Last week I attended a talk by Dennis Avery, author with Fred Singer of Unstoppable Global Warming Every 1500 Years (there is a summary here). The talk (and tasty lunch) was sponsored by the Heartland Institute, and was apparently enthusiastically received by its audience. Still whoozy from a bit of contention during the question period, a perplexed member of the audience told me privately that he thought a Point/CounterPoint discussion might be useful (he didn’t know I wrote for realclimate; it was just a hypothetical thought). But here’s my attempt to accommodate.
Note: The Points are paraphrases from the slides and my notes from Avery’s talk.
Point. The existence of the medieval warm and the Little Ice Age climate intervals, and the 1500 year D-O cycles in glacial climate, proves that the warming in the past decades is a natural phenomenon, not caused by human industry at all.
CounterPoint. The existence of climate changes in the past is not news to the climate change scientific community; there is a whole chapter about it in the upcoming IPCC Scientific Assessment. Nor do past, natural variations in climate negate the global warming forecast. Most past climate changes, like the glacial interglacial cycle, can be explained based on changes in solar heating and greenhouse gases, but the warming in the last few decades cannot be explained without the impact of human-released greenhouse gases. Avery was very careful to crop his temperature plots at 1985, rather than show the data to 2005.
Point. Hundreds of researchers have published on the Little Ice Age and Medieval warm climates, proving that there is no scientific consensus on global warming.
CounterPoint. Natural and human-induced climate changes both exist. Studying one does not imply disbelief in the other.
Point. Human populations of Europe and India thrived during the medieval warm time, so clearly warming is good for us.
CounterPoint. No one asserts that the present-day warmth is a calamity, although perhaps some residents of Tuvalu or New Orleans might feel differently, and the Mayans may have been less than enthusiastic about the medieval climate. The projected temperature for 2100 under business-as-usual is another matter entirely, warmer than the Earth has been in millions of years.
Point. NASA identified a huge energy hole over the tropical Pacific, which sucked out as much heat as doubling CO2. NASA scientists asked modelers to replicate this, and they failed, by 200-400%, even when they knew the answer in advance!
CounterPoint. This appears to be a reference to Chen et al., 2002. Satellite data from the equatorial Pacific showed an increase in IR heat flux to space of about 5 W/m2 from 1985 to 2005, and a decrease in reflected visible light of about 2 W/m2, leaving a 3 W/m2 change in net heat flux.
Avery’s implicit promise would seem to be that with rising CO2, the heavens will part and let the excess energy out, a Lindzenesque mechanism to nullify global warming. The measured change in heat fluxes in the equatorial Pacific is indeed comparable to the radiative effect of doubling CO2 but the CO2 number is a global average, while the equatorial Pacific is just one region. The measurements probably reflect a regional rearrangement of cloud cover or ocean temperature, a decadal variation with no clear implication at all for the global mean heat budget of the Earth. The global heat imbalance has been inferred (Hansen et al, Science, 2005), and it is consistent with rising greenhouse gas concentrations and transient heating of the ocean.
A word about models in science (as opposed to in think-tank economics, Mr. Avery’s home turf). Models would have little use if they were so easy to bend into any answer we thought we knew about in advance. One can always be critical of models, but there is no model that avoids global warming by parting the heavens, or that is exquisitely sensitive to solar variability but insensitive to CO2, the worlds that Mr. Avery wishes for.
Avery’s talk also dusted off many of the good old good ones, like the cosmic-ray / cloud connection, the temperature lead of CO2 through the deglaciation, the Antarctic warming, the cooling during the period 1940-1970, the now-resolved satellite temperature discrepancy from ground temperatures, and even the ancient CO2 band saturation myth.
In addition to Chen, Avery offered to us the work of Maureen Raymo and Gerard Bond. Bond didn’t think his work cast any doubt on the possibility of anthropogenic warming, neither do Raymo or Chen. Hint: if you want to sound like you know what you’re talking about, the accent on the fourth syllable of foraminifera, not foraminifera.
Point. Environmentalists do what they do because they miss having their mommies reading Grimm’s Fairy Tales to them. They like getting all scared.
CounterPoint. To hybrid-phrase Thomas Jefferson and Richard Feynman, I tremble for humanity when I reflect that nature cannot be fooled. You’re damn right I’m scared.
==== Re: Post # 42 Comment by Barton Paul Levenson ====
Well, yes, not all viewpoints are tolerated for serious discussion when the scientific issues involved are well settled. I can’t imagine the Astronomical Journal printing a paper defending geocentrism, or Brain, Behavior and Evolution printing one defending creationism. That’s the proper analogy to denialism, since the science behind it is equally crappy.
====
Why not simply ignore these “denialists” then? Their views are not published in mainstream journals anyways, so why this hypersensitive concern about what they say?
Lastly, the science of AGW is a consensus, not universal agreement.
[Response:Books like Avery’s are not aimed at scientists, they are aimed at policymakers and voters. Hence hypersensitivity. David]
RE 40 (Levenson):
The reply to “But being a religion in a sense, questioning ANY of the orthodoxy of AGW is not allowed. Out heretics!” (despite the tiresome ‘robed priests’ argumentation) is fine, esp. outlining proper analogies.
The larger issue is not addressed, however, IMHO. Any crank can question anything. I can question whether the planet is an oblate spheroid.
Rather, the issue is whether the question displays wisdom, and whether the question is fundamentally valid and worthy of discussion.
The better reply to “questioning any of the orthodoxy” is: where’s your data? Where is your falsifiable hypothesis? Show me your evidence (not boilerplate from the usual suspects).
Best,
D
#49 (Charles Muller)
The Parmesan paper is sound. Its basic ecology that climate dictates what communities of plants and animals live in specific locations. When climate changes biotic communities are effected. When climate changes living things are often unable to adapt and become extinct. The fossil record shows overwhelming evidence of this. There is no reason to think that AGW will be any different.
A recent paper in Nature confirmed that the recent AGW has caused amphibians to become extinct in central america and a paper in Proceedings of the Royal Academy confirmed that AGW is killing amphibians in Europe.
http://www.newscientist.com/article/dn10369-global-warming-fuels-fungal-toadkiller.html
A bit of good news on those frogs:
http://www.sciencedaily.com/releases/2006/06/060606183033.htm
Thanks for the post, David. Glad to have experts to challenge these denialists. As a non-expert, I’ve struggled to answer them as best I could in other ways.
