The scientific case for accelerated global warming, which Stern took as given. is not cut and dried. A significant point, rarely if ever noted in the media, is that the increase in surface heat loss as the surface temperature increases is nonlinear and provides a strong damping factor against surface temperature warming - suggestions of a runaway process are false. CO2 contributes to warming by reducing infrared radiation to space. Meteorologist William Kininmonth notes that initial introduction of carbon dioxide to the atmosphere leads to a reduction of about 20 W/m2 at 50 parts per million by volume (ppmv) concentration. A further increase to the present concentration of 380 ppmv causes an additional reduction of ONLY 10 W/m2. IPCC's calculations suggest that a doubling of carbon dioxide from pre-industrial levels will only reduce the infrared radiation to space (the radiative forcing) by about 4 W/m2.

That is, the more than six-fold increase in CO2 from 50 ppmv to recent levels of 380 ppmv has led to only a 50% increase in CO2's warming impact on global temperature, and the forecast further increases will have little impact.

It's also worth noting that paleohistorical records show that in many (? most) previous global warmings, increased CO2 concentrations have followed warming rather than preceding it, and have therefore not been a causative agent.

Stern has form with politically-inspired distortions in earlier UN work. For example, in a major publication he claimed that the average income in the 20 poorest nations fell over the period (from memory) 1980-98. However, the 20 poorest nations in 1980 included China and India, which then had rapid per capita growth. The 20 pn in 1980 had a population of maybe 2.5 bn. The 20 (not all the same) pn in 1998 had a population of maybe 100-200m. That is, 2.3 billion-plus people had been lifted from poverty in the period when Stern claimed things were getting worse!

Kang, Lomborg’s book was not “widely discredited.” On the contrary, his detractors were discredited – the attempts to discredit him in the Scientific American, including by leading IPCC researchers, were woeful.

I thoroughly enjoy public debate. I absolutely support democratic exchange. So let the debate rage.

But let's not deny that vested interests behind the fossil fuel industry have much at stake. Not surprisingly, then, that there are websites out there attempting to discredit the reality of global warming and the need for strong policy responses. Not surprising, either, that some innocent folk are persuaded.

There are two kinds of climate sceptics: 1) Those that support the fossil fuel industry and are paid for doing the job. 2) Those who support the fossil fuel industry and are not paid for doing the job. The work of the two are indistinguishable, so who can tell who is who?

I say to the latter group, I admire your generous commitment. You are far more credible than your paid counterparts because you do it for free.

It could be you have just been duped by industry PR, but that should not take away from your selfless commitment to a cause.

The cause of keeping on burning fossil fuel, and denigrating those who want a safer, more sustainable future, is to some a rather curious one. But we live in a democracy and you should be applauded for your democratic participation.

Where is my favorite anti global warming warrior Andrew Bolt when you need him?

F**k the science - it is counter intuitive and just plain silly to not believe that as the species that engineers so much of the built environment and mnipulstes the rest as best we can we are not impacting on the environment

And it is prudential to believe that the impact is probably, if not negative, at the very least altering the status quo and rearranging weather patterns for example - at best we can take cold comfort in the knowledge that if we dry up, some where else will be blooming and fertile where once dust was the order of the day.

It is almost bizarre to witness the ALMOST Pauline Conversion of John Howard on this matter - it is as if he has been visited by God (but is still a bit of a doubting Thomas) in the true spirit of the Oakshott conservative he leads by intimation - from behind.

If all we do is develop a national policy and ethos on water conservation we are back in the game - but when you have irrigators farming marginal land - using in excess fo 97% of available water - you have to wonder - and wonder still more when some of them say if we take measures to save water the best application for what is saved it is to use for more irrigation! For many the root of the problem are city folk using dishwashers and having the temerity to water a lawn - when metro/regional town use of available water is a mere drop in an ever rapidly emptying bucket

If we cant get that right - I am investing in copmanies that make hats and sunblock - I expect to die a rich and thirsty man

Gecko, I confess. I went down a deep coal mine in NE England around 1958, crawled through two-feet (60 cm) high seams and blew out coal dust for two days.

Other than that, I have no connection with nor carry a (?solar-powered) torch for fossil fuel industries.

However, I have followed the AGW debate since being briefed by leading IPCC scientists in 1989 or 90, and have been at times involved in AGW policy formulation. I even persuaded the pre-Beattie Queensland Coalition government, not widely regarded as green-tinged, to support Kyoto on a precautionary basis.

But the more I learn, the more sceptical I become.

Wobbles that one about the perma frost was knocked on the head by the Russians themselves.

The big issue is what credence can anyone place on climate models that have a spatial resolution of 480km, and yet still cant model how clouds are created and behave, cant accommodate local topographical features, cant model things like the Freemantle doctors, yet project out 50 years with the positive assurrance that we should spend megabucks.

Can anyone point to any example whereby we have committed substantial funds in advance to resolve a prediction that is only 25 years out.never mind 50.

Who believes economic or stock market predictions 5 or 10 years out never mind something as complex as climate going out for 50 years.

Big business may have an vested interest in making sure they dont lose, but government funded scientists in the hundreds have a vested interest in making sure the problem is portrayed as something infintely worse than it is in reality. Thats why if there is any doubt about a paremeter or interpretation they always take the most extreme position.

It might be alright if the available evidence supported their predictions but it still doesnt.

Gecko, Derek et al, I am a past member of the AGO's consultative panel on the landuse change and forestry section of the national greenhouse inventory. I left in total disgust at the shonky methodology that was developed by the IPCC.

The examples I used in respect of my farm and trees were provided to highlight the complete crock of the proverbial that is "greenhouse accounting". Accounting is, above all else, a record of fact provided for the purpose of obtaining a true and fair view of the matters concerned. For vegetation based carbon measurements, "Greenhouse accounting" is an oxymoron.

It is a rigid set of rules that have a nominal relevance to european conditions but serve to seriously distort the situation in Australia and, if we ratify Kyoto, will cause a totally undeserved detriment to Australian businesses, workers and job seekers.

Remember that next time you drive through the countryside and see trees that were ringbarked decades ago but still have their carbon intact. Remember that as you see endless lines of fence posts that have been there for more than half a century but which the IPCC in its infinite wisdom has deemed to be already out in the atmosphere warming someone's backside.

If the IPCC's projections were provided for a prospectus for an investment company the whole damned lot of them would be doing a stretch in stir by now.