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A critique of Wood on global warming

July 26th, 2006

I’ve been sent a critique of Alan Wood’s piece in the Oz claiming that global warming is a hoax. It’s written by a climate scientist who knows what he is talking about on this issue. Wood obviously doesn’t know or doesn’t care.

I was very disappointed in Wood’s piece. While his economic views are very different from mine, his columns on economic issues are usually rigorous, and if he makes a factual claim, it’s generally reliable. But his standards seem to desert him when he writes on this topic.

The response is in the (now relatively uncommon) form of a point-by-point fisking. Wood’s text is in plain type and the comment’s in italics.

One fairly trivial point is quite revealing. Wood claims, incorrectly, that the Mann “hockey stick” graph was “for a time, incorporated … into the IPCC’s logo.” As the analysis makes clear, the repetition of this bogus factoid indicates that Wood is sourcing his material from the denialist echo chamber, and not doing his own research. This is standard practice for our legion of rightwing hacks (and quite a few lefties as well), but it’s not the kind of thing I’d expect from Alan Wood.

Debate on climate change far from over (Alan Wood, Australian 91/7/06)
with a critique by Roger Jones*

*The views expressed here represent personal opinion based on assessing a wide a range of sources, professional experience in assessing both past and future climate, and do not represent the position of any organization

AT lunchtime on Monday, John Howard and Victoria’s Steve Bracks were on their feet talking about energy, climate change and the environment. While their approaches were notably different, there is one thing on which they both agree: the UN’s Intergovernmental Panel on Climate Change is the font of all scientific wisdom on global warming.
In fact it has become quite fashionable of late to assert the global warming debate is over and an overwhelming scientific consensus prevails. This is simply untrue.

As acknowledged in an Australian Bureau of Agriculture and Resource Economics report on climate change scenarios, also released on Monday, there are still considerable scientific uncertainties surrounding the nature and extent of future climate change.

This is what ABARE said in their report on Monday:

It is important to recognise the current scientific uncertainties surrounding the nature and extent of future climate change and the likely impacts thereof. Hence, a sensible approach to climate change must involve a reasonable balance between multinational action to mitigate future emissions to meet given concentration or temperature change targets and the necessary adaptation policy measures to cope with any unavoidable potential climate change impacts.

Of course, no-one can argue against taking a sensible approach. The IPCC offers full descriptions of the scientific uncertainties known to about 2000 in their Third Assessment Report. This is a red herring as to whether global warming poses serious risks or not. The “expert� consensus on whether global is real does not gainsay the uncertainties, quite the contrary.

A report released in the US on Friday has torn apart one of the main props used by the IPCC to illustrate the need for urgent action on climate change. The report raises serious questions about the IPCC process and the findings on which world governments rely in forming their climate change policies.

First, some background.

In telling the global warming story the IPCC, since 2001, has relied very, very heavily on what has become known as the “hockey stick”. It is based on a 1999 paper, the principal author of which was paleoclimatologist Michael Mann.

Before the publication of his paper the generally accepted view of the past 1000 years was that there was a period of elevated temperatures known as the Medieval Warm Period, which was followed by the Little Ice Age, and then a new period of global warming.

Mann’s hockey stick eliminated the Medieval Warm Period, flattening the fluctuations in global temperatures over most of the past millennium (the handle of the hockey stick) until we get to the 20th century, where the rate of global warming takes off in a sharp upward surge (the blade of the hockey stick).

There are several errors of fact here:
• They are not global temperatures, they are the northern hemisphere only
• It did not eliminate the medieval warm period but it is flatter than far more localised records
And of interpretation
• The IPPC did not rely very, very heavily on the “hockey stick�. It was a statement in the Summary for Policymakers (SPM) that approved by all governments. It was one dot point of many and one panel of a single figure of five in the SPM.

This is the basis for the IPCC claim, now widely accepted, that the 20th century was the warmest in the past 1000 years, the 1990s were the warmest decade in the past millennium, and 1998 was the warmest year in the past 1000 years. Scary stuff!

What the IPCC said was this: New analyses of proxy data for the Northern Hemisphere indicate that the increase in temperature in the 20th century is likely to have been the largest of any century during the past 1,000 years. It is also likely that, in the Northern Hemisphere, the 1990s was the warmest decade and 1998 the warmest year (Figure 1b). Because less data are available, less is known about annual averages prior to 1,000 years before present and for conditions prevailing in most of the Southern Hemisphere prior to 1861
In this case likely gives a level of confidence to that statement that it is 66–90% of being true, i.e. more than twice as likely as not, but not highly likely to be true (>90%).

This is a statistically verifiable sequence if one believes the first statement, because if the latter 20th century is the warmest period and the 90s the warmest decade and 98 the warmest year, the likelihood of a departure that large from a cooler previous period is exceedingly remote. So for the NAS to find the latter less plausible than the former, does not make much sense. This type of analysis can be seen for Svalbard/Spitzbergen here:

http://www.realclimate.org/index.php?p=309

Two Canadians, Steve McIntyre, an engineer, and Ross McKitrick, an economist, challenged Mann’s work in 2003. They argued his technique produced hockey sticks from just about any set of data. Mann responded in a notably less than scientific manner by withholding adverse statistical results and important data, and discouraging the publication of criticism of his work.

Mann was cranky but did not prevent their access. He challenged them to reproduce his method from the science and declined to hand over his analytic code.

A Wall Street Journal report of the controversy last year attracted the attention of the US House Committee on Energy and Commerce. It wrote to Mann and his co-authors, as well as to the IPCC, demanding relevant information and then approached independent US statisticians for advice on assessing the data provided.

Leading US statistician Edward Wegman, of George Mason University, who is chairman of the US National Academy of Sciences’ committee on applied and theoretical statistics, agreed to assemble a group of statisticians to assess the Mann data. Their report was released last Friday and supported McKitrick and McIntyre’s criticisms of the hockey stick, finding Mann’s statistical work flawed and unable to support the claims of the hottest century, decade and year of the past millennium.

The Wegman et al. paper is interesting but for the wrong reasons: It summarises palaeoclimatic proxies and carries out an analysis of how to produce hockey sticks from random data. They did not produce a bootstrap analysis of the data used by Mann et al., which would prove that the hockey stick through Mann et al’s analysis was or was not an artifact. They merely showed that the analysis could produce spurious results, not that it did. The corroborating scientific analyses produced since (by scientists that were unrelated to Mann in Wegman et al’s analysis) show that underlying data was not red noise.

