Climate change.

It should be obvious that I am in that much-pilloried camp of 'climate change sceptic'. If you believe some people, then I am a flat-earthist conspiracy-theorist traitor who should be put on trial for high crimes against humanity. Yes, those are all quotes from influential people or organisations (Gordon Brown, the New Statesman, Robert Kennedy Jr, and NASA's James Hansen). Climate depot has many more of these lovely, though-provoking claims.

Strangely enough, I do not agree with this characterisation. Firstly, what is my position:

1. Climate change happens.
2. Man is having an effect on the climate.
3. That effect is caused by many things - greenhouse gasses (CO2, Methane, Ozone etc), black soot, water vapour and others.
4. Splitting man's effect on the climate from the natural variations is extremely difficult and is based on vague assumptions. Although we are having an effect (see 2), we have no way of knowing with any accuracy what that is.
   
5. Concentrating on CO2 ignores the other causes (see 3).
   
6. We have little idea beyond vague estimations of the sizes of the land and sea carbon sinks.
7. Scientists have proved extremely bad at predicting the future in complex systems - see the spread of bird flu, CJD, Swine flu, long-term weather forecasting and the financial systems.
   
8. Best, middle and worst cases should always be being presented, with details on the confidence levels. The media only ever reports the worst case ("Oh my God! We're all going to drown"). Experts routinely outline the worst case when interviewed.
9. I want a better climate. Simple laws like the various Clean-Air Acts have massively improved the lifestyle of people living in the relevant countries. Lower exhaust emissions from vehicles would likewise be a boon.
10. They have got it wrong before. (Actually, Hansen's paper is good in that it does show three different scenarios. One of the the things under dispute is which one he meant).
    
11. A great deal of the future effect of climate change will depend on the past variability of both temperature and CO2 concentrations in the atmosphere - and the CRU emails show that such past data is hard to obtain (and, perhaps, easy to fiddle).
12. Even the current temperature is hard to measure to the required accuracy.
    
13. And finally, just to show I am an evil baby-killing real right-winger, I want energy security.
    

In the next post, I shall outline the way we *should* be tackling these problems.