Daniel Botkin, emeritus professor of ecology at UC Santa Barbara, argues in the Wall Street Journal (Oct 17, page A19) that global warming will not have much impact on life on Earth. We’ll summarize some of his points and then take our turn:
Botkin: The warm climates in the past 2.5 million years did not lead to extinctions.
Response: For the past 2.5 million years the climate has oscillated between interglacials which were (at most) a little warmer than today and glacials which were considerably colder than today. There is no precedent in the past 2.5 million years for so much warming so fast. The ecosystem has had 2.5 million years to adapt to glacial-interglacial swings, but we are asking it to adapt to a completely new climate in just a few centuries. The past is not a very good analog for the future in this case. And anyway, the human species can suffer quite a bit before we start talking extinction.
Botkin: Tropical diseases are affected by other things besides temperature
Response: I’m personally more worried about dust bowls than malaria in the temperate latitudes. Droughts don’t lead to too many extinctions either, but they can destroy civilizations. It is true that tropical diseases are affected by many things besides temperature, but temperature is important, and the coming warming is certainly not going to make the fight against malaria any easier.
Botkin: Kilimanjaro again.
Response: Been there, done that. The article Botkin cites is from American Scientist, an unreviewed pop science magazine, and it is mainly a rehash of old arguments that have been discussed and disposed of elsewhere. And anyway, the issue is a red-herring. Even if it turned out that for some bizarre reason the Kilimanjaro glacier, which is thousands of years old, picked just this moment to melt purely by coincidence, it would not in any way affect the validity of our prediction of future warming. Glaciers are melting around the world, confirming the general warming trends that we measure. There are also many other confirmations of the physics behind the predictions. It’s a case of attacking the science by attacking an icon, rather than taking on the underlying scientific arguments directly.
Botkin: The medieval optimum was a good time
Response: Maybe it was, if you’re interested in Europe and don’t mind the droughts in the American Southwest. But the business-as-usual forecast for 2100 is an entirely different beast than the medieval climate. The Earth is already probably warmer than it was in medieval times. Beware the bait and switch!
—
Botkin argues for clear-thinking rationality in the discussion about anthropogenic climate change, against twisting the truth, as it were. We couldn’t agree more. Doctor, heal thyself.
For years the Wall Street Journal has been lying to you about the existence of global warming. It doesn’t exist, it’s a conspiracy, the satellites show it’s just urban heat islands, it’s not CO2, it’s all the sun, it’s water vapor, and on and on. Now that those arguments are losing traction, they have moved on from denying global warming’s existence to soothing you with reassurances that it ain’t gonna be such a bad thing.
Fool me once, shame on…shame on you. Fool me–you can’t get fooled again.
-George W. Bush
Dean, re #99. You do know that Antarctica is a big place, right? And you do know that there’s a whole helluva lot of water around it, right? And you do know that the oceans are a really big heat reservoir, right? If you take these trends and read the realclimate piece you cite, that should give you the answer. Basically, most of the energy that warms the poles comes from elsewhere–at least the north pole. Energy flow to Antarctica is a lot more limited, and has been more limited than usual in recent decades. That said, the ice balance to the some of the main ice sheets on the continent is negative, so warming is starting to occur.
Re: 99: Dean,
A classic case (common in science) of a misleading first impression. It is, in fact, possible for Antarctica to warm and grow. The key is that warmer air holds more moisture. Imagine that the temperature over the Antarctic interior rises, yet remains below freezing. The warmer air holds more moisture, so when it snows, it snows more. Warmer, and growing! For now.
#26 JS McIntyre: I recall E.O. Wilson suggesting that what we’re attempting to do is create a global civilization that requires the resources of three or four earths.
The problem, of course, is that there is a line of doomsayers spanning hundreds of years whos prophecies never came true.
In the last hundred years we’ve had everyone from Carnegie telling congress we are almost out of steel, to Carson telling everyone synthetic pesticides were worse than natural pesticies, to Ehrlich telling everyone that we were almost out of everything. Peak oil, dying oceans, nuclear winter, skin cancer from ozone, AIDS killing everyone, and on and on…the din is never ending.
And incredibly, none have come true, have they? In some cases there has been mitigating factors that were perhaps because of corrective actions. But overwhelmingly folks just seem to lose interest and move on to the next disaster when the first disaster never materializes.
What is the most grave prediction you can think of that actually had a measurable impact that came true over a 20+ year window?
Well dean I suggest trying to hold two thoughts in your head at the same time. It can cause both and does. What you desire is the typical either/or fallacy. And that’s exactly what you have.
Okay, Dean, you’ve got a USA Today article from January 2002 about the West Antarctic ice sheet (judging just by the URL you gave).
So put that into a search engine, Google Scholar, look for work published this year. Like this:
http://scholar.google.com/scholar?num=100&hl=en&lr=&newwindow=1&safe=off&scoring=r&q=%22West+Antarctic+Ice+Sheet%22&as_ylo=2007&btnG=Search
This won’t give you as simple an answer as USA Today, and you’ll want to read through some of the material to make up your own mind.
Do give up the certainty that “both cannot be true.” You have to specify where, and when, and for how long before you know much about either statement being true or not. Think about how large Antarctica is — do you know how big?
Think about any country you’re familiar with, for example the United States. Can climate change cause some areas to warm and others to cool? Some to get wetter, and some to get drier? Can both be true of the United States, once you look a little closer at the details?
This is why it’s important to be skeptical. Simple answers are pushed at you. Don’t trust a 2002 USA Today article to be good information, if you want to understand what’s being learned.
You know about the International Polar Year studies? You can look them up. If the answers were all simple and understood, they wouldn’t be putting such effort into this new work.
Great article as always! I’m glad to see the WSJ called on its stance.
I’d also kind of like to see RC do a review of John Stossel who is at it again (still).
Says he: “The truth is, that while everyone agrees that the earth has warmed, lots of good scientists don’t agree that it’s mostly our fault, and don’t agree that it’s going to be a catastrophe. So when Gore says, ‘The debate is over,’ I say, ‘Give Me a Break!'”
Man vs. Nature, 10/19/07
http://www.abcnews.go.com/2020/Stossel/story?id=3751219&page=1
He may be a little low brow compared to your usual fare, but he gets a wide audience and does a lot of damage. Just my 2 cents.
This may be useful on the original topic:
http://adsabs.harvard.edu/abs/2007ERL…..111001K
PERSPECTIVE: On the verge of dangerous anthropogenic interference with the climate system?
——excerpt——
“The article by Danny Harvey in this issue [2] offers a fresh perspective by rephrasing the concept of ‘dangerous interference’ as a problem of risk assessment. As Harvey points out, identification of ‘dangerous interference’ does not require us to know with certainty that future climate change will be dangerous—an impossible task given that our knowledge about future climate change includes uncertainty. Rather, it requires the assertion that interference would lead to a significant probability of dangerous climate change beyond some risk tolerance, and therefore would pose an unacceptable risk.
