Petersean
Clerk
A page of history is worth a volume of logic.
Posts: 36
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Post by Petersean on Jun 17, 2008 20:55:21 GMT
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Post by James Hannam on Jul 1, 2008 8:34:49 GMT
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Post by bjorn on Jul 1, 2008 10:06:29 GMT
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Post by josephbfischer on Jul 8, 2008 6:37:31 GMT
YouTube on Global Warming As would be expected, there is a lot about Global Warming on YouTube. Here is a link to an interesting variant use of Pascal's wager to argue that we should do everything we can to combat global warming, WHETHER IT IS TRUE OR NOT! www.youtube.com/watch?v=mF_anaVcCXgBy the way, if you have the time, the sections on the limitations of science might be worth sharing with non-scientists.
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Post by unkleE on Jul 16, 2008 0:47:50 GMT
It's time I entered this fraught topic again. I wish to make three points: 1. Use of isolated statistics (e.g. "Gliding average for the last 34 month indicates definitely a global temperature fall") is not, I believe, a very scientific way of drawing a conclusion. Climate and other natural world data can be highly variable, and many apparent anomalies can be found, especially over a relatively short time period. They may indicate something significant (and we would be foolish not to keep our eyes out for this), but they may also indicate the normal variation that occurs about a trend. No-one should base a conclusion on such statistics, though of course we should not ignore them either. 2. If one wants to quote such isolated statistics, one can find many that support the climate change models, for example: - "[Globally] 1998 was the warmest year on record in the last 150 years. Although the eight years since then have not been warmer than 1998, they do include the globe’s second, third, fourth, fifth, sixth and seventh warmest years on record. The planet is not cooling." (Australian climate change modeller, responding to the isolated statistic that 1998 was the hottest year, and it has been cooler since.)
- 2005 was the hottest year on record across Australia, and the five year period 2003-2007 was also the hottest on record.
- As predicted by climate change models, patterns of rainfall are changing. Some relatively unpopulated parts of northwestern Australia are receiving above average rain. But the Murray Darling River basin, which produces 40% of Australia's agricultural production and 70% of its irrigated agriculture, has, overall this century, experienced its lowest rainfall on record.
- Streamflows in the Murray Darling remain very low, with the current drought the worst on record. 2006 had the lowest inflows on record, and while 2007/08 was "only" the sixth lowest, June 2008 was the lowest monthly flow on record.
Australia is suffering its worst drought, highest temperatures and a significant and disastrous re-distribution of rainfall. It's all according to the models. 3. But in the end, we should base our conclusions on the full data set and the most expert interpretation of it. The models are one way of summarising that knowledge base, and they are the best science we have. Yes, they may be in error, but the probability is that they are not. They will almost certainly be adjusted and refined, but it is unlikely the news will get significantly better. I suggest a more accurate way to express doubts about the climate change models would be to recognise they are the best science available, but say that we should continue to watch the apparent anomalies. They will either disappear or be incorporated into the models. I have some graphs and references here.
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Post by James Hannam on Aug 4, 2008 16:34:43 GMT
This study in the Journal of Hydrology finds that climate models have a very bad record of predicition. www.atypon-link.com/IAHS/doi/pdf/10.1623/hysj.53.4.671?cookieSet=1As I said above, I think basing our conclusions on global warming on these models is a mistake. The models, at the moment, are demonstrably wrong and we have no reason to assume that they will turn out to be right in the longer term. Best wishes James
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Post by unkleE on Aug 4, 2008 23:33:02 GMT
Funny you should raise this topic again James, because I was just about to also. I was unfortunately unable to get your link to work (something about cookies, so maybe I can sort it), but the Journal of Hydrology is pretty reputable. But I was going to post evidence of something more sinister, so here goes. An interesting article in the Sydney Morning Herald has outlined how: 1. Exxon Mobil has admitted that it has funded climate change denial groups in an effort to reduce pressure on the company about the impacts of its products (see also this report). For example, Exxon has supplied $0.7M in funding to the Oregon Petition, "which urges US rejection of the Kyoto Protocol and claims there is "no convincing scientific evidence" for global warming", and which is organised by a former tobacco consultant. Brad Miller, chairman of the US House of Representatives oversight committee on science and technology, last year said Exxon's support for sceptics "appears to be an effort to distort public discussion". 2. A number of well publicised claims that throw doubt on global warming have been shown to be untrue and deliberately misleading, for example: - Famous botanist, David Bellamy, said in 2005 that according to the World Glacier Monitoring Service in Switzerland, most glaciers in the world were growing. However checking revealed that the Service's data shows they are actually retreating.