The social network analysis is highly flawed. It all hangs on the following statement: In particular, if there is a tight relationship among the authors and there are not a large number of individuals engaged in a particular topic area, then one may suspect that the peer review process does not fully vet papers before they are published. Indeed, a common practice among associate editors for scholarly journals is to look in the list of references for a submitted paper to see who else is writing in a given area and thus who might legitimately be called on to provide knowledgeable peer review. Of course, if a given discipline area is small and the authors in the area are tightly coupled, then this process is likely to turn up very sympathetic referees.

So one may suspect peer review does not fully vet papers and it is likely that the reviews will be sympathetic. That word likely is the same one that the IPCC used to say that the 20th century Northern Hemisphere warming was the largest in the past millennium and that the 90’s were the warmest decade and 1998 the warmest year. So, without any foundation, suspicion and likelihood is attributed. To then link the Mann network which is a close network, with the palaeoclimate reconstruction network, which is not, the authors use common data sets of temperature proxies. This is like accusing economists of collusion when they use the same GDP data. Wegman and his colleagues manage to gainsay recent debates that have surrounded the use of peer review. Those debates have been widely publicized and have concluded that it is not flawless but is the best method going.

The recommendations about the IPCC and how it operates come with no analysis in the report, and thus there are no grounds for the recommendations the report makes. The report attacks the whole notion of peer review both within science and the IPCC without a shred of evidence.

That they want to involve statisticians in ongoing work is interesting. What level of education in statistics does one need to have? Skill in statistics does not mean a better understanding of science or even uncertainty. For example, Bjorn Lomborg in his book The Skeptical Environmentalist notoriously misrepresents the underlying science contributing to a range of environmental risks (not to mention his selective use of statistics). Ian Castles also, attacked the IPCC SRES scenarios on statistical grounds, without showing that the underlying assumptions relating population and energy use were in fact incorrect. The idea of using statisticians without training and a publication record in the relevant science, or as an integral part of a larger team should not be given air. However, more resources would also be required to fund the greater scrutiny if it were applied. My own experience in the current funding environment is that the biggest restriction to peer review is resources. I apply a skeptical filter to the papers I review and to my best knowledge, so do my colleagues. However, peer review is a gift economy that does not sit well with targeted funding.

What the Wegman et al. report does not do is assess the scientific nature of Mann et al.’s work and whether it has been supported by other research (although it summarises some of that research).

In his article Wood also overlooks a National Academies of Science report published in the previous week that does address the science. http://www.nap.edu/catalog/11676.html
However that report was not conclusive on the matter of the hockey stick. The NAS report says:

Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically diverse sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onwards. Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium. The substantial uncertainties currently present in the quantitative assessment of large-scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the high level of confidence we place in the Little Ice Age cooling and 20th century warming. Even less confidence can be placed in the original conclusions by Mann et al. (1999) that “the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium” because the uncertainties inherent in temperature reconstructions for individual years and decades are larger than those for longer time periods, and because not all of the available proxies record temperature information on such short timescales.

The report confirmed that the latter part of the twentieth century was warmer than for the previous 400 years but ducked on extending this conclusion to the last millennium despite the attribution of plausibility above. However, that the larger fraction of sites showing that a warmer 20th century has occurred suggests that the “warmest period over the last millennium in the Northern Hemisphere� could only be false if some contra-indication was introduced into the numbers and analysis (this allows also for area-weighting of the data).
The NAS report has been claimed as vindication by Mann and his supporters and also by McIntyre and McKitrick and their supporters. Why is this so?

By not quantifying their levels of confidence in these conclusions the NAS committee has allowed the reader to interpret this information in any way they see fit. But, they do not say that Mann et al.’s statement was implausible. The inference is that it is difficult to verify on the available evidence.

However, the committee does say that support evidence exists for the statement that warming during the late twentieth century is more spatially coherent at any other time since the 9th century A.D. and the larger number of sites shows exceptional warming. Given that the committee found itself unable to clarify any levels of confidence in their findings, or even come to any conclusions as to whether simple or area-weighted averages were preferable to determine areal trends, the whole report does little to clarify an issue where entrenched views that have little to do with the science of palaeoclimatology abound.

The NAS report suffers by not treating uncertainty and confidence in any rigorous manner, so has served to muddy the debate rather than clarify it. People will interpret words like likely, plausible and less confidence but still plausible in the way they see fit if not provided with internally consistent methodology and guidance. In its Third Assessment Report, the IPCC introduced methods to quantify and clarify uncertainty and confidence. Although not perfect, this development should now be seen as best practice in communicating contentious issues. It is a pity that the NAS does not do this.

Yet the IPCC used the hockey stick in its publications, media releases, press conferences – where senior IPCC figures sat with the chart as a backdrop – and, for a time, incorporated it into the IPCC’s logo.

This last statement is patently untrue. McIntyre wrote on Prometheus (Roger Pielke Jr’s blog) It could almost characterized as the logo for IPCC TAR. Figure 1 below shows Sir John Houghton, at the press conference releasing IPCC TAR, standing in front of the Hockey Stick. The graphic was used repeatedly in IPCC TAR and was one of the most prominent graphics in the Summary for Policymakers. http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/000630does_the_hockey_stic.html

By the time Wood gets the Chinese Whisper, the hockey stick has graduated onto IPCC’s logo. This misrepresentation of the logo has been repeated on a number of web sites.

As to the use of the graph, the IPCC uses a range of signature graphs. Communication is its business.

It is important to understand that this is a debate about the use of statistics. Mann did no original scientific work, using available data and manipulating it in a new way.

The work was original. This comment implies that experiment and measurement is the only original thing you can do. This debate should be about science – statistics is a tool. It is possible to use a tool poorly and come up with the right answer and also to it well and be wrong.

However, it destroys the idea of an alarming escalation in global temperatures and, as the Wall Street Journal remarked on Friday, brings the present temperature rise within the range of natural historical variation.

No it does not – plenty of other studies confirm high 20th century warming. The evidence is not only trend but “footprint� and has been confirmed by modeling. AGW produces very different spatial patterns to hemispheric warming.