In his article [2], Harvey puts this idea into operation by presenting a back-of-the-envelope calculation to identify allowable CO2 concentrations under uncertainty about climate sensitivity to anthropogenic forcing and the location of a temperature threshold beyond which dangerous climate change will occur. Conditional on his assumptions, Harvey delivers an interesting result…..
…
… we are on the verge of or even committed to dangerous interference with the climate system if we (1) set the risk tolerance for experiencing dangerous climate change to 1% and (2) allocate at least 5% probability to the belief that climate sensitivity is 4.5 °C or higher. In the language of the IPCC, the latter would mean that such a high climate sensitivity is anything but extremely unlikely ([1], footnote 6 and p 9), a view that is shared by many in the scientific community. Even if the risk tolerance is increased to 10%, the maximum allowable CO2 equivalent concentration remains below 460 ppm ([2], figure 7(c)). We are bound to reach that concentration in the near future, as it can be surpassed both by addition of new greenhouse gases and by a reduction of global dimming.
Given the potential significance of this result, let us take a step back, and investigate its underlying assumptions. The concept of ‘dangerous anthropogenic interference’ is inextricably linked to the idea of a threshold beyond which climate change can be labeled dangerous. This idea enters Harvey’s analysis in the form of a probability distribution for the—as he calls it—’harm threshold’ measured in terms of global mean temperature increase since preindustrial time.
…
the magnitude of the anthropogenic perturbation of the carbon cycle forces us to go back far into the past, if we want to look for clues of what might happen in the future. Certainly, some of the climate changes reflected in figure 1 are a result of volcanism and continental drift, in particular the opening and closing of sea passages. However, recent data indicate that the carbon cycle was a major player in the transition from the Eocene hothouse to the modern-day icehouse world (e.g. Moran et al [11], Zachos et al [12]). The studies by Zachos et al [12] and Pearson and Palmer [13] found that carbon dioxide concentrations in the atmosphere decreased from well above 1000 ppm during the Eocene to below or around 300 ppm during the Mio-, Plio- and Pleistocene. On the basis of their data, it is likely that present-day levels of atmospheric carbon dioxide have not occurred for the last 23 million years. Moreover, projections of the growing anthropogenic perturbation of the carbon cycle in the 21st century, including scenarios that aim at stabilizing atmospheric CO2 concentration at twice its preindustrial value, carry us to carbon dioxide levels that were last seen during the Oligocene, where major restructuring of the climate system occurred.
But what about time scales? Certainly, climate policy cannot be concerned with climate changes that unravel over millions of years. However, the slowest processes in the climate system, i.e., heat penetration into the deep ocean and changes in ice sheet volume, operate on time scales of thousands of years, with deglaciation potentially occurring much faster within hundreds of years. Hence, if the driver is sufficiently fast, rapid climate change can occur. This is evidenced in the paleoclimatic record shown in figure 1 by the event called Paleocene Eocene Thermal Maximum (PETM) 55 million years ago. During the PETM, global temperatures rose by 5 10 °C to presumably the hottest conditions during the Cenozoic era in a matter of several thousand years (Zachos et al [14]) due to a large perturbation of the carbon cycle (Zachos et al [15]) of hitherto unknown cause (Pagani et al [16]). A millennial time scale is still far beyond the time horizon of current socio-economic activity, but this is just the time scale for the system to equilibrate (bar the removal of carbon dioxide from the atmosphere ocean-biosphere reservoir which proceeds much more slowly [15]). Significant changes will be felt much earlier. And when it comes to assessing ‘dangerous anthropogenic interference with the climate system’ that has the potential to change the face of the planet for a hundred thousand or more years to come, an extension of our time horizon to several hundred years seems to be appropriate….
——-end excerpt——
Worth reading, folks, I think as a mere reader of all this.
I’d sure like to hear more from those who’ve been kicking risk levels around. William Connolley? Judith Curry? Is this the sort of assessment you all are thinking of?
Re 61 Chris: “That’s the problem with the models – weatherman can’t predict the weather with any accuracy more than 2 days in advance – so why should be believe the models that predict years or scores of year ahead?”
Oh, but if I had a penny for every time this simple-minded, ignorant saw has been uttered.
Once again…., GCMs don’t predict the weather years or scores of year ahead, they predict climate trends years or scores of year ahead.
You need to learn that there is a difference between weather, which is specific to a particular place at a particular time, and climate, which is the average of weather over long time spans. Knowing the climate that is typical of a particular place will tell you nothing about what the weather will be at that particular place on a particular day in the future.
robert (#102) wrote:
I know that based upon altitude measurements it was thought that the mass balance may have been increasing, but the most recent study that I am aware of is based on GRACE but does not appear to be a blessing…
They are showing some very slight growth in EAIS as the result of precipitation increase it would appear, but this is quite small in comparison to the melt loss in WAIS.
Anyway, if someone has something more recent, I would be interested.
Re 103 matt: “Peak oil, dying oceans, nuclear winter, skin cancer from ozone, AIDS killing everyone, and on and on…the din is never ending.
And incredibly, none have come true, have they?”
As a matter of fact…
some data suggests that oil may be peaking
http://www.theoildrum.com/node/3001
large regions of ocean are dying
http://www.msnbc.msn.com/id/4624359/
http://oceanservice.noaa.gov/products/pubs_hypox.html
and skin cancer is very much on the rise in the southern hemisphere
http://www.blackwell-synergy.com/doi/abs/10.1034/j.1600-0781.2002.02782.x
You were saying?
> What is the most grave prediction you can think of that actually
> had a measurable impact that came true over a 20+ year window?
The evolution of antibiotic resistance and its lateral transfer among bacteria. Got MRSA in your high school yet?
Could someone comment on the state of this region today referenced on john-daly.com:
“A considerable change of climate inexplicable at present to us must have taken place in the Circumpolar Regions, by which the severity of the cold that has for centuries past enclosed the seas in the high northern latitudes in an impenetrable barrier of ice has been, during the last two years, greatly abated.”
“2000 square leagues of ice with which the Greenland Seas between the latitudes of 74° and 80°N have been hitherto covered, has in the last two years entirely disappeared.”
“The floods which have the whole summer inundated all those parts of Germany where rivers have their sources in snowy mountains, afford ample proof that new sources of warmth have been opened …”
This is not the latest scare story from the greenhouse industry, but extracts from a letter by the President of the Royal Society addressed to the British Admiralty, recommending they send a ship to the Arctic to investigate the dramatic changes.
The letter was written, not in the year 2000, but in 1817. History repeating itself?
Did this area re-freeze or stay melted? Is 2000 square leagues (24000 mi2) a lot or a little compared to melting we are seeing today? Is 24000 mi2 melting in two years a lot?
Link: http://www.john-daly.com/press/press-00b.htm#ice-melt
Re #99 / #101 /#105
Hi Dean, to add more perspective to what Ray/Hank said:
1st. Simply put more global warming = more moisture, and therefore more rain and snow. The real difference is that the snow melts faster, this is already being evidenced in many areas around the globe. The Antarctic is a bigger refrigerator so it has more potential to stay cooler but it will lose the battle.
http://www.jpl.nasa.gov/news/news.cfm?release=2006-028
2nd. Don’t trust newspapers with a blanket ‘they know what they are talking about’ license. Remember they only ask questions from the limits and bias of their own perspective. Trust the science and thousands of experts that study this every day, not a media organization that only looks at it so they can get another article that will help sell papers or support a biased view.