For instance, when they trot out the warming precedes the CO2 build up, or GW has happened in the past & is therefore natural, I say, well that’s really scary. What if those natural warming processes decide to start kicking in addition to our human induced warming, and carbon starts surging up due to the warming, causing even greater warming, why, we could be in hot water well before the scientists are suggesting….literally.
Re the economic arguments, I ask, how can reducing our emissions (through reduction of energy, resource, water, and product comsuption) cost? Seems to me it would save us money.
#50 Hank #53 Joseph
Pounds et al paper, quoted by Parmesan, is the problem, not the solution.
Point 1 : in a previous paper, Pounds 2001 (Nature) mainly charged extreme drought and UV radiation stress (allready due to GW). In 2006, he turns to cloud cover, cooler days and warmer nights. Two different climatic explanations in 5 years : why no, but quite strange.
Point 2 : thermal variations noted by Pounds 2006 do not exceed 1°C in DTR. Have a look at Piotrowski 2004 paper for chytrid life cycle : it reproduces at 4-25°C, survives up to 30 °C. A small T amplitude in a tropical forest is not expected to affect decisively chytrid life cycle.
Point 3 : for their quite complex and speculative hypothesis (more cloud > warmer nights but not cooler days > less mortality of chytrid > extinction), Pounds et al. suppose cloud change have been decisive. Have a look at ISCCP data for 1987-1998 (period of their study) : personally, I did no find a clear trend on Central America.
Point 4 : chytrid, only identifid in 1993 as a source of amphibian decline (Berger 1998), allready affects large populations in Central America, North America, Europe and Australia, whatever climate changes these regions are affected by. Everywhere mortality rates are high. More than 90 species are affected. Climate trends of the past decades is not the main driver of this epizooty. On its African origin and dissemination by trade, Weldon et al. on this link :
http://www.cdc.gov/ncidod/EID/vol10no12/03-0804.htm
Point 5 : just good sense. Your cow gets a pathological prion and subsquently died of encephalitis. Summer temperature anomaly was 1°C above normal during the drama. You’ll blame prion or meteo ? Even if Pounds 2006 is correct (local variations partially induced by anthropogenic GW favorize local growth of chytrid), the reasoning is spurious : chytrid is the main culprit.
Berger L. et al. (1998). Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America, Proc. Natl. Acad. Sci. USA, 95, 9031-9036.
Piotrowski J.S. et al. (2004), Physiology of Batrachochytrium dendrobatidis, a chytrid pathogen of amphibians, Mycologia, 96, 9-15.
Pounds J.A. (2001), Climate and amphibian declines, Nature, 410, 639�640.
Pounds J.A. et al. (2006), Widespread amphibian extinctions from epidemic disease driven by global warming, Nature, 439, 161-167.
#53 (Joseph)
Yes, basic biology and ecology tell us that populations adapt to environmental variations. That’s why many informations of Parmesan paper are rather comforting: the more phenologic and distribution changes you notice, the strongest the adaptative response you infer for the observed populations (except for extinction or pop. contraction, of course) – as she notes herself in “Evolution and plasticity” chapter. You’re OK (and Parmesan too) : the rate and range of climate change will be decisive for biodiversity. In my initial point, I don’t say there’s no threat (because there is one, like for acidification), just that an excessive alarmism based on inaccurate estimations is not the good way for a long-term work on public opinion. The prudential and precise method of RC is by far more convincing for readers.
I read realclimate because it educates me in new areas where I need educating. But this site seems to me increasingly clogged with useless junk. Too many posts come from a small number of self-important argumentative people who write self-referential notes that are of little or no importance.
The contributors to (editors of) realclimate do not, for obvious reasons, want to limit the content of these posts. But why not put a limit on the number of posts per person per year? I would think something like 4 would be plenty. With fewer opportunities, maybe these people would think harder.
In fact, why not limit the number of posts by the contributors? Some of them never comment at all, while others comment on nearly every other post. This limit would reduce the burden on devoted but harried people like Ray Pierre, who has grown noticeably grumpy in responding to so many mindless posts, and Gavin, who seems well along the way to this state of mind.
Most of the public would benefit from fewer but better-reasoned posts from the outside and fewer grumpy responses from within.
Bill Ruddiman
[Response:It is interesting to watch the discussion take on a direction of its own, usually after about comment #30 or #50 or so. And hey, what about me? Aren’t I grumpy enough for you? David]
There are at a minimum two topics here. The first is a scientific one, are there 1500 year D-O cycles in the Holocene, or at least the recent Holocene, which for arbitrary purposes we might take as recorded history. If there are, how much are they influencing current climate change.
The second, and in my judgement more important question (and I gather the original poster agrees with me on this) is how and why is this issue being raised in by Singer and Avery. Specific to this thread, why at the Heartland Institute which is a nonprofit organization devoted to discovering and promoting free-market solutions to social and economic problems.” Now certain of our friends have been tutt-tutting the participation of scientists in politics, but you can get a good hint of what this is really about take a look at this video.
Apologies for being slightly off-topic. I did some searching but could not come up with the right search or a proper answer.
Urbanization/surbanization/desertification of the world clearly has some effect on albedo and heat transport. The denialists often point to the heat island effect as confusing temperature measurements, yadda, yadda etc. But doesn’t the increasing amount of light colored concrete and buildings increase the overall planet albedo – and thus offset GHG increases associated? How much exactly per square meter on a global basis? And do urban areas (heat island effect) actually release more heat at night (loss to planet) than forested areas which retain the heat in the form of water vapor? Deserts lose more heat at night than forests right?
What I guess I’m really asking is do we have accurate measures of the different terrain forcings (slightly complicated by feedbacks)? Such forcings must have influenced past warmings and coolings. Today, we have the Caspian Sea drying up leaving desert instead of water – that’s gotta change the overall albedo. Desertification in the Amazon and Africa has gotta change the albedo as well.
I’m not saying this is a “good thing” in that if it is slowing the heating by any significance it would be another masking effect that goes away like SO2 as we adopt better land management practices and/or the fact that the processes are somewhat self-limiting [only so much desertification will occur regardless of human efforts]. And so we may find additional GHG produce a larger temperature increase in the end than we are getting now.