There remains plenty of room for argument about the projections of future temperature rises and their implications, based on what are still primitive climate change models. But there is no escaping the damage done to the IPCC’s reputation. It has relied heavily on a badly flawed piece of work, produced by what Wegman discovered was a small, insular group of paleoclimatologists who incestuously peer review, reinforce and defend each others’ work.

Wegman et al. discovered no such thing. They conducted a Committee of un-American Activities-type analysis but much more sophisticated and used guilt by association. Their independent analysis showed separate clusters of researchers. They had no information on who the reviewers were and what was in the reviews. There are sufficient researchers available to offer proper peer review. The best they managed was that the different analyses were using common data (well, duh) and inferred that was somehow suspect.

The claim of primitivity in climate change models is interesting. These models are dynamic, are run in open mode from a set of initial conditions and external forcing and do a good job of many global processes. They are not perfect, but are continually being improved – the improvements are openly detailed in the international literature and in IPCC assessments. In contrast, many of the economic models that seem to be preferred in many circles are not dynamic, being based on general equilibrium and internally optimise themselves assuming “perfect knowledge� of processes that are poorly understood.

Significantly, former commonwealth statistician Ian Castles and his colleague David Henderson, former head of the Organisation for Economic Co-operation and Development’s economics department, have also exposed statistical and analytical flaws in the economic scenarios underlying the IPCC’s climate change projections. As with McIntyre and McKitrick’s criticism of the hockey stick, the IPCC establishment initially tried to ignore, then discredit, their work.

Here is what the International Energy Agency said about Castles and Henderson: We are aware of the fact that the validity of some of the assumptions underlying the IPCC-SRES scenarios, and particularly the scenarios of the A1 family were recently challenged by I. Castles and D. Henderson. One of their main objections centred on the use of GDP data measured at Market Exchange Rates (MER) instead of Purchasing Power Parities (PPP). As the rebuttal written by Nakicenovic et al. and published in issue 2 of 2003 of Energy and Environment provides some reasonable answers to the issues raised, we stick to our choice of reference framework. ENERGY TO 2050 Scenarios for a Sustainable Future IEA, 2003.

However, last year a House of Lords committee looking at the economics of climate change praised their work and said that without them the debate on emissions scenarios would not have taken place.

This confusion can arise when all pieces of information are treated equally rather than being assessed properly – the same happened in the New South Wales Parliament background paper on climate change science http://www.parliament.nsw.gov.au/prod/parlment/publications.nsf/0/FB07F849FCBA7B76CA2571150023166E

The Lords committee also expressed concerns that the IPCC was an increasingly politicised body that tried to suppress dissent. It warned of a risk it was becoming a knowledge monopoly, “in some respects unwilling to listen to those who do not pursue the consensus line”.

In an article last week in Canadian newspaper the National Post, McIntyre and McKitrick say the IPCC’s lead author, who selected Mann’s hockey stick for prominent display, was none other than Mann himself. They quote eminent US climate science academic Kurt Cuffey as saying the IPCC’s use of the hockey stick sent “a very misleading message”.

They ask a pertinent question.

If the IPCC process isn’t fixed, and there is no evidence the IPCC intends to do anything about it, how do we know it won’t send out another very misleading message in its upcoming Fourth Assessment report?

It was interesting to see the word Fraud associated with the article. Deliberate deception intended to mislead a third party for personal gain. Hmmm.

Categories: General Tags:
  1. Con
    July 27th, 2006 at 01:06 | #1

    I guess the sad part in all of this has been the general indifference of most right wing (Mankiw and Tyler Cowen are notable exceptions) thinkers on climate change. Even businesses in the US and UK are coming around to green/alternative sources of energy (BP, Goldman Sacks and GE). This really should not be a political/idealogical issue. I’d be interested in comments as to why it has been so slow to take up (energy lobbying I guess is one issue). Yet the analysis on climate change and Co2 levels is clear.

    Are the The Centre of Independent Studies and Institute of Public Affairs coming around? A brief look at their sites suggests not. Then you take an ok commentator of economics like Alan Wood and wonder what what the hell went wrong? His follow up article ragarding fees and commissions for managed funds was excellent yet when it comes to climate change you get the sense of brain fade.

    I see no reason why libertarians cannot be environmentalist or at least concerned about climate change. Yes the market is mispricing the destruction of the earth due to free riders/externalities. We covered this is eco101 so lets move on and fix the issue. The alternative is to wait before it becomes a crisis and we have the Carbon Dictatorship mentioned by Flannery in The Weather Makers. Better to regulate and give up some freedom and growth now than capitulate in 20-30 years.

    Also being a general optimist maybe the unleashing of some carrot and stick on society will help us turn this into a win-win situation. We were bold enough many years ago to force superannuation on our workforce to save for retirement and its working better than most expected. Even the libertarians who were completely against it at inception have turned to approval.

  2. July 27th, 2006 at 08:04 | #2

    The US House Committee on Energy and Commerce gathered, so I read in the MSM, personal details of scientists who were not global warming “sceptics”. A bit like another more famous US House Committee.

  3. July 27th, 2006 at 08:13 | #3

    (Quick google), ah yes:

    “THIS IS HIGHLY usual,” declared a spokesman for the House Energy and Commerce Committee when asked this week whether the request by committee Chairman Joe Barton (R-Tex.) for information from three climate scientists was out of the ordinary. He and his boss are alone in that view. Many scientists and some of Mr. Barton’s Republican colleagues say they were stunned by the manner in which the committee, whose chairman rejects the existence of climate change, demanded personal and private information last month from researchers whose work supports a contrary conclusion. The scientists, co-authors of an influential 1999 study showing a dramatic increase in global warming over the past millennium, were told to hand over not only raw data but personal financial information, information on grants received and distributed, and computer codes.

    Rep. Sherwood L. Boehlert (R-N.Y.), chairman of the House Science Committee, has called the investigation “misguided and illegitimate.” Raymond S. Bradley of the University of Massachusetts, one of the targets, calls it “intrusive, far-reaching and intimidating.” Alan I. Leshner, chief executive of the American Association for the Advancement of Science, said that although scientists “are used to answering really hard questions,” in his 22 years as a government scientist he never heard of a similar inquiry, which he suspects could “have a chilling effect on the willingness of people to work in areas that are politically relevant.”

