Nature is doing the experiment for us, so there is no need for me to dispute with the RealClimate people. And no appropriate dangling threads to grab hold of at the moment, either. But all these things keep going around and around in my head and keeping me awake, and I am hoping they will go away if I write them down, so you will have to bear with me. Or go somewhere else, until the next post. That would also be fine. I am afraid all my links are recorded at work, where I have been collecting them in epsiodes of slackness, so I can’t put them in now.
I contend that:
* People who post comments on RealClimate erring on the ‘we’ll all be rooned’ side are not slapped down, unlike those who post comments erring on the ‘she’ll be right’ side.
* People who argue on RealClimate about the difference between 0.08 and 0.11 degrees as if it means something, and attribute deviations in multi-decadal averages of that magnitude to specific reafforestation events, are not doing anything worthwhile. They are finding patterns in noise, just like any good animist tribesman. We can only make very broad, careful statements with data as noisy as we have.
* If my y = mx + c correlation, where y = deltaT and c = [CO2], curves up at the end, it must mean that something other than CO2 is primarily responsible for the last fifteen years. This might be falling aerosols, or the delayed effect of rising CFCs, or something else, but we can be certain that the real ‘m’ for forcing due to carbon dioxide is not as great as the ‘m’ we might extrapolate from looking at the last fifteen years alone.
* The forcings used by Hansen et al. in 1988, an apparently seminal paper to which I was directed by Eli Rabett, are just that same y = mx + c that a dumb ox like myself could have come up with.
* I have learned what I ought to have realised from Beer’s Law, that y = mx + c ought to be y = m log(x) + c. NB: This means that any correlation curve ought to be curving down, not up.
* None of the specific predictions of the Hansen et al. model seem to have come to pass: China, Central Asia, the margins of the Arctic and Antarctic ice shelves, and shallow seas like the Caribbean, don’t seem to have experienced more intense warming than other parts of the world over the past eighteen years.
* The argument that anthropic influences on water vapour can be ignored because water vapour has a short residence time in the atmosphere does not hold, er, water. Ozone has a short residence time, too. It is the steady state concentration, averaged over space and time, that is important, and I cannot imagine how this could not have been affected by human activities. I feel that anthropogenic water vapour will be far more significant than a 30% loading on the [CO2] forcing, and it will be much more complicated to work out.
* The arguments about the ocean heating up and outgassing carbon dioxide, and the ocean becoming acidic, ignore the fact that the ocean is a very thin warm bit on top of a very thick cold bit. It is the mixing of these bits that is important. I found some US Geological Survey data of ships sailing here, there, and everywhere and measuring the carbon dioxide concentration in the water. There was a very broad range in carbon dioxide concentrations. The concentration in the water was often higher than atmospheric concentration. There wasn’t any trend to less carbon dioxide in warmer water. Why is this? Well,
* When I was last in Devil Bunny City I went to a talk by a physical chemist from New Zealand who talked about how mass and heat transport are coupled: you can’t calculate the flux of carbon dioxide from water to atmosphere and vice versa just by looking at the concentrations, you need to know the relative temperatures too. I worked out his equations in Excel, and a gas will move against a pressure gradient if it is moving with a temperature gradient: i.e., if the air is hotter than the water, the concentration of carbon dioxide in the water will be higher than in the air. He wrote two papers on this in 1991-1992 in the climate scientists’ journal of record, Geophysical Research Letters. They have each been cited exactly four (4!) times. I found a paper from 2003 by a collection of climate scientist chaps from Princeton and other places, who estimated carbon uptake in various places and come to the conclusion: ‘there is more carbon dioxide uptake at low latitudes, and less at high latitudes, than the models predict.’ Well, this is because the physics in those models is wrong.
Now, I might be in error. I may not have read enough and may be overlooking lots of things. But everything I have found has reinforced my belief that it is very wrong to make drastic and expensive changes in policy on the basis of projections of existing climate change models. The models do not contain all of the relevant physics. The models do not have proven predictive value. Extrapolations of the models to the future, to give ‘we’ll all be rooned’ gleefully and credulously reported by the popular science media, is irresponsible evangelism, not science.
Here's another quote from Diarmaid MacCulloch's book about the Reformation, page 571:
Personally leading an investigation to discover the causes of the storms, James
uncovered a story of a gathering at North Berwick parish kirk the previous
Hallowe'en (31 October 1589) over which Devil himself had presided, with the
agenda of plotting the King's destruction, principally through manipulation of
the weather. The details were abundant, or at least became so after the suspects
had been subjected to prolonged torture.