biffvernon

There is a posibility that AGW is real and that unless we reduce CO2 to 350ppm the human race will be toast. At what probability of this being the case would it be worth doing as Hansen suggests - a World War II style mobilization of all nations to avert the calamity? 90%, 50%, 10% 1%?

The thing is, Jethro, that article and many more of a similar ilk, get demolished pretty much as soon as they appear by scientists for whom it's a speciality. There's little point in repeating the arguements ad nauseam. If you are interested, then I suggest you keep up with the RealClimate and Eli Rabett blogs and for old stuff like the article in question trawl through the archives. It's all out there.

No, it isn't. It disperses just as quickly as the wind blows. And that's much too quickly to have a measurable climatic effect.

Well I wouldn't give it house room after merely reading the title, but others have put the effort into more comprehensive discreditation.

Syun-Ichi Akasofu did some valuable work on the Northern Lights in the late 50s and 60s. Now he is notorious for his contributions as a climate change skeptic.

What little evidence there is comes from Europe. These were not global phenomena.

From Platts blog

Why do people keep trying to claim that the Earth has cooled? Do they think that if they repeat it often enough it will come true? It hasn't and it won't.

Erm...could you give an example or two? Not from ancient 'science' but from modern, 20th century, peer-reviewed science-as-we now-know-it.No other area of science has been so thoroughly studied by so many scientists involving so many disciplines, arriving at the consensus that global warming is real is mostly of human making and is a serious threat to human affairs.

A what? China has had a rather chilly winter. La Nina and all that.

Looks like I will never know what the Dawlish referred to then Put "Lyman et al 2006" into Google and the first result is http://oceans.pmel.noaa.gov/Pdf/heat_2006.pdf It starts: Correction to “Recent Cooling 1 of the Upper Ocean” Josh K. Willis1, John M. Lyman2,3, Gregory C. Johnson2 and John Gilson4 Revised and Resubmitted 10 July 2007 to Geophysical Research Letters Abstract. Two systematic biases have been discovered in the ocean temperature data used by Lyman et al. [2006]. These biases are both substantially larger than sampling errors estimated in Lyman et al. [2006], and appear to be the cause of the rapid cooling reported in that work.

No, I'm not playing silly games. I just did not understand the reference to Dawlish. So I asked for clarification. I even Googled Dawlish but just came up with lots of references to a town in Devon (Can't find the confused smilie) I also don't understand what you say about ocean temperatures. Since when do we have a decent sample of deep ocean temperatures that shows them to be cooling? Please provide references so that I too may believe.

Gosh! Can you get a GCSE in Earth Sytems Science now? I thought it was just an MSc course. I'm not trying to stifle debate. I've asked where the error in Hansen's paper lies, but answer comes there none.

Sorry, I don't know who Dawlish is. A town in Devon? I'm Biff Vernon - I don't hide behind a pseudonym of internet forums. Your question was "What problem are you on about? Please explain what you can and no one else can see." (English corrected) The problem, a veritable mastodon in the room, is that we may get runaway global warming triggering an extinction event not seen since the Permo-Triassic, i.e. we'll all be toast. I've not seen yet, from any of the good folk who cast doubt on such talk, is where the paper by Jim Hansen et al. gets it wrong. The phrase put up or shut up comes to mind.

While some non-scientists like to point out the gaps in our understanding, Earth system scientists are actually confident that a great deal is known about their subject. We know what CO2 does and how it does it, we know where the heat goes and we know what the consequences will be. Of course, there are uncertainties, (as there are in all sciences) concerning timing and magnitude and the interaction between sub-systems to provide feedback leading to tipping points, but obervations are constantly reinforcing the models and allowing thir refinement. If, Bluecon, you are really interested in 'factual info' I suggest you start with the most recent paper on the subject available as 3.6mb pdf here. Read it in cojunction with the discussion here.

Oooo! It even refers to science. Trouble is, it isn't science.

