Video description

On the 19th of July in 2011 the National Press Club of Australia held a debate on climate change. I will be analysing the claims Monckton made during the debate and if they are correct or not.

Monckton introduces the argument that the Central England temperature record can be used as a proxy for global temperatures. But can it be used that way?

Transcript

So science - if you're saying that a scientific consensus is somehow not a consensus of opinion, but a consensus of evidence, you have to say - and you did not say - what evidence you mean. On the evidence that I have seen, let us just take one example of it - if we go back to 1750, how much warming has there been since then? Well, using the Central England temperature record as a proxy for global temperatures - it's not bad for that purpose. It's at the right latitude - we've had 0.9 Celsius of warming in response to an addition of greenhouse gases to the atmosphere by us, which is almost equivalent to a doubling of CO2 concentration. That's going to give you around one Celsius of warming per doubling of CO2 concentration.

Over the last 60 years we, again see one Celsius of warming per century happening. All the evidence points to one Celsius of warming for a doubling of CO2 and not the 3.3 predicted by the IPCC as its central estimate on current emissions, or the 5.1 Celsius over the next 90 years predicted by your government. These are exaggerations which are not the consensus in the literature and you should understand that the literature is much wider and reflects far more scientific opinions than many of you have been willing to allow or discover. Get on with your work.

This is again a repeat of the climate sensitivity calculation he used during his opening statement to make the case that a doubling of CO2 will only cause a warming of 1 degree. I already pointed out that the calculation itself is flawed. As it ignores for example temperature equilibrium, absorption of heat by the oceans, and increases in CO2 emissions. All of which will cause problems if you do a simple projection of a current trend into the future.

But there is one new point made by Monckton in this section, which is that the Central England temperature record can be used as a proxy for global temperatures. What he said is analogous to saying that the population statistics of Ohio can be used to extrapolate population statistics for the entirety of the United States.

You can't use a local dataset as a proxy for global temperatures, you will get the wrong answer if you do this. Local temperatures and trends can significantly deviate from the global trend, as such you cannot use them for global temperature trend calculations or for global climate sensitivity calculations.

Sources

1. The equilibrium sensitivity of the Earth’s temperature to radiation changes
2. Working out climate sensitivity from satellite measurements

Media resources

1. NASA - Striking a Solar Balance
2. NASA – Piecing Together the Temperature Puzzle
3. CO2 Emissions vs IPCC Scenarios
4. File:Kingdom of Great Britain.png
5. File:EnglandGovernmentMidlands.png
6. File:Ohio in United States.svg
7. File:USA orthographic.svg
8. NASA | NASA's Analysis of 2012 Global Temperature