A popular misconception in the public mind is that science “proves” things by turning them from ideas and theories into absolute “facts”. This more or less confuses science with mathematics. Mathematical theories can be proven; in science, nothing is absolutely certain.
Scientists apply statistical criteria: they conclude theories are well-established if they have less than a 1-in-20 or 1-in-100 chance of being wrong. These are referred to as the 95% or 99% confidence levels.
In practice people have to act on scientific theories, implicitly taking account of the probabilities. The acceptable probability is a value judgement – it depends on the consequences. A 10% chance of rain in a weather forecast may encourage a person to carry an umbrella but still go for a walk. But a 10% chance that an aircraft might crash would encourage few people to fly.
What is concerning about potential human-induced climate change is that it is likely to have adverse effects on humans and ecosystems. Whether we do something about climate change by reducing global greenhouse gas emissions, or choose to adapt to it, depends on the potential costs and benefits.
It is a matter of risk management, with risk being defined as the probability multiplied by the consequences. What we decide to do is a value judgement, based on the best estimates of both the probability and the potential consequences.
There is a common engineering example illustrating probability and consequences, using the different standards for engineering design which are applied to culverts, versus bridges, versus large dams.
A culvert, where the consequences of an overflow would be minor flooding of a street, is built to cope with around a 1 in 10-year flood. That is, it has a 10% chance of failure in any given year.
A bridge, where failure could mean inconvenience or at worst some loss of life, is built to cope with something like a 1-in-100-year flood. That is, it has a 1% chance of failure each year.
A large dam, where failure could mean loss of thousands of lives, is built to cope with a 1-in-1000-year, or even a 1-in-10,000 year flood. That is, it has a 0.1 or 0.01% chance of failure.
Similar reflection on probabilities, risk and consequences applies when we consider coping with climate change. Take a change in rainfall. If the chance of a dangerous amount of rainfall change is very small we might ignore it. But if there was a 50% chance and the consequences were serious floods or water shortages, we might take account of that in decision-making. We might decide to adapt to the risk by building flood control levee banks or dams. Or we may try to lower the likelihood of serious climate change by cutting global greenhouse gas concentrations.
In the case of providing advice on potential climate change, scientists have had to depart from the traditional pure science criterion, where we only discuss what is accepted at the 95% or 99% probability level. We have had to take the consequences into account and make statements relevant to risk management.
The Intergovernmental Panel on Climate Change (IPCC) has rightly adopted the position that scientific advice should be “policy relevant but not policy prescriptive”. This means scientists should address the issue of risk management, even for outcomes less than 95% certain.
In other words, we should state the risks, provide response options and their consequences, but not tell governments what to do. This recognises that scientific advice is just one input to a policy decision.
I believe that is what the IPCC has done. Given that some outcomes are difficult to quantify, scientists argue about makes a credible risk. One example in the IPCC’s Fourth Assessment Report in 2007 was the estimated range of uncertainty regarding global sea-level rise.
The quantifiable elements were thermal expansion of the ocean waters and the melting of mountain glaciers, for which data were available. But, for the possibility that much of the ice in the huge ice sheets of Greenland and Antarctica might melt or slide into the sea, several glaciological processes were just being identified, and were yet to be well quantified.
So, the IPCC Fourth Assessment Report stated the sea-level rise by 2100 as a range of 18 to 59 cm, with a caveat that processes yet to be quantified could increase this estimate by another 10 to 20 cm. Subsequent estimates put this extra contribution from Greenland and Antarctica even higher. The Arctic sea ice has melted faster than expected, and several outlet glaciers in Greenland and Antarctica have accelerated. So IPCC was hardly scaremongering – if anything it was being rather conservative.
Policy is value-laden, while science can only tease out the possibilities and probabilities. Some have now agreed we need to avoid a global average warming of more than 2°C. But this “limit” is uncertain and value-laden. What is “dangerous” to someone living near the coast in Vanuatu may be quite different from what someone in Russia or inland Australia might consider dangerous. Many of us think a 2°C limit may not be strict enough to avoid a dangerous degree of climate change. But that is a value judegment made under uncertainty.
Only time will tell what is an acceptable risk and to whom.
The Conversation
Comments (85)
Comments on this article are now closed.
Ben Heard
Director, ThinkClimate Consulting (logged in via email @thinkclimateconsulting.com.au)
Good article Barrie, and thanks for you text books by the way.
What you lay out is indeed the way it should work. To imagine that there is any responsible policy action that does not aggressively seek to avoid temperature rises of 4 or more degrees, even as the certainty of that outcome lessens, shows only how we approach climate change differently to building a dam.
But I think it highlights a real quandary for climate scientists.
Climate change is hard, complicated, nuanced stuff. That…
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Tim Scanlon
(Climate and Agronomic Extension at Department of Agriculture and Food - Western Australia)
I agree with this article, that science is probabilities and that our risk management is a factor of that.
But one point that wasn't really discussed was that we have certainty over the changes that have already occurred, thus we already know a level of change is required (or is happening in some instances). So if we are to look at probabilities and risk management, it is important to place the current "sunk" risks with the future risk management.
I'd also like to add a point that Curt Stager…
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David Arthur
n/a (logged in via email @fastel.com.au)
Gday Tim, my response to Stager's suggestion is that we are more likely to bring on a repeat of the Paleocene-Eocene Thermal Maximum than have our heirs and successors experience a reglaciation.