Of course we're not in control of the climate. Would that we were. We've chucked a great big spanner in the works and our best hope is to attempt the almost impossible task of sticking our hand in and retrieving as many of the spanner bits as we can. Let's hurry up before it's irretrievably lost. Shame on those who are still intent on throwing more spanners in.

Skipping lightly over your command of English, the problem is that what goes down, comes up. In this case the oceans are acting as a heat sink, masking the rise in global temperatures of the whole atmospher-ocean system. If you don't put your thermometer where the temperature is rising you may miss what's happening.

What your boggling mind seems to have failed to grasp is that if we measure the temperature of the air only, we fail to see the heat that has gone below the ocean waves. The oceans are a truely mind-boggling heat store - there is a lot of water and water has a very high heat capacity. Atmospheric warming is one thing, global warming is something very different as it includes the water. Unfortunately for all of us, the more research is done the more it appears that Hanson et al are right. His analogy of World War II has merit. In the 30's there were plenty of people who took a relaxed view of the future while some predicted dire catastrophe.

Sorry but that is just not true. One might, perhaps, claim that sea surface temperatures "are showing a slight cooling". That is at least open to measurement. The ocean is a very different beast to the sea surface. The trouble with that little girlie current in the Pacific is that it takes warm water downwards to where no thermometer can reach, hiding the problem from all who refuse to see.

One really shouldn't talk of 'global warming' when one means 'global atmospheric warming'. If a lot of heat is being absorbed by the oceans we may not notice a rise in air temperatures. But that heat will come back and bite us in it's own good time.

Having read countless reports from Roger Harrabin over the years, I regard him as a trustworthy journalist. Earlier this week my local weather station at Donna Nook recorded temperatures of 25 C. Ha, proof of global warming. Then the record dropped to absolute zero till next day. Then they fixed it. Folks who are so quick to doubt the science may sometimes not realise just how much questioning goes into any piece of scientific work. Long before a paper gets peer reviewed prior to acceptance for publication in a professional journal with a reputation to uphold, there is usually an enormous but unseen amount of discussion amongst co-authors and colleages within the departmant both formally and in the coffe bar. It just does not do the carear of a scientist any good to have his or her name on a paper that subsequently is shown to be rubbish. I'm not saying that rubbish does not occassionally get through the system, but it is a lot less common than some would like to imagine.

Nope. Reminds me of my first foray into computer modelling - involving rabbits and foxes on a Sinclair Spectrum It's a timescale thingy. The next 40 years of world population is a very short timescale in relation to the population dynamics. We're just looking at a little bit of the curve. Most of the people who we expect to be alive in 2050 are either alive already (so we can count them) or their mums are alive (so we can count them and ask them how many babies they intend having). Can we predict the population ten generations down the line? Now that would be hard. It's the difference between forecasting tonight's weather and next month's weather.

It depends what you mean by a 'hard problem'. Forecasting the weather here for next month is a hard problem. Weather is a chaotic system for which we have an incomplete knowledge of initial conditions. It's such a hard problem it will probably always be impossible. With population it's a different kind of problem. We can build a scenario based on certain assumptions that is very robust. There are known unknowns, such as the timing of the next flu pandemic or politico-economic upheavals or the arrival of a large meterite, that could make reality very different from the most likely scenario. And then there are unknown unknowns. Still, I will be surprised if the world population is more than half a billion away from 9 billion in 2008, with a greater likelihood of a lower than a higher number.

That's not such a hard problem. We know the initial conditions and have a good understanding of population dynamics and where the unknowns are. Estimates of world population levelling off at around 9 billion by mid century are made with confidence. Significant undershoot could result from disease pandemic or global financial and energy disruption combined with bad weather leading to massive food shortage, but we hope not. The most significant non-disaster factor is women's education along with primary health care and social security which have a lowering effect on birth rate. Climate forecasting is much more difficult.