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A cautionary tale…
Memo Steve Fielding: here’s an answer to your question
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“I need to hear an explanation of why carbon emissions have been going up over the last decade and temperatures haven’t been going up.” — Senator Steve Fielding Steve Fielding is confused about something that puzzles a lot of people — why doesn’t the temperature trend follow the essentially monotonic increase in atmospheric CO2?
To some extent the answer is found in his graphs. Over any time scale you choose, there are multiple influences on climate, and these influences in turn vary on different time scales. For example, the sunspot cycle (which affects the sun’s solar output) varies across about 11 years. The southern oscillation (ie. El Nino/La Nina cycles) — the dynamics of which are not particularly well understood or predicted — has a quasi-decadal cycle (three to seven years). And this is just one of a number of such regional oscillations internal to the climate system that have global consequences for climate. Other events such as volcanic eruptions also have transient effects. Given that the climate state over a given period is the result of the combination of these effects, you are bound to see a fair bit of noise in the time series. Steve Fielding’s HadCRU data shows this noise, and it should be clear that over shorter periods – say, of much less than a decade — it would be dangerous to draw conclusions about trends in climate. For example, if you fitted a linear trend through, say, the 1992 to 1998 segment of the series, you would conclude that the world was warming at a terrifyingly rapid rate. But 1992 was a cool year, largely because of the effects of the previous year’s Pinatubo eruption, and 1998 was a very hot year, largely because of a record el Nino. Thus to expect CO2 and temperature to change in perfect lock step is to imply that climate must be influenced only by CO2 or otherwise not at all. The messier truth — as with most complex phenomena — is that there are multiple influences. These are borne out by the sawtooth pattern of change seen in the data. So it is the underlying trend, and that only, that we believe to be driven by CO2. In light of this, it is neither surprising nor unprecedented that trends in temperature and CO2 don’t match over shorter periods. The RealClimate site did a good job of illustrating this point (see here):
The blue lines are trends for successive eight year segments of the record. It makes clear that you can find just about any trend in the data if you look in the right place (or time, more accurately) — it also makes clear that even if you insist on doing so, there is no cooling trend in recent years. Full disclosure, however: the above graph uses the NASA global surface temperature analysis, which is slightly different to, but broadly consistent with and equally well regarded as the Hadley/Climate Research Unit (HadCRU) data used by Fielding. The complete NASA GISS record is below, and shows slightly different results for the most recent years.
Seen in the context of the longer term variability in the record, in neither case does the “so-called” cooling of recent years appear unprecedented — it is entirely consistent with the variability seen throughout. |
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36 Comments
Yes, but I’d have thought Fielding ‘as an engineer’ (as he keeps saying) might have been numerate enough to work out for himself how multiple forcings with multiple frequencies are likely to play out. Either he isn’t a very good engineer, or he’s being disingenuous.
Thank you Mr McHugh for keeping your arguement to the question at hand and not attacking the messenger to feel superior. I dont think Mr Fielding was right but it seemed a reasonable question to this layman.
Please factor in the decimation of the worlds rainforests that began in earnest around about 1980 from memory. In other words, can you partial out the effects of the politically orchestrated global decimation of the rainforests over the last 30 years and see what relationship is left in the data?
Agree Mark, I would have thought as an engineer he would have had a pretty good idea of control mechanisms and feedback, PID controllers and the like.
Maybe he’s a Civil engineer? That would explain quite a lot.
Mechanical Engineers build weapons. Civil engineers build targets.
Steve worked for Hewlett Packard in Australia. Very little engineering is done by large US companies outside of the US, it is mostly marketing. This would explain his difficulties with understanding noisy trend data rather nicely. Uncertainty in marketing is a deal breaker. Steve had to go to the US for his answer on climate change just as he would have done when working for HP. No need to use your brain when you can get a trip to the US for free. The cargo cultists in this country are alive and well.
I vote for a double dissolution so we can redeploy him to where real facts and science don’t matter.
Oh OK, You’ve answered it. Solved. Well done.
So let’s put ALL our human effort and resources behind your understanding of the situation. Like, you know, we did in the fifties. Oh, btw, where did those moon bases, undersea cities, increased leisure time go again?
