Raycom, AGW is a prediction of climate science. It's not a separate theory. If you know some physics and calculus you really need to read a text book to understand this stuff properly. If you don't you are working on blind trust, and there is plenty to distrust out there, especially bloggers who are vague about to whom they are accountable.

I've studied some of the material on the "CO2Science" blog and it's propaganda. For example, their materials on the medieval warm period don't add up. Their "best" data covers a number of relatively short warm periods at different locations spanning about 600 years. This does not add up to a global warm period, but a series of disjoint high points in the temperature record.

Philip, AGW is an hypothesis, which warmists ( a collective term for AGW believers) consider to be settled science and a major influence on climate.

However, the science is not settled. There is not even agreement about key factors.

For a start, the IPCC, the arch proponent of AGW, asserts a CO2 atmospheric residence time of 50 to 200 years, whereas there have been numerous studies that report measurements of 5 to 10 years ( see http://www.co2web.info/ESEF3VO2.pdf). The IPCC asserts that 21% of the CO2 in the atmosphere comes from fossil fuels, whereas Segalstad concludes that it is 4%.

There is no scientific evidence that anthropogenic CO2 emissions have had a measurable impact on climate.

Yet, warmist climate scientists arrogantly deride any questioning of their 'settled science'. They do so for political reasons -- having a vested interest in continuing to con politicians and the media -- and not as practitioners of scientific method, which invites questioning

Come on you guys. The salient point in Philip's article is that the IEA has shown that the production of oil is going to progressively decline over the next 50 years or so, to the point where humanity is not going to be able to cultivate enough food to feed itself, unless we manage to radically transform the way we use energy. What's to nitpick about?

At least we suburb-dwellers will still have our vege gardens;-)

Raycom, the resident time of CO_2 is not the relevant measure. The measure you want is the airborne fraction of emissions. CO_2 is in constant flux between the oceans and the atmosphere. A given molecule may well be in the atmosphere for only a few years, and no one is arguing about that. The relevant issue is the rate of flow between the atmosphere and the rest of the environment. If you increase the flow to the atmosphere, you have to increase the rate of absorption to balance out. We know the rate of human CO_2 emission to reasonable accuracy, and we can measure total CO_2 in the atmosphere to reasonable accuracy. The long-term trend in airborne CO_2 matches the Bern model (i.e. prediction) well. If only 4% of the CO_2 in the atmosphere is from anthropogenic sources, why is it increasing exponentially in line with increases in human emissions?

You are absolutely right that AGW is a hypothesis. Climate science is a theory, and a well-established one. A hypothesis is a testable prediction arising from a theory. Why do you want to argue about that?

Why do you think scientists have any interest in conning anyone? The rational response if you accept the mainstream science is to invest more in clean energy not more in climate science. It's the denial camp who are generating lots of jobs for climate scientists by refusing to accept that we know enough to take action.

Philip, you love to refer to 'the theory', but the dangerous AGW hypothesis has failed to stand up to testing.

As Bob Carter, who is well versed in the climate science field, has pointed out, no paper has yet been published that unambiguously invalidates the null hypothesis of a natural origin for observed modern climate change, despite about US$100 billion (US$79 billion in the US alone) having been spent since 1990 and the intense efforts of many scientists to find evidence that favours dangerous AGW.

On the other hand, there is abundant compelling scientific evidence that invalidates the IPCC's hypothesis that human greenhouse emissions (especially of CO2) will cause dangerous global warming. For references to some eight tests of the hypothesis of dangerous AGW, see end-note 228 on pp286-288 of Bob Carter's book, 'Climate: the Counter Consensus'. This book is a must-read for anyone who is serious about finding out the truth about climate change.

Raycom, Bob Carter has an agenda. His material is slathered with non-scientific language (of which this is a small sample: "Public opinion will soon demand an explanation as to why experienced editors and hardened investigative journalists, worldwide, have melted before the blowtorch of self-induced guilt, political correctness and special interest expediency that marks the sophisms of global warming alarmists" whereas his own side are "climate rationalists"). This is an emotional rant, not wording you would expect in a scientific paper. It's not just the tone: the content of the paper I've quoted is gibberish, more repetition of blog talking points than a scientific analysis.

His claim that the AGW hypothesis isn't supported by evidence is nonsense. A wide range of attribution studies show that natural influences alone are insufficient to explain climate variability over the last 100 years. For example, the claim that it's all the sun is wrong both in terms of the physics (the variation is insufficient) and, in recent decades, the trend. We have just started to emerge from the deepest solar low in nearly 100 years yet 2010 set a new record for temperatures. And no, we did not have an unusually strong El Niño.

The decline in Arctic sea ice and Antarctic ice mass, and many other lines of evidence support the mainstream hypothesis. The null hypothesis is that natural variability is responsible for all change, yet the major known natural influences are either insufficient or do not correlate with the change. This is very well known, and all good attribution studies start our with attempting to account for natural variability. What's left is anthropogenic change, and that change is consistent with the underlying physics.

Here's some reading for you: http://scholar.google.com.au/scholar?q=climate+change+attribution

As I said before, if you think the physics wrong is, read Principles of Planetary Climate. You will need to be comfortable with calculus to understand it in depth, but if you have the confidence to tell thousands of PhDs they are idiots, that should be a small obstacle. Report back here when you find the error.