    Mr. Barton’s attempt to dismiss all this as turf-battling on the part of Mr. Boehlert, like his spokesman’s claim that such demands for data are normal, is disingenuous. While the Energy and Commerce Committee does sometimes ask for raw data when it looks at regulatory decisions or particular government technology purchases, there is no precedent for congressional intervention in a scientific debate…

    I suppose the “social network analysis” thing is the excuse for this kind of behaviour? And wouldn’t the published record, including CVs, be enough?

    And shouldn’t “R.Tex” read “T.Rex”?

  4. July 27th, 2006 at 08:14 | #4

    Sorry, the link to the full article is here.

  5. Mike Hart
    July 27th, 2006 at 09:41 | #5

    A small comment, said it before will say it again, I make my living transiting the continent and the maritime regions in the air. I am acutely aware of weather patterns and changes, for a decade now wind patterns have been disturbed, cloud growth and composition has changed and so have the temperatures, in short, it has become less predictable, drier and in most places much hotter. Ten years of personal observation day in and day out is a definite trend to me. We ignore the evidence at our peril. Woods and his fellow campers are fools.

  6. Terje (say TAY-A)
    July 27th, 2006 at 10:12 | #6

    I see no reason why libertarians cannot be environmentalist or at least concerned about climate change. Yes the market is mispricing the destruction of the earth due to free riders/externalities. We covered this is eco101 so lets move on and fix the issue.

    As one of the locals that self identifies as a libertarian I will offer a response. Basically I agree with the first sentence. There is no reason you can’t believe in having substantially improved levels of economic freedom (which is not the same as financial freedom) and also have concerns about climate change. I personally have concerns about climate change. However I remain sceptical about the claim that the science is all sorted out even though I recognise that the “CO2 will cook us” has become part of pop culture. My major concern is that there are moves to cement this conclusion even though there are still substantial holes in our understanding of the earths climate.

    I agree with your second sentence, although perhaps not the sentiment about how widespread the problem of externalities is. I think a lot of the free riding occurs where property rights are not secure. In Brazil the government has historically said that in some regions it won’t give people secure property rights until they have cleared the rainforest. For this example the government is culpible rather than the market system. In NSW we have a noxious weed problem in National parks, this is not due to a failure of the market system. The market system is not perfect, however it carries with it certain levels of accountability that government sponsored distribution of wealth and resources simply don’t.

    I am quite supportive of a carbon tax if the revenue is used to abolish some other taxes. For instance a carbon tax in NSW could be used to abolish payroll taxes. And such a tax will over time become increasingly easy to avoid. I am very optimistic about alternative means at generating electricity. For instance I think Enviromission has a very interesting piece of solar technology in its patent bag. And I think that solutions based on photovoltaics are still pretty much on track to being cost competative within the next decade (In about 1993 I was told that it would probably take until 2015, which still seems about right).

    So I see no reason why libertarians cannot be environmentalists or concerned about climate change. I also see no reason why more environmentalists cannot become libertarians.

  7. July 27th, 2006 at 10:21 | #7

    Terje – “So I see no reason why libertarians cannot be environmentalists or concerned about climate change. I also see no reason why more environmentalists cannot become libertarians.”

    Because creating a long term sustainable economy will require zero growth. How does that fit with market values?

    For a purely mathematical treatise on this please read or watch this:
    http://www.globalpublicmedia.com/lectures/461

    “The retired Professor of Physics from the University of Colorado in Boulder examines the arithmetic of steady growth, continued over modest periods of time, in a finite environment. These concepts are applied to populations and to fossil fuels such as petroleum and coal.”

  8. derrida derider
    July 27th, 2006 at 10:51 | #8

    That last link, Ender, is the classic approach to economics by physical scientists – part of a long tradition. Both the neoclassical (prices) and Austrian (new knowledge) adjustment mechanisms are ignored through ignorance.

    Never underestimate the adaptability of humans given time and incentive.

  9. July 27th, 2006 at 11:01 | #9

    Oh, dear Ender. If that is the best evidence you have for that contention then I would be suggesting you either abandon it or get cracking on some serious empirical research.

  10. Terje (say TAY-A)
    July 27th, 2006 at 11:13 | #10

    Ender,

    There seems to be two implicit assumptions in your statement.

    Firstly you appear to assume that growth in economic output means consuming more physical resources. This ignores questions about the nature and form of consumption. Microsoft could hypothetically double its sales without any increase in the use of physical resources. Soft products like media, software, songs etc form an increasing component of our lives and yet any incremental increase in consumption of this nature may mean no increase in the physical burden on the planet. Our level of wealth has less to do with the amount of matter we own and control and much more to do with the form that such matter takes.

    Secondly you appear to assume that an increase in market trade (ie growth in GDP output) is a necessary result of libertarian style economic freedom. A glance at Maslow’s hierarchy of needs might be enlightening.

    Regards,
    Terje.

  11. July 27th, 2006 at 11:48 | #11

    Andrew ,Derrida
    I am interested now – what part of economics trancends physics? Surely from the physical scientists point of view economics ignores physical constraints? Perhaps you can point me to some reading on this.

    Terje – Microsoft products though useful do not feed anyone. The talk mentioned physical constraints not intellectual. I do not think that pure market forces would be happy with zero growth – surely they would always be striving to increase? Or is redistibuting the wealth from the poor to the rich sufficient as what happens now?

  12. Terje (say TAY-A)
    July 27th, 2006 at 12:02 | #12

    I do not think that pure market forces would be happy with zero growth – surely they would always be striving to increase? Or is redistibuting the wealth from the poor to the rich sufficient as what happens now?

    Neither do I. However a doubling of GDP does not mean a doubling of physical resource use. The two are not related in a linear fashion. And it is not unfeasable to envisage a world in which we have growing GDP and a declining use of physical resources.

    Your comment about Microsoft makes the point nicely. In buying Microsoft products we are consuming useful things that don’t burden the planet. Eating more would require more physical resources but buying a copy of some online software that is already widely in use would not. Both require an increase in GDP but only one puts an additional burden on physical resources.

  13. wilful
    July 27th, 2006 at 12:06 | #13

    Ender, while i’m deeply sympathetic to your argument, there’s more to economic growth than physical inputs. For example, we now use fibre optics instead of copper wires, using a bit of sand to transmit 1000 times the information. Videoconferencing is beginning to replace some business travel. There are many examples of how the economy is (or can and should) decouple from physical resource constraints.