In his response to Botkin’s comments on the melting of the Kilimanjaro glaciers and ice caps, David writes, “The article Botkin cites is from American Scientist, an unreviewed pop science magazine, and it is mainly a rehash of old arguments that have been discussed and disposed of elsewhere.”
David’s comment is disappointing on several levels.
Like the Mote and Kaser article (Am. Sci., July-August 2007), most articles in American Scientist are invited and not subject to external review by reviewers selected by the editors. However, Mote and Kaser are summarizing for a general audience of scientists and engineers research that they and colleagues have published in peer-reviewed journals — and recent research, not “old arguments”. I found the M & K arguments subtle and persuasive and in a Google Scholar search didn’t find any sign of those arguments having been “discussed and disposed of elsewhere”. Perhaps David can enlighten us as to where that happened, precisely. Those who select topics for American Scientist do have a bit of the contrarian, frequently choosing recent research that represents a paradigm shift or contradicts some bit of accepted wisdom.
Perhaps more to the point, even though most American Scientist articles are non-“peer reviewed”, most of the readers of American Scientist are peer reviewed, being members of a Sigma Xi, an honor society for scientists and engineers, founded in 1886. Over the decades, I have found American Scientist one of the best sources of review articles across the breadth of science and engineering and, in addition, containing several excellent continuing columns and dozens of informative reviews of science, math, and technology books.
David would have done better to point out that Botkin rather substantially mis-represents the point that Mote and Kaser are making. Botkin writes that Mote and Kaser “explained why the glacier on Mt. Kilimanjaro could not be melting from global warming”. A sentence or so later, he writes, “That it could not be global warming directly (i.e., the result of air around the glacier warming) was made clear by the fact that the air temperature at that altitude of the glacier is below freezing.” Ah, yes, “directly” — a weasel word not appearing in his lead sentence.
Both Botkin’s piece and the Mote and Kaser article suffer from the old investing adage, “What the bottom line giveth, the footnote taketh away.” Mote and Kaser write, “Indeed, warming fails spectacularly to explain the behavior of the glaciers and plateau ice on Africa’s Kilimanjaro massif …”. Toward the end of their article, they write, “It is possible, though, that there is an indirect connection between the accumulation of greenhouse gases and Kilimanjaro’s disappearing ice: There is strong evidence of an association over the last 200 years or so between Indian Ocean surface temperatures and atmospheric circulation and precipitation patterns that either feed or starve the ice on Kilimanjaro. These patterns have been starving the ice since the late 19th century … Any contribution of rising greenhouse gases to this circulation pattern necessarily emerged only in the last few years, hence it is responsible for at most a fraction of the recent decline in ice and a much smaller fraction of the total decline.”
Given the logarithmic dependence of temperature and unknown dependence of precipitation on greenhouse gas concentration and the gradual accumulation of greenhouse gases since the early 19th century, I am unpersuaded by the last assertion quoted above.
Another subtlety of the Mote and Kaser argument that Botkin ignores is that completely different mechanisms are at work on the ice cap on the summit plateau and the glaciers on the 55 degree slopes below the summits. They note that the slope glaciers gain net mass from snowfall at high altitude and lose net mass at lower altitude. They define the equilibrium line altitude as that altitude where these processes balance. They further state that “On many tropical glaciers, both the direct impact of global warming and the indirect one — changes in atmospheric moisture concentration — are responsible for the observed mass losses. The mere fact that ice is disappearing sheds no light on which mechanism is responsible.”
All of this is far away from Botkin’s assertion that Mote and Kaser “explained why the glacier on Mt. Kilimanjaro could not be melting from global warming.” They do nothing of the sort. At the same time, they do show that Kilimanjaro is not quite the “Poster Mountain” for AGW that our “common sense” and environmental enthusiasm might suggest.
Best regards.
Full text pdf is here Hank:
http://www.iop.org/EJ/article/1748-9326/2/1/011001/erl7_1_011001.pdf
And the referenced paper here:
http://www.iop.org/EJ/article/1748-9326/2/1/014001/erl7_1_014001.pdf
…worth a look.
LesPorter thunders:
[[Corporations that do not display active responsibility to the future of the species need to be dismantled and their assets converted to systems that will demonstrate social responsibility.]]
Does someone here “The Internationale” in the background?
I think we can leave corporations alone as long as illegal conduct is banned. Government control of economies has a long record of massive failure.
Chris writes:
[[That’s the problem with the models – weatherman can’t predict the weather with any accuracy more than 2 days in advance – so why should be believe the models that predict years or scores of year ahead?]]
You’re confusing weather with climate. Weather — day to day variation — is chaotic and cannot be predicted past a few days; predicting the weather is an “initial conditions problem.” Climate — weather averaged over a large region over a period of 30 years or more — is deterministic and often easy to predict. To illustrate the difference, I don’t know what the temperature will be tomorrow in Cairo, Egypt (weather). I do know that it is likely to be hotter than in Oslo, Norway (climate).
Hank, Since risk assessment is part of my day job, I thought I’d chime in. I have been advocating a risk-assessment approach to climate change for quite awhile now. The approach is generally a reasonable one for decision-making and resource allocation in situations with varying degrees of uncertainty. The problem is that it requires estimates of both probability of occurrence for various adverse events and for the probable consequences of those events. Both of these are still quite uncertain and there is unlikely to be universal agreement on the probabilities to choose for the outcomes and consequences. We can apply a subjectivist probability analysis–selecting probability distributions for various levels of confidence. This can work quite well if we have many experts and confine ourselves to the mean of their subjective probabilities, but even this can be a fraught proposition if some experts actively seek a particular outcome or if some experts think others will try to manipulate the process. Thus, for the prediction of mean risk to be valid, there has to be confidence among in the process as well. Transparency is essential, but so is a process that gives contributors confidence that the process will not be susceptible to manipulation by making extreme predictions to push the mean in a given direction. An averaging process that rejects outliers is such a process, but the rejection process needs to be agreed upon.
Once you have a risk estimate, you can make intelligent decisions about allocation of resources toward mitigation–targeting funds so as to maximize risk reduction.
It is a complicated process, but it is one humans tend to follow naturally when faced with a difficult and complicated project that faces lots of different risks.
Difficulties arise when you try to formalize it–people don’t seem to like to be told what to do with mathematical certainty. Another difficulty arises when you face many interlocking risks where reducing one risk affects the probability or cost estimates for the others–and remember you have to keep the process transparent. The whole issue of sustainability–preserving environmental quality, development, mitigating climate change…–is such an issue.
It’s a bit of a challenge, but it is an approach I have strongly advocated for years, so I clearly think the challenges can be managed.
[[Who is correct here? And where can I find some sort of ‘proof’ that the ‘CO2 causes global warming’ hypothesis is right?]]