I just emailed Fielding and provided a link to this article. I have asked him to respond.
So the global temp increases and it’s man made global warming.
The global temp doesn’t increase and it’s man made global warming.
Yes you hero’s seem to be on the right track except you seem to admit it’s a complex system with ‘multiple forcings’ which always apply when the actual figures don’t match your guesses.There seems to be no event which can’t be used to support your theory?
Dudes if the planet is getting warmer/colder/same and it’s caused by man-made CO2 then if there is more CO2 the effect will be reflected in actual temperatures or not.
If you have to start making bullshit adjustments it becomes too hard to argue which ‘multiple forcings’ are having what effect.
So until the planet actually starts warming just relax and shut-up.
Also it all sounds eerily similar to the South Park ‘Hybrid Car/Smug Alert’ episode which i have not provided a link to but George you may still respond if you like.
“I just emailed Fielding and provided a link to this article. I have asked him to respond”
Just in case Steve Fielding does look at this…
The 1991 eruption of Mt Pinatubo lowered the global temps by about 0.6C. From this NASA article (bottom of third paragraph):
http://earthobservatory.nasa.gov/IOTD/view.php?id=1510
Please use your imagination to adjust the Real Climate graph above upward by 0.6C for the period 1991-92.
The 1982 eruption of El Chichon also lowered the global temps. See this NOAA / Mauna Loa article on how much solar radiation was reduced:
http://www.mlo.noaa.gov/programs/gmdlidar/mlo/gmdlidar_mlo.html
The El Chichon eruption masked the “other” Super El Nino - it is apparent here:
http://www.cdc.noaa.gov/people/klaus.wolter/MEI/ts.gif
It actually was stronger than the 1997-98 El Nino.
Please use your imagination to adjust the Real Climate graph above upward by a similar amount to Pinatubo for the period 1982-83.
Steve Fielding: The other question you should ask is why the temperature graphs used to support the global warming trend (as the Real Climate graph above) do not discount the effects of these volcanoes. These volcanos can not in any way be attributed to anthropogenic influence - so their effects should be accounted for. Accounting for these would suggest that temperatures have not increased in nearly 30 years…
James Bennett, what the fuck are you on about dude? Do you have any idea how to read a chart? Do you understand about fluctuations in real world systems? Are you able to comprehend trends and how read them from large sets of data? Do you have some basic understanding of statistics?
If not, do yourself a favour and read some books before firing off your mouth on what you obviously do not understand.
George, people like you are the reason for my skeptisism. Do your personalised plates on your car have FIGJAM on them? You tosser.
The real question is, if it’s a complex mix of things which can obviously all have an major effect, then why are you singling out Human Produced CO2 for policy action which will cripple human production and development if done quickly? This tenet is the centre of most current government policy initiatives and industry initiatives right now … and a lovely source of funding for a lot of academics and consultants, (and bankers / brokers if a ‘trading scheme is introduced) so please don’t tell me the “proponents” have nothing to gain / protect. That is just plain bullsh_t and it does not factor in admitting you were WRONG as a factor … pride.
The second question is, why were the global temperature variations so large over the last several thousand years when we simply were not doing what we are doing now, nor in the volumes we are doing it. Why did the earths temperature vary from ice-ages to very warm periods … annecdotally much warmer than now? If you tell me they were all due to volcanic eruptions, I will go to sleep …
Nobody (sensible) is arguing against sustainability … clearly ripping coal out of the ground and burning it, or burning oil are not sustainable activities … we will eventually run out.
Nobody (sensible) is arguing that there is climate change … because the climate is always changing, nor that we should prepare via building codes, land zoning, etc.
What some of us are asking is “should we be betting the farm” on you computer models when some of the folks who wrote them now doubt that they are anywhere near accurate. They would want to be more accurate that the economic models used for forecasting which have proved absolutely useless.
Get involved in reality … the debate is NOT closed. Just because Al Gore says so, does not mean we aren’t allowed to talk about it any more … you now have permission to question and not regurgitate.
George, why don’t YOU go and read some of the books that will challenge your narrow populist view.
Go on, I dare you.