    Try this on for size: http://www.wupperinst.org/FactorFour/

  14. July 27th, 2006 at 12:24 | #14

    Terje – “And it is not unfeasable to envisage a world in which we have growing GDP and a declining use of physical resources.”

    I am not really arguing with you here I am trying to learn however I would have thought though resource use/GDP output is reducing it can never be zero. To my mind it is more like a limit curve approaching but never reaching zero growth.

    I guess it does come down to population again. No matter how you look at it twice as many people will eat twice as much or only be able to eat half as much. Though software is an example of something that does not require resources the computer that it runs on is. If MS sells more copies of program X then surely that implies more computer Ys to run the program on using more resources to both make the computer and supply electricty to it. I agree that present compters may be made with less resources however a computer cannot be made with zero resources.

    wilful – Yes you can do it however this is the problem. Doubling wealth halving resource use this year, is quadrupling growth, quatering resource use next year and so on. The resource use still increases even though the GDP growth is great. Even if the underlying resource growth is 1% that will mean in 70 years we will need to find twice as much resources as we have now and 4 times as much in 140 years etc. Where do these resources come from?

  15. July 27th, 2006 at 12:31 | #15

    Even the resource constraints are being reduced for physical production – GDP figures would recognise the initial use of a resource for production, the cost of breaking that down through a recycling process and any subsequent use of thatr resource.
    Three GDP “events”, one resource – the only things that cannot be recovered are the energy used and the time involved.

  16. July 27th, 2006 at 12:41 | #16

    Andrew – “the initial use of a resource for production, the cost of breaking that down through a recycling process and any subsequent use of thatr resource.”

    However why would a pure free market recycle? Surely the lowest cost is to use the resource once and then use new cheaper resources. As far as I am aware the only major recycling efforts are motivated by government regulation or intervention.

    The Earth biosphere as a system recycles everything and uses a, for our purposes, an unlimited power supply and strives for steady state systems. These systems have lasted for billions of years with the limited resources of the planet. Surely we can take some lessons from this.

  17. Terje (say TAY-A)
    July 27th, 2006 at 12:51 | #17

    However why would a pure free market recycle?

    Perhaps because there are not many privately owned rubbish tips.

    Perhaps because much of the time recycling makes good economic sence.

    Perhaps because people in their capacity as individuals are concerned about the enviroment.

  18. Terje (say TAY-A)
    July 27th, 2006 at 12:55 | #18

    I guess it does come down to population again. No matter how you look at it twice as many people will eat twice as much or only be able to eat half as much.

    World population growth is slowing and population is expected to platue this century. I don’t think market dynamics are likely to work against this. Affluence typically provides security in old age and in the process lowers many of the economic imperatives that cause people to have lots of children.

  19. Terje (say TAY-A)
    July 27th, 2006 at 13:00 | #19

    It is worth noting that some of the highest levels of population growth are occuring in some of the poorest nation. For example Africa is expected to have a much higher growth rate over the coming decades than rich places like the USA and Europe.

    http://en.wikipedia.org/wiki/Image:Population_growth_rate_world.PNG

  20. July 27th, 2006 at 13:01 | #20

    Terje – “Perhaps because there are not many privately owned rubbish tips.”

    I find this a bit odd. Surely in a pure market there would have to be privately owned rubbish tips. Does libertarian thinking imply basic government services?

    “Perhaps because much of the time recycling makes good economic sence.”

    How – the cost of collecting the material and reprocessing it will just about always be more than the virgin material. It is also ver unusal that the reprocessed material is used in exactly the same application. An exception is congealed electricity (aluminium) where the cost of reprocessing scrap is 5% of the cost of refining the ore.

  21. July 27th, 2006 at 13:12 | #21

    Ender,
    As the resources get more difficult to find / mine / process, alternatives, like recycling, become more viable. If you need iron and the mountain a few kilometres away is 60% pure iron you will probably mine it. You might not, though, if there is a scrap yard full of old cars right next to you.
    That is the benefit of a proper price system – you can look at the relative prices of the various options and make a call on which is best for you. This will change over time and from location to location.
    A centrally planned system will probably tell you to use one or the other, regardless of the costs.

  22. Terje (say TAY-A)
    July 27th, 2006 at 13:18 | #22

    Your point about the cost of collecting is a reasonable concern and it would be foolish to burn up resources on collection if extracting the virgin material is less resource intensive. However the scrap metal industry seems to do just fine and I have little reason to doubt its viability.

    Does libertarian thinking imply basic government services?

    My point was that garbage services are currently mandated and in some ways subsidised. A private sector solution might change the economic balance in favour of recycling. Then again it might not. I merely caution against making assumptions.

    My own position is that I am in favour of most services currently offered by local governments and some of the services offered by state governments. At the end of the day I am a libertarian not an anarchist. I believe in smaller government not zero government.

  23. jquiggin
    July 27th, 2006 at 13:24 | #23

    Note that GDP is the wrong measure for all this, being Gross, Domestic and a Product. What we want is Full National Income, which excludes depreciation and net payments to foreigners and includes the value of leisure (also environmental services, but that needs more fundamental modifications to the accounts)

  24. July 27th, 2006 at 13:29 | #24

    Terje – “At the end of the day I am a libertarian not an anarchist”

    Fair enough I guess we really just differ on degree. As a sort of a socialist I like the blend that we currently have in Australia. I like the socialised medicine and care for less fortunate people however I am also in favour of free markets and the benefits they bring.

    I just think that economics now matter how you look at it cannot transcend basic physics. The only system that we know that has lasted a very long time uses steady state systems.

    The example from the lecture of the bacteria in the bottle is revealing. At 5 minutes to 12 the bottle is only 3% full however at 12:00 it is full. Are we at 5 minutes to 12?

    “Second Question; if you were an average bacterium in that bottle at what time would you first realise that you were running of space? Well let’s just look at the last minute in the bottle. At 12 noon its full, one minute before its half full, 2 minutes before its ¼ full than 1/8th than a 1/16th . Let me ask you, at 5 minutes before 12 when the bottle is only 3% full and is 97% open space just yearning for development, how many of you would realise there’s a problem?”

  25. Con
    July 27th, 2006 at 13:37 | #25

    But the so called libertarian think tanks are forever silent on the increasing evidence for climate change. At best a slight tip of the hat but nothing more. Is it a case of the free market think tanks scared of owning up to market imperfections?

