Recall the saying, “There are lies, damned lies, and statistics”. I would add a further term at the end – ” There are lies, damned lies, statistics, and models.” What sparked this bout of negativity? Well, last week I went to a talk from one of the NZ representative of the International Panel on Climate Change. The talk was headed, “Where are we, and how do we get out of this?” The entire talk was devoted to where we are, and it was fairly grim, and the second part, how do we get out of this, was blank. Maybe there is no way out. Anyway, let me try to recall what was said. If there are errors here from the IPCC, assume they are due to my faulty memory.
The first thing to note is the goal back in the 1990s was to limit greenhouse emissions so as to keep the increase in temperature to 1.5 degrees C above pre-industrial levels. One could question that as a goal because pre-industrial was the so-called “Little Ice Age”, and arguably that is not a good reference point. Be that as it may, the governments of the world agreed to work on limiting emissions. First there was the Rio agreement in 1992, then the Paris agreement, which is supposedly legally binding on 196 parties, and the aim was to “pursue efforts” to limit the temperature raise to 1.5 degrees.
So how are we doing? It is one of the less successful agreements, in my view. The object was to limit and reduce emissions of CO2; what has actually happened is we have doubled the rate of emissions, and much of that since the “legally binding 2016 agreement”. The original target was not to hit the 1.5 degree rise before the end of the century. If we extrapolate current trends, we strike it in this decade. Oops!
So what are the effects? Currently, the odd good thing, but mainly the outcomes are bad to awful. What is somewhat unexpected is the effects differ by hemisphere, possibly because the Southern Hemisphere has most of the ocean, and ocean has an albedo about a third of that of land, so it absorbs so much more heat. The greatest increase in local temperature has come from that Arctic; it is heating rapidly. Funnily enough, the Antarctic is not following, and there are even spots where it is cooling. The heating of the Arctic does little for sea level rise because the ice was always floating, but the Greenland Ice Sheet is shedding water at a rate of 270 billion t/a, which contributes to the rising sea levels. Antarctica is losing ice at a rate of about 150 billion t/a, mainly due to warmer water undercutting the ice and melting from below. The end position is unclear; climate models suggest the two large Antarctic ice sheets should collapse, but there are some claims that the ice sheets are growing. Recall my comment on models?
The other problem is weather. The winds are part of a gigantic heat engine, and the winds strengthen as the temperature difference increases. Accordingly, the rapid heating of the Arctic will moderate the temperature difference in the Northern hemisphere. Although that is not a free pass because hurricanes and typhoons are generated by seawater evaporating, so they will get stronger as the planet heats. The other problem for the Northern hemisphere is quieter wind systems lead to longer and more severe droughts. For the Southern Hemisphere, as we are finding out, the wind systems become stronger and we have “atmospheric rivers” pouring large amounts of water from the tropics over us. But one interesting fact is that precipitation seems to be increasing over Antarctica. That may save us somewhat from being too inundated by sea-level rise.
So where does this leave us? Well, the IPCC has modelled a huge number of possible futures, but my feeling is, almost all of them will not happen. We know the situation is getting bad, but what is being done to fix things? Not a lot. And it is not that good plans are not being implemented. If this talk was indicative, we have NO GOOD PLANS. Does that mean we cannot do anything? No it does not. But as General Wesley Clark said there are two sorts of plans: those that won’t work and those that might work. You have to take one that might work and make it work, And herein lies some problems. We don’t know for sure what will work, although some seem highly probable, but we also have no mechanism to make them work. Recall what I said about the rate of emissions doubling when everyone was supposed to be reducing them? We have governments carrying out emissions trading schemes, as if that would solve the problem, but it is just raising costs; the rate of emissions is increasing. There might be a legally binding treaty, but if everyone is violating it, what good is that? There is no method to get governments to impose plans that might work, and politicians, usually, could not tell whether a plan could work, although they may well predict, correctly, if left to them it would not work. This is a highly technical problem that has to be understood to solve it. Politicians simply do not have the technical background.