[Solanum]

Originally Posted by renormalised

The Earth's climate is an extremely complicated beast and is affected by many, many variables in those physical and dynamic processes which impinge upon it. Be it more CO2, or less, changes in solar insolation, atm' water content etc etc etc. Just concentrating on one particular variable or process is not how you go about understanding what's happening.

Indeed, but as far as the science is concerned no one is concentrating on one variable, and it is exactly that complexity that makes it difficult for those of us without the relevant background (including me) to argue about what is or isn't driving climate change. It's weird how people will accept all kinds of wacky ideas in astronomy but refuse to accept far better proven ideas in climatology.

Originally Posted by renormalised

Whether there's more or less CO2, or water vapour or any other "greenhouse" gas in the atmosphere is immaterial. What is important is how adding or reducing the amount of those gases effects the processes which drive the changes that occur, and in what direction they occur. We all know that putting any "greenhouse" gas into the atmosphere in concentrations higher than what is statistically normal over the long term measurements, will cause some changes in the overall temperature balance of the planet. CO2 being the least effective of the gases, in comparison with others such as methane or water vapour. However, it's how the increase in CO2 not only changes the heat balance but also how it affects the capacity of those other gases to also effect the climate. Nothing is changed or effected in isolation from everything else. Change one variable and you affect all the others.

Absolutely, but again, as far as science is concerned no one is claiming anything is due to a single factor.

Originally Posted by renormalised

Paradoxically, an increase in the amount of CO2, over time and normal levels...given its effect on sea level, water salinity and such...could most likely produce a rapid decrease in global temperatures, and for a rather protracted period, before any overall warming occured. Witness the last Ice Age...the Northern icecaps were already undergoing melting well before any change in global atmospheric CO2 levels. The crazy thing is that when the levels of CO2 began to change rapidly, it actually helped trigger a rapid cooling and return to deep ice age conditions...the Younger Dryas. It lasted for about 1000 or so years, until the atmopshere, oceans and land came back into balance and normal interglacial conditions established themselves.

That is a rather gross simplification. Firstly, the evidence that CO2 increased during the Younger Dryas is limited (ice core data only) and there is other data that suggests otherwise (e.g. stomatal counts). One explanation is that there was a very large decrease in CO2 at the start of the Younger Dryas followed by a slower (and more limited) rise. As far as science is concerned this is something that isn't decided. But you should bear in mind that both CO2 and temperature are higher than they have been for at least the last six ice ages. It hasn't been this hot and CO2 hasn't been this high for at least 600,000 years.

Originally Posted by renormalised

What annoys me is the vested interests on both sides of the argument. One, on the alarmist scientists and eco' lobby who are pushing the own agendas and two, the global petrochemical and energy producing corporations who have a vested interest in keeping the status quo and have many of the politicians in their pockets. Neither side is right in their assumptions and all this arguing too and fro...and the general misunderstanding of the general public w.r.t. this matter (something encouraged and promulgated by an even more ignorant media) is not helping the situation.

I'm not sure what the vested interests of science are, unless you mean more funding? How do we know that the 'assumptions' of anyone are wrong? I'm not sure what 'assumptions' the scientists are making.

Originally Posted by renormalised

Yes, you can't expect the public in general to have a detailed understanding of the science, or even the politics involved. But they are not being given anything better to hang their opinions and concerns upon than what's being fed to them.

The public can't conduct the science, so they can only take what is being fed to them. If you read the summary for policy makers from the IPCC Fourth Assessment, it is easily understandable by most people. But bear in mind that the IPCC represents a compromise view and is necessarily slightly out of date, so is almost certainly an UNDERESTIMATE of the real scientific understanding.

Originally Posted by renormalised

That's where grave mistakes can be made. We need to take a pragmatic, but measured and well informed approach to the problem. Either way, not doing anything or doing too much would be disasterous, just the same as not moving fast enough or moving too fast would be deletarious.

We know we're affecting the climate, that's a given. We've been causing large scale regional climate changes for thousands of years, and these have been in addition to those that occur naturally. What we should realise is that doing nothing will be just as bad as doing too much and putting ourselves in a position that when change does occur we can't adapt ourselves to those changes...at least in a way that doesn't impact too much on us. Change will occur, that's inevitable. It won't be easy but let's not make things more difficult than what they would otherwise be. Stop all this nonsensical arguing about who's right and who's wrong and just get on with what needs to be done.

I agree, but we can only base what's being done on the science and the science indicates that we cannot do enough to undo what is done, therefore we have to decide how much climate change we are prepared to put up with which, comes down to politics. I would remind everyone that so far we are tracking the worst case scenario in both CO2 (and other greenhouse gas emissions) and global temperatures and have been ever scince the iPCC was created. So in effect to date we have done nothing and we are pretty much getting what was predicted 20 years ago.