Thanks to fossil fuel use to date, warming feedbacks already initiated (ie tipping points already being crossed) are loss of Arctic sea ice, so that boreal summer sunlight absorbtion in the Arctic Ocean is increasing (less sunlight reflection), sublimation of offshore Siberian methane clathrates, and methane outgassing from thawing permafrost.
Tim Scanlon
(Climate and Agronomic Extension at Department of Agriculture and Food - Western Australia)
I'm not sure if you've read Stager's work, but he is not talking about decades or hundreds of years, but 10s of thousands of years.
Most of his book is referring to changes leading up to the tipping point where the effects reverse (Climate Whiplash as he calls it). So yes those changes will occur, but at some point they will reverse and will once again enter back into natural cycles. Humans or at least life on Earth, will continue to inhabit the planet, so an ice age is a possibility. He was being slightly facetious with the comment, using hyperbole to underline the massive impacts we are having on the climate and the Earth.
Videos of his presentation on Climate Whiplash:
http://www.youtube.com/watch?v=1w3gpuYxEq0
http://www.themonthly.com.au/climate-whiplash-curt-stager-3385
My blog on the book here:
http://thetysonadams.blogspot.com/2011/05/books-you-should-read-climate-change.html
David Arthur
n/a (logged in via email @fastel.com.au)
Thanks Tim, I've not read Stager, but I am aware of the time-scale of glacial-interglacial transitions.
My understanding is that from the onset of the Pleistocene, up to about 1 Mya, there was glacial-interglacial cycling with a period of around 41,000 years (the "41 ka world"). Since then, the world has been glaciated for much longer periods, but with similar interglacial periods as previously (the "100 ka world").
Anthropogenic influence has certainly shifted the world from "100 ka" climate…
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John Harland
bicycle technician (logged in via email @gmail.com)
I don't know what world you are living in, Sam Chafe, but i maintain that controlling speeds in urban areas is a basic element of creating civilised neighbourhoods. There is substantial evidence of major reduction of risk with lower speed limits.
Civilisation is the process of living with other people. There is sound evidence in the cases of alcohol, gambling and tobacco that there are serious effects from excesses of each of these on a lot of people other than the primary consumer. It is proper…
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John Harland
bicycle technician (logged in via email @gmail.com)
It is not the invention of the internal combustion engine that caused all the ills associated with it. It is the overuse of the technology.
A century ago the motorcar was a solution to pollution: the hundreds of tonnes of horse droppings on the streets of cities and washing down into our rivers.
If we were to blame the inventors, perhaps we should blame the inventor of the wheel, or the first users of fire.
A major aspect of risk assessment is the question of what are reasonable levels of usage now and into the future, not trying to blame things on well-intentioned people in the past.
Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
I find the suggestion that the development of the internal combustion engine should have anticipated the problems of CO2 emissions some 150 years later just a bit rich. Solutions are very clear in retrospect, but I doubt anyone was concerned with 'risk management' in those days. In fact, scientific advances have seldom, if ever, included a risk management plan. All up, if the benefits of scientific research are balanced against problems thereby created, benefit is the clear winner. It is perfectly…
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Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
That's a pity. I was with you until you wrote: "Areas where such has been the case include gambling, food, alcohol, road rules, and even tobacco, where little thought has been given to freedom of choice and individual inconvenience."
I think a lot of thought went into how we should balance individual freedom of choice and a government's duty to protect citizens from adverse effects of the freedom to market and sell substances or 'entertainment' that may have adverse health or social consequences. To suggest that tobacco policy is not informed by science is a bit rich, in my view.
Seems more a case of your values and judgement differing from those of many others.
Ben Heard
Director, ThinkClimate Consulting (logged in via email @thinkclimateconsulting.com.au)
Well put Lennert.
To imagine that the processes required to mandate the wearing of seatbelts, drop the suburban speed limit to 50 or the progressive mandatory phase in of safety features in cars have not taken due account of the trade of in freedom of choice is quite silly, and I dare say insulting to the professionals that work in the area.
James Jenkin
EFL Teacher Trainer (logged in via email @gmail.com)
Ben, I don't think professional researchers should be thinking about freedom of choice. Why would they? It's an expert's job to describe the impacts of a collision at 60 kmh and 50 kmh, but not to decide whether people should accept a law that reduces the speed limit. That's the government's responsibility.
I think that's Pittock's point.
There seems to be a tendency for governments tend to lift one area of research and use it as policy. As we know, they call this sort of law-making 'evidence…
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Ben Heard
Director, ThinkClimate Consulting (logged in via email @thinkclimateconsulting.com.au)
Hi James, my use of the term "professionals" was a little broader than you may have taken on board. Of course, we need the objective results of the influence of speed in collision to continue the current example. For sure. That's one part of the decision, very early in the process. But you keep running it, and naturally the safest speed is pretty much walking pace on that basis! So in those decisions that have been made, a whole range of factors intersect, including how deeply we are prepared to…
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John Nicol
(logged in via Facebook)
I have to agree Sam. There is no doubt the articles main point is a very important one in a lot of areas, including climate change. For example, what is the risk that all the money spent on fairly dubious modelling will lead us in the right direction? What is the risk that instead of the globe becoming warmer, we suddenly start towards a freezing planet which will require all of our engenuity ot stay alive, rather than garnering at least some benefits from warming such as better crops etc…
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David Arthur
n/a (logged in via email @fastel.com.au)
"What is the risk that instead of the globe becoming warmer, we suddenly start towards a freezing planet ...?"
