As noted in my previous post, the IPCC report on climate change is out. If you look at the technical report, it starts with pages of corrections. I would have thought that in these days the use of a word processor could permit the changes to be made immediately, but what do I know? Anyway, what are the conclusions? As far as I can make out, they have spent an enormous effort measuring greenhouse gas emissions and modelling, and have concluded that greenhouse gases are the cause of our problem and if we stopped emitting right now, totally, things would not get appreciably worse than they are now over the next century. As far as I can make out, that is it. They argue that CO2 emissions give a linear effect and for every trillion tonnes emitted, temperatures will rise by 0.45 Centigrade degrees, with a fairly high error margin. So we have to stop emitting.
The problem is, can we? In NZ we have a very high fraction of our electricity from renewable sources and we recently had a night of brown-outs in one region. It was the coldest night of the year, there was a storm over most of the country, but oddly enough there was hardly any wind at a wind farm. A large hydro station went out as well because the storm blew weeds into an intake and the station had to shut down and clean it out. The point is that when electricity generation is a commercial venture, it is not in the generating companies’ interests to have a whole lot of spare capacity and it make no sense to tear down what is working well and making money to spend a lot replacing it. So, the policy of using what we have means we are stuck where we are. China has announced, according to our news, that its coal-fired power stations will maximise and plateau their output of CO2 in about ten years. We have no chance of zero emissions in the foreseeable future. Politicians and environmentalists can dream on but there is too much inertia in an economy. Like a battleship steering straight for the wharf, the inevitable will happen.
Is there a solution? My opinion is, if you have to persist in reducing the heat being radiated to space, the best option is to stop letting so much energy from the sun into the system. The simplest experiment I can think of is to put huge amounts of finely dispersed white material, like the silica a volcano puts up, over the North Polar regions each summer to reflect sunlight back to space. If we can stop as much winter ice melting, we would be on the way to stop the potential overturn of the Gulf Stream and stop the Northern Siberian methane emissions. Just maybe this would also encourage more snow in the winter as the dust falls out.
Then obvious question is, how permanent would such a dispersion be? The short answer is, I don’t know, and it may be difficult to predict because of what is called the Arctic oscillation. When that is in a positive phase it appears that winds tend to circulate over the poles, so it may be possible to maintain dust over summer. It is less clear what happens in the negative phase. However, either way someone needs to calculate how much light has to be blocked to stop the Arctic (and Antarctic) warming. Maybe such a scheme would not be practical, but unless we at least make an effort to find out, we are in trouble.
This raises the question of who pays? In my opinion, every country with a port benefits if we can stop major sea level rising, so all should. Of course, we shall find that not all are cooperative. A further problem is that the outcome is somewhat unpredictable. The dust only has to last during the late spring and summer, because the objective is to reflect sunlight. For the period when the sun is absent it is irrelevant. We would also have to be sure the dust was not hazardous to health but we have lived through volcanic eruptions that have caused major lowering of the temperature world-wide so there will be suitable material.
There will always be some who lose on the deal. The suggestion of putting the dust over the Arctic would make the weather less pleasant in Murmansk, Fairbanks, Yukon, etc, but it would only return it to what it used to be. It is less clear what it would do elsewhere. If the arctic became colder, presumably there would be colder winter storms in more temperate regions. However, it might be better that we manage the climate than then planet does, thus if the Gulf Stream went, Europe would suffer both rising sea levels and temperatures and weather more like that of Kerguelen. In my opinion, it is worth trying.
But what is the betting any proposal for geoengineering has no show of getting off the ground? The politically correct want to solve the problem by everyone giving up something, they have not done the sums to estimate the consequences, and worse, some will give things up but enough won’t so that such sacrifices will be totally ineffective. We have the tragedy of the commons: if some are not going to cooperate and the scheme hence must fail, why should you even try? We need to find ways of reducing emissions other than by stopping an activity, as opposed to the emission.