    On the other side of the spectrum, the zero economic growth tribe are part of the same loony set as the right wing nutters.

  26. Con
    July 27th, 2006 at 13:37 | #26

    But the so called libertarian think tanks are forever silent on the increasing evidence for climate change. At best a slight tip of the hat but nothing more. Is it a case of the free market think tanks scared of owning up to market imperfections?

    On the other side of the spectrum, the zero economic growth tribe are part of the same loony set as the right wing nutters.

  27. wilful
    July 27th, 2006 at 13:47 | #27

    Except for the fact that there are very few members of this zero economic growth tribe and we never hear from them, whereas we hear far too much from the noisy minority of libertarian think tanks.

  28. Terje (say TAY-A)
    July 27th, 2006 at 14:56 | #28

    I just think that economics now matter how you look at it cannot transcend basic physics.

    Neither do I. Do you know of anybody that maintains that economics can transend physical laws?

    The example from the lecture of the bacteria in the bottle is revealing. At 5 minutes to 12 the bottle is only 3% full however at 12:00 it is full. Are we at 5 minutes to 12?

    Personally I don’t think we are. Population growth is slowing. Technology is opening up many alternate ways of capturing energy. I don’t think our ecological footprint is going through sustained exponential growth, although there are some obvious areas of concern.

  29. July 27th, 2006 at 14:56 | #29

    wilful,
    If you want to see where the zero economic growth “tribe”, try this thread.
    They all seem to be there.

  30. July 27th, 2006 at 15:20 | #30

    Terje – “Do you know of anybody that maintains that economics can transend physical laws?”

    So how do you fit exponential growth with finite resources? Any growth at all is exponential. If it is 1% year the quantity will double in 70 years, 2% will double in 35 years. 0.5% will double in 140 years. There is no growth that is not exponential. This really basic arithmetic and was the point that the maths professor was making.

    Population growth is slowing however if it does not get to zero it will still double in certain time frames. Every time it doubles there are more people than the sum total of all the previous periods – again simple arithmetic.

  31. July 27th, 2006 at 15:34 | #31

    Ender,
    You do it by dropping your assumption that the finite resources are “consumed”. They are used and can then be re-used.

  32. July 27th, 2006 at 15:49 | #32

    Andrew – “They are used and can then be re-used”

    You said this “Three GDP “eventsâ€?, one resource – the only things that cannot be recovered are the energy used and the time involved.”

    So how can the energy be recycled? Resources include energy. Things like cement are very difficult if not impossible to recycle. With any recycling process there is wastage. The shortfall must be made up from somewhere so even with recycling there is still use of virgin material.

    I am sorry Andrew the assumption that resources are consumed is valid. It may make the underlying resource growth smaller however it does not make it zero. Any growth above zero is exponential.

  33. Terje (say TAY-A)
    July 27th, 2006 at 16:29 | #33

    So how do you fit exponential growth with finite resources?

    Perhaps you could start by telling me the point in time at which an exponential growth curve ceases to be finite?

  34. Andrew
    July 27th, 2006 at 16:31 | #34

    From Endor;
    “Second Question; if you were an average bacterium in that bottle at what time would you first realise that you were running of space? Well let’s just look at the last minute in the bottle. At 12 noon its full, one minute before its half full, 2 minutes before its ¼ full than 1/8th than a 1/16th . Let me ask you, at 5 minutes before 12 when the bottle is only 3% full and is 97% open space just yearning for development, how many of you would realise there’s a problem?�
    The last time I looked the world wasn’t doubling in population every minute – so I guess we’ve got quite a bit of time up our sleeve to determine if we have a problem or not.
    In the meantime, we would be foolish not to take steps to improve the environment and mitigate climate change risk that didn’t cost too much.
    For mine – I think the evidence that greenhouse gas emissions are degrading the environment are now pretty clear. What is not clear is what the impact of climate change will be, the timeframe it will take and even whether it is worth worrying about today.
    As insurance against the bad outcomes – we should start adjusting behaviour today. However, like most forms of insurance, it is only worth doing if the premiums are not too high.
    Simple things like more efficient energy consumption, R&D into renewables, going nuclear, and carbon trading are all sensible steps that won’t slow down world development too much.

    Endor also said
    “Any growth above zero is exponential.”
    Err – no it’s not.

  35. Terje (say TAY-A)
    July 27th, 2006 at 16:34 | #35

    Simple things like more efficient energy consumption, R&D into renewables, going nuclear, and carbon trading are all sensible steps that won’t slow down world development too much.

    I am not sure I agree on the bit about going nuclear.

  36. July 27th, 2006 at 16:35 | #36

    Andrew – “Endor also said
    “Any growth above zero is exponential.�
    Err – no it’s not.”

    So what is it?

    Terje – “Perhaps you could start by telling me the point in time at which an exponential growth curve ceases to be finite?”

    I can’t that’s the point. Exponential growth is infinite however the resources that it uses are finite.

  37. Andrew
    July 27th, 2006 at 16:50 | #37

    An example – If Brisbane added 50,000 new residents each year – it is clearly growing. Growth is above zero – but it is not exponential growth.

  38. July 27th, 2006 at 17:02 | #38

    Andrew – “An example – If Brisbane added 50,000 new residents each year – it is clearly growing. Growth is above zero – but it is not exponential growth.”

    Ok if the population of Brisbane is 1.5 million then it would be experiencing 50 000 /1 500 000 X 100 = 3.3% growth per year. The doubling time would therefore be 70/3.3 = 21 years. So in 2027 the population of Brisbane would be 3 million in another 21 years 6 million another 21 years 12 million. So given a 3.3% growth rate the Brisbane council must double water and services etc to cope with population growth every 21 years.

    The opening point of the maths professor’s talk is that people really do not understand the exponential function however it is really simple mathematics. It is really worth a read or watch the talk.

  39. July 27th, 2006 at 17:15 | #39

    Ender,
    I think you are guilty of simple mathematical basis error. If Brisbane is experiencing growth 50,000 residents per year that is only 3.3% while there are 1.5 million residents. Next year there would be 1.55 million residents, so 50,000 growth gives 50 000 /1 550 000 X 100 = 3.2% growth. The year after, 3.1% growth. Still growing – but not exponentially. Doubling would then be in 30 years, but the next doubling would be 60 years, then 120 years etc. Growth, but not exponential growth.
    Simple mathematics.