By what mechanism is the planet susceptible to freezing? At least in the case of global warming, the mechanism and processes driving it are clear, which is a starting point for risk assessment.
John Harland
bicycle technician (logged in via email @gmail.com)
The idea that a working-class family would not want to cycle is a middleclass prejudice that led not only to unsound regulation, but a failure to attend to the socio-economic impacts of the bicycle helmet regulation.
Those in the cycle trade in less-wealthy areas faced the reality. Working people do cycle, and their kids do too. They faced major ethical dilemmas, as well as financial difficulty, with helmet mandation.
Only now, when investment in a cycle-hire scheme is threatened, are $5 helmets…
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Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
No, Mr. Arthur, if individuals are deliquent in their responsibilities, they are taken to task by whatever person or group to which they owe such responsibility. We do not need new governmental regulation to enforce such compliance. We have more than enough already.
David Arthur
n/a (logged in via email @fastel.com.au)
Smoking in confined spaces? Asbestos? Victims may sue if they are still alive as you suggest, but taxpayer still winds up wearing at least some costs.
Your remark that we already have too much government regulation is a value judgement. In response, I'd remark that government has a duty of care towards all citizens, which includes but is not restricted to a duty of maintaining liberty.
Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
Are you arguing for public lynching, Sam?
You value individual freedom (and rightly so) and would not sacrifice it even to protect weaker members of society who do not control their behaviour as well as you think you do. Fair enough.
But even you will probably agree there must be limits to individual freedom. Would you be happy with the freedom to stalk, for all? To smoke in a hospital waiting room? Or to have sex in public? To advertise explicit (gay, for good measure) pornography on billboards?
I am certainly not advocating none of those, but pointing out that most of us do see a role for regulation at the expense of some individual freedoms.
Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
Dear Mr. Hartland,
I was very interested in your comments about the lack of research, and therefore justification, concerning bicycles. It appears that it was the determination of a small coterie of individuals adamant that bicycles should be the way of the future that has burdened us with bicycle paths and right of way on busy suburban streets. And as an example of burgeoning (atavistic) advance, we could hardly do better. It is the doomsayers of societal presumption that have scored their…
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Dale Bloom
Laboratory analyst (logged in via email @mail.com)
This is one of the very few articles I have seen that relates global warming to risk management, and carrying out effective risk management strategies and practices would be the most probable way of reducing global warming, without creating some other type of environmental disaster further down the track.
It is important to realise that science largely got us into the current situation. The combustion engine and CO2 producing power stations are based on science principles, and large amounts of science research was carried out on these in the past, to eventually create an environmental disaster of global warming some decades later.
It is apparent that insufficient risk management was undertaken by scientists in the past, when developing methods of power generation and transport, and it can only be hoped that this is not the same in the future.
Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
From Wikipedia:
1791: John Barber receives British patent #1833 for A Method for Rising Inflammable Air for the Purposes of Producing Motion and Facilitating Metallurgical Operations. In it he describes a turbine.
Could John have foreseen CO2-induced climate change? And if it were possible, should we have avoided the industrial revolution and stick with horse power, water- and windmills and the like?
I think you expect a bit much foresight and control over events from scientists. Niels Bohr knew what the consequences of his work could likely be, but in the case of fossil-fuel based power generation and transport the knowledge of adverse effects on climate only gradually emerged relatively recently when the world was well and truly addicted to fossil fuels.
David Arthur
n/a (logged in via email @fastel.com.au)
Knowledge and hence anticipation of greenhouse warming was well-established by mid-20th century (eg work by GS Callendar, work by Gilbert Plass).
However, people did not know about sunlight reflection due to increasing levels of industrial air pollution. This countered the warming that would otherwise have occurred, up until pollution declines in the 1980s (action to prevent acid rain in the West) and 1990s (decrease of Soviet-era industrial pollution in the former Soviet bloc).
Air pollution has resumed post-2000 - Chinese industrial takeoff is powered by high-sulfur coal. The last few years have also seen a minimum in solar output (nowhere near as severe as the Maunder Minimum).
Richard Davis
Telecommunications Engineer (logged in via email @bigpond.net.au)
Dale. On general level your comment is quite valid we have certainly changed the way that things are assessed particularly from the 60's onward. I think you are confusing science with market based engineering, industrial chemistry, medicine and more.
It was only from the late 60's and onward that "some" scientists and engineers have refused to work on particular projects and the ethics of such projects questioned.
Richard Davis
Telecommunications Engineer (logged in via email @bigpond.net.au)
Sorry wrong even Oppenheimer and others questioned the value of nukes. but my general point is the same.
Dale Bloom
Laboratory analyst (logged in via email @mail.com)
Hi Richard,
Science research is an interesting area in terms of time and money spent, and worldwide it has been estimated that less than 10% of research is now carried out in universities.
However, the universities initially train science researchers, and they also train teachers, who then train students.
I would disagree that the message of risk management is being passed down the line.
Risk management is workable and cost effective, and the Du Pont company is an example of a company that has had a policy of zero injuries and zero waste for some decades, and it also tries to establish zero energy consumption in a number of its processing plants, by carrying out co-generation.
All that is based on risk management, and the Du Pont company has prospered during that time, to become one of the largest companies in the world,
Unfortunately, not many companies have a policy of zero injuries, zero waste and zero energy consumption.
Richard Davis
Telecommunications Engineer (logged in via email @bigpond.net.au)
Hi Dale , I am still confused as to the connection between pure science and its application. To understand the splitting of the atom and how it might immediately be put to use (unfortunately during a militaristic age) are different things?