Try the IPCC AR4 report. Here’s a link:
http://ipcc-wg1.ucar.edu/wg1/wg1-report.html
If you want to understand the mechanism involved, find a good book on atmosphere physics, like John Houghton’s “The Physics of Atmospheres” (3rd ed. 2002), or Grant W. Petty’s “A First Course in Atmospheric Radiation” (2006). Or try my climatology pages:
http://members.aol.com/bpl1960/Climatology.html
Regarding Doom Sayers who’s prophecies never come true.. Doom sayers may serve an important function in society……
Regarding Carson telling everyone synthetic pesticides were worse than natural pesticies….. there really was a major issue there, and it was, in part, that pesticides such as DDT did not break down. These days, pesticide manufacturers make pesticides that break down fairly rapidly. An issue was raised, and a solution was found. One can argue that the reason we have not yet degraded our environment beyond recognition ( no American Eagles , ospreys, hawks, owls,or people ) is because people pointed out that there were problems and then acted on this knowledge.
…to Ehrlich telling everyone that we were almost out of everything. Peak oil…
Do you have to commute a distance or heat a house? The price of petroleum products is saying a something about available supply.
dying oceans…. the dead area at the mouth of the Mississippi? The degradation of Long Island sound? Bleaching of coral..
nuclear winter… a large scale nuclear exchange is likely to make the planet uninhabitable or barely habitable by humans… the major nuclear powers realized this and have cut back nuclear arsenals and work towards non-proliferation.
skin cancer from ozone,… you probably mean skin cancer from higher UV from lack of filtering ozone. If I am not mistaken, there has been a significant increase in skin cancer, especially in the southern hemisphere, where the ozone destruction was greatest. We humans have cut down our production of ozone destroying substances in an attempt to mitigate this problem. Is that a bad thing? There was a problem noted, and solutions were found.
AIDS killing everyone….. when modern western mores met the AIDS virus, humanity was on a high mortality track that fortunately was derailed by research, education and subsequent changes in behavior.
and on and on…the din is never ending.
An optimist can discern an important pattern in these examples. The din is a good thing and will continue as long as people identify problems and address them. Many problems did not come to fruition because people addressed them with thought and reason and then took action to mitigate them.
One can worry about unpleasant possibilities, ignore them, or address them.
People most likely do have a limited capacity to keep multiple disasters in mind all the time. Ignoring doom sayers does not make them go away however. There is a local urban legend about a highway bridge that collapsed one night. A driver who stopped in time got out and tried to warn an on coming BMW to stop. Legend has it the driver of the beemer was giving the first driver the finger as he sped over the edge and plunged to his death.
But they can and often do address problems and change their behaviors accordingly and go on with life.
Re #103 (Matt) Doomsaying
It seems to me that your reasoning “doomsayers were wrong before, so there will be no problem now” is not correct.
Firstly, the conclusion does not follow at all from the premise. It is perfectly possible that doomsayers were wrong a thousand times before, but still are correct today, especially because the problems we are facing now are unprecedented in scale.
Actually I hate the term doomsayer. Mostly we are talking about people who had the wisdom to look ahead and point out serious consequences of a BAU scenario.
Secondly, some dire predictions did not came true only BECAUSE people acted on the predictions:
– the pesticide crisis Rachel Carson pointed out did not come to pass because of reduced pesticide use.
– skin cancer on a large scale will probably be averted because we stopped destroying the ozone layer
Thirdly, some other predictions are still about the future, and actually have a good chance of coming true:
– In 1970 “Limits to Growth” predicted that humanity would get into trouble (under a BAU scenario) about half way into the 21st century. This could be due to various different constraints: raw material depletion, energy shortage, pollution, lack of water. Please do get LtG from the library and check it against what we know now. In fact, Matthew Simmons (investment banker and energy adviser to George Bush, surely an unbiased source in this) already did just this: http://www.greatchange.org/ov-simmons,club_of_rome_revisted.pdf
– peak oil: if you go through the literature, you’ll see that most experts now agree that it will occur within the next decade or so. The exact point in time largely depends on political events, not physics, so it is hard to pin down. But it is simple arithmetic that oil demand will outstrip production soon. Checked the oil price lately?
In conclusion then, we’d better take the climate predictions of IPCC very seriously.
I just don’t understand what deniers achieve by first denying climate change, and, now, denying human influence upon it, or whether it is even bad.
I can’t wait to see responses to Stossel’s latest piece, where a half dozen scientists use ‘facts’ that are seemingly taken directly from the British case regarding the use of Gore’s film in schools.
#107 Hank Roberts As Harvey points out, identification of ‘dangerous interference’ does not require us to know with certainty that future climate change will be dangerous—an impossible task given that our knowledge about future climate change includes uncertainty. Rather, it requires the assertion that interference would lead to a significant probability of dangerous climate change beyond some risk tolerance, and therefore would pose an unacceptable risk.
The problem with this line of thinking is that if you set the threshold at 5 or 10% of “something really bad happening” on a binary event (or series of related events) based on the opinion of experts, then we will end up spending money on an almost infinitely long list.
What is the probability a skyscraper will fall over and kill thousands due to an unexpected even in the next 100 years? What is the probability a volcano will erupt and surprise a large population in the next 100 years? What is the probability and hundreds of bridges deemed “structurally good enough” will collapse without warning? Major city flooding unexpectedly? Skin cancers shooting through the roof? Wars due to misunderstandings? Major city loosing power during an extreme cold or heat wave?
In fact, I could spend all night writing out a list of things that could happen with 5% probability in the next 100 years that would show potentially 50M lives at risk. And if I give odds of 5% and you accept those, how can you possible refute it when I increase those odds to 85% over a 100 year time scale IF one or more humans are involved OR if a system that isn’t completely understood is involved. You can’t. And since that list would involve 50M lives, how can you NOT want to pursue those?
The other problem with a 5% (or 95% figure) for a complex system is that it means it’s a guess. If you get to watch an event happen one time and you don’t understand the cause, you have no way of knowing the probability was 90% or 10%. That’s good news for the expert, because it means if they state something bad will happen with 90% certainty, and it doesn’t happen, then the experts can say “thank god, I’m relieved to be wrong” without any accountability for their alarmism. Example? The statement “we’re 85% sure that country XYZ has nukes, and they will use them for evil. They must be stopped”. It doesn’t take much fanning of the flames for everyone to start thinking “Geez, they are right. If just one nuke gets launched, millions could die. And think of a dirty bomb in NYC! We must stop them. And you know what? If we’re wrong, I’ll be relieved. Better safe than sorry.”
I’d bet that world consensus of world experts was easily at 85% that Iraq had nukes and was planning on doing something bad with them. Yet my guess is that most readers of this board were against the invasion and wanted more study on the subject. How is consensus of world experts there different that here? Experts on both sides were (and are) scared to death.
Y2K bug? Ozone hole? DDT? Kuwait oil fires and nuclear winter?
See how troublesome that line of thinking is?