  40. July 27th, 2006 at 17:28 | #40

    Andrew – “Next year there would be 1.55 million residents, so 50,000 growth gives 50 000 /1 550 000 X 100 = 3.2%”

    However populations do not grow like this. How do you make the next year’s growth exactly the same as the previous year? Populations grow from new people and immigration. Are you going to stop the people in Brisbane having babies? Good luck with that one. If you are a free libertarian – who the hell are you to say I cannot have 10 children and so on ….

    A fixed amount of 50 000 per year represents falling growth not a constant rate and is completely impossible to achieve in the real world. Also a GDP growth of 3% per year is exponential, If you artifically limited it to say 1 billion per year that is reducing growth. How would you impose the limit of 1 billion if you believe in free markets.

    It actually reinforces my point that we need to achieve near to zero growth or even negative growth to make a sustainable society. Anything else as has been demonstated here will lead to exponential growth and eventually run into resource limits.

  41. Andrew
    July 27th, 2006 at 17:44 | #41

    Ender,
    I presume the point you are trying to make is that if the economy keeps growing – at some point we run out of resources to fuel the growth. No argument there.
    But my counterpoints are;
    Firstly that we are still a long way from this being a problem – because economic growth is not exponential, and for the reasons many have outlined above, population growth can be much lower than economic growth.
    And secondly; even when it does start to become a problem – who knows where we’ll be as a human race… (with tongue in cheek) maybe an Isaac Asimov future!!! (have you read the Foundation trilogy?)
    Whatever decisions we make today – they need to balance economic development with not stuffing up the environment for the future. I don’t think the too objectives are incompatible.
    It seems to me that the climate change debate gets dominated by people with extreme views/agendas on both sides. The pro-carbon fuel lobby v’s those who see climate change as a useful tool to advance an anti-development agenda.
    Surely there’s a sensible middle ground?

  42. Andrew
    July 27th, 2006 at 17:47 | #42

    Ender – real world experience should tell you that populations do not grow exponentially – there are natural limitations. Brisbane is far more likely to grow at a constant 50,000 new people each year than at 3% per year.

    Growth does not have to be exponential.

  43. July 27th, 2006 at 17:57 | #43

    Andrew – “I presume the point you are trying to make is that if the economy keeps growing – at some point we run out of resources to fuel the growth. No argument there.”

    Yes that is exactly the point I am making.

    “Firstly that we are still a long way from this being a problem – because economic growth is not exponential, and for the reasons many have outlined above, population growth can be much lower than economic growth.”

    OK firstly any growth rate (rather than growth amount like 50 000) that is sustained is exponential. If the economy is growing at 3% per year, not a fixed amount per year, it is exponential. Secondly go back the bacteria in a bottle. At 5 mins before the bottle is full it is only 3% full. Taking this in its allegorical form rather than a description of reality how do you know that we are not at the point equivilent to 5 mins before the bottle is full?

    I have read the entire Asimov Foundation series incuding where it is tied to the Robots/Elijah Baley novels etc and the extension novels written by different authors. I am science ficion/ fantasy junkie. Perhaps this is our future – who knows.

    There is a sensible middle ground however it may be that we have to accept steady state economics powered by the sun rather that endless growth fuelled by finite and irreplaceable fossil fuels.

  44. Andrew
    July 27th, 2006 at 18:12 | #44

    “Taking this in its allegorical form rather than a description of reality how do you know that we are not at the point equivilent to 5 mins before the bottle is full?”
    Honest answer – I don’t!
    But you have again gone back to the example where growth doubles (the old rice on a chess board problem) – the real world does not work this way. The population is not doubling every minute – and the rate of doubling will slow over time because of natural constraints. My ‘hunch’ is that we have plenty of time on our side.
    I agree – perhaps one day we will need to “accept steady state economics powered by the sun” – but wouldn’t it be a shame if we accepted that too soon when we don’t need to? Perhaps one day we will have the technology to solve all the resource constraints and science fiction becomes science reality?

  45. July 27th, 2006 at 18:12 | #45

    Ender,
    I was simply making a point about your mathematics, not your overall point.
    As to your overall point – you are simply wrong. The population growth rate is dropping, not rising, and world population is expected to peak in about 2050 and thereafter to decline. See here.
    It has been dropping since the 1960′s so I think that counts as a long term trend. If current projections are correct, global population should top off at around 9 billion people.
    I am not going to try to limit how many kids people can have – they are doing it by themselves.

  46. Terje
    July 27th, 2006 at 18:46 | #46

    Exponential growth does not become infinite. If a population grows at 3 percent per annum then the population will always be finite.

  47. July 27th, 2006 at 19:55 | #47

    Andrew – “The population growth rate is dropping, not rising, and world population is expected to peak in about 2050 and thereafter to decline”

    Yes but you want to continue to grow the world economy you will continue to grow resource use. Population may flatten out but for who?

    Terje – “Exponential growth does not become infinite” – Please read the lecture. Consider the case of the chess board and the reward of one grain of rice on the first square, 2 on the second and so on. The exponential function rises to infinity.

    As in the previous example a 3% growth rate means a doubling every 70/3 = 23.33 years. Where do you think it stops?

  48. Terje
    July 27th, 2006 at 20:25 | #48

    It gets bigger and bigger but never does it become non-finite.

  49. Terje
    July 27th, 2006 at 20:55 | #49

    Lets do the math;

    p(t) = p(0) * (1 + r)^t

    where:-

    r = growth rate. Eg 0.03
    t = the number of years since growth started.
    p(t) is the population in year t.

    now clearly for all finite values of “t” then p(t) is also finite.

  50. July 27th, 2006 at 20:56 | #50

    Terje – OK – yes you are correct the function approaches infinity for finite periods of time. That is not really the point.

  51. Terje (say TAY-A)
    July 28th, 2006 at 00:57 | #51

    Ender,

    I understand your point. I first heard it told as a story about lillipads on a pond where each day the number of lillipads doubles. After 100 days the pond is half full. The closing question is how many days until it is completely full. I also became fanatical about compound interest around that time. I think I was 13 or 14 and it had a big impact on how I saw the world.