@AndrewMFern, I sympathise; I get uncomfortable when people state flatly ‘the debate is over’. But the crux is within your ‘global temperature variations so large over the last several thousand years’ statement. The current problem is not solely the magnitude of the projected change, it’s the speed that is almost unprecedented. And where there are precedents, they’re always accompanied by mass extinctions, presumably because climatic zones moved faster than many species could migrate or adapt.
And yes, I have much confidence in climate models than economic ones, because the former are based on physics, whereas the latter are based on (extremely rudimentary understanding of) human psychology.
ANDREWMFERN, just so we all know, are you a climate scientist?
Good to see the facts and general logic haven’t got in the way of a good slanging match.
AndrewMFern raises some good ‘points’, among a fair amount of invective, but they deserve to be challenged.
Why single out CO2? Cos it’s the easiest one to control, and more importantly, measure. You can only manage what you can manage they say. But don’t forget, the other Kyoto gases will be part of the scheme, except for agricultural methane, which will come in later.
This nonsense of ‘crippling production and development’ is a bit of hyperbole. Reducing emissions by 30% will not cripple production or destroy the universe. If a 30% reduction translates directly to a 30% increase (which seems mathematically unlikely) then I think we’ll survive. Sydney residents are about to wear that same increase to cover a network upgrade, ditto Qld. This will not be the straw that breaks the camel’s back. It will just encourage people to think a bit more about their energy use.
Your second question is answered in detail by a number of sources. Start with the Internet. There’s lot of information on it.
We are not betting the farm. Don’t get your information from Voelte or the Business Council of Australia. Start with Treasury modelling for a start. The costs aren’t that high.
The science of changing the climate with increased GHG emissions is essentially closed. Give the EU High Commission a call, or the White House, or the Chinese Govt if you know Mandarin, and ask them how much doubt they have about whether or not emissions are changing the climate. What is up for debate is how to act, and whether or not Stephen Fielding is an unbearable moron beholden to his masters. I suspect the latter is true.
… because what you are saying is that thousands of scientists around the world who have contributed thousands upon thousands of research papers and ongoing data are somehow misguided. Yeah, I guess you are a narrow tobacco/oil paid “scientists” must be right.
Nicely expressed there, Andrew.
When climate change effects aren’t clearly understood, how can their causes be? ??
I would think that the sanest approach to climate change would be to work at ameliorating its effects as or before they happen. Starting with each person. Learn your local geography (if you have any), and be aware of likely risks. Participate in social networks - no man is an island. Get fit and healthy. Get ‘unstuck’. Pray more. Yeah, plant a tree, whatever, but don’t expect the ‘Govt. Show’ to be of much help. Your life is in your hands.
Thoughtless urgency of the sort propagated so widely most likely won’t help the climate situation; look at where thoughtless urgency for economic development has put us today socially, ecologically, economically(!).
Although our education probably hasn’t prepared us very well at all for the kind of clear thinking we each need in the face of a situation of this scale, either individually or socially, we are still human, after all, and quite smart. Really smart actually. Probably a lot smarter than we think..
Terrific plan Scottyea. How do you prepare for more heat?
And praying more? Probably do just as much good to drink beer.
Very good, Evan, you’ve started to think about it!
Well, maybe just imagine that you’d asked the same question ten years ago…
“What is up for debate is how to act”, Evan.
My position is that “science” is not qualified or competent to “fix” the climate.
Spot on Ian. The answers to Sen Fielding’s questions are pretty simple, and it is to someone’s discredit that they were either not answered or the answers were not understood.
Can I add some answers to Fielding’s other questions:
Q: Is it the case that CO2 increased by 5 percent since 1998 while global temperature cooled during the same period?
A: No, temperature has increased since 1998, despite the 98 El Nino. You can see this for yourself on this graph: http://www.woodfortrees.org/plot/gistemp/from:1998/to:2009/plot/gistemp/from:1998/to:2009/trend
Q: Is it the case that the rate and magnitude of warming between 1979 and 1998 (the late 20th-century phase of global warming) were not unusual as compared with warmings that have occurred earlier in the Earth’s history? If the warming was not unusual, why is it perceived to have been caused by human CO2 emissions and, in any event, why is warming a problem if the Earth has experienced similar warmings in the past?