How should all real discoveries be assessed as such. The discovery is one thing. Its application another and not really the realm of science or possibly scientists.
John Nicol
(logged in via Facebook)
This is an interesting article which has lead to wider comment.
Traditionally there was always a distinction between pure and applied science as practiced in research institutions - that which was curiosity based and that which sought to solve problems in industry, society or the environment.
However, it was always acknowledged and hoped, that the former, sometimes referred to as "blue sky" research, would turn out to be useful, and in general, most major scientific advances which have been…
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Dale Bloom
Laboratory analyst (logged in via email @mail.com)
Hi John,
There have been successes that have come about either directly or indirectly from science, and a great many failures that could have been avoided, and this is everything from cane toads to Fukushima.
I would also place global warming as a situation that has come about as a consequence of science, and my basic question is, what should scientists be doing to avoid creating such disasters in the future?
I would think better risk management practices would be an answer.
John Nicol
(logged in via Facebook)
Dale, I think you would need to expand a bit on your thesis that science has lead to global warming. In the first instance of course, we are not certain that increase CO2 has any effect on either or cooling - it could do either which may be why there has been no statistically significcant warming since 1995 (Phil Jones, CRU). CO2 is a strong absorber in the lower atmosphere, but in the region above cloud level, it is responsible for radiation on its own, about 55% of the insolation from the sun…
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Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
John, I think you need to update yourself on Phil Jones' statements in BBC interviews, and refrain from selectively quoting what he said.
In his famous February 2010 interview, prof Jones said: "I calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods." (http://news.bbc.co.uk/2/hi/8511670.stm)
Bit dishonest to just write "there has been no statistically significcant [sic] warming since 1995" like you did, don't you think?
Moreover, in June 2011 the BBC had another interview with Phil Jones, which denialists don't seem to know about. The title of that piece: "Global warming since 1995 'now significant'" (http://www.bbc.co.uk/news/science-environment-13719510).
Ross James
Engineer (logged in via email @bigpond.net.au)
I wonder if it's still significant, now that 2011 data is complete, with temperature relatively low for the year. I certainly can't detect any upward trend over the past 10 years or so, from UAH or RSS data.
David Arthur
n/a (logged in via email @fastel.com.au)
We may reasonably expect 2011 to be relatively cool.
1. La Nina events give cooler atmospheric temperatures than El Nino years. The present La Nina is weakening, and the next El Nino is on the way.
2. 2011 is at the tail end of a period of low solar output. Solar intensity will pick up over the next few years.
Mind you, I wouldn't bother with UAH or this RSS data. I'd stick to credible data sets like GISS and NOAA, which were investigated by the Koch-funded BEST project and found to be reliable.
John Nicol
(logged in via Facebook)
I agree with you Ross. None of the current data sets demonstrate any warming since since about 2000, and I think Phil Jones' later remark referes to the period since 1995, for which there has been warming. I must say that I was very surprised that he came out and made the "no significant" statement, using 1995 as a starting point. This lack of trend is confirmed by the people who are searching for the reason and laying the blame on Chinese emissions of sulphate aerosols in their new, large, coal-fired power stations.
Ross James
Engineer (logged in via email @bigpond.net.au)
John, that's exactly right. There's a lot of effort now going into trying to explain the recent lack of warming, so it's pretty universally accepted. 2011 continues that trend. (2012 is predicted to be much hotter, but it's off to a cold start).
I noticed Lennert mentioned GISS data. He should be aware that correspondence from within GISS points out that their data is focussed on USA, and even they refer to Hadcrut for the global picture. Also, GISS deviates significantly from the other data sets, probably due to all the interpolations and extrapolations they use to make of for missing data points.
Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
Okay Ross, enlighten me. Can you please provide links to the graphs that show the recent lack of warming, and the evidence that that lack of warming is 'pretty much universally accepted'?
Ross James
Engineer (logged in via email @bigpond.net.au)
Lennert. Happy to, but short on time now. See how I go. Hadcrut data http://www.cru.uea.ac.uk/cru/data/temperature/hadcrut3vgl.txt Last column shows the global average. UAH - http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt
You can see a plot of UAH data here : http://www.drroyspencer.com/2012/01/uah-global-temperature-update-for-dec-2011-0-13-deg-c/
RSS - have to go to a meeting, so will follow up. As John pointed out, there's lots of effort being made now to try to explain the lack of recent warming.
I plot these myself ad do my own analysis.
David Arthur
n/a (logged in via email @fastel.com.au)
I forgot to mention the Chinese industrial takeoff in my response to Ross's comments based on an absence of recent warming.
Before you go poo-poohing sulfate aerosols as reflecting sunlight, note that emitting sulfate aerosols into the stratosphere is known to induce global cooling, eg Pinatubo eruption 1992, and is one option being considered for geoengineering the climate.
[I have no problem with sulfate aerosols over the Arctic to substitute for summertime sunlight reflection off Arctic pack ice when the latter has melted in a couple of decades, but I don't want it in the Southern hemisphere because of consequent ozone depletion.]
John Nicol
(logged in via Facebook)
Lennert,
I may have appeared to be selective, but was unaware of the quote to which you have just directed me and I accept that as his current view. However, several recent papers have come out trying to explain why there has been "no warming between 2002 and 2009 and looking at aerosols as a possible constraining mechanism. One in particular by Foster, Mann and some others showed all of the sets giving no warming at all over this period, hence their concern to explain it. This may well be…
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Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
Sorry if I was a bit harsh, John, but I get pretty annoyed about all the misquotations and distortions by climate denialists. You may well have honestly believed what you wrote, but in that case the fact remains that you uncritically quoted misinformation you picked up from the denialist blogosphere.
