What our government can do ,is to support and adopt clear and serious politics to less down the CO2 ,and in the same time balance between social and economical policies,via serious education system .

Solar Attic Fan

What our government can do ,is to support and adopt clear and serious politics to less down the CO2 ,and in the same time balance between social and economical policies,via serious education system .

@richard and others
I too think that a carbon tax is the right approach, as I am still convinced that CO2 emissions arising from human activity is the major cause of climate change. So tax CO2 emissions without exception or allowances - on the simple basis that we tax things that are undesireable, collectively and individually (eg. tobacco, lead in petrol) and should not tax things that are good (eg. income). If sufficient evidence emerges that climate change is not happening or that CO2 is not a major contributor, we can change the tax measures - knowing that we are still waiting for concept of income tax to be abolished in Britain, now that Napoleonic wars are over!

As regards the use of mathematical models in any sphere, have things moved on since Einstein observed “As far as the laws of mathematics are certain, they are not real and as far as they are real, they are not certain.”?

Despite the weaknesses, I prefer that options for policies be drawn up and implemented based on more formal working out of options, using data, methods and models that are open to public scrutiny. That still leaves considerable room for the exercise of judgement in the political sphere. In this Republic, I consider that the Executive side of government is out of control and not subject to the kind of checks and balances that we deserve.

You will all have your own favourite examples government by whimsy(eg. the Ahern/McCreevey/Parlon decentralisation v the National Spatial Strataegy) and/or arbitrary interference (eg. the non-connecting LUAS lines being joined by a non-connect Metro North v what the 1998 Atkins report recommended following the DTI proposals)

I agree but in fairness to BW his article was restricted to the actions which the Irish Govt should take in relation to climate change. I don’t think BW made any assertions as to global climate change based on the data he analysed.

Looking at Dublin and not seeing warming is evidence of nothing whatsoever. If Dublin shot up in temperature, or its temperature collapsed, that would not - by itself - be evidence for global warming or cooling.

The Wunsch link did not work for me. I see no reason to believe Lovelock ahead of him. Is it not the case that both say that the importance of the Gulf Stream is over-rated?

The point of citing Lovelock is that he posits that Ireland’s problems will come from how the rest of the World is affected. An anology might be the dramatic increases in global food prices in 2007. John Beddington has said we will need to increase global food production by 50% by 2030. At the same time, global water reserves continue to decline and more of Southern Europe and and Africa are become arid due to climate change. Climate, Food, Energy, Water and Population are inextricably interlinked.

Whether or not it gets one or two degrees hotter at Dublin Airport or whether the sea will ise by 5cm or 30cm over the next 20 years will hardly be the main factor to be taken into account in planning for climate change. If the debate were restricted solely to the expenditure on sea defences then it would be more relevant.

@RT

Is it correct to say that climate change models are more accurate in predicting the changes that will take place over the next 70-100 years than they are in predicting what will take place over the next 20-40 years, or has that problem been solved?

I ask this because you have mentioned a number of times about the change which will have occurred by 2100, whereas a Government will be much more concerned about the change that will possibly have occurred by 2035. I understand that there is now widespread agreement that the rate of change will not be linear. I would of course bow to your superior knowledge on the point.

The most sophisticated models that have run a scenario of a shutdown of the meridional overturning circulation (aka the Gulf Stream) suggest that the associated cooling over the British Isles is roughly equal in size to the expected warming over this century. That is, should the Gulf Stream shut down by 2100 (a very unlikely prospect), we will return to today’s climate. If the Gulf Stream would continue, we will suffer a climate in 2100 that is comparable to the one in Northern Spain today.

Interesting quote on projections above. The problem with projections, and presumably models, surely lies in the baseline assumptions and the quality of the model in reflecting reality.

Nassim Nicholas Taleb’s book ‘The Black Swan’ is well worth a look on this. He discusses the effects of high impact, low probability events, black swans. Direct quote (pages 160-161) on response to a lecture he gave to the Woodrow Wilson Institute:

“One anonymous person explained to me privately after the talk that in January 2004 his department was forecasting the price of oil for twenty five years later at $27 a barrel, slightly higher than it was at the time. Six months later, after oil doubled in price, they had to revise their estimate to $54 a barrel…It did not dawn on them that it was pointless to forecast a second time”.

In short, no one can predict the future!

For example, the Earth could heat up quite significantly, causing ice to melt, dumping large amounts of cold freshwater into the North Atlantic current of the Gulf Stream. If this “shut down” the current, then we’d likely see Ireland’s average temperatures go down, not up.

This wouldn’t be “weak evidence” or evidence against climate change, it would simply show that an overall trend of warming leads to vastly different regional effects - some warming, some cooling. What matters is the overall trend.

Incidentally, I suspect that it is because of this that people have shifted away from the term “global warming”, since it encourages people to point to cold periods somewhat simplistically as refutations of the theory. That’s why the term “climate change” is handier.