A: Past warming has been caused by Milankovitch cycles: millennia long changes in the shape of the earth’s orbit around the sun, accelerated by natural positive feedbacks. There is no Milankovitch cycle tipping point currently occurring, and the current rate of warming increase, as opposed to the amount, is hundreds of times faster than that observed in the geological record. The causal factor is greenhouse gas emissions.
If warming reached the same level as it has in the geological past, it would be a problem. The last time the world experienced temperature rises of this magnitude was 55 million years ago, after the so-called Palaeocene-Eocene Thermal Maximum event. Then, the culprits were clathrates - large pockets of frozen methane - which were released from the deep ocean in explosive belches that filled the atmosphere with around 5 gigatonnes of carbon. The already warm planet warmed further by 5 or 6 °C, tropical forests sprang up in ice-free polar regions, and the oceans turned so acidic from dissolved carbon dioxide that there was a vast die-off of sea life. Sea levels rose to 100 metres higher than today’s and desert stretched from southern Africa into Europe. This would not be good.
Q: Is it the case that all computer models projected a steady increase in temperature for the period 1990 to 2008, whereas in fact there were only eight years of warming followed by 10 years of stasis and cooling? If so, why is it assumed that long-term climate projections by the same models are suitable as a basis for public policy-making?
A: No, it is not the case that all computer models projected steady warming. Most models endeavour to incorporate fluctuations such as El Nino in order to generate a range of possible futures. The earth’s climate is still within the range of projections. It would be outside the projections if the temperature did not warm further for the next 15 years or so. Phrasing the question as “8 years of warming, 10 years of stasis and cooling” is deceptive, because it makes it sound as if we are cooler now than in 1990, while in fact we are much hotter.
It’s good to see Crikey running articles that argue there are “multiple influences on climate” and that some of these are “not particularly well understood or predicted”. Where I differ with Ian McHugh is with his statement that “it is the underlying trend, and that only, that we believe to be driven by CO2”.
The current underlying warming trend started around 150 years ago when Earth emerged from the Little Ice Age. This process of warming ran for about a century before large scale human CO2 production kicked in after WWII.
Similarly, the Medieval Warming happened before human CO2 production of any scale.
So what drove those trends? It wasn’t human produced CO2, so I don’t see how we can assume all natural factors are now irrelevant and assign present long-term warming to our CO2 emissions. I think that point is fundamental and needs to be answered.
JamesH: You say that “it makes it sound as if we are cooler now than in 1990, while in fact we are much hotter”
Really? take a look at the UAH temperature data*. the average temperature for the 12 months of 1990 was +0.08C above the 30 year mean. For the past 12 months the average is +0.11C.
The difference is 0.03C - that’s 3/100ths of a degree centigrade.
You call that “much hotter”?
*UAH data is here: http://vortex.nsstc.uah.edu/public/msu/t2lt/tltglhmam_5.2
George, I may have been a little terse above … My apologies, you are not a tosser. Well, I don’t know you but I will give you the benefit of the doubt. You are very condescending which is may not be the best way to get your point across.
For the record (broken) let me state again, nobody (sensible) is debating:
1. whether or not we should move toward sustainable power generation and transport away from fossil fuels. I am not.
2. whether or not the climate is changing. I am not.
Evan, yes I am aware of the Internet … thank you
Has the earth’s temperature ever changed at this rate before … I belive the answer to this is we cannot be sure. Either we are sure, or we aren’t. I summise that we aren’t.
To be clear, I am agnostic about this. If you can get all the scientists to be civil to each other and agree, you’ll have me. I don’t see all the physicists or materials scientists, or chemists disagreeing on the fundamentals of their academic professions. So, until then I will maintain my position that our number 1 issue is sustainability, not human caused carbon neutrality.
Now, if we change the focus to human sustainability I think we’d agree or more than we all disagree on.
Are we really that far apart anyway, or is it more about everyone being ‘right’.
Cheers
sorry … should of course read “… human caused global warming … “
Just in case there are any English teachers here.