David:
A delta T is a delta T and ~10 degrees in a century is an off the IPCC scale killer. So your equivocation on the impact, regional or hemispheric ,of the rapid rate of change of the Younger Dryas is risky , because, being as far as we know, the holocene Worst Thing Yet, the YD excursion is authentically interesting- and the last thing anybody should, pardon the expression, deny.
Please retract before this microgaff turns into a mutant hockey stick- the usual suspects only need half a data point to fill a rubber spreadsheet, and you are in the process of giving them a whole one
Re: #105
Dear Hank,
This is the crux of the problem. We are swilling in simple answers from both extremes, with op-eds from the likes of Botkin at one pole, and people like Beverley (#70) being influenced by alarmist sources at the other pole …
… and, although I appreciate the reference you provided, and found this post useful, the excerpt you just posted would not appear to me to reassure Beverley and many others who share her opinion that it is already too late to tackle climate change.
Meanwhile, there are efforts that could be listed for Beverley from outside the scientific literature documenting actions being taken in the real world (i.e. not invented by journalists!) by engineers, businesses and governments to better understand, address and mitigate climate change.
Perhaps it is time for another site aimed at highlighting RealSolutions, as mentioned by Les (#47) and Ike (#54), to enable non-scientists to pose questions to be answered by industry professionals (engineers, business leaders)?
Matt, you dumped a basket of red herrings in the thread. Not useful.
Re 112 matt: “Is 2000 square leagues (24000 mi2) a lot or a little compared to melting we are seeing today? Is 24000 mi2 melting in two years a lot?”
Matt, the area of Arctic sea ice that melted this year was by far the maximum observed since satellite observation of Arctic sea ice began in 1979, exceeding the previous record of 2005 by 1.2 million km2 (461,000 miles2). That is over 19 times the estimated melt referred to in your quote, but it’s hard to make a direct comparison since there was no satellite observation of the entire Arctic in 1817.
See the extent of this year’s melt for yourself at:
http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html
Re 99
Did anyone else notice that the USA Today article reporting that Antarctica is cooling was published in 2002? The Grace satellite results showing significant mass loss of Antarctica was published in 2006. http://www.jpl.nasa.gov/news/news.cfm?release=2006-028
“University of East Anglia researchers gauged CO2 absorption through more than 90,000 measurements from merchant ships equipped with automatic instruments.
“Results of their 10-year study in the North Atlantic show CO2 uptake halved between the mid-90s and 2000 to 2005.” http://news.bbc.co.uk/2/hi/uk_news/7053903.stm
#127 Jim Eager: That is over 19 times the estimated melt referred to in your quote, but it’s hard to make a direct comparison since there was no satellite observation of the entire Arctic in 1817
Thanks, extremely helpful
#126 Hank Roberts: Matt, you dumped a basket of red herrings in the thread. Not useful.
Sorry about that, didn’t mean to derail. I’ll sharpen it to a single question for you since you brought up a very good question on risk assessment.
In the run up to the Iraq war, world consensus (85%) was that Sadaam had WMDs and was likely to use them. Was it prudent for the US invade or should we have waited for more data? How does this differ from the current state on climate science? I’ll guess your position was “wait for more info on Iraq” and “act now on global warming”
Is that correct?
re 103
“The problem, of course, is that there is a line of doomsayers spanning hundreds of years whos prophecies never came true.”
Ah, but that’s not the case here. Wilson’s statement is based on observable activity taking place across the spectrum of international economics.
In case you haven’t been following it, China and India (and the U.S.) – to mention three – have been making every effort to lock up energy reserves across the planet. Ironically, the melting Arctic is spurring talk of securing untapped energy reserves found there. Nuclear power is being reconsidered by more and more nations. Whether oil production has peaked in terms of available supply, it is not increasing in any appreciable manner and all the while demand for energy is on the rise.
Raw materials are in increasing demand. China, in its efforts to keep its economic progress moving forward, first trashed itself ecologically and is now in the process of taking whatever it can from surrounding nations.
Food production has essentially leveled out. There is just so much arable land and all the while population is on the rise. The competition for food that is available is also on the rise, increasing grain prices and by doing so, locking out poorer countries
If the rest of the world were to achieve the lifestyle of the U.S., that would mean they’d want our power consumption levels, as well. 300,000,000 people and we’re using somewhere in the neighborhood of 25% of the world’s energy. You don’t need to be a rocket scientist to understand the math doesn’t add up to a happy resolution.
I’ll recommend to sources for you to look into this for yourself. The first is “Collapse” by Diamond, mentioned in the post you responded to (26), the second is the Lester Brown book cited in 52, which you can access at no cost in the links I provided. Combined or separately, both lend credence – via well-argued and cited discussions – to the remarks I attributed to E.O. Wilson.
This is in response to comment 114 by Jim Dukelow regarding the American Scientist essay “The Shrinking Glaciers of Kilimanjaro: Can Global Warming Be Blamed?”…
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1, Jim, you state:
Perhaps even more to the point, American Scientist is not a peer reviewed journal devoted to climatology.
2. You state:
Why would it be necessary for the “M & K arguments” to be “disposed of” if they hadn’t appeared in a peer-reviewed journal devoted to climatology?
3. You state:
Why would it be necessary to “despose of” their arguments if these were simply a “review” (read “rehash”) of arguments from primary literature which had been “desposed of”?
4. You quote them as saying:
Why?
Best estimates by NASA is that relative to 1880, the forcing due to anthropogenic greenhouse gases has exceeded the positive forcing due to solar variability from 1882 on. The deline in the mass balance of Kilimanjaro was first noticed (at least according to your subtle contrarian paradigm-shifting authors) in the 1880s.
5. You state:
At this point you have me confused. In (4) you quoted them as stating that this was precisely what they were doing for all but “the last few years” with regard to atmospheric circulation. And the rest of the article is attempting much the same with regard to the warming by greenhouse gases.
*
Now let’s go to the “subtle” article itself. They state that sublimation is independent of temperature.
I quote:
However, the partial pressure of saturation rises as an exponential function of temperature – even at well below zero. As such the process of evaporation directly from solid to gas is very much dependent upon temperature. However, given the latitude, I doubt that temperature has had that great of an effect as seasonality in the tropics is largely expressed in terms of humidity, not temperature.
They state that the diffuse effects of increased infrared radiation could not be “the cause” of the sculpted appearance and easterly-westerly direction of the sculpted features.
I quote:
And again:
In this they are right – if it were simply infrared radiation operating on its own. However, to assume that the resulting structure receives its most of its energy from the source which is responsible for the directionality of the structure is fallacious. It would be like assuming that since hurricanes always spin in a way that is determined by the rotation of the earth, it must be the rotation of the earth which is primarily responsible for the source of their energy and not evaporation.
They suggest that the directionality is due to solar radiation because of its easterly-westerly direction.
I quote:
However, they do not eliminate the possibility that it is actually the wind – which would likely have the same directionality. What is likely is that since sublimation is a form of evaporation, albeit evaporation going directly from solid to gas, and since the gaseous state will result in moist air convection, it is in fact the wind that is responsible for the sculpting – whatever the primary source of energy is which is responsible for the directionality of the sculpting.