Of course, a friend of mine proposed years ago that the government should give everyone mirrors to set out in their front yards to increase the planet albedo to offset the GHG warming. It couldn’t hurt at this point…
==== Comment # 52 by Dano: ====
The larger issue is not addressed, however, IMHO. Any crank can question anything. I can question whether the planet is an oblate spheroid.
====
AGW is different. Much “proof” rests on computer models that extend far into the future. And as much as we dislike cranks, they exist on every subject.
==== Dano said: ====
Rather, the issue is whether the question displays wisdom, and whether the question is fundamentally valid and worthy of discussion.
====
I would not agree. Al Gore can go around stating that the oceans are going to rise several meters flooding coastal cities and he basically goes unchallenged, uncorrected, and lauded for his fearmongering.
Scientists can go around stating that polar bears are currently drowning because of global warming. This is complete and utter nonsense yet because it was stated by scientists and is supportive of AGW, it can not be questioned, at least not by the general public.
The Tuvalu Island myth has also been propagated, without context, by scientists and environmentalists. Questioning them about their deliberate misrepresetation on the subject will earn you the label “denialist”.
There are many more examples where scientists are knowingly feeding into this apocalyptic frenzy with disregard for the totality of the facts. It is a sad spectacle to observe, but is one reason why the general public has still not given their support to seriously tackle AGW yet.
[Response:The oceans could rise by several meters. It has in the past, it could again. Polar bears are expected to lose their viability if there is no sea ice. Not next week, but in the decades ahead. What I know about Tuvalu I read in Mark Lynas’ book “High Tide”. It’s not a myth that the people there have to evacuate. The totallity of the facts seems clear to me. David]
Scientists can go around stating that polar bears are currently drowning because of global warming
This is ridiculous, Paul. The problem for polar bears is there will not be sufficient ice on which to hunt. The fact that Arctic ice is shrinking is well documented. Facts are facts. Don’t blame science.
Polar bears are at risk of extinction in the next half-century.
Fact. Deal with it.
Re 61 (PaulG):
I’m not going to expend bandwidth going back and forth. The meaning of my argumentation perhaps can be expressed this way:
1. The usual suspects present no data of their own to explain likely outcomes, no falsifiable hypotheses, none of their own computer models expressing their findings of physical principles, no formulae, barely any journal articles, no theories, no writing on the back of a napkin, nothing. Silence. No, not silence: what is the sound of hand-waving?
In other words: If not x, then what?
2. The supporters/water carriers of the usual suspects tend to conflate and confuse issues, often without factual backing/citations. For example: no provided evidence that The Tuvalu Island myth has also been propagated, without context, by scientists, just unattributed vague assertions.
Wisdom provides much of what is lacking in 1 and 2 above. Sadly, I see no ‘wisdom’ button on The Google.
Best,
D
Hmm…Arctic sea ice has been shrinking rapidly (as such things go) over the past quarter century
==== Comment by David to my post # 61 ====
[Response:The oceans could rise by several meters. It has in the past, it could again. Polar bears are expected to lose their viability if there is no sea ice. Not next week, but in the decades ahead. What I know about Tuvalu I read in Mark Lynas’ book “High Tide”. It’s not a myth that the people there have to evacuate. The totallity of the facts seems clear to me. David]
====
I agree David, sea levels COULD rise by several meters. And in what time frame? 500 years? 1000 years? A little context would be helpful (though less effective for scaring the general public).
Currently the polar bear population in Canada is very viable. Some drowned bears have been observed. Why is this simple, factual observation of several dead polar bears misrepresented as proof of global warming?
Polar bears have always drowned in the past. And in the future, their viability may be threatened. But taking the observation of 4 dead polar bears at present, does not constitute any kind of “proof” but more of a misrepresentation, by scientists, to influence public opinion unfairly.
Regarding the Tuvalu Islands, these are low lying islands, subject to erosion, have suffered from poor coastal management, and offer little economic opportunity for it’s inhabitants.
But I have seen is no evidence that rapidly increasing sea levels (because sea levels haven’t been rising rapidly) have forced even one person to flee the Tuvalu Islands. So why is Tuvalu also presented as “proof” of AGW?
[Response: You are right, the time scale needs to be considered when talking about sea level rise. The German Advisory Council on Global Change concludes in its latest ocean report (which I presented in Nairobi two weeks ago) that for a 3 ºC global warming, sea levels are likely to rise by 3-5 meters by the year 2300.
Your last sentence I don’t understand – sea level has risen by 15-20 cm in the past 100 years, and by 3 cm in the past ten years, as a response to climate warming (See Cazenave and Nerem (2004) for a review). In the previous millennia, sea level has not risen even remotely at this rate (think of it – the current rate of rise would imply 3 meters lower sea level in the middle ages, which simply was not the case). So what’s the basis of your claim that “sea levels haven’t been rising rapidly”?
p.s. There are several good TV documentaries about the situation in Tuvalu, yet strangely, some people who have never been there and sit high and dry in the US (cowardly hiding behind anonymity, or would you make such claims with your full name, putting your personal credibility on the line, Paul G?) simply proclaim there is no problem. Would you also do this face to face with a citizen of Tuvalu? I suspect the people struggling with the flooding of their villages would find this denial somewhat cynical. -stefan]
=== Re: Post # 64 by Dano: ====
Re 61 (PaulG):
I’m not going to expend bandwidth going back and forth. The meaning of my argumentation perhaps can be expressed this way:
1. The usual suspects present no data of their own to explain likely outcomes, no falsifiable hypotheses, none of their own computer models expressing their findings of physical principles, no formulae, barely any journal articles, no theories, no writing on the back of a napkin, nothing. Silence. No, not silence: what is the sound of hand-waving?
In other words: If not x, then what?
2. The supporters/water carriers of the usual suspects tend to conflate and confuse issues, often without factual backing/citations. For example: no provided evidence that The Tuvalu Island myth has also been propagated, without context, by scientists, just unattributed vague assertions.
Wisdom provides much of what is lacking in 1 and 2 above. Sadly, I see no ‘wisdom’ button on The Google.