Tamas, it makes more sense to compare longer-term trends than compare any two specific years which may suffer from random fluctuations, like El Nino. The least square fit linear trend to the UAH data from 1990 to 2008 shows an increase of 0.3 degrees or thereabouts, not 0.03. http://www.woodfortrees.org/plot/uah/from:1990/to:2009/plot/uah/from:1990/to:2009/trend/plot/uah/from:1990/to:2009/mean:12
It’s pretty clear that ecosystems, ice cover, etc, are responding to this overall warming trend. If, for example, you have 12 years of drought then 1 year of good rain doesn’t reset everything back to normal.
Strictly speaking, any period less than 30 years is likely to be a bit overwhelmed by randomness, but 1990 is what the Senator said.
JamesH: Let’s compare longer term trends then.
The slope of the linear regression line of the UAH data from December 1979 - May 2009 is 0.001045.
This translates to a trend of 0.125C per decade increase, or a total trend increase of 0.38C over the 366 months of data.
This is just not a crisis or something we need to panic about. In fact, I think it’s just normal variability.
And how is it “pretty clear that ecosystems and icecover are responding” to this less than terrifying increase? What examples do you have?
Hi Tamas,
The longer the trend, the less likely that it represents “normal” variability (however you define that) and the more likely it represents the action of some specific forcing factor of the climate. The only factor that really fits current warming is increases in greenhouse gases, which have been rising since the industrial revolution became coal fired (incidentally, there is an argument, still controversial, that human action did drive the Medieval Warm Period and the Little Ice Age: http://en.wikipedia.org/wiki/Plows,_Plagues_and_Petroleum. One of the principal critics of this argument is Gavin Schmidt, founder of RealClimate - climate science’s consensus isn’t mindless. The general consensus is that earlier periods of warming and cooling were driven by the sun, but that no significant solar change is happening currently: http://www.skepticalscience.com/argument.php?a=22).
One reason this is a crisis (though panic is not necessarily the appropriate response) is that the warming trend appears to be accelerating; as are emissions of CO2. Another is that positive feedback loops can and do happen and are demonstrated to have happened in the past, for example in the Palaeocene-Eocene Thermal Maximum when warming triggered the release of frozen methane.
Examples: Arctic Sea ice has steadily decreased since 1979: http://www.woodfortrees.org/plot/nsidc-seaice-n/from:1979/to:2009/plot/nsidc-seaice-n/from:1979/to:2009/trend/plot/nsidc-seaice-n/from:1979/to:2009/mean:12
Antarctic sea ice has grown, but this is in fact consistent with global warming models: http://skepticalscience.com/Why-is-Antarctic-sea-ice-increasing.html
Greenland’s ice cover is in decline, as are glaciers worldwide: http://www.skepticalscience.com/greenland-cooling-gaining-ice.htm
Changing patterns of species migration, behaviour, etc and other ecosystem impacts are well documented: http://cns.utexas.edu/communications/File/AnnRev_CCimpacts2006.pdf
HTH
Hi JamesH:
You say that “The only factor that really fits current warming is increases in greenhouse gases, which have been rising since the industrial revolution became coal fired “.
I just can’t agree with that statement. The current warming trend has lasted for over 150 years. The factors driving this warming trend are unknown. It’s a nice theory that it’s driven by CO2, but there’s no evidence for this. There are many, many other factors that could be driving the warming, not least of which is solar activity.
The current sunspot cycle is the weakest in decades so I fully expect to see continued cooling. Which leads me to your next point. You say that “the warming trend appears to be accelerating”
Again, I don’t accept that. The UAH data I refer to above doesn’t show acceleration. It shows a very mild warming trend that has flattened out in the past 10 years. As I keep repeating, May 2009 was only 0.04C above the 30 year mean temperature. All despite rising CO2.
Finally, some of the stuff you site above is rebutted by many other sources. eg: Some glaciers are growing, some are shrinking. But we only survey a very small percentage of the 150,000+ glaciers in the world.
Also, it seems that any “Changing patterns of species migration, behaviour” etc are always assigned to global warming. But we’ve only had 0.7C warming in a hundred years and 0.4C in 30 years. So couldn’t there be other explanations for all this?