And if I look at NASA's GISS (http://climate.nasa.gov/keyIndicators/index.cfm#globalTemp), I see no evidence of stabilising temperatures. Increasing sulphur levels and La Nina included.
All this talk about "Global warming has stopped since... [fill in the most recent peak year]" suffers from the fact that you can't establish statistically significant trends over short periods of time. The warmest years in the past century were 2005 and 2010, and each past decade was warmer than the one before for at least half a century.
Over the longer term, the warming is clear. And there is little doubt about what causes it among the experts who studied the matter.
John Nicol
(logged in via Facebook)
Thanks Lennert, I accept your apology.
BTW I didn't pick up the quotation from the blogsphere but directly from a TV interview showing Phil Jones on the BBC.
With regard to the highest temperatures being measured during the last ten years, this is exactly what one expects to be the case.
In about 1850 the globe emerged from the well documented little Ice age (LIA) At that point in time, or about 100m years before actually, it had three choices - 1. it could stay cool 2. it could get…
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Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
Long story John, but I get the impression few climatologists agree with much of what you say. For example, they think the Medieval Warm Period was likely mostly a north-Atlantic affair helped by warm ocean currents. And England does grow grapes. And I can't quite follow your reasoning, but if you indeed argue that it is purely coincidental that every decade was warmer than the past for at least the past 50 years, I find that very implausible.
Skeptics who do believe in the greenhouse effect of about +30C, but do not believe that if you increase greenhouse gas concentrations, you get higher temperatures.should be taught basic logic.
On the whole I think you read too much in the denialist blogosphere, and too little in the scientific literature.
Michael J. I. Brown
(ARC Future Fellow and Senior Lecturer at Monash University)
John Nicol is chair of the "sceptic" Australian Climate Science Coalition, which includes Ian Plimer, Bob Carter, David Archibald and other vocal "sceptics".
Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
To add: "The Australian Climate Science Coalition (ACSC) is a climate change skeptics website created by the the Australian Environment Foundation (AEF), a spin-off group created by the corporate funded think tank, the Institute of Public Affairs." (http://www.sourcewatch.org/index.php?title=Australian_Climate_Science_Coalition)
John Nicol
(logged in via Facebook)
Hi Michael, at it again, eh!
Michael Brown just loves pointing this out (my connection to ACSC, (a group of very experienced scientists in paleogeology and climate science) on any blog I visit. I guess that is because he himself is a nobody and certainly knows nothing about climate science as is clearly evidenced by his refusal to enter any scientific debate on the topic and simply refers everyone to AGW sites such RealClimate and John Cook's Skeptical Science, neither of which is exactly a centre of scientific rigour.
John Nicol
Lorna Jarrett
PhD candidate, science education; Physics teacher (logged in via email @diment.org)
Ad hominem John! Game set and match to Michael.
It seems to me that a lot of "climate sceptics" are geologists. The rest of us might legitimately wonder whether their views are influenced by employment in, or links to extractive industries which release greenhouse gases - and the associated enculturation.
My take on the issue - we can't be certain that there is warming - but which risk would you rather take: some damage to the economy, the loss of some jobs (had that happen to me more than once, didn't kill me), the move to renewable energy sources and the PRESERVATION of fossil fuel resources for future generations - or massive loss of life in developing countries, floods of refugees, extinctions, spread of infectious disease and crop-failure?
Michael J. I. Brown
(ARC Future Fellow and Senior Lecturer at Monash University)
John Nicol claims I know little about climate science. Certainly I do not know as much as the professional climate scientists and I limit my commentary accordingly.
This is in contrast to members of the sceptic ACSC, who are trying to rewrite climate science despite their limited expertise. Archibald's paper on solar cycles and temperature is a classic example of selective use of data. McLean predicted last year would be the coldest since the 1950s, and it was anything but. There is an extensive online list of the errors in Plimer's books.
John Nicol himself claims in an online essay that the generally accepted view of how CO2 in the atmosphere absorbs infrared light is wrong. Despite writing this eassy in 2008, John Nicol has yet to compare his model with readily available data. One does not need to be a climate scientist to find this puzzling.
David Arthur
n/a (logged in via email @fastel.com.au)
You may know something of geology (no need for the paleo prefix, because rocks are generally old), but as our discussions show, your understanding of climate is sadly wanting.
Why not tell us what you know of the Paleocene-Eocene Thermal Maximum?
John Nicol
(logged in via Facebook)
I agree with you Lennert, few of the modelers would accept it. However, with regard to the MWP being mostly a North Atlantic phenomenon, the same is the case today as exemplified in one simple way by the melting of Arctic Ice and the increase in Antarctic ice and reduction in temperatures.
An interesting remark on this from the IPCC chart of the earth showing isotherm corresponding maximum and minimum rises in temperature over the past many years (not sure now just what the time period was…
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David Arthur
n/a (logged in via email @fastel.com.au)
FYI, Mr Nicol, present Arctic ice melting is unprecedented because never before in the historical record has there been such Siberian permafrost thawing. There has likewise never been such methane emissions from the Arctic continental shelf of Siberia from methane clathrates.