- A website claimed the American Physical Society (the premier body of US physicists) no longer accepted the truth of human-induced global warming. However the Society's website says the evidence in favour of global warming is "incontrovertible".
If these reports are true, there seem to be parallels with the dishonest and partly successful attempt by tobacco companies to stifle the truth about the links between smoking and lung cancer. So now we don't only have the conspiracy theories throwing doubt on global warming, but also conspiracy theories on where much of the scepticism is coming from. I still say we should trust the scientists on this one, accept the fuzziness about some details, recognise that the broad consensus that the data points unambiguously in one direction, but remain open to any new information that is reliable. (Otherwise we are just like Jesus-mythers all over again.) Let's take heed of the old Who song: "Won't be fooled again!"
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Post by James Hannam on Aug 5, 2008 16:08:01 GMT
I agree there is a great deal of misinformation in this debate. Bellamy was skewered by George Monbiot on live TV when he first made the glacier claim. It was excruciating to watch for anyone brought up to see Bellamy as a cuddly friend of nature. I don't take much notice of the various sceptical blogs etc. The only site I check regularly in the Hadley Centre which gives actual (and flat) global temperatures. But, if the models don't work, I don't think we can ignore that. Here's an interesting article/review by Freeman Dyson from NYRB: www.nybooks.com/articles/21494Best wishes James
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Post by humphreyclarke on Aug 5, 2008 20:36:42 GMT
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Post by unkleE on Aug 6, 2008 8:30:54 GMT
We seem to be going round in circles. I want to make a brief response and then suggest a re-framing of the question. Humphrey, I looked up the reference, and as far as I can see, the 'heroic first approximations' applies to the estimates for the carbon uptake of forests, not the whole global warming models. The rest of the article supports the truth of global warming. And of course the models are "wrong", if "wrong" means approximate, or containing errors or not exact. All natural world computer models are wrong in this sense. But that doesn't mean they can't be used if they are the best information available. In Australia (and other semi arid places like South Africa and southern USA) most of our urban water supplies supplied from surface water are based on models and data that are "wrong", in that they have large and unknown errors because we just don't have long enough hydrologic records to make them more accurate. But we need water supplies, so we do the best we can, and keep on upgrading the models when we have more info. I believe it is the same with global warming models. They are the best we have, and we are better with approximate information rather than none. Interestingly, that same site lists many other NewScientist articles on global warming, including this one about Arctic ice being the thinnest ever measured, and this one reporting how climate change impacts are already being felt in biological communities. James, I checked out your reference too and it gave me the idea of re-framing this "problem". Instead of focusing on whether climate change is truly happening, and whether the models are predicting it well, why not focus on the problem we on this forum face in forming a conclusion and deciding on a course of action. (Of course we are just a microcosm of the western world.) Then the problem is clear, and we can agree on the facts, which are (roughly): - The majority of relevant scientists believe human-induced climate change is occurring and is a serious threat to humankind and the entire world.
- Nevertheless, some scientists disagree with parts of the evidence, and some details of the models and predictions are questionable.
- If the consensus is correct, delaying could make things worse, but if the consensus is wrong, then acting too soon may be costly.
- If we do a risk analysis, the consequences of delaying when we should have acted are probably worse and more widespread (e.g. it will be life and death for some people and some ecologies, as well as economically costly) than if we act too hastily, when the cost will be mainly economic.
- Prudence therefore indicates we should start to move, with a plan that will not be too costly, and keep monitoring, moving to a stronger plan if the models prove to be accurate.
And this, of course, is pretty much what is suggested in one of the books reviewed by Freeman Dyson - A Question of Balance: Weighing the Options on Global Warming Policies by William Nordhaus, an economist. I thought that seemed like a very sensible course of action in principle, though of course his economic estimates would need verification. I can't help feeling others have done this before, and the consequences of taking a "low cost backstop" option may be more than he estimates, but that could easily be checked, and no doubt will be. Can we perhaps agree on that, and instead of being climate change sceptics, be climate change precautionary?
