Background

This week I took part in the Spectator debate speaking against the motion: “The global warming concern is over”. A poll prior to the debate revealed that the audience was heavily in favour of the motion and against myself and my colleagues Sir David King and Professor Tim Palmer: 63% For, 22% Against, 15% Don’t Know.

The good news is that our arguments seemed to make some sense to the Don’t Knows, as the final vote was 64% For, 32% Against, 5% Don’t Know. It seems that over 90% of the Don’t Knows who made up their minds adopted the position that climate change is indeed a concern.

I would not consider myself a climate change journalist, and certainly not a climate change scientist, and I suspect that it was only via a twitter altercation that I ended up on the platform. Nevertheless, I enjoyed the opportunity to meet some climate change experts and to think about the arguments and concerns of the opponents to the climate change consensus.

My biggest disappointment in the debate was that I failed to ask the questions that would have helped me appreciate exactly what separates the two sides of the debate. Are we agreed on the science, but arguing about economics and future policies? Or, is it pointless debating future policies, because the other side still don’t accept the basic science?

However, a couple of days after the debate, I put some of the relevant questions to Fraser Nelson, editor of the Spectator. The magazine, like the vast majority of those who attended the debate, appears to be suspicious of (even hostile to) the scientific consensus on climate change, so I am glad Fraser has responded to my questions in such a positive way.

You can find my original questions and Fraser’s response here.

Responding to Fraser’s Blog

Fraser, thanks for taking the time to respond.

I like your 4-point framing of the orthodox position:

1. That the planet is warming
2. That manmade activity is, in some part, responsible
3. That decarbonisation is the only effective solution
4. There is a degree of urgency to it.

However, it is only worth discussing (3& 4) if (1 & 2) are true. My five questions were an attempt focus on your points (1) and (2) to see where we diverge.

My original five questions are below:

1. Do you agree that increases in CO2 and other greenhouse gases lead to an increase in the global temperature?

2. Do you agree CO2 levels in the atmosphere have increased from 280ppmv to 380ppmv (35%) during period of industrialisation?

3. Do you agree that the Earth’s climate has warmed by 0.6 degrees in the last 50 years?

4. Do you agree human contribution to greenhouse gases in the atmosphere is a major factor in the warming over the last century?

5. Do you agree best scientific predictions estimate further rise of 1.1 to 6 C over 100 yrs based on good (not perfect) models?

It is very good to know that you answer Yes to question (3), i.e., you agree that the planet is warming. I get the impression that some Spectator writers are not even prepared to accept this. For example, Melanie Phillips on BBC Question Time (27.11.09) said: “I have always thought [global warming] was a scam… There is no evidence for global warming … let me tell you that the seas are not rising anymore than is in any way out of the ordinary, the ice is not decreasing it is increasing, the polar bears are increasing in number and the temperature is going down not up. There is no evidence for this whatsoever.”

Where do you stand on questions (1) & (2)? These should be utterly obvious Yes’s, as the answers relate to basic physics and established observations. However, I need to check, because I am sometimes shocked at where some climate “skeptics” stand on these straightforward questions.

When Johnny Ball appeared on BBC2’s Daily Politics, he said (and wrote something similar on the BBC website): “Only 4% of the CO2 that goes into the atmosphere is put their by man, the rest is completely natural.” Ball’s maths is untangled here, and the bottom line is that CO2 levels have increased by 35% and this is due to human activity.

Fraser, when it comes to question (4) you reply: “I’m not yet persuaded. How much is man’s activity contributing to global warming? Is it 20 percent? 80 percent? I haven’t seen a proper paper that attempts to quantify it — perhaps Simon can find me one.”

This section from the report by the IPCC (Climate Change 2007: Working Group I: The Physical Science Basis) explains: “It is very unlikely that the 20th-century warming can be explained by natural causes.” Similarly, this page from the Skeptical Science website explains: “While there are many drivers of climate, CO2 is the most dominant radiative forcing and is increasing faster than any other forcing.” I think charts on these websites are very convincing. In particular, without the manmade influence, it is clear that it is impossible to accurately model the observed climate data over the last five decades.

Would you now be willing to answer “Yes” to my first four questions? We could then discuss question 5.

If you still feel unable to say Yes to my first four questions, then I can suggest that you and I meet up with Professor Tim Palmer who also took part in the Spectator debate?

You are the editor of one of the most influential magazines in Britain and you have taken a stand that challenges the orthodox science. I am merely keen to know exactly where that doubt comes from and which elements of the scientific argument worry you.

That’s enough on the main point for the time being, but I have also added a couple of extra brief comments below.

1. You suggested that “the IPCC had maximum credibility” on my credibility spectrum, but in fact it did not appear. I referred to organisations such as AAAS and the Royal Society.
    

    

2. You said: “I’m more than prepared to believe that all the clever people are capable of being wrong, and the dotty dissenting scientist can be right.” I agree that we must always listen to mavericks, but you can only accept the maverick’s position if you are convinced by their arguments and evidence. If we meet with Tim Palmer, then we can discuss which of their arguments you find most compelling.
    

    

3. You said: “As a Gershwin once put it, they all laughed at Christopher Columbus”. I think the scientific consensus in 1492 was that the world was round. For example, Dante’s Divine Comedy (early 14th century) assumes that the Earth is a sphere. In fact, knowledge of a spherical Earth in scientific circles dates back several centuries prior to this.
   One or two columnists in the fifteenth century edition of “Ye Olde Spectator” might have laughed at Columbus, but scientists and smart folk did not find flat earth views very convincing. 

    

Originally posted on slsingh’s posterous