I suggest you look up the work from the International Arctic Research Center at U Alaska Fairbanks, lead by Natalia Shakhova and Igor Semiletov.
Ross James
Engineer (logged in via email @bigpond.net.au)
Can you define "historical record", please. I see things like "temperature is at a record high" where record means the last 160 years. Or "record low Arctic ice" where records (from satellites ) only go back 30 years. I'll try yo find this myself, but if you know the answer (no doubt you've questioned this yourself) perhaps you can save me the search.
We know the Northwest Passage has been open many times in the recent past, so we know low ice area is not unusual.
David Arthur
n/a (logged in via email @fastel.com.au)
Historical record: what's been written down since people started to write. I have seen no mention of reports of Siberian tundra thawing prior to the 20th century, or of methane outgassing from the Arctic shelf off Siberia prior to the last couple of decades.
David Arthur
n/a (logged in via email @fastel.com.au)
Dear Mr Nicol, you write: "Arrhenius, Callendar and later authors have not made any real case for the EGHE beyond extending the basic GHE, but this fact is not well understood."
FYI, Mr Nicol, they didn't NEED to extend the basic [understanding of] GHE, because it was already irrefutably established. Given that, Denial of EGHE must be faith-based, perhaps motivated by the wishful thinking of stockholders in fossil-fuel producers and users; it is certainly not founded in reason.
Ross James
Engineer (logged in via email @bigpond.net.au)
I'm not sure which data sets you're referring to. It looks like you're using GISS, and ignoring all the others (see my comments above re GISS). You can't just take the set that suits you and ignore RSS, UHA, Hadcrut etc. They show 1998 to be the warmest year in recent times, 2010 was warmish, 2011 was much cooler. None of these data sets show a warming trend over the past 10 - 12 years. 2005 and 2010 were certainly not the warmest years, unless you ignore 1998.
I'm not saying global warming has stopped long term, but it's certainly not following the models in the short term, and it's certainly shown that there's much stronger forces at work than CO2, though it may still have a small long term influence.
Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
"2005 and 2010 were certainly not the warmest years, unless you ignore 1998."
Now you do what you accuse me of: selective use of evidence. Your statement only applies to UAH and Roy Spencer has been known for being wrong on previous occasions. If I am not mistaken, all other data series have 2010 and 2005 as warmer than 1998. See e.g. http://www.economist.com/blogs/dailychart/2010/12/climate_change
Besides, since we know 1998 was so hot because of an exceptionally strong El Nino and the later…
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Ross James
Engineer (logged in via email @bigpond.net.au)
Have a look at Hadcrut - I supplied the link earlier. Hadcrut, RSS, UHA are in agreement on this. GIISS is the odd one out. When I get time tomorrow I'll list the actual data.
David Arthur
n/a (logged in via email @fastel.com.au)
What about NCDC (NOAA)? I understand that's the most detailed global data set of the lot.
Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
See here: http://en.wikipedia.org/wiki/Instrumental_temperature_record#Warmest_years
Warmest years, global:
1. 2005
2. 2010
3. 1998
Land:
1. 2007
2. 2010
3. 2005
4. 1998
Ocean:
1. 2003
2. 1998
3. 2005
"Although the NCDC temperature record begins in 1880, less accurate reconstructions of earlier temperatures suggest these years may be the warmest for several centuries to millennia."
David Arthur
n/a (logged in via email @fastel.com.au)
By preventing heat dissipation to space, thereby driving heat retention in oceans and transfer to ice caps, I'd say that CO2 has a large, over-riding influence. Ref Lacis et al "Atmospheric CO2: Principal Control Knob
Governing Earth’s Temperature", Science, v 330, 15 Oct 2010.
Dale Bloom
Laboratory analyst (logged in via email @mail.com)
Hi John,
Much of science has actually pushed or increased consumption, and increased consumption increases the demand for electricity, increases road transport, increases the extraction of resources from the environment etc.
Indirectly, science has often lead to global warming, and I would disagree that science did not see it coming years ago. If pollution into the atmosphere is increasing, combined with increased extraction of natural resources, then something has to eventually collapse or give out, and this would have been known about 40 years ago.
I see proper risk management as the best approach to reducing global warming, and my argument is that risk management is not widespread enough, or not being properly carried out properly.
As an example, how many universities or research institution have a policy of zero injuries, zero waste, and zero energy consumption.
It is possible, and it is being done elsewhere, but not in Australia from what I have seen.
John Nicol
(logged in via Facebook)
What you are saying Dale may be technically true in hindsight.
However, the intention of the science which may fortuitously have increased consumption, after, might I say, providing for a much increased standard of living, would not have been intended to do so and I really doubt, being 77 years of age, that anyone would have forseen, as I said earlier, the possibility of modelers seeking to show that the increases in CO2 may have caused the much celebrated increase in global temperature from 1979…
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Dale Bloom
Laboratory analyst (logged in via email @mail.com)
Hi John.
“I can't think of a University any where in the world which has a policy of zero use of energy, but would like to hear of one.”
I haven’t seen one either, but there are private companies in Australia achieving it, and even councils in some other countries.
I have yet to see a university or research institution in Australia with a policy of zero injuries, zero waste and zero energy consumption on its website (and not hidden away somewhere), and obviously they are not fair dinkum about…
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John Nicol
(logged in via Facebook)
Dale, I think you would need to expand a bit on your thesis that science has lead to global warming. In the first instance of course, we are not certain that increase CO2 has any effect on either or cooling - it could do either which may be why there has been no statistically significcant warming since 1995 (Phil Jones, CRU). CO2 is a strong absorber in the lower atmosphere, but in the region above cloud level, it is responsible for radiation on its own, about 55% of the insolation from the sun…
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Richard Davis
Telecommunications Engineer (logged in via email @bigpond.net.au)
The term risk management in some ways to me screams risk adverse hence lots of crap movies from Hollywood.