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Post by humphreyclarke on Aug 6, 2008 10:09:54 GMT
Hi Unkee I appreciate your persistence with a couple of hardened sceptics. I accept that we are faced with the impact of unprecedented climate change and that we need to take action to mitigate its effects. I do have this niggly little hunch at the back of my head that it we aren't heading for a 'Stern Review' type apocalypse but if pushed I would have to agree with the IPCC. I continue to 'live green' in any case. The models do have to be wrong by a lot for us to be out of the woods. You might be interested in the Faraday Institute Lectures on the Enviroment. www.st-edmunds.cam.ac.uk/faraday/Multimedia.phpProf. Sir John Houghton is a speaker there and he does talk about a range of issues, including Dawkins and 'The God Delusion' H
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Post by James Hannam on Aug 6, 2008 12:41:11 GMT
Hi there Unlkee, I fear we still won't be in agreement. Even Stern found that the effects of global warming using the IPCC forecast would not be especially unmanageable in comparison to the world economy. - The majority of relevant scientists believe human-induced climate change is occurring and is a serious threat to humankind and the entire world.
Agreed.
- Nevertheless, some scientists disagree with parts of the evidence, and some details of the models and predictions are questionable.
Agreed.
- If the consensus is correct, delaying could make things worse, but if the consensus is wrong, then acting too soon may be costly.
No. If the consensus is right, it may still be better to wait and see, then adapt, rather than taking pre-emptive action now. The conclusion of the book reviewed by Dyson was that the present value of doing nothing and the most sensible pre-emptive measure was about $1 trillion (IIRC). Actually, the oil price is increasing the cost of carbon anyway so it may be less than that now. The 'green' solutions of Kyoto and Stern are ruinously expensive. Going beyond Kyoto is recklessly stupid in my view.
- If we do a risk analysis, the consequences of delaying when we should have acted are probably worse and more widespread (e.g. it will be life and death for some people and some ecologies, as well as economically costly) than if we act too hastily, when the cost will be mainly economic.
No. Economic costs are the same as human costs in most of the world. Witness the bio fuels fiasco which is inflating food prices and directly contributing to starvation in poor areas. If we slow down world growth now we will directly contribute to keeping the poor impoverished and hence at greater risk of death.
- Prudence therefore indicates we should start to move, with a plan that will not be too costly, and keep monitoring, moving to a stronger plan if the models prove to be accurate.
Yes. But the recent increases in oil prices already represent the boundaries of what is prudent at present.
If precautionary means following ruinous courses of action, then no. If it means keeping an eye on the ball and reacting quickly to new data, then fine. Best wishes James
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Post by James Hannam on Aug 7, 2008 12:19:44 GMT
Here's a good example of what is wrong with global warming propaganda: www.guardian.co.uk/commentisfree/2008/aug/07/carbonemissions.climatechangeFrom that article: This is pure scare mongering, threatening us with the apocalypse without any idea of either the economics or empirical science of the question. According to the Hadley Centre, average temperatures have increased by 1 degree in the 20th century (see here: hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/). So far, this has not caused much of a problem and the advantages have been considerable. So we are left with three questions: 1) How great will global warming be? Answer: we don't know. 2) Will the effects be good or bad? Answer: A small amount of warming is good on balance. After that we don't know. 3) What can we actually do to change it rather than adapt to it? Answer: In practical terms, nothing. Best wishes James
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Post by unkleE on Aug 7, 2008 13:24:02 GMT
James,
Are you being serious, or just trying to bait me? Please tell me you wrote this post on April 1.
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Post by James Hannam on Aug 7, 2008 16:10:14 GMT
Hi Unklee,
I think again we have found we are talking past each other.
You, if I understand you, believe that the consensus of climate scientists, through their computer models, provide sufficient evidence to expect global warming on a scale that we cannot cope with and hence we should seriously impoverish ourselves now trying to prevent it.
I believe we have no such evidence because the models are inaccurate. Further, I believe that the costs of preventing global warming are greater than the costs of adapting to it.
I accept we haven't a lot of common ground!
Best wishes
James
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