====
Dano, my question is why, with the science so compelling, is there such inaction on this subject in Canada and the US? My belief is that the general public is not convinced of the seriousness of the situation. And why would this be? I think there are two reasons:
1) Constant environmental alarmism over the last few decades has numbed the general public over AGW.
2) The public may be (and appears to be) concerned about AGW, but not to the point where they are prepared to pay higher taxes, higher prices for fuel and live with lower economic growth.
It is difficult to motivate people over a problem that could manifest itself in 50 years. How to address this, I do not know.
I do stand by my assertion that some scientists have been misrepresenting their findings in the name of attempting to spur the public to action. However, for the reasons stated previously, this tactic is not working.
Regards,
In the second to last counterpoint it is mentioned that Avery’s expertise is in economic think-tanks. This is a subtle statement disqualifying him from being able to be right. This site has promoted the view that scientists know better than economists about future temperatures. In fact the business of predicting future temperatures bears many similarities to predicting future commodity prices. The equivalent economists may take the oil price rises of the last few years and inversely correlate it to proven reserves and predict that oil prices will continue to rise. Thus ignoring fundamentals like the underlying inflation and negative feedbacks (high oil prices reducing demand eventually bringing them back). The underlying temperature inflation rate due to CO2 cannot be inferred from the last 3 decades in isolation, just as the oil price inflation cannot be. Scientists are again setting themselves up to look stupid if there’s a decade with a downward wobble in temperature. I challenge now any scientist here to say that average temperatures cannot possibly go down in the next decade.
66. On polar bears:
Paul G,
– When I google under “polar bears thriving”, I find, among other things, this: http://www.cbc.ca/health/story/2005/07/15/polar-bears050715.html : “But Andrew Derocher, chair of the International Polar Bear Specialist Group, said the population of bears in the Davis Strait area seems to be doing well.”
– But when I look up Derocher, and follow through to his polar-bear interests, I end up here: http://pbsg.npolar.no/ . When you look at the “threats”, you find that “climate change” is prominent. Some quotes:
“Polar bears are totally reliant on the sea ice as their primary habitat. If climate change alters the period of ice cover, bears may be forced on shore for extended periods and forced to rely on stored fat. If these periods become excessively long, mortality will increase. Such changes are thought to be occurring in western Hudson Bay. Further, if the ice changes in character such that there is more open water, young cubs which are unable to swim long distances may suffer greater mortality. Sea ice is also used for access to den areas and if ice patterns change, existing den areas may be unreachable. Another factor is that in some areas, warmer temperatures and higher winds may reduce ice thickness and increase ice drift. Because polar bears must walk against the moving ice (like walking the wrong way on an escalator) increased ice movements will increase energy use and reduce growth and reproduction.”
“Polar bears are a keystone species in ice-covered Arctic marine ecosystems and alterations to the distribution, density or abundance of this top predator will likely have impacts throughout the arctic ecosystem. There is little doubt that polar bears and other ice-inhabiting marine mammals in the Arctic, are being, or will be, negatively affected by the effects of climate change via changes to their habitats.”
So, although, Derocher is quoted on the Davis Strait bears by people claiming that “the bears are alright”, in general his view (or the view of the group of which he is chair) seems clearly to be that GW is a threat to them.
Like some cherries, anyone?
#53 (Joseph)
Thank for the second reference. I read the Bosch et al. 2006 paper you mention, concerning climatic epidemiology of chytrids in Spain (two species, a toad and a salamander). Their conclusion ar far less advanced that Pounds 2006. In fact, they analyse trends in temperature in humidity in the area, notably induced by NAO shift of the past decades, but do not correlate them to frequency or mortality rates of disease outbreaks. Climate-drive is not excluded neither proved, but as they precise in conclusion : “However, we do not rule out the introduction of B. dendrobatidis in initiating the Penalara epidemic. Chytrid-related declines are probably the result of a complex web of interaction, and the effects of climate will be conditional on other factors such as host density, amphibian community composition, microbial competitors and zooplankton predators, to name but a few.” To be continued…
(For RC and #58 Bill : sorry for these totally off-topics developments, I notice a certain annoyance and I stop there on frogs !)
Re ” If CO2 is only a marginal contributor to the recent global warming, then significant warming might be inevitable regardless of our efforts to reduce CO2 emissions, yet these efforts would tie up resources that could be better spent addressing the consequences of warming.”
And if your mother had wheels, she’d be a trolley.
CO2 is the main driver of the present anthropogenic global warming.
Since we are getting into this, allow me to point out the “if pigs were horses, cows would fly attack” being used. Assuming something that is wrong or at best questionable and then reasoning from it as if it were revealed truth can be hard to deal with, because it is easy to get sucked in. Stefan’s response is exactly the correct one, you point out that the argument fails on its assumptions.
It is also an interesting difference between science and math and social sciences. In the former case you do the exercise to derive a contradiction or impossibility. For anyone who reads the Economist or deals with economics, this is a mode of argument to justify a preferred conclusion and you ignore the contradictions.
#66 Paul and Stefan comment
Concerning sea level trends, maybe Paul alludes to its acceleration, still weak on the past cenury (Church 2006 : 0,013 mm/yr/yr). Topex/Jason/Poseidon measures 3 mm/yr for 1993-present, higher rate than 1,7 mm/yr for 1900-2000. But as Lombard, Cazenave et al. precise, the thermosteric part exhibits strong decadal variations and “the pattern of sea-level trends derived from Topex/Poseidon altimetry over 1993â��2003, which is mainly caused by thermal expansion, is very likely a non-permanent feature. Thus past and future extrapolation based on this 10-year altimetry pattern should be considered with caution”
Lombard et al. (2005), Contribution of thermal expansion to present-day sea-level change revisited, Global and Planetary Change[/i] 47 (2005) 1�16
]In order to argue that scientists are conspiring to incite public panic about AGW, one would need to show how scientists would benefit from that. There is no monetary gain for scientists here unlike for denialists in the oil industry. And most scientists are very careful, skeptical thinkers because nothing is more horrifying to a scientist than losing his/her credibility. So most scientists would NOT write thousands of papers about global warming and its effects without evidence. Doing that would be to their detriment, not benefit. One could argue perhaps that some scientists advovating the damage that is already started with global warming are gluttons for publicity; they like to hear themselves talk on TV and write blogs all over the internet. Ok, we’re all human, but again this would be to the scientists’ detriment because so much publicity about a false claim would only cause them to be ridiculed for all to witness. Plus, maybe in the performing arts no publicity is bad publicity; but for scientists the worst kind of publicity is the one that challenges their scientific and intellectual integrity. So there is no motive to conspire here.