If you read my posts carefully you will see that I have not questioned economists ability to conduct statistical analysis. RT’s assertion that economits cannot analyse climate change date is nonsense is no more than an attack on a straw man.

An interdisciplinary approach is highly desirable. A single disciplinary approach by economists is substantially less desirable. I have questioned economists’ ability to make projections based on statistical analysis without the input of climatologists/ geo-scientists/ meterologists or whatever else you want to call them.

RT has clearly had access to many such geo-scientists and has taken time to learn about their discipline but is blase about how crucial their input is in any statistical analysis purely because they are less skilled in statistical analysis. I cannot understand this attitude.

For clarity, my two main criticisms of the OP were as follows:

1. It does not appear to have been done in co-operation with a geo-scientist who could point out large underlying changes in the global ecosystem which may dramatically alter the trends which are analysed. If somebody were to show you similar graphs of house prices over the 40 years to 2006 would it have revealed the credit bubble underlying international markets? Similarly for pensions.

2. My interpretation of the piece (without re-reading it again) is that it suggests that we should base our actions and policies on how climate change will affect the climate of Ireland. I think that the economic, social and security effects of climate change in Ireland will be largely determined by how climate change affects the climates of other countries with particular emphasis on Africa and Europe. An ancillary criticism which I did not make is that Ireland has a role in determining EU policy for the good of Europe, and so we should live up to those responsibilities by looking at Europe as a whole.

Brendan’s post has shone a light on the whole question about how analysis of climate change is conducted and gives clues as to why “experts” might differ so strongly. I welcome Brendan’s skilled efforts for that reason. On the other hand, I fear that ignorant members of the public, civil service and political classes conclude to themselves as follows: “Now I have seen some real analysis of climate change and it is clear things are not going to change so much; we really shouldn’t get so worked up over this.”

I am aware of the welfare aspect of climate change. See http://ideas.repec.org/e/pto90.html

Perhaps I shouldn’t be surprised that you feel the need to state that you are not a climate change ‘denier’, but in a way it highlights one of the main irritants in the public debate on climate change - anyone who raises a question about the current orthodoxy is liable to find themselves labelled a ‘denier’.

The trouble with the climate change debate though, in Ireland as elsewhere, is that economists are too little involved in it, not too much. At either end of the spectrum of debate on this issue, there are the eco-fundamentalists for whom ’saving the planet’ has more to do with a secular religious creed than any sober evaluation of the scientific facts and the equally vocal climate change ‘deniers’ who, not content with having stupidly used up half the world’s known reserves of fossil fuels in the past century, can’t wait to make profits squandering the remaining 50%, mainly to ensure a comfortable lifestyle for the earth’s few, irrespective of any environmental considerations.

Small wonder then that most of the rest of us, caught in the middle, opt for the eco-fundis analysis as the less obnoxious of the two extremes. No progressive politician worth his/her salt wants to be labelled a ‘climate change denier’ either. The net result is there is a real risk of very bad decisions being made in the name of mitigating climate change, policies that will then fall prey to the law of unintended consequences, economically and ecologically - the rush to biofuels in the 1980s and 90s illustrates the point.

At national level, for a whole host of reasons, the debate on climate change policy would benefit from a wider enagement by economists - as well as contributions from philosphers, archaeologists and historians, but we’ll leave them aside for the moment. Enthusiasts for a transition to a ‘green economy’ in Ireland have a depressing, if natural, tendency to overstate claims of what can be achieved by their policies. Even more depressingly most of what they claim goes unchallenged, in the media or by economists. Political cheerleaders of all political colours are not slow to jump on the eco-bandwagon - a few years back they were all enthusing merrily about Ireland becoming a ‘world leader’ in biofuels production and as late as Budget 2006 €260m was being set aside to subsidise the growth of noxious weeds throughout the country. Today, it’s all about our wind resources generating enough hot air to power the whole of the European Union. Our carbon free future will have us all on the pig’s back in no time at all, or so it appears.

In Copenhagen in December, we are likely to sign up to targets of 20% reduction in carbon emissions. Unfortunately, there does not appear to have been any rigorous anlaysis of the economic impact of this target, apart from some ESRI estimates and the Irish Exporters Association claim that it will cost the Irish economy €1bn.

December’s Budget will also see the introduction of a carbon tax - the last time this issue was examined it emerged that the emissions’ savings that could be achieved from the ‘deterrent’ effect of this form of taxation were so small as to make it hardly justifiable as an environment measure. This time around it seems no public consutlation is being conducted in advance of itnroducing this measure and because the government needs money, economists seem prepared to go along with this tax because it will raise much needed revenue. That’s not good enough!

Then there is the huge issue of energy policy - I’ve yet to see every possible option for Ireland’s future energy resources set out in terms of a proper comparative costs/benefits analysis.

These are all very critical issues for our economy, even in the short term. Perhaps it might be worth considering a special economics conference, along the lines of those that have already been conducted on the economic crisis, on Ireland’s policy response to climate change?