Furthermore, what is in all likelihood responsible for the sculpted appearance of the ice itself is the fact that it is going directly from solid to gas instead of going through the intermediate state of being a liquid which would shapelessly flow in direct contact with the solid over a more extended distance with greater heat exchange, not the source of the energy which is responsible for the sculpted appearance.
I agree with them on one major point: sublimation is the primary process at work.
However, greenhouse gases have dominated solar radiation since before the loss of Kilimanjaro’s ice was observed and would have been comparable for some time before this. As such, the sublimation of the ice of Kiliminjaro could historically just as easily be driven by infrared radiation as solar radiation. Moreover, the intensity of forcing due to greenhouse gases would in all likelihood exceeded that of solar radiation in the tropics well before the climate system as a whole given the greater intensity of infrared radiation in the tropics. It is afterall where the super greenhouse effect is observed. The cause of the sculpted appearance of the ice is in all likelihood the fact that it is immediately going from solid to gas. The cause of its directionality is in all likelihood moist air convection combined with the directionality of the wind.
*
Finally, it took me a moment’s thought to arrive at each one of my criticisms and each element in my own explanation. As such I find the arguments of the authors of the piece neither subtle nor persuasive.
David wrote in the original post:
> There is no precedent in the past 2.5 million years for
> so much warming so fast.
Dr. Seitz points out that the recovery from the Younger Dryas cooling is faster than the current warming.
I’d guess the distinction is between change in longterm climate due to changing the atmosphere by increasing CO2, compared to a short-term temperature change that ‘fixed itself’ in only a thousand years or so, caused by some onetime event (glacial melt flood, comet strike, both?)
The various “geo-engineering” fixes like increasing sulfates in the atmosphere would be comparable to creating another Younger Dryas event, maybe?
http://www.ldeo.columbia.edu/res/pi/arch/examples.shtml
“… the annual-mean temperature increased by as much as 10°C in 10 years.”
Ron Taylor (#128) wrote:
Yep. I did.
Please see 109. Glad to see someone else bring it up, though. This is something people need to be reminded of, particularly when they claim the opposite.
Matt (#123) wrote:
Matt, by your line of reasoning, what of risk of “something really bad happening” would ever qualify as a reason for lifting a finger?
Incidentally, the probability of something “really bad happening” is more like 100% – if we don’t adjust our course. Droughts, famines, floods, wars – heck, according to the experts all of this is happening already, albeit on a much more limited scale. But continuing as we are things will get a whole lot worse.
Re 123
Risk management is about estimating the likelihood of an event happening and what the consequences will be.
Skyscrapers do not just “unexpected” fall over. They fall over a result of expected events, such as earthquakes, windstorms, floods, terrorist acts, and human error such as failure to maintain. These risks are carefully considered and engineered allowances made in the basis of design.
The problem with global warming is that it increases flood and weather stresses on all existing structures, and makes designing new structures more difficult because the climate is changing, and historical baselines are no longer as predictive.
You may spend all night, but the list of events that will affect a population of 50M with probability of 5% in the next 100 years is rather short.
1) Global warming
2) War (made more likely as a result of resource stresses caused by Global warming)
3) Crop failure as a result of global warming.
4) Sea level rise as a result of global warming destroying industrial and civic infrastructure.
5) Population displacement as a result of global warming.
There are Earthquakes which have likelihood of occurrence that is much higher, but each they will affect fewer than 50M people. Other geologic events such as a collapse of islands into the sea resulting in giant tsunamis would affect more people, but have a lower likelihood of occurrence.
The policy makers of the world do spend treasure and lives on an almost infinitely long list of priorities. We spent a pile of money fixing the Y2K bug – and it worked. I helped put out the Kuwait oil fires, and it was not easy. We were able to put those fires out because we did our home work, planned, and we worked hard. We put our lives on the line and were lucky enough to come back with a perfect safety record. With good planning and teamwork, anything that can be dreamed, can be accomplished, whether the goal is going to the moon, finding a better way to control malaria, or discontinue the use of the chlorinated hydrocarbons that produced the Ozone Hole.
I do not know about “world experts” but the guys that I know at Oak Ridge that know more about nuclear fuel cycles than anybody else in the free world, were quite certain than Iraq did not have nukes. In this case, the ”experts” were ignored, and you know what happed. If you want to accomplish things, Do your home work.
Regarding the Kilimanjaro issue, this has been extensively discussed at RC. See, for example:
Tropical Glacier Retreat, May 23 2005 RC, Raymond Pierrehumbert:
Quote:
“The widespread retreat is all the more notable because tropical mountain glaciers are old. They have survived thousands of years of natural climate fluctuations, only to dwindle at a time when other climate indicators — notably surface temperature — are showing the imprint of human influence on climate. Quelccaya is at least 1500 years old, Dasuopo is 9000 years old, and Huascaran has seen 19000 years. A date for the ultimate demise of these glaciers has not been fixed, but the Northern Ice Field on Kilimanjaro may be gone in as little as twenty years, after having survived the past 11,000 years.”
That’s why the retreat of these glaciers are a strong idicator of unprecedented global warming (and also why the so-called “Maunder Minimum” is not evidence that it has happened before).
Quote:
“In contrast to the midlatitude case, tropical glaciers do not have summertime melt seasons characterized by above-freezing air temperature. Lower altitude portions can be warmed directly by year-round exposure to above-freezing air, but at higher altitudes absorption of sunlight ultimately supplies all the energy which sustains ablation. However, the other terms in the energy balance directly or indirectly affect the amount of absorbed solar radiation which is available for ablation. These terms are sensitive to air temperature, atmospheric humidity, cloudiness, and wind.”
That’s why the ‘freezing temperatures’ claims of M&K are very misleading.
Final quote:
“The Kilimanjaro glacier has waxed and waned since the time of its inception about 11,000 years ago. An unusually wet decade around 1880 put the glacier into strongly positive mass balance, bulking up its mass. Early 20th century explorers found the glacier recovering towards equilibrium from this anomalous state. However, rather than finding a new equilibrium in the 20th century, the glacier has continued to retreat, and is now on the brink of disappearing. Though air temperature has so far remained below freezing, melting has begun to occur, and the glacier is suffering net ablation over its entire surface. Air temperature increases similar to those observed aloft since 1960, amplified by associated increases in humidity, account for a significant portion of the enhanced ablation leading to this strongly negative mass balance, but the exact proportion is highly uncertain because of the short span of energy and mass balance observations.”
In comparison, the M&K article at American Scientist concludes that “If human-induced global warming has played any role in the shrinkage of Kilimanjaro’s ice, it could only have joined the game quite late, after the result was already clearly decided, acting at most as an accessory, influencing the outcome indirectly.”
So, M&K claim that in the absence of accumulation of fossil fuel-sourced CO2 in the atmosphere, Kilimanjaro would have melted anyway – despite the fact it had been around for 11,000 years.
Jhozae (#122) wrote:
There are a great many people who don’t want us to do something about climate change, whether it is out of a misplaced desire to avoid the economic costs (e.g., economic conservatives – who don’t realize that things will be must more costly in the long-run if we don’t do something about it soon), out of a misplaced desire to protect individual freedom (those who don’t realize that freedom will be far greater jeopardy later if we do not act, the economy endures a great deal of damage, people become desperate, and governments take truly draconian measures), the desire financial gain (e.g.those who have been recieving money from Exxon in exchange for their “skepticism”), and the desire to see the world through an ideology freed from facts and independent of scientific discoveries.
In each case, they begin with the conclusion that they want to arrive at, then try to cut their “opponent’s” argument off at the head by beginning with the scientific claims, then when it becomes clear that this position is no longer tenable, work their way forward. Deny the trend. Deny that we are the cause of it. Deny whether it is bad. Then deny whether we can (read “should”) do anything about it. Then there are probably those who have just come in on the middle of it and hew to the opinions of those that they respect and identify with.
You write: “There is no precedent in the past 2.5 million years for so much warming so fast.”
Could you please list the five centuries from the past 2.5 million years when warming has been fastest. An estimate of warming speeds respectively for the top five will be appreciated, with an accuracy of about plus minus 0,2 degrees Celsius.
Thank you.
Among the vanquished or savaged, there have always been people who’ve screeched non-alarmism even after the cracks were apparent.
an example:
“Internal MnDOT documents reviewed by the Star Tribune reveal that last year bridge officials talked openly about the possibility of the bridge collapsing …”
“MnDOT rejected a recommendation from the consultant to install high-tech sensors to detect cracking on critical sections of the I-35W bridge less than a year before the bridge collapsed. …”
Matt, re #123. How many events do you know of in nature that are binary and unique? I don’t count too many. Most of them belong to a class of events and occur with some distribution of cost vs. probability. Probability doesn’t do particularly well with the probability of a single event, but the probability of a given # of events occurring can be estimated quite well. That is why Warren Buffett is a wealthy man.
And there are ways of reducing subjectivity in setting the probabilities as I alluded to above. One way is to establish a type of futures market. Another is to look at insurance premiums for disasters. And I also dispute your assertion that there are many Super Catastrophes (or Supercats in the insurance business) that have 5% or even a 1% probability of occurrence. The Asian Earthquake/Tsunami is about as bad as it usually gets, and that was a few hundred thousand fatalities. The 1918 flu pandemic comes close. It would appear that you are guided by “hunches” here rather than solid information. Risk assessment works, and lots of people have made money for years off of it.
Interestingly, one place where things seem to break down is when a risk is hard to calculate–e.g. another major terrorist attack in the continental US. Then insurance dries up. However, this too is reflective of a reality–an unknown risk is an even greater concern than a high risk. This is why a laugh at so-called skeptics who say the models are no good. I respond that we’d better be able to trust them, or we cannot cap the risk due to climate change–and policy will be driven by high-impact, pollitically sensitive events like Katrina. Believe me, if you are a skeptic who wants to limit mitigation of climate change to sane levels, the models are your best friends.
Re 131: Matt, your OT question about the response to Sodamn Insane and his putative WMD is way off topic, but to try to keep the issue to risk assessment generally, I would note that
1)the WMD in question were thought to be chemical and possibly biological, not nuclear
2)the risks of Iraq’s WMD were contained. Even if Iraq had had smallpox, we could have traced the strain back to them and retalliated massively for an attack–even one perpetrated by a terrorist. Moreover, as everyone who has used them has found out, chemical weapons aren’t particularly effective or easy to use.
3)Thus, the probability of an attack was negligible, and the impact would also likely have been small.
Because the risk=probability x consequence was small, there was no justification from a strategic point of view. The decision was 100% political.
In contrast, the risks from climate are not at present capped. Many remain quite uncertain and those we know potentially could have a very high cost. The two situations are not at all commensurate.
Dodo, if you’re not trying to be funny, try the ‘start here’ link at the top of each page, to get a better idea of what’s knowable from the real world. This may help:
http://www.globalwarmingart.com/wiki/Image:Ice_Age_Temperature_Rev_png
[edit for conciseness – there is no need to cut and paste all previous discussions]
Response to #133 Timothy Chase:
Timothy Chase needs to work on his reading skills. I noted that although the Mote and Kaser article was a non-peer-reviewed invited article, it was summarizing recent research that they and colleagues had done on the Kilimanjaro ice cap and glaciers and on mountain glaciers more generally and had published in peer-reviewed “climatology” journals.
The comment about the M&K arguments being neither “old arguments” nor “discussed and disposed of elsewhere” was a reference to David’s snarky throw-away comments in his posting. I did a Google Scholar search looking for the elsewhere-disposal of those arguments and didn’t find anything. I asked David to provide pointers to the elsewhere-disposal and haven’t heard anything back.
Timothy’s “Why?” mirrors my own regarding the M&K assertions that AGW could contribute at most a fraction to recent ice loss on Kilimanjaro and a small fraction to overall ice loss. I noted the logarithmic dependence of temperature on GHG concentration and the unknown dependence of precipitation on GHG concentration and growth in GHGs since the early 19th century to express my lack of persuasion about M&K’s “fraction” and “small fraction”
*
Reading skills again. Exactly how are “independent of temperature” and “fairly insenstive to temperature” the same. Although the partial pressure of water at temperatures below freezing depends exponentially on temperature, the absolute values are small and the incremental increase is also small. Further, the heat required to sublimate ice to vapor is several times greater than the heat required to melt ice to water.
*
Reading skills again. Timothy skips over the second part of the M&K directionality argument where they note “whereas when the Sun is to the south or north (soltices) the summit is typically cloud-free. For the same reason, the edges of the ice are retreating more slowly on the west, southwest, and northwest sides.”
*
Reading skills again. Timothy Chase skips over M&K’s discussion of penitentes: “Penitentes are seen also in many places in the Andes and the Himalaya, where they are sometimes much larger. These finger-like features arise when initial irregularities in a flat surface result in collection of dust in pockets, which accelerates melting in those places by enhancing absorption of solar radiation. The cups between the penitentes are protected from ventilation even as the wind brushing the peaks of the developing spires enhances sublimation, which cools the surface. If infrared radiation and sensible heat transfer were the dominant factors, these sculpted features would not long survive. Solar radiation and sublimation are sculptors; infrared radiation and sensible heat transfer are diffuse, coming equally from all directions, and so they are smoothers. The prevalence of sculpted features on Kilimanjaro’s peak provides strong evidence against the role of smoothers, which are energetically closely related to air temperature.”
*
Perhaps a few more moments and a closer reading of M&K are needed. I found the M&K paper persuasive, except in those areas (e.g., the “fraction” and “small fraction” argument and their failure to note that the loss of mass in the steep slope glaciers was predominantly due to AGW) where I didn’t find them persuasive. I don’t find Timothy Chase’s arguments persuasive, except in those areas where he agrees with me, but doesn’t seem to realize it.
Best regards.
Here comes the sun. Again. Or, GLOBAL WARMING DELUSIONS IN THE VATICAN. Just watched ROME REPORTS last night on EWTN, the U.S. Catholic TV channel (do I ever regret getting cable 2 months ago!!), based on their report of 10/10/07, which can be seen at http://www.romereports.com/index.php?lnk=750&id=461 (the part about GW is about in the middle).
