A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).



Australian Speakers Agency


The nerds have the numbers on precious metals investments on the ASX

The Skeptics Handbook

Think it has been debunked? See here.

The Skeptics Handbook II

Climate Money Paper



AGW is a religion

Science based ideas are falsifiable, whereas religious ones are not (thanks Karl Popper). The acid test for climate scientists: “What evidence would convince you that carbon was not significant?” [...]

What is evidence?

Evidence means observations, made by people at some time and place. Things you can see, hold, hear and record. Computer models are not, and can never be evidence. [...]

Found: the hot spot? Not

The gap between real world data and thermometers is a make-or-break issue for the AGW theory. The models predict a hot-spot in the atmosphere above the tropics, but the weather balloons (called radiosondes) can’t find any sign of it. Most claims that the hot-spot has been found are not providing any new data, they are just massaging the same old numbers with a different statistical tool. Here are three variations (though the third is not a statistical-spin, it’s just nonsense).

1-Some AGW supporters claim that Santer et al has found the hot-spot. But his paper boils downs to a statistical reanalysis that suggests that due to noise and error, the hot-spot might be there. Santer hasn’t actually found the missing hot spot. He has a case, but it’s not a strong one. The statistical counterargument is at Climate Audit.


The missing hotspot

The ‘Hotspot’ is crucial to the climate debate.

If greenhouses gases are warming the planet that warming will happen first in the cold blob of air 8-12 km above the tropics. It’s freezing cold up there, but it ought to be slightly less freezing cold thanks to greenhouse gases. All 20-odd climate models predict warming there first—it’s the fingerprint of greenhouse gas warming, as opposed to warming by some other cause, like solar magnetic effects, volcanic eruptions, solar irradiance, or ozone depletion etc etc.

Look at A above, the greenhouse gas fingerprint is markedly different from the rest and dominates the overall predicted pattern in graph F. The big problem for the believers of AGW is that years of radiosonde measurements can’t find any warming, as shown in part E of Figure 5.7 in section 5.5 on page 116 of the US CCSP 2006 report


Submission to the Henry Tax Review

Submission for Treasury Secretary, Ken Henry for Australia’s future tax system

Regarding: the Emissions Trading Scheme, and any tax relating to carbon dioxide.

Before Australia commits to any tax the Australian people deserve to know that the taxation rules are based on the latest and best scientific evidence available. The evidence about climate change has changed dramatically since 2003. I was a committed believer that action was needed, but like many other scientists I have changed my mind. Please bear in mind that the theory of greenhouse gas emissions causing atmospheric warming is just that—a theory, and it has no empirical observable evidence to back it up.

The need for any carbon tax regime hinges on the question below: