little DOUBT being sown about whether it is a bad thing, as it seems so obvious to most that it would be. DOUBT is all you need to maintain the status quo, as it is a straw which people are keen to cling on to. But it is a straw. You don't have to prove anything one way or the other. You just say, "there is no conclusive proof" = DOUBT (however small) = inaction. That pretty much sums up the climate debate. A great way of signing up to DOUBT is to stay ill-informed. Or you can adhere to conspiracy theories. Or you can give more weight to anything at all that supports doubt and wilfully ignore anything that doesn't. This is why the book that I suggested people read is called Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming: Amazon.fr: Naomi Oreskes, Erik M. Conway: Livres anglais et étrangers Doubt will only go away when London is underwater. And even then, there will still be luddites who insist that it isn't proof. But of course, by then, it will be far far too late to do anything constructive. There is currently a window of opportunity to do something about the situation, but that window is rapidly closing. It's more like one of those doors that starts shutting on Indiana Jones in some underground temple where he just has time to wriggle out before it slams shut on him, entombing him forever. That is Hollywood. This is the real world. You can start rushing for the exit, or pretend that the door isn't going to close (or that there is no door to close).
I'm wracking my brains, but I can think of no good reason why it shouldn't coincide with the Olympics
Agreed but if CO2 isn't the cause, and policy is being implemented on the assumption that it is the cause, then the effort will be wasted. Take energy useage surveys. My local Ducati dealership has had to have an enegry useage survey and will be fined if his energy useage doesn't drop by a certain percentage. Lighting is a major contributor to his energy bill but it would cost £20,000 to install LED lighting, so what will he do ?, pay the fines, because it's cheaper. He sees it as just another tax. The whole 'green economy' thing is a scam, all it adds is additional cost and deflects from the main issue which is that we have an impending energy crisis if we wish to maintain our current standard of living.
The main issue is that we will all be underwater or in a desert if we wish to maintain our current standard of living. You think that's a cost? Wait until the problems really get underway and you have to pay an "anti-flooding" tax, or a massive hike in food prices or God knows what else. Why do people think that the status quo costs nothing and that the only cost is in planning for disaster? The whole point is that it is cheaper to plan to avoid the disaster than it is to deal with the disaster. Why is it so hard for people to get their heads around that?