They interview Viscount Monckton, who claims Mars and Jupiter are warming, just as Earth is, and it’s “that large, bright, hot object bang in the center of our solar system” that’s causing the warming, not SUVs in outerspace. [Well, at least these presumably Catholic reporters are OK with the sun, not earth, being in the center.]
They also claim that despite the Pope speaking out strongly about GW and our need to mitigate it, that secretly he really has no idea what’s causing it, but somehow is speaking with forked tongue by alluding that it’s due to human GHG emissions, which heart of hearts he doesn’t really believe.
Then they go on to damn environmentalists as nature worshippers — the old “discredit the messengers, discredit the message” technique.
They refer to a Vatican Climate Change Conference last April. My priest used that to try and dissuade me from believing GW was real. It hosted some scientist, Antonio Zichichi; the RC folks apprised me that he doesn’t know what he’s talking about (see #37 & #38 at https://www.realclimate.org/index.php/archives/2007/04/the-lag-between-temp-and-co2 ).
This isn’t funny to me (the way WSJ editorials are, since I consider them jokes anyway). And I would think this would be demoralizing to Catholics around the world. At least the Church’s earlier Gallileo mistake didn’t involve life-threatening environmental harms, only a shift in world view, but AGW is an issue of much more importance, especially for our moral leaders to be getting wrong.
If anything they should be erring on the side of (that good old virtue) prudence in avoiding false negatives (failing to recognize a problem when it actually exists), and should not even have to have scientific-level certainty. What’s happened to virtue in our world?
Re 144. Thanks Hank, but I still can’t find a list of the fastest warming centuries. And don’t bother sending more wiki links – my question was actually meant for David Archer.
I think it is impossible to make such a statement on centennial scale warming speed based on available proxy data from the past 2 500 000 years.
But David deems it appropriate to make such an assertion, so he should explain.
[Response: The forecast for 2100 puts the Earth warmer than it has been in 2.5 million years, based on oxygen isotopes in deep sea sediments. The CO2 is rising faster than it has throughout the ice core record which goes back 650,000 years. For atmospheric CO2 to change as quickly as it is now (faster than the atmosphere / ocean exchange time or the silicate weathering time scale of 100,000 years) requires a large source of CO2 released directly to the atmosphere. Such an event leaves traces behind, such as the acid-driven dissolution of CaCO3 in sediments, and, depending on the source of the carbon, a signature in carbon isotopic composition of the ocean. There is no evidence for an analogous event to fossil fuel release since the Paleocene Eocene thermal maximum event, 55 million years ago. David.]
in response to everyone responding to #99
My point is that I got ridiculed for saying the Antarctic ice sheet was growing. So I posted my sources for claiming such. Now I’m being lambasted because I don’t understand how a warming trend can cause ice sheets to grow.
I actually do understand how ice sheets can grow due to warmer weather (more precip, still cold, hence more ice). But how can AWG be causing both a growing ice sheet (as the realclimate link explains) AND a shrinking Antarctic ice sheet (as has been pronounced as fact in this discussion)?
Maybe I can’t hold two thoughts in my head at once, but when someone tells me that I’m damned either way, I tend to just plain not believe them.
I found another link to a paper that said the south pacific temperature has been decreasing for about the last decade. How does that fit into the argument? I haven’t read the paper, but here’s the link to the abstract:
http://www.agu.org/pubs/crossref/2002/2002GL015191.shtml
So which is it? Is the ice sheet growing or is it shrinking? And where is the size of the ice sheet respective to the historical changes in the ice sheet?
Does anyone REALLY know????
#102 Robert wrote:
>
Hmmm, although this is easier to understand and sort of correct in this one instance…”that warmer air holds more water vapor”…it is technically more correct to say (the warmer the liquid water the more evaporation happens over condensation and you increase the water cycle).
This is critical because, the technically incorrect but easier to understand (to the public) “warmer air holds more water” idea suddenly breaks down if you want to use it correctly to explain all the actual observed effects of global warming (climate distortion, climate disruption, the “anthropocene”) by humans warming the air-which warms liquid water by releasing more carbon dioxide.
For instance, if you warm the air…and it “holds more water vapor”…then how do you explain that parts of land masses world-wide on average can (and are drying out), bigger and longer droughts are happening and hot deserts are expanding by just warming the air while having more rainfall simultaneously!!! (and yes, this is really happening [IPCC]).
Basically, the air is almost always having both evaporation and condensation at the same time depending on temperature of the “liquid” water. The warmer the liquid, the more evaporation and the more rainfall/snowfall happens all other things being equal…think tropics being so humid.
The opposite is much more startling. Cool the air down enough (even on the Earth’s surface) and condensation increases while evaporation rates can go down to almost zero…now you have a real desert because there is almost no precipitaion…
Guess what the biggest and most intense desert is on the entire planet as defined by lack of precipition…ANTARCTICA!!!
Go far north and you get ANOTHER desert. Go up in the atmosphere…and you get ANOTHER desert…and one of the most important reasons that carbon dioxide becomes THE greenhouse gas to worry about…high up, there is no other abundant greenhouse gas left except carbon dioxide…and THAT is where the Earth’s heat is not being let out…and it’s increasing in thickness!!!
Now, how do you expain that different isotope ratios of oxygen (O16/O18) can tell scientists temperatures 800,000 and even millions of years ago (in ice cores, corals, stalagmites and ocean bed sediment cores- which is true by the way). The seeming idea that “warm air can hold more vapor than cold air” breaks down again…ouch!!!!
The real reason is back to evaporation vs. condensation. If the air gets warmer, then there is more energy in the water and now the heavier O18 can escape easier because evaporation is increasing…so the ratios change depending on water temperature…not, incorrectly, that the warmer air can hold more water vapor.
The answer is that by warming the water, the rate of evaporation exceeds the rate of condensation even more with the air making the water warmer.
So, if you pursue the incorrect idea that “warmer air holds more water vapor” too much, it can lead you to false conclusions about the threat of global warming. Physics and real life observations show that this evaporation vs. condensation fact is now and will be in the future a real bear for humanity and your kids…
but only if you forget that partially correct idea that “warmer air holds more water vapor.” This is critical.
Regarding comment no.131 by Matt,who says [[“In the run up to the Iraq war, world consensus (85%) was that Sadaam had WMDs and was likely to use them. Was it prudent for the US invade or should we have waited for more data? How does this differ from the current state on climate science? I’ll guess your position was “wait for more info on Iraq” and “act now on global warming””]]
We’re comparing starting a preemptive war with building sea walls and erecting solar panels? The former is of unknown length, unknown killed and maimed and unknown cost, the latter is a hedge against the forces of nature. There isn’t a meaningful comparison here.
Engineering projects use probability of occurrence as a tool to help in the design,of say a dam. You could build it a half mile high and protect against a 1000 year flood, but why would you, when practicality and economic restrictions require that protection be limited to say a 200 year flood.