And considering Bill Ruddimann’s comment, I agree and am often perplexed that all these very accomplished scientists (both editors and comment posters) have so much time to write blogs and respond to comments. Don’t they teach, work with graduate students and have their own science to pursue? I understand this is about educating voters and developing public policy. But some of the back and forth is useless and tedious to read swaying everyone from the main points of the discussion. This causes everyone to burn out, even just casual readers.
[Response:I don’t know what can be done about the large volume of comments swamping the readers, except to edit more, which would be considerably more work and thought for the contributors. As for the “don’t these scientists have other things to do” question, I’ve thought about your question quite a bit since you asked it 24 hours ago. I find it extremely stimulating to write a blog post for realclimate. I get more feedback, some of it rather bare-knuckles, than I ever do from writing a paper for publication. In the past few years, most of my time is spent doing what they call “outreach”, including teaching classes on global warming, writing books on it (first out, second nearly done, third contracted for). Realclimate may be preaching to the choir, as an earlier commenter suggested, but it also gets a lot of traction with journalists and other scientists. Writing a blog entry takes some time, responding to comments is just fun. I personally am not burning out from all the volume. Fire away! David]
The public may be (and appears to be) concerned about AGW, but not to the point where they are prepared to pay higher taxes, higher prices for fuel and live with lower economic growth.
It is difficult to motivate people over a problem that could manifest itself in 50 years. How to address this, I do not know.
California is taking aggressive action and this is a key reason for Schwarzenegger regaining his popularity in the State. You’ll see some real action if the Supreme Court rules that California can regulate CO2 as an auto pollutant. It’s wrong to assume there’s no popular support for action, just because the Federal government is inactive.
“It is difficult to motivate people over a problem that could manifest itself in 50 years. How to address this, I do not know”
Those who believe the problem might affect them in 50 years really have to walk around with closed eyes!
By the way, if some people always believe, that on an economical point it’s too expensive to act, we could also look at it from different perspective: why not invest in alternative energy sources and for the development of it. It would bring us an advantage over the uprising countries like India and China and it would also create a lot of new employments.
But today those economists are still thinking in the “oil era”. Oil still rules the world, it is still the “cheapest” energy source on earth and I doubt this will change soon, unfortunately.
I don’t understand why solar effects have been played down when so many scientific articles that reconstruct paleoclimates correlate solar effects with climate change.
The typical dismissal argues that current rises in temperatures can not be due to solar activity because over the past 30 years there has been no significant change in solar activity to correlate with the increased temperatures during that same time. But there are several studies that show that we have been in a period of very high solar activity the past 50 years, even though activity has been level during that time plus or minus 1%. But by analogy if I start a pot of water at room temperature and turn on the stove burner to high, the stove burner has risen to a high level of activity and remains at that level for a period of time. Meanwhile during that time the water shows a definite trend of warming. To argue that the level trend of the burner does not correlate with the rising trend of the water would be very fallacious if not absurd. Given enough time we should be able to resolve the issue. What we would expect is that if the burner’s output stays level, then at some point in time the water will also reach a temperature plateau.
And in fact that now may be the case. The ocean has shown a gradual increase in temperature during the past period of high solar activity, and now as Lyman and Willis’ paper show the ocean’s temperature steadily rose during that period but has now leveled off and started to fall. (And this coincides with reports showing that solar activity is now slowing http://science.nasa.gov/headlines/y2006/10may_longrange.htm).
These observations persuade me to believe that solar is the more important warming force as the high levels of CO2 would never predict that the oceans should be cooling
Re #73: Charles, I haven’t checked those citations yet (mainly looking for their reasoning as to why they expect the stearic rate to slow), although of course I agree that any relatively short-term trend must have a caveat attached to it, but I would point out that the data from the last couple of years showing accelerated melt in both Greenland and Antarctica (equaling about 1 mm/yr if memory serves) needs to be added to the overall figure. The upshot is that unless we have some reason to expect the melt rate to decline (and I think there is every expectation of the reverse), then a substantial drop in the stearic rise will be compensated for and perhaps more than compensated for by increased melt. I should note my understanding that much of the data relating to sea level and melt is still a little fuzzy around the edges, but that this should change within the next two to three years by way of the far more more accurate and comprehensive data collection that recently became possible via the GRACE gravitometric satellites and the ARGO ocean sensor array.
#77 Steve
Lombard et al. (2005) analyse the last 50 years for sea-level change and sea temperature (surface, 500 m, 800 m). They do not find a regular trend, but high variability dominated by signals from ENSO and PDO (and a significant but less signature from NAO). The variablity for these periods (typically a decade) can reach three times the average of 1950-90 and there’s also short periods of negative trends. As the present se-level trend from Topex-Jason is supposed to be 50% thermosteric (rather than 25% for the average of the XXth century), they deduce that we’re currently in such an oscillation. (But as far I know, there’s for the moment no sign of deceleration since 1993).
Of course, as you say, if melting of glaciers is accelerating, this could maintain a high rate for sea-level change. But GRACE measurements (for Greenland or Antarctica) are very short and we still don’t know if the melting 2002-2006 will continue. For Greenland and GRACE, compare for example the values of Luthcke et al. this week in Science (2003-2005 : -101 Gt/yr +/-16) with those of Chen et al. two months ago (2002-2005 : -239 +/- 23 Gt/yr) : great uncertainty because of too short measurements (and need for a gravity calibration / post-rebound of the instrument, I guess). Last point : melting of Greenland is of course sensitive to GW and its polar amplification, but NAO phases maintain their influence on decadal periods (because of mass gain in altitude from snow precipitations).
That’s for decadal variability of melting and sea-level. But on long term, we should expect the sea-level continue to accelerate. The rate of acceleration will be desicive for human affairs, of course.
Is this another slosh in the bath tub?
8 November 2006
Flotilla of icebergs noticed 300km south of Invercargill (New Zealand) (at around 49d30m South by 168d East. – GoogleEarth these coords.)
http://www.stuff.co.nz/stuff/0,2106,3853336a7693,00.html
then
24 November 2006
60km off the coast of Timaru (at around 44d30mSouth by 172dEast)
And another 1km long berg 80km of the Catlins (at around 46d30mSouth 171dEast.)
http://www.stuff.co.nz/stuff/0,2106,3876276a11,00.html
So thatâ??s about 600km in 16 days or about 38km a day on average.
If the denialists want to have a look at SOMETHING going on (whatever it is), they can think about joining me on Sunday morning at a high point on Bankâ??s Peninsula (say 43d48mS 173d02mE) to have a look at a very rare site indeed.
When was the last time cubic-kilometre size bergs crossed latitude 45 degrees South heading northwards into the Pacific?
Re #68: “This site has promoted the view that scientists know better than economists about future temperatures. In fact the business of predicting future temperatures bears many similarities to predicting future commodity prices.” Now *that* is a breathtaking claim. Marco, of course Avery *could* be right if one looks at his claims in the absence of any prior knowledge of the science, but such an approach seems less than useful. Should scientists similarly expect to succeed in the commodities market based only on their knowledge of climate?
“The underlying temperature inflation rate due to CO2 cannot be inferred from the last 3 decades in isolation, just as the oil price inflation cannot be.” And of course you’re right that this would be a mistake. The recent temperature record is only part of the evidence. That evidence, and the reasoning based upon it, is discussed extensively on this site. Reading through the FAQs linked on the right bar will give you a fair start at understanding the basics.
“I challenge now any scientist here to say that average temperatures cannot possibly go down in the next decade.” Marco, I’m sure you’ll be pleased to find out that James Annan, an occasional guest author here, would be very happy to enter into a substantial bet with you along the lines you describe. Please do report back on how much money you’re willing to stake.
Re: 79 “Should scientists similarly expect to succeed in the commodities market based only on their knowledge of climate?”
I don’t see why not. If they can predict better a mild or colder winter than expected this has obvious implications in the market for heating oil for instance. Another point is that you don’t really have to understand a market to have an insight on it. Temperatures may overshoot until the gulf stream is eroded, which may cause global average temperatures to undershoot the long term trend. In nature positive feedbacks tend to have a life for a while, but often trigger an equally powerful negative feedback. Some successful traders have little knowledge of models that underpin their strategy.
As for the bet, I believe I probably couldn’t get odds of any more than 5 to 1 from a brief reading of the relevant research. This would imply a 1 in five chance that environmental scientists would have egg on their face due to the average global temperatures in 2016 being lower than the equivalent 2006 measures. I would be willing to wager plenty at odds of 5:1 if I had trust in the betting systems that can work on such long terms. I am willing to place a friendly $50 bet at even odds just for the thrill :)
Re 17:
An alternate theory must accout for:
“1) The cooling trend in the stratosphere as opposed to warming in the tropo.
2) The trend in diurnal range, night warming more than day.
3) The seasonal trend, winters warming more than summers.”
Wouldn’t increased cloudiness account for all of these things (assuming the clouds were tropospheric)?
An earlier posting seems not to have made it past the moderators; I will try again.
In my post, #66 stefan responded:
===
“You are right, the time scale needs to be considered when talking about sea level rise. The German Advisory Council on Global Change concludes in its latest ocean report (which I presented in Nairobi two weeks ago) that for a 3 ºC global warming, sea levels are likely to rise by 3-5 meters by the year 2300.
Your last sentence I don’t understand – sea level has risen by 15-20 cm in the past 100 years, and by 3 cm in the past ten years, as a response to climate warming (See Cazenave and Nerem (2004) for a review). In the previous millennia, sea level has not risen even remotely at this rate (think of it – the current rate of rise would imply 3 meters lower sea level in the middle ages, which simply was not the case). So what’s the basis of your claim that “sea levels haven’t been rising rapidly”?
====
Paul G.:
Stefan, when I argue about context, I would ask, is 100 years enough? How much have sea levels risen in the last 1000 years? 5000 years?
The Tuvalu Islands have been losing their battle with the seas well before AGW started.
[Response: Evidence? The sea level reconstructions for the Holocene in the scientific literature suggest it has been dropping slightly, not rising, for several thousand years since the post-glacial high stand. -stefan]
===stefan said: ===
p.s. There are several good TV documentaries about the situation in Tuvalu, yet strangely, some people who have never been there and sit high and dry in the US (cowardly hiding behind anonymity, or would you make such claims with your full name, putting your personal credibility on the line, Paul G?) simply proclaim there is no problem. Would you also do this face to face with a citizen of Tuvalu? I suspect the people struggling with the flooding of their villages would find this denial somewhat cynical. -stefan]
====
Paul G.:
I will ignore the ad hominems, my point about Tuvalu is that, at present, it is not “proof” of the effects of AGW. Plausibly, it could be in the future, but that is much different then how this has been presented to the general public.
[Response: I’m not aware of anyone claiming that the case of Tuvalu is “proof” for global warming or sea level rise. It’s just one location! We have good global data sets for sea level, from tide gauges going back to 1880, and since 1993 from satellite altimeter. We also understand that this sea level rise is caused by humans, since it is due to the modern global warming and not some remnant from the last Ice Age, say. (Postglacial rebound from the Ice Age actually causes a drop of global sea level by .3 mm/yr, thereby compensating about 10% of the current 3 mm/yr climatically induced rise.) So, Tuvalu is no proof of global warming, it simply is an illustration of the effects that the anthropogenic sea level rise is having on people. -stefan]
Flooding of their villages has happened many times in the past, and unless evidence is provided substantiating changes in the frequency and/or intensity of flooding, does not strengthen the case for AGW being the current source of the majority of the Tuvalu Island’s problems.
Lastly, sentimentality for the plight of the Tuvalese seems somewhat self-serving. Were you concerned about their poverty and plight before the issue of AGW, or only because of it?
Regards,
Is the official position of this website that there are NO climate cycles whatsoever?
If so, what is the website’s position on the recent (past 3 million years) of glaciation cycles?