My basic point is that we are a small species and we don’t control the planet. Natural forces are vastly more powerful than us. None of this is to argue against sensible environmentalism, but I don’t accept that we need to change our way of life based on a theory that is far from proven.
“But we only survey a very small percentage of the 150,000+ glaciers in the world.”
Eh? Ice is one of the easiest targets for satellite remote sensing, and we can and do use it for pretty comprehensive monitoring of ice coverage. With the advent of GRACE and radar satellites, we get a pretty good handle on glacier thickness as well as extent, and can do so irrespective of cloud cover.
Mark,
GRACE doesn’t specifically monitor glaciers. My understanding is that it can’t resolve to the detail required for accurate glacial observations. It’s main job is to detect much larger gravitational anomalies.
Do you know any other satellites that are used to study glaciers? That’s a serious question. I’d be interested to see the data.
Tamas,
The contention that there is no evidence is, frankly, bizarre. CO2 in the atmosphere is well measured. The role of CO2 and other greenhouse gases in setting earth’s temperature is well understood on theoretical, experimental, and observational grounds. The increase in CO2 in the atmosphere can be directly attributed to human burning of fossil fuels by the measurement of isotope ratios. Likewise the increase in methane can be directly attributed to land clearing and increases in livestock numbers. Finally, no other potential explanatory variable: sunspots, cosmic rays, etc; correlates with changes in temperature over the last 150 years nearly as well as greenhouse gas levels and other pollutants do. All of this is backed up by one of the most multidisciplinary, multinational research efforts in history. Saying that “it could be something else” falls foul of Ockham’s razor; the burden of proof is on you.
I am not sure what you mean by “we don’t control the planet”. Human expansion has been responsible for one of the greatest extinction rates ever achieved, running neck and neck with the dinosaur killing K-T impact IIRC. I haven’t seen any “vast, powerful natural forces” stepping in to stop us.
“Change our way of life” - The amount of change required of us is not relevant to the empirical question of whether or not greenhouse warming is occurring. But generally, a well managed transition to an environmentally sustainable economy requires that we transition to some new power sources (probably a mix of renewables and nuclear), introduce a new tax (or C&T) system about as complex as the GST, and become more energy efficient. I don’t see how this represents a fundamental change in our way of life. On the other hand, at the worse end of the greenhouse prediction spectrum: having to abandon our major coastal cities because the temperature has risen 5 degrees and the sea level has risen 100 metres - THAT’s a fundamental change in our way of life.
JamesH:
You say “Human expansion has been responsible for one of the greatest extinction rates ever achieved”
Really? Name 10 species that have become extinct in the last 10 years. Hell, how about the last hundred years? Bet you can’t.
You then assert my saying climate change could be caused by something other than CO2 “falls foul of Ockham’s razor” and the burden of proof is on me. That’s a striking inversion of how science works. If you put up a hypothesis, you provide the proof.
And let’s talk about the proof. Name all the factors that control the environment. Go on, name ‘em.
Of course you cannot do so, therefore you can’t isolate CO2 and say it must be the cause. We just don’t know what causes climate change. Admitting our ignorance is a lot better than pretending to know everything.
Finally, you assert that temperature may rise 5 degrees and oceans by 100m. That’s just plain hysterical.
The AR4 IPCC report predicts sea level rises of between 0.18 and 0.56m (2090-2099 relative to 1980-1999). And temperature over the last 30 years show a trend increase of around 0.12C per decade.
So it’ll take a 4,000 years to hit your 5C temperature increase at current rates and the 100m ocean level rise will take will take about 17,000 years under the IPCC’s ‘worst case’.
Think humanity might be able to cope with it over 17,000 years?
Tamas,
“Scientists estimate that during the 20th century, between 20,000 and two million species actually became extinct, but the precise total cannot be determined more accurately within the limits of present knowledge”. If you want lists of known species, I suggest you start with wikipedia.
http://en.wikipedia.org/wiki/Holocene_extinction_event
The proof of the hypothesis that CO2 has caused change in climate has already been given. If you want to claim that some other factor, as yet unknown, causes observed climate change, that is your hypothesis and you have to prove it. Ockham’s razor dictates that we shouldn’t reach for unknowns when we can give an explanation in terms of known factors.
