James,
Thanks for clarifying that you don't believe we can determine trends from a mere decade. I'm not sure then why you started your criticism of climate change modelling with those facts, but let us put that aside now. It seems the discussion has moved on and covered a number of other matters I was planning to get to, so I want to try to conclude my comments by making three points.
1. The accuracy of climate models
2. Risk management
3. Conspiracy theories
1. The accuracy of climate modelsI think you are ignoring both the evidence and the scientific method here, and so make a quite misleading set of statements.
Science depends on both data and understanding of the physics (often expressed in computer models). When there was less data, less understanding and poorer models, the predictions were poorer. As all three have improved, so have the predictions.
But predictions were made way back, and they have, in the main, turned out to be correct. Others on this forum have shown how general predictions go back a long way, and have become more specific.
For example, the
IPCC's first report in 1990 predicted future rises in temperature of between 0.15
oC and 0.3
oC per decade for the next 15 years. (Note that the predictions gave a wide range, due to uncertainty, but all values within the range indicated a temperature rise.)
The observed values were about 0.2
oC, well within the range predicted. Of course that period is too short to fully test a model (for the same reasons we have already discussed), but it does show that as much as we can verify the models, they seem to be close to the mark.
So it seems that in this report alone you have had for 7 years the verification you want.
Of course the latest models haven't had time to be fully verified, but (1) they are based on improving understanding of the Physics (in fact models are simply expressions of the latest scientific understanding) and (2) they build on the success of earlier models in making broader-scale predictions.
These same models show that human causes are a significant factor.
I have already pointed out that the global temperature is made up of a steady rise caused by global warming overlaid with variations caused by other effects such as El Nino, La Nina, etc. And I have also pointed out that the global models find it easier to predicted average long term temperatures, and harder to predict the variations. Of course we would like to better predict the variations, and newer models are getting better at that, but these are not climate change, and they are less important. We are discussing climate change, that is the important question, a steady rise has been predicted and the predictions have been found to be broadly accurate.
The reason why the variations around the broad trend are not so easily predicted can be found in the literature - they are smaller spatial or temporal scale, they have not been all been studied in enough detail, some are beyond climatology (e.g. volcanic eruptions, which can have a significant short term effect), etc.
So your comment about not predicting the flatter temperatures in this millennium are irrelevant to climate change, and obscure the clear fact that the predictions of long term global warming are being shown to be true.
2. Risk managementSo it seems clear that the best scientific evidence, based on an understanding of the Physics expressed via ever-improving models, points to continued global temperature rises and consequent other environmental effects. Some of these effects are already being seen (e.g. loss of arctic sea ice). Some of them lead to positive and negative feedback.
None of this is 'certain' - nothing in science is 'certain', everything is subject to new information and new understandings. But we can say that the broad direction s are as certain as they can be at this stage, and the main doubts are about finer detail, how feedbacks will work and balance each other, etc.
So we are in a classic risk management situation, where risk = consequence x likelihood. So what are the risks associated with doing nothing or acting on the basis of the best evidence we have?
If we do nothing and climate change is real, then we will do enormous harm to millions of people - cyclones and flooding in Bangladesh, a country where already millions suffer from poverty, hunger and a capricious climate; loss of topsoil and groundwater in Nepal, affecting poor subsistent farmers; a dramatic reduction of available water in north Africa, where drought and starvation are already endemic; total flooding of small island communities in Tuvalu and Maldives; not to mention massive coastal erosion and loss of billions of dollars of expensive properties in the west. There would also eventually be massive direct costs to business.
The consequences are absolutely massive, and even if the likelihood was small, this would be a serious threat. In Sydney we spent millions enlarging the Warragamba Dam for a maximum probable flood that almost certainly won't happen in the design life of the dam. But it was done because of the consequences of failure to the tens of thousand of people who live downstream. And the likelihood of disastrous climate change is, according to the best science, much, much greater.
If we act now and it was unnecessary, what would be the cost? Perhaps our standard of living would take a small hit - but since it has risen dramatically in the past 5 decades, all we would see is a slight return to the past. (As a conservative, you should be happy - a return to the days of the Fonz, Leave it to Beaver and The Brady Bunch!
) Some economists say it won't impact much at all, others say it will. Half of business investors think it won't make much difference. It will yield some other environmental benefits.
But regardless, we in the developed world have created the problem through our industrialisation, transport and energy consumption, so we have an obligation to put things right. To
not do so would be 'wicked'.
3. Conspiracy theoriesFinally, to the scurrilous allegations that many climate-change sceptics make about the scientists - either they are reckless or venal.
I trained as an engineering hydrologist, and worked for 30+ years as a natural resource and environmental; data collector and analyser, and a water environment manager and policy advisor. I worked with, and supervised, many environmental scientists. They were almost 100% extremely cautious - much too cautious for a manager trying to address real world problems. I never came across a reckless scientist (that I can recall).
I am not a climate change expert, but I needed to understand the predictions, so I read the literature a little. On one occasion our organisation contracted a bunch of scientists to advise us, and I spent an evening meal discussing with several CSIRO climate change experts as well as getting their input at the workshop the next day. Again I had the same impression - not reckless but extremely cautious. There are no doubt reckless scientists in the world, but not 90% of them!
The inference in some climate sceptic writings is that the scientists are taking orders from some leftist-green conspiracy to undermine the capitalist system that has somehow taken over even conservative governments. I hope we can dismiss that 'theory' - there are doubtless scientists whose research can be bought (as the smoking lobby discovered), but not 90% of them. The CSIRO scientists I talked with were working for the Howard government, one of the most conservative in my lifetime, and with its fair share of climate change deniers - there was no incentive their to talk it up!
I suggest to you that if there is any conspiracy, it is far more likely to work the other way round - rich energy companies using their muscle to influence governments and public opinion-makers like Aussie shock jocks who have been shown to be for sale, plus the natural conservatism of that great champion of fair reporting, the Fox network.
So all things considered, I think the climate science is on as good grounds as it can be, the sceptical view has no real science, just carping criticisms and bad statistics, and risk management demands we start to act now.
I agree with you on one point - we need to be wise and careful how we respond to the facts.
Best wishes.
) Some economists say it won't impact much at all, others say it will. Half of business investors think it won't make much difference. It will yield some other environmental benefits.
