At long last some common sense being injected into the debate. The very idea that one can create a series of equations that can accurately model something as complex as the climate is delusional nonsense of the first order. But projecting them out for 100 years and using these "projections" as the basis of some very expensive public policy is fraud, plain and simple.

This is even more so when one learns about all the elements of the climate that they cant model,or do so very poorly, for example:
1. The way clouds are formed and their effect upon the climate.
2. The role of aerosols in cooling.
3. The effect of well known such as the Freemantle doctor.
4. Economic growth factors as used to postulate the scenarios of Co2 growth.

But when various Ministers of the enviroment are induced to make public anouncements about the dire consequences facing us based upon a GCM with a horizontal resolution of 400kms, and they dont tell us, then the atmospheric science community is deserving of nothing but condemnation.

Rhian,

the author misrepresents the position of the IPCC and the state of knowledge about GW. "IPCC is apparently of the belief that they know all they need to know about climate change" Oh?

Mark,

When I built a Crdedit Scoring Systen for a Bank, what I did was, I took a large sample of HISTORICAL loan applications and accompanying demographiic data without -at first- knowing whether the loan became unproductive or were paid-off without any problem- Historically.
Afterwards, the algorithm developed was used to predict whether "past" loan did or did not go bad. [known outcone.] Achieved 90%+ correct prediction with only 20 variables.

Climate: What one should NOT be doing is extrapolating using current data points into the future, say, y=abx, for NOW. Rather, models based on data say 2000BCE to 1500 CE [4,000 years], can be used to forecast weather [known] patterns 1500-2000 CE. Then we compare the model's predictions against KNOWN outcomes. Measure the variance and then draw conclusions.

Mark Lawson you are a heretic to the Church of Greenism and Peter Garrett will have you burned at the stake as when
he defeats the Great Howard Devil.

Our whole planet's ecosystem is very complex.CO2 is just one of many ways we are affecting our environment.It seems to be a common human foilble in all our prejudices,to premote what we as individuals think is right,rather than considering all the possibilities.

Our focus on CO2 may be only part of the problem.All the fossil fuels we burn today,were taken from the atmosphere by plants millions of years ago.CO2 in the atmosphere then,was at much higher concentrations and life thrived.

If we release half of the CO2 that existed when life thrived millions of years ago,why would this change our planet beyond the point of redemption,when life in the past blossomed under much higher CO2 concentrations? We need to do more home work.

1. The way clouds are formed and their effect upon the climate.

The way clouds are formed is quite well known, and cloud is factored into models. High level clouds in general increase warming, low level cloud decreases warming (due to the albedo effect). Since higher temperatures increase evaporation from the seas, more low level cloud is formed- what is known as a negative feedback.

2. The role of aerosols in cooling.

Again, well known and factored into global models. From where do the aerosols originate? In general, aerosols decrease warming- for instance the global cooling for a couple of years after the Krakatoa eruption.

3. The effect of well known such as the Freemantle doctor.

The Fremantle Doctor has an effect on global weather and climate? Learn something new every day.

4. Economic growth factors as used to postulate the scenarios of Co2 growth.

What's so hard about modelling the growth or otherwise of C02 (and other greenhouse gases) emissions?

The models are junk science because they are locked into unreality by the IPCC accounting standards. The best example is the modelling of carbon emissions from land clearing. According to IPCC 10% of all wood from clearing must be recorded as being burned as firewood in the year of clearing but most Australian firewood is aged ironbark that is 30 to 40 years old. And given the amount of clearing in the Amazon, Queensland and other tropical savanah who the hell do they think actually used this firewood?

The rest of the wood volume is deemed be emitted in year 1 (all burned on site) but I still have tree stumps on my place from the original clearing in 1927. Most clearing debris won't burn at all in year 1 and many paddocks still have a large volume of dead wood many decades after the clearing. The cost of raking it up and burning is only justified for cropping land (which is less than 2% of total).

The land use change portion of the global carbon emissions total is 19% but it is almost entirely bollocks. They are recording emissions now that will not take place for 40 or 50 years.

And when you start projecting out 50 to 100 years, with errors in basic inputs in the order of 20%, then the only possible results will be gross exaggerations.

The IPCC know absolute jack $%&@# about land clearing or forest management. They formed their accounting rules without any consultation with forestry experts as to what actually takes place or how fast wood breaks down. And they then fed complete garbage into the models and got complete garbage back out again.

And whenever our experts try to explain the nature and extent of their errors, they have this pack of green morons who accuse us of being on the oil company payroll.