If not, what is the website’s position on what portion of warming is caused by the current climate cycle that we are now in?
I think that the website cannot take both positions that there are indeed climate cycles but there is no natural cycle contributing to the current warming today.
[Response: This is a revealing comment, and I’ll try and address the underlying points. First off, this website has no official positions on anything. All of us are individual scientists with individual views. No one is responsible for anything any of the others say. However, 90% of what we talk about here is not controversial in the scientific community, and so the fact that we tend to agree more often than not is no surprise. Next, you juxtapose ‘climate cycles’ and the current anthropogenic warming as though they must be mutally exclusive. Think about the logic here: does the fact that your radio alarm goes off at the same time every morning imply that you can’t have also turned it on at some point in the afternoon? So of course we are interested in natural variability – try reading our publication lists for dozens of papers on such topics. Note that I use the term ‘natural varibiabilty’ rather than climate cycles because actually very little past variability can explained using ‘cycles’ in the colloquial sense. An exception to that is pacing of the glacial-interglacial cycles by changes in the orbit of the Earth, which since the 1970s, has been textbook stuff.
The shortest of these cycles, precessional forcing, has a period of around 20,000 years which implies that its change over a century or two is completely negligable. You need to go look over 6 or 10 thousand years to find evidence of precessionally driven changes (at that time, NH summer insolation was higher than today, tropical insolation a little lower), and models do a pretty good job of replicating the data from that time. If that was all that was going on we’d be on a pretty stable course right now since that forcing has ‘bottomed out’ and will soon (next few thousand years) start warming the NH summers again. All very interesting, but of little relevance for today’s situation.
Your fundamental misconception is however the idea that only one thing causes climate change. This is wrong on all time scales. There are multitudes of effects – greenhouse gases, volcanoes, orbital forcing, tectonics, solar, land use, aerosols, etc. etc. all of which can play varying roles at various times. At times long ago in the past it can be tricky to separate them out (the ratio of solar to volcanic in the late 17th Century for instance), what happened during the Eocene, or during a D-O event etc., but the closer you get to the present the more precisely we know many of these factors – we know that GHGs have increased sharply, as have aerosols. We know solar has been pretty stable for decades, we know when the big volcanoes went off. So, like detectives from CSI we have a pretty good idea of whodunnit this time around.
To conclude, of course natural variability is important – but natural variability cannot explain recent trends. More to the point, forcing from GHGs is currently the fastest growing warming factor and is likely to stay that way for decades to come. -gavin]
People have been trying to get global warming skeptics to bet for a while now, but without any success that I know about. See William Connolley’s comments at
mustelid.blogspot.com/2005/06/betting-on-climate-change-or-not.html
One problem is specifying the bet in some meaningful manner. For example, your offer to bet about comparing two specific years doesn’t make a whole lot of sense. A volcanic eruption could easily lower temperatures significantly for a year or two.
re: 82, Marco Parigi,
5:1 odds: That sounds like you believe that the GW-ers are probably right, doesn’t it?
If you’re only willing to place $50 on a 1:1, what that says to me is that you don’t really have confidence in your point of view: You just want to be able to say, “I bet on it,” and are willing to pay the $50 to be able to make that statement.
If you really want to make some money on a deal, Annan seems to be set up for it:
http://julesandjames.blogspot.com/2005/06/betting-summary.html
If the purpose of this comment board is to talk about “unstoppable hot air”, can anyone give me a clue as to how we are to go about educating people that have heard one side of the story but are unwilling to even contemplate the other?
Does climate change come under risk communication, and if it doesn’t, should it?
I’m studying for a masters in climate change, and have joined the online forum for students Facebook, and the number of groups set up on Global Warming being just a theory, or being a lie is astounding. These students (a lot still in high school in the US) seriously believe Michael Crichton’s book and without anyone there to put them right it’s only going to get worse. Believe me, I’ve tried, and all I get back is personal attacks. What is happening in the education system to get climate change on the curriculum?
In #30, Steve mentions the wave of anti-climate change propaganda that the world is going to recieve in the run up to the AR4, so how are we to deal with this? It feels like an uphill battle!
Sorry to bring people down, but I love that realclimate often has both sides of the argument and I need to find a way of replicating it elsewhere!
Thanks
Hi Vicky,
I agree with you about the state of the discussion forums. It’s amazing to me that so many people, especially young people, refuse to entertain opposing points of view. I suspect that the best way to effect change in such environments is to ask questions. Tonight at the provincial museum in Edmonton, at 7:30, there is a free lecture by a geologist (Bruno Wiskel) who is promoting his new book “The Emperor’s New Climate: Debunking the Myth of Global Warming.” Perhaps someone who reads RC can attend and ask some good questions. I think that would be the most effective thing to do.
#85 Gavin response
Very interesting. Maybe we should distinguish intrinsic variability (chaotic) and natural variability (induced by natural forcings : solar, volcanoes, etc.). The two are “natural” in essence… but not the same nature, I guess (mecanisms, time scales, amplitudes, etc.).
Another point : it seems that it will be more and more difficult to separate clearly these natural variabilities from human-induced variabilities. For example, nebulosity is perceived as natural, but human aerosols influence it. Or ENSO or PDO are considered as natural, but maybe GHG warming modifies the ENSO or PDO signals. Etc.
Last point (detail) : I often read on RC that solar forcing has no change for the last 50 years. But we measure irradiance since 1978. There’s no trend during 1978-2006, OK. What is more surprising for me is no trend between 1950 and 1980. On the classic sunspots graphs (thereafter a Nasa link), we can see a maximum for the XXth century around 1960, then a low value around 1970, and then a mid value around 1980. I suppose the “yo-yo” in 1950-1980 sunspots can be considered as a proxy for some variations of irradiance. Of course, it’s not particularly pertinent for recent warming 1978-2006, but I’m just curious about 1950-80.
http://science.nasa.gov/ssl/pad/solar/images/zurich.gif
This may help:
http://home.badc.rl.ac.uk/lawrence/blog/2005/12/08/solar_irradiance_and_sunspot_cycles
illustrations include:
http://home.badc.rl.ac.uk/lawrence/static/2005/12/08/Solankiclimate.jpg
http://home.badc.rl.ac.uk/lawrence/static/2005/12/08/Krikovasolanki.jpg
http://www.eurekalert.org/pub_releases/2006-11/uow-rfo112006.php
Something else you didn’t know about nature that may affect the climate but which is not in your computer models.