Name all the factors (by “the environment” I take it you mean “the global temperature”): The IPCC summary of relevant science is that the factors controlling the global temperature are: Long lived greenhouse gases; ozone; stratospheric water vapour; changes in albedo, including land use changes, ice changes and the effects of soot on snow; aerosols including direct and indirect cloud-forming effects; linear contrails (from planes); and solar irradiance. Also volcanoes, but these are episodic and fairly unpredictable. See IPCC Ar4 WG1 Summary p.4
I’ve never claimed to know everything, and nor has any scientist or group of scientists - in fact, the IPCC bends over backwards to quantify and deal with uncertainties. I do claim that our collective knowledge of the climate is sufficient to provide a proven basis for action. You seem to be assuming that because you don’t know the answers to these questions, no-one else does either.
the 5 degree/100 m, which I did say is at the worse end of predictions, is based on what has occurred in the geological record, not on “hysteria”. See my earlier post. The IPCC AR4 report is not the “worst case”, because it expressly did not include non linear ice melt caused by positive feedback or abrupt ice sheet collapse, because these are not yet well understood. That doesn’t mean they can’t happen. See p. 17 of the WG1 summary. Recent assessments indicate that sea level rises of 4 to 6 metres or more could occur within a few centuries based upon rapid melting of the greenland and west antarctic ice sheets. See this article: http://www.pnas.org/content/early/2009/02/25/0812355106.
I do think a) most of humanity would find that very difficult to cope with and b) that includes my kids and grandkids on that time scale. The 100 m rise is a possibility on a short millenia time scale, i.e. 1-2000 years
It is simply not good enough to proclaim ignorance as an excuse for inaction, especially when the answers to your questions are already known and in the literature.
What an incredibly ignorant comment:
http://en.wikipedia.org/wiki/Extinct_Australian_animals
There are 23 birds, 4 frogs, and 27 mammal species known to have become extinct since European settlement of Australia.
Then it is followed with a grieb=vous misunderstanging of the scientific process. YOu don’t ‘prove’ anything, a scientist presents a theory that remains in place until it can be DISPROVEN.
Then, you follow with my favourite line of reasoning on this topic, the ‘pre-emptive boy who cried wolf’ argument. IE, that the outcomes seem so bad that they can’t possibly be true. What utter nonsense.
Further, you’ve assumed a linear progression of temperature and sea level rise. On what basis are you supporting that theory? There are very few directly linear relationships in nature, and I very much doubt this is one of them. It is this lack of linearity that is causing the concern among scientists; we know there is a strong relationship between GHGs (note it is a lot more than CO2 involved) and temperature, but we don’t know how that relationship varies as CO2 increases. Is it exponential? I hope not. But it could be. Avoiding it is called the precautionary principle, and I suggest you read up on it.
I’ve had these arguments with a number of sceptics in the last few months, and been often accused of not being open minded. I disagree, I am open minded, until this sort of nonsense comes out. There is no science at all on the sceptical side of the argument, and reams of the stuff on the AGW hypothesis side. Further, the sceptical side relies on armchair science, and an enormous intergovenmental and international conspiracy. All the smart people are doing something about climate change Tamas, and fortunately, they’re not listening to you or your kind.
Evan - I am not denying that humans have an impact, and I accept that you nicely rebutted me with that list, but I just don’t buy the argument that we have wiped out millions of species.
JamesH say that ““Scientists estimate that during the 20th century, between 20,000 and two million species actually became extinct, but the precise total cannot be determined more accurately within the limits of present knowledge”.
Surely if we’d wiped out 2 million species we’d be able to list a few more of them. That “scientific” statment is just a guess without any supporting data.
Evan - you also mention the precautionary principle. What about applying it to the global warming hypothesis before we wreck our economy. Shouldn’t we test the theory for every possible weakness before we start switching off the power?
And there is a lot of science on the skeptical side Evan. It is being reported much more now and this debate is turning. Anyway, I’m off to the Cage-Match if you want to debate me further there:
http://blogs.crikey.com.au/rooted/2009/04/08/climate-change-cage-match-a-fight-to-the-death/
Shorter Tamas: I don’t believe it, because I don’t believe it, because I don’t believe it.