Dale Bloom
Laboratory analyst (logged in via email @mail.com)
Hi Richard,
In a basic form, risk assessment means considering the consequences before undertaking an action. For a company, it can be as simple as employees going through a prepared checklist before purchasing something, and that checklist considers everything from cost of the item, to the eventual waste disposal of the item, or the possibility of recycling the item.
That’s the way some companies are now doing it, but not that many I believe.
Science in its purist form would mean carrying out observations, and then forming a hypothesis about the observations that is tested by undertaking experiments. Even then, risk assessments should be undertaken.
Something must have gone wrong to develop systems that eventually produced large amounts of pollution that now jeopardise so many species of life on the planet.
Peter Lang
Retired geologist and engineer (logged in via email @netspeed.com.au)
This is an excellent article (except for the value laden bits). I agree with the approach suggested. This describes the sort of policy advice that should be provided to governments, not the scaremongering and ideologically based type of advice that has been provided to date.
When talking about policies for prevention the policy advisers should also use risk analysis to assess whether or not their proposed policy will actually change the climate by the amount and in the way they expect. For…
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Ross James
Engineer (logged in via email @bigpond.net.au)
The IPCC gave probability ranges for their temperature predictions. All scenarios trended temperature upwards withing a range. Real data, however stayed flat, including last year.
So far, it seems there are only two possible conclusions for the IPCC computer models. Either they are wrong, or it's too early to confirm their reliability. The longer we go with no further warming, the more difficult it is to believe in them.
I seem to remember that the IPCC, and most reports, use terms like "there is a high probability that..." I'm interested to see the terminology used in AR5 if the lack of temperature increase continues, Antarctic ice keeps increasing, and Arctic ice remains stable.
Ben Heard
Director, ThinkClimate Consulting (logged in via email @thinkclimateconsulting.com.au)
Typically artful selective use of information, deliberately oversimplifying the approaches taken by the IPCC, how the models work, and what they are meant to represent.
All models, always, are wrong. Some models are useful. So far, climate modelling is proving useful, though with a tendency to underestimate impacts.
Plus a bit of out and out rubbish. Very high temperatures continue, Artic ice is plummeting in both extent and volume. Antarctic ice behaviour is interesting, but nothing like as simple as you present.
How do you folks live with yourselves, just trotting out crap like this every chance you get?
Lorna Jarrett
PhD candidate, science education; Physics teacher (logged in via email @diment.org)
Remember Ben - never feed the trolls!
Ben Heard
Director, ThinkClimate Consulting (logged in via email @thinkclimateconsulting.com.au)
Ha ha ha!!! You are so right, and I keep breaking my own rules in that regard. Thanks for the reminder.
Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
I am sure you are capable of making your own choices with respect to advertising, Mr Veerman, and that you are a responsible parent with respect to advising your children. However, to expect to be insulated from the real world and influences which you do not care for bespeaks a fragility which I suspect is not in your character. I repeat, responsibility for addiction lies with the addicted. They may seek help from whomever they like but they should not expect society to be transformed or mitigated…
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Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
Dear Mr. Arthur and Mr. Veerman,
I believe you are becoming over-excited, gentleman, and are resorting to hyperbole. There are currently regulations and laws which answer your queries and I have not suggested that individual responsibility should extend to the breaking of such laws. Duty is a much discussed topic among those of a government-reliant persuasion, but seldom do we see the idea of individual responsibility being accentuated. My simple case, and it is an easy one to understand, is that first reliance is with the individual, not the government. If help is required, by all means seek it, but do not penalise the rest of us in the process. Self-reliance is paramount and should be encouraged; dependency on government ultimately can destroy initiative and is destructive to society at large.
David Arthur
n/a (logged in via email @fastel.com.au)
Dear Mr Chafe, I assure that it is not over-excitement from which I suffer; consequently, it is not hyperbole to which I am driven.
I was discussing cases where one individual or entity is adversely affecting another by polluting the environment. As is apparent, current laws and regulations are not adequate for all circumstances at present, let alone in the future.
The recommendation that self-reliance, rather than regulation, should be applied to resolve such situations is Good News for the world's arms dealers.
Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
Being kept awake by late night parties happens to the best of us, Mr Arthur. I'm not keen on it either but there are regulations governing that sort of thing; it's just that they are not always conformed with. Seems like the party was in the Christmas-New Year's period when late night parties are not uncommon. Sometimes we have to tolerate such things. You can always appeal to the council or the owner or the police if they continue. Otherwise, you might have to move to a quieter location. Unsatisfactory, but that's life.
David Arthur
n/a (logged in via email @fastel.com.au)
Can you see that their activity was impinging on my rights to a good night's sleep, necessary if I was to conduct my lawful work and then safely drive home?
Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
Really, Mr. Hartland, I don't think there is much more I can say on this, except that I was unaware that the fundamental fallacy of Marx' work was that conditions of small community living could not be replicated in large communities. I thought it was that he expected capitalism to fail and be replaced by socialism and rule of the proletariat. Also, my suggestion that bicycles were little used by the 'working class', if it still exists, has nothing to do with middle class bias; it is simply based on my own observations and information that it's the bourgeoisies who are dead keen on the idea. However, I do agree with you about the driving of kids to school, although I don't know that many kids have been hit by cars. But I certainly wouldn't legislate against parents doing this, driving that is, not hitting. In the end, I think we will have to agree to disagree about the long and pernicious arm of governmental legislation.
John Harland
bicycle technician (logged in via email @gmail.com)
Ben Heard wrote: "To imagine that the processes required to mandate the wearing of seatbelts, drop the suburban speed limit to 50 or the progressive mandatory phase in of safety features in cars have not taken due account of the trade of in freedom of choice is quite silly, and I dare say insulting to the professionals that work in the area".
While the data is pretty robust on the issues mentioned, the process to allow flashing lights on bicycles was done without either proper research or process…
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David Arthur
n/a (logged in via email @fastel.com.au)
Thanks John. As someone who suffered a career-altering head injury some three decades ago, I have a strong personal preference for cycle helmets.
My injury did not occur while I was cycling. However, while I was unconscious in hospital, one of my classmates suffered a more severe head injury (from which he subsequently died) when he lost control of his bicycle and collided with another vehicle.
Regarding flashing lights, as motorist and cyclist I can attest as to their effectiveness in terms of warning motorists of the presence of cyclists.
Ben Heard
Director, ThinkClimate Consulting (logged in via email @thinkclimateconsulting.com.au)
Interesting stuff John.
"Allow" flashing lights? Does that mean such a thing needed approval? Seems weird to me. I'm grateful for mine, and for other's using them when I am driving, I can see them a lot better!
Helmets are an interesting one... I was glad of mine on the one day I had a bad stack... probably would not be typing had I not been wearing it...
Interesting area. I'd very happy to concede that there will be notable exceptions to the predominantly sensible processes that prevail in such decision making.
John Harland
bicycle technician (logged in via email @gmail.com)
Ben Heard wrote:
> "Allow" flashing lights? Does that mean such a thing needed approval?
Flashing lights are generally not allowed for normal lighting of moving vehicles.
> Helmets . . . I was glad of mine . . .
Most helmets I have inspected in the light of claims of that kind have been broken. There is seldom any sign of the foam having crushed and having absorbed impact.
Helmet designs are generally tested using hard metal headforms, that crush the foam. Real heads flex on impact.
It appears that the foam does not flex sufficiently to accommodate that skull flexure. The helmet breaks and it would seem to be the skull that absorbs the impact, not the foam.
Risk analysis needs to be based on real data or realistic simulations. Magnesium headforms are not a realistic simulation.
Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
Dear Mr. Veerman,
I think you misconstrue my central point about gambling, alcohol, road rules, food and tobacco. I happen to believe that individuals should be primarily responsible for their own actions and behaviour, and not rely on government directives to protect them. My concern is the extent to which proscription impinges on freedom of choice and individual inconvenience and whether the price that's paid in that regard is too high; therein, an assessment of risk and consequences would be…
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Lennert Veerman
(Senior Research Fellow, School of Population Health at University of Queensland)
Well, that is exactly what I mean. I happen to differ in my preference for the balance between individual freedom and protection from harm. I think it is perfectly allright to sacrifice people's freedom not to wear seatbelts to protect them from possible fatal or disabling injury.
Arguments for unlimited individual freedom don't take into account that people are constrained in their choices. A person who is addicted to gambling has very little real freedom to choose his or her behaviour: that…
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David Arthur
n/a (logged in via email @fastel.com.au)
While individuals should be responsible for their actions and behaviour, it is through regulation and government that we seek respite from the threats posed by those individuals who are somehow incapable of such responsibility.
Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
Dear Mr. Hartland,
I believe that the underlying philosophy of your concern for speed limits, alcohol, gambling and tobacco is safety and the desirability of ever increasing standards of safety. This is a common concern in many areas these days, including the protection of children and the constant overseeing of their activities; this extends to attempts to influence school principals and teachers as to the best way their child can be taught. This is not the way to inform children of self-reliance…
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Sam Chafe
Retired scientist (logged in via email @iprimus.com.au)
Alas, Mr. Arthur, if your suggestion that self-reliance constitutes an encouragement to arms dealers is not hyperbole, I don't know what is. I daresay we have plenty of laws currently on the books to allay temptations to deal in arms. I would counsel you to be a little more tolerant of other people and try and sort out differences using your self-reliance. It is seen as an unvarying solution to any problem at all by some to appeal to governmental authority, and I believe you may be such a person. You may think that we don't have enough rules and regulations, but I can assure you that we already have too many. Live and let live, Mr. Arthur, you cannot have the rest of the world beat in time with your own personal rhythm.
David Arthur
n/a (logged in via email @fastel.com.au)
Mr Chafe, a couple of weeks ago I was kept awake by drunken louts having a party in the house up the hill from me.
They told me to **** off when I asked them to turn their stereo down, and the town's policeman was away on leave. By the time a police vehicle arrived from the nearest regional centre two hours later, they'd fallen asleep, having asserted their right to party.
Self-reliance? No shops were open at that hour of night for me to purchase ear-muffs.
The issue for me was that, the next day, I was required to work a full day of manual labour, then drive to my home 300 km away, in time for Christmas.
Can you see that their activity was impinging on my rights to a good night's sleep, necessary if I was to conduct my lawful work and then safely drive? By the tenor of your remarks, it seems that you are incapable of such understanding.