You can ignore this, like my post about the recent cooling of the ocean, but, sooner or later you may start to feel a twinge of uncertainty. Then, you might become a scientist and not an advocate.
Just think, once relieved of the need to prove something, you may actually discover something.
Have you asked yourself this question: If you discovered something which cast doubt on AGW, not disproved it, but just cast doubt on it, would you have the courage to publish it?
If your answer is: “Don’t be ridiculous. There is no doubt about serious AGW!” we can conclude you stopped being a scientist sometime ago.
[Response: If I find anything interesting, I will endeavour to have it published in the highest profile journal that’s relevant. I’ll be sure to mail you a copy. ;) Meanwhile, uncertainties (of which there are many) in the carbon cycle make absolutely no difference to most climate model results because CO2 in those models is prescribed from observed atmospheric concentrations. For carbon cycle models it might make a difference in estimates of future carbon cycle feedbacks, maybe David could weigh in?, but it just adds to the already large uncertainties in that sub-field. – gavin]
Re 91
Helpful at proving anthropogenic climate change more natural than extraterrestial ;-)
re 88.
The National Weather Service has 150 professionally trained meteorologists and hydrologists with education/outreach responsibility in weather, water and climate.
http://www.nws.noaa.gov/organization.php
Unfortunately, many NWS people have been telling the public that there is no global warming problem or that global warming theory is not part of their duty in serving in the public interest.
…
Heather, from Hanover writes:
Why is it that the summers seem to get hotter and hotter? Is it because of the ozone is depleating? If the temperture continues to rise how long will humans be able to survive in the heat?
Deputy Director of the National Weather Service, John E. Jones, Jr.
Heather, I’m not really a climate change expert, so I can’t offer much insight here. I can tell you that under the President’s leadership this week, more than 30 nations came together here in Washington, D.C. to establish an Earth observation system aimed at providing scientific data needed to understand our climate.
http://www.whitehouse.gov/ask/20030801.html
re 94. That should say NWS has about 150 offices … total staff in the US is about 5500, nearly half of the total staff in NOAA.
Re #92: Joel, your comment about ocean cooling was ignored because the issue was thoroughly addressed in this RC post three months ago, to say nothing of a number of other places in the climate blogosphere. The upshot is that even the authors of the study think their results are less than definitive. Note in particular that if the authors are correct in their supposition that the rate of melting has greatly increased in the last several years, that would simply mean that there is a different pattern of warming since it takes the application of a very large amount of heat to melt that much ice. And of course, such a massive spike in the rate of ice melting is pretty much the last thing we would want to see happening at this early stage in the warming process. Let’s hope it isn’t.
>91
Captions: “… the most recent two or three decades of warming are not correlated with the solar irradiance … and thus could be explained by anthropogenic warming…. the recent flurry of interest in cosmic rays and clouds cannot explain the last thirty years of temperature increase either.” Agreed, human activity is natural, not created by extraterrestrials.
>92
The waxy material is left in the ground after bad forest fires and contributes to severe erosion by enhancing runoff. No surprise it would show up in thick annual layers after severe erosion periods. Is that mentioned in the actual research?
Google Results … about 88,800 for: forest fire waxy layer soil erosion
Re: Post #96 by Steve Bloom
Ending your post on ocean cooling, you say:
“…..such a massive spike in the rate of ice melting is pretty much the last thing we would want to see happening at this early stage in the warming process. Let’s hope it isn’t.”
Yet at RC, on the same subject, you state:
“Their results infer a net addition . . . 6mm/yr for the last two years (the difference between the 3mm/yr observed rise and their inferred 3mm/yr fall from cooling). This is in sharp contradiction to GRACE and altimetry results for that time frame. . . . So far, the only new GRACE results (regional mapping of Greenland melt) have only made the discrepancy *worse*”
http://tinyurl.com/yll8qr
Here, the possibility of a sudden, dramtic increase in sea level is presented as a potentially serious concern, but at the Climate Science site, you all but discount this possibility.
Is there an explanation for your two different viewpoints?
Regards,
Re: 87 5:1 odds: That sounds like you believe that the GW-ers are probably right, doesn’t it? If you’re only willing to place $50 on a 1:1, what that says to me is that you don’t really have confidence in your point of view: You just want to be able to say, “I bet on it,” and are willing to pay the $50 to be able to make that statement.
If you really want to make some money on a deal, Annan seems to be set up for it:
My point wasn’t really whether I thought GW was happening or not. I don’t see why I should sell myself short by only doubling my money, if some cocky environmental-scientist/bookmaker would pay at odds of 5 to 1. Especially for a bet with such a long lead time.
I will expand on my original point which was that Climate, like weather (or the stockmarket) in general is a chaotic system, with a lot of unknown positive and negative feedbacks. Basically any economists model of a complex financial system is also subject to these. This often makes a “blind monkey” selection of stock portfolio perform better than a selection by highly paid experts with their models. Importantly the models often predict perfectly all past patterns, and often fail when the application of the model to make stock decisions changes the system enough for the model to need substantial revision to regain accuracy, also making previous long term predictions less useful. The types of things that would unexpectedly disrupt the usefulness of current models are incessantly being talked about on this site. Whether it be Man-made particulates, volcanic activity, change in ocean currents, reductions in CFC’s and CH4, Ice movements or various unexpected combinational effects – It doesn’t really matter. A blind monkey may make better bets than the scientific consensus. Just as the warning with stocks go – stocks can go down as well as up (even if the long term trend is considered up). Temperatures can go down as well as up. It is a warning that should be made to investors who buy land in high altitude cold place in the expectation that things will get warmer. Investors in general don’t seem to be heeding the “water rising” message by the number buying expensive houses on beach frontage globally!
Thanks for the link to the post about the ocean cooling on this website. Very interesting.
The question still remains, since the climate models didn’t predict this, which do we trust, the models or the data? So far, I get the impression that the “warmers” rather trust the models. But, if the data is true, that the ocean has cooled recently, the warmers claim things are worse than we thought.
You can forgive an agnostic for having problems with this sort of reasoning.