Finally, up to recent times I was personally inclined to accept that the science on global warming was pretty much settled and that the climate models on which the IPCC base their conclusions are broadly correct. Then along came the global economic crisis. With the benefit of hindsight, most economists now agree that the financial and regulatory models of the past twenty years were flawed. It turns out that the models were wrong, or were modelling the wrong things. The LTCM debacle fo the 1990s is a typical example of what can go wrong: the celebrated geniuses involved won the Nobel Prize for economics in 1996; by 1997 their model was a busted flush because it was based on short term data rather than an appreciation of long term trends. As historian Niall Ferguson put it: “The Nobel Prize winners had known plenty of mathematics, but not enough history. They had understood the beautiful theory of Planet Finance, but overlooked the messy past of Planet Earth.”

Perhaps unwittingly, Prof. Walsh’s exercise on the met data for Dublin Airport points to a problem that may be part of climate modelling in general : the timescales that are used. Fifty years of data is far too short a timescale to tell you anything useful about climate change - a hundred, ten thousand or 100,000 years may not be enough. We just don’t know enough about how earth cycles work over longer periods to draw any conclusions from short range climate models and in any case, our predictive capacity as human beings is inherently flawed. What climate modelling is telling us may either exaggerate global awarming effects or, worse, underestimate them. At any rate , what happened with the financial models somewhat undermines confidence.

“Two degrees above today is Pareto indeterminate. Two degrees of warming is potentially Pareto superior, though.”

You are saying that nobody will be worse off with a 2 degree C increase in temp?

But you miss the substantive point. This is ALL about welfare economics. It is welfare trade off across groups and across generations. Regardless of you views on what is happening (if anything).

The policy prescriptions alone are already the largest influence on shifts in welfare across arbitrary groups and across time, when one looks at all the taxes, regulation, subsidy etc. associated with this issue.

Economist need to look at this and provide information to policymakers to determine whether all this flurry of action makes any sense.

As the slope is weak, it would be even weaker with that omitted. Not saying there is necessarily a strong argument for omitting outliers and shaping the dataset like that (although I wold be inclined to think so as they will contribute disproportionately to the error minimised slope), but at least would be interesting to see how much that one point contributes.

(As a vaguely related example, recently I was looking at correlations in commodity prices; the omission of two extreme points (out of a dataset of hundreds) reduced the correlation from approx 0.4 to 0.25.)

The 2020 forecast comes out of the decadal forecast, the summer 09 out of the annual forecast.

Let’s hope the latter forecast is correct.

I don’t know whether the data are homogenous. Urbanisation would have implied an upward trend, while Brendan finds no trend. So, the data may have been overhomogenised and mask an upward trend, the data may have been correct homogenised and there is no trend, or the data may not have been homogenised and urbanisation masks a downward trend.

Two degrees above today is Pareto indeterminate. Two degrees of warming is potentially Pareto superior, though.

Watch the hubris.

The economic literature (or more accurately econometric literature) may be more advance on statistical issues than the field of climate science, there are pitfall for the unwary in the understanding and interpretation of data.

For example, are you Dublin/Dublin airport data adjusted for urban heat islane affects? What about homogeneity of measurment (can you vouch for the fact that the measurement equipment has not move location, or that the location has not chaged in nature (e.g. a big tree grown over the site)?

That nothwithstanding your points are valid, but I tihk you miss the more important area of potential economic contribution, which is in hthe area of welfare economics.

For example, what is the Pareto comaprison of world+2 degree C compared with world climate today? That is probably fairly easy to answer, it is very most likely reduced.

But go further and find the normative intrudes. How much welfare should Irish citizens forego for the greater good and how are you going to convince them to do so?

It is a minfield

Whilst the IPCC debate may be moving on, I think it is important to address queries raised by those not closely engaged with climate science. Brendan has provided a solid analysis of the data to hand, and in a far more balanced and logical way than many of my family and friends would when criticising the lousy summers. To their minds there is a clear absence of any indication of ‘warming’ - the current weekend excepted.

The point, I would suggest, is that it is never a good idea to tell people to just ‘leave it to the experts’. The experts must always be willing to explain apparent anomalies - many times over - to bring the general populace along with the flow.

My take on climate change and climate policy is summarised here: http://ideas.repec.org/p/esr/wpaper/rb20090101.html

To summarise, we should replace all domestic climate policy with a simple carbon tax that tracks the ETS permit price. This would raise taxes and cut public spending, and has the additional advantage that Ministers Gormley and Ryan will have time again to focus on their jobs (which I believe includes drinking water quality, local government, broadband, electricity, …).

That said, I believe that there is enough evidence of climate change arising from human activity.
Whatever about the weather in Dublin (which is what Brendan wrote most about, although he has clearly looked at data for other parts of Ireland), the issue of climate change remains. What consequences will climate change have for hydrology cycles? How do we manage the impact on humans of changes in the availability of fresh water?

If Stern and meterologists are out, can you point out where else I should look for some enlightenment on these issues?

My question on dealing with the issue remains, even if you consider that answering it is beyond the scope of this forum.