But actually the idea that something we breath out along with most animals, plants and trees which forms just 0.038% of the earth’s atmosphere is the primary source of climate change is IMO plain stupid in any case. Surely if that were indeed the case we could cut carbon emissions simply by cutting down a couple of rain forests lol or maybe it’s all caused by smokers lol

Actually I wouldn’t say the alternative theories to man made climate changed are exactly boring one theory out there is it’s due to the return of Nibiru. The brown dwarf binary of our sun. Another theory is Galactic alignment and the whole end of the Mayan Calendar on 21st December 2012. Apart from those ideas there’s also the onset of an ice age caused by increased sub-oceanic volcanism. These theories are probable mostly on the fringes, but I wouldn’t say they were boring, they are quite interesting ideas and certainly well out of the box.

And I find your justification for that extremely weak; namely that ‘all life on our planet’ is an unhelpful exaggeration because even with a mass extinction cockroaches and bacteria might thrive.

That strikes me as both a rather relaxed position to take and also missing the point somewhat.

This too seems to be a serious problem with most people advocating action. When presented with someone who questions even the language that we use when urging change, they immediately characterize the person with whom they are disagreeing as having the view “don’t worry about global warming”.

If this is how you attack someone who politely points out that we should be careful to ensure that our language can never be accused of being an exaggeration, then you are doing as much harm to the cause as Plane Stupid, and George Monbiot.

“A low-range optimistic estimate of 2°C of 21st century warming will shift the Earth’s global mean surface temperature into conditions which have not existed since the middle Pliocene, 3 million years ago. More than 4°C of atmospheric heating will take the planet’s climate back, within a century, to the largely ice-free world that existed prior to about 35 million years ago. The average ‘species’ lifetime’ is only 1 to 3 million years. So it is quite possible that in the comparative geological instant of a century, planetary conditions will be transformed to a state unlike anything that most of the world’s modern species have encountered.”

A temperature rise of 2°C has generally been taken as a ‘safe’ level, but it looks pretty unlikely we’ll manage that. There’s now talk of trying to limit the increase to 4°C, despite all the uncertainties of feedbacks.

The point of the Hansen paper above was that previous estimes on climate sensitivity to CO2 have been too conservative, leaving out longer term feedback effects.

Instead of a doubling of CO2 (which we’re on course to do) causing a 3°C rise, it could lead to a 6°C rise.

6°C is mass extinction territory.

So given all the uncertainties and the possibility of positive feedbacks, the level of CO2 that currently exists may already be dangerously high.

Don’t worry about Global Warming…

…bacteria will survive.

I’m not sure people will find that terribly reassuring.

Let’s face it, global warming is not going to kill me. It is not going to kill the fish that I have in my fish tank. It is very unlikely to kill, for example, the current generation of salmon, and it is not hugely likely to kill off the beetles that I saw last time I was in the Sahara. Most of them will get eaten, as has been happening for a while now.

You have now added the phrase “as it currently exists”. That is much better, it moves things back towards a point at which sensible discussion can take place. We may introduce hige change, which is very bad for us, and very bad for certain species. It is very likely very, very god fr other species, though. Certain bacteria, for example, will thrive if humanity gets squeezed closer together in the future. Cockroaches may have a field day, as it were.

You are right, I cannot prove that the phrase “all life on the planet” was dishonest. It could well have just been horribly ignorant.

Exaggeration weakens the arguments, and these are important arguments, and ought not to be forgotten. The debate must be kept honest, or it will be lost. I do despair of those who cannot see this, and who will allow hyperbole to slip in, which weakens the case for action among the general population. Tell people obvious untruths among the genuine facts, and this will not tend to make them want to learn more.

Because what’s concerning many people, including scientists working on the field, is that AGW really could be a major concern for life on the planet as it currently exists.

There is considerable uncertainty about what might happen when, what feedback effects might kick in, positive or negative etc. But we know there’s a timelag for the warming effects and we know that CO2 emissions, far from being reduced, have continued to increase.

If this continues, or the temperature rise turns out to be at the high end of the model predictions, then the possibility of catastrophic effects appears real.

There have been mass extiction events before associated with climactic change, some of them warming events. And even if the temperature rise was less this time round, the comparative rapidity could have devestating impacts on ecological sytems already stressed by human impact.

A mass extiction event may be an outlier, but there’s evidence to suggest it’s a possibility if action isn’t taken to reduce emissions.

I think that your reply above was in response to my stating that dishonesty is poisoning the debate. I view part of the quote you have used above as a prime example of this dishonesty. This is not a major issue for “all life on the planet”.

It is an issue for mankind. We are not going to reduce the number of animals, plants, or bacteria alive. We may change the distribution somewhat, but that is really only an issue if it hurts us, and future generations.

Anyone calling for serious action (such as either me or my wife no longer seeing our family, who live 1,000 miles apart) needs to work out exactly how much pain we ourselves should take against future generations benefiting. This is a serious point. Should I leave my wife, or should one of us accept that we will not see our parents again? If it is still acceptable fr us to take the train to see them, or to fly, then whee should the line be drawn.

This is not e being facetious, it is a genuine question. Part of th reason that I pose it is that many of those urging action are being extremely hypocritical, and this needs to be addressed. If the proponents of action have had children, then they should not dare tell me not to bike up North to see my family. If they commute to work (I have always moved t be in walking or tube distance), they cannot with a straight face tell me that I cannot drive a car with a big engine for fun once in a while.

And they are completely missing the big picture with either of these pronouncements.

I gave this link before;

www.aps.org/policy/statements/07_1.cfm

“The evidence is incontrovertible: Global warming is occurring. If no mitigating actions are taken, significant disruptions in the Earth’s physical and ecological systems, social systems, security and human health are likely to occur. We must reduce emissions of greenhouse gases beginning now.”

That’s a pretty good summary of the scientific consensus. And if you listen to many of the scientists involved in climate research they’re actually very worried. So far, for all the ‘discussion’ about climate change, and all the science begind it, we’ve actually seen very little action. We’re already heading into unknown territory and if this continues, even a short time longer, there appears to be the potential for catastrophis effects.

www.columbia.edu/~jeh1/2008/TargetCO2_20080407.pdf

“Humanity today, collectively, must face the uncomfortable fact that industrial civilization itself has become the principal driver of global climate. If we stay our present course, using fossil fuels to feed a growing appetite for energy-intensive life styles, we will soon leave the climate of the Holocene, the world of prior human history. The eventual response to doubling preindustrial atmospheric CO2 likely would be a nearly ice free planet.”

“Continued growth of greenhouse gas emissions,for just another decade, practically eliminates the possibility of near-term return of atmospheric composition beneath the tipping level for catastrophic effects.”

“The most difficult task, phase out over the next 20-25 years of coal use that does not capture CO2, is herculean, yet feasible when compared with the efforts that went into World War II. The stakes, for all life on the planet, surpass those of any previous crisis. The greatest danger is continued ignorance and denial, which could make tragic consequences unavoidable.”

It has become religion, on both sides (the discussion of what to do now, not the question of what the science says).

This whole discussion is poisoned. It is no longer possible, it seems, to have an adult conversation about the correct response to climate change.

I have heard someone claim that the planet will die if we do not mend our ways. Language like that is extreme enough to be laughable, but it not untypical of the public face of the lobby groups.