    However I think the scenerio that you are attempting to paint is built on lots of assumptions. Some of them are:-

    1. It assumes that economic output is correlated in a linear fashion with the useage of physcial resources.

    2. Physical resources are not re-used.

    3. The pool of physical resouces are bounded (ie we are stuck with one pond for our lillipads).

    4. The clock is currently at 5 minutes to twelve.

    History suggests that our current civilization will will come to a terrible end one day. However if I had to place a bet on such a thing then I would say that you and I will both have come to a terrible end long before our civilisation starts its inevitable decline.

    Regards,
    Terje.

  52. July 28th, 2006 at 10:23 | #52

    Terje – “1. It assumes that economic output is correlated in a linear fashion with the useage of physcial resources.”

    No it doesn’t – I am assuming that economic growth will cause a rise in use of resources. It does not matter if the ratio of input to output is greater because this only reduces the growth of resource use not eliminates it. Also we are not using the reducing rate of consumption to reduce use of resources. What is happening is that rate of resource consumption stays the same or increases and we use the vastly increased output to make ourselves vastly more rich.

    “2. Physical resources are not re-used.”
    Fossil fuel energy cannot be re-used and is finite. Other resources are re-used to some extent however the massive growth in landfills testifies to the fact that we do not do this very well at present. Some products cannot be recycled. In most cases except for metals the recycled product is very rarely the same as the virgin product. In this case re-cycling reduces consumption however, as the primary product still needs virgin material this material is still depleted. In Nature all products are composed of the same building blocks that are assembled and torn down as required.

    “3. The pool of physical resouces are bounded (ie we are stuck with one pond for our lillipads).”
    Ok where are the other lillypads?

    “4. The clock is currently at 5 minutes to twelve.”
    I am not assuming that at all. To a bacteria in the 97% empty bottle at 5 mins before 12:00 it would seem like that there is plenty of room for all future needs of bacteria civilisation. However 5 mins later there is none. I am asking you how do you know that we are not in the same boat (or bottle). Even if the bacteria find 3 more bottles all 4 will be filled at 2 minutes past 12:00.

    I agree that I will be re-cycled long before this becomes a problem however how close to 12:00 are we?

  53. July 28th, 2006 at 10:25 | #53

    JQ – thank you for allowing this completely off topic discussion to continue. I hope that it is at least a bit interesting.

  54. Terje (say TAY-A)
    July 28th, 2006 at 10:40 | #54

    I agree that I will be re-cycled long before this becomes a problem however how close to 12:00 are we?

    I suspect that we are at least several centuries away. Probably more like thousands of years but its hard to be very certain over such time frames and it depends on what happens in the mean time.

  55. wilful
    July 28th, 2006 at 12:50 | #55

    I oscillate between optimism and pessimism on human consumption and its significance to the biosphere. We’ve definitely overshot the limits in some areas and there will be crashes in food available using current technologies (overfishing, no more fossil groundwater, massive soil erosion), but what if we all start eating vat food, algae etc? Problem solved? And there’s currently more of a problem with over-production and poor distribution of food than growing enough.

    I think innovation will easily account for resource substitution in all other areas of human endeavour, I’m not totally sure about food. There are lots of free kicks still in the system though, Australian agriculture is terribly wasteful and could easily provide similar outputs on a lot less inputs.

    All the population trends have us levelling out at about 9 – 9.5 billion. Far too high, but certainly not exponential.

    The big issue (IMHO) is biodiversity. We’re permanently losing uncountable species, and this will only accelerate with global climate change. Much of this is inevitable. This is going to impoverish us in the future, not necessarily materially but spiritually. Humanity could live fulfilling lives on a desert planet, but I don’t think this is a good thing at all.

    We will get through to a carbon constrained future, quite quickly I believe, though the time lag of what’s already in the system means many consequences are already set.

    It will be fascinating when we observe external stimuli driving climate change (a hotter sun or whatever). Do we start to terraform to counteract natural processes? Are we the ultimate expression of Gaia?

  56. July 28th, 2006 at 14:08 | #56

    I oscillate between optimism and pessimism on human consumption and its significance to the biosphere. We’ve definitely overshot the limits in some areas and there will be crashes in food available using current technologies (overfishing, no more fossil groundwater, massive soil erosion), but what if we all start eating vat food, algae etc? Problem solved? And there’s currently more of a problem with over-production and poor distribution of food than growing enough.

    I think its very pessimistic.. You could have voiced the above opinion 100 years ago with the same amount of conviction. It doesn’t change the fact that 100 years ago, we hadn’t overshot the limit, there were no crashes in food available, no huge problems in distribution. Things have improved, even with a massive population growth.

  57. Terje
    August 5th, 2006 at 03:29 | #57

    Wilful,

    If we need more land for food then we just need more vegetarians. Meat production requires a lot more resources. Once again this would appear to be something the price mechanism can sort out, so long as land rights are solid.

    Regards,
    Terje.

  58. August 6th, 2006 at 13:50 | #58

    I’ll bring up one fact which both sides in the text above completely neglect.
    You may verify the following from other sources, but there is measured scientific data implying that the “global warming” extends throughout Solar system in the last dozen or so years (early 1990′s ’till now). Most oustanding examples are Mars (ex. melting ice caps during this period, first time since seen in 19th cent.); Jupiter (ex. Giant Red Spot movement in lattitude [first time since first observed!] and appearance of new giant storm, both clearly related to increased Jupiter temperatures); Saturn (measured drastic increase in wind speeds during the same period, first time since measured, approx. 19th century). Similar, though less striking or harder to clearly prove data exist for other planets (ex. Pluto’s increasing measured temperatures although it is actually moving away from the Sun…). Let’s not forget the Earth itself (I beleive in measured Earth global warming data…).
    What is causing this? The strongest Sun activity since we measure it (via count of dark spots, circa 450 yrs ago) is considered the most likely as it coincidentally occures in this same period of the time…

    Taking into account this evidence, my personal opinion is that we contribute little (and actually may be helping with cooling effect) to the Earth global warming . Simply said, if Earth heated up at the similar rate as Mars, Jupiter and Saturn during this time interval, one would expect much higher temperature increases…

    How this makes sense? There are scientific works that examine not only production of the greenhouse gases by our Earh polluting efforts but the shading (cooling) effect of the pollution particulate matter we produce … It is just possible that our overall pollution effect on Earth climate is slight cooling… But, while the first part of this post is exact measurement related, this part is not yet clear and further scientific study may prove/disprove it…

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