Archive for the ‘Jim Hansen’ Category

Duelling climate policy parables: in the face of RealClimate`s "tragedy of the commons", MasterResource`s Emperor has no clothes

May 26th, 2009 No comments

I`ve done a bit of blogging over the past few weeks regarding the “The tragedy of climate commons” post by climate scientist Gavin Schmidt and ensuing discussion at the RealClimate website.  Schmidt wrote the post in response to the implied suggestion by Chip Knappenberger at the MasterResource blog that, since unilateral policy action by the US would by itself be unlikely to significantly affect future climate (given the the rapid growth in CO2 emissions by China, India etc.), the wisest course for the US would be to do nothing.  

Knappenberger has now responded to Schmidt, this time with a parable of his own.  Knappenberger has good points, but he and Schmidt are talking past each other.  Since Rob Bradley, CEO of the Institute for Energy Research (BTW, no longer funded by pro-carbon-tax Exxon, all of you Exxon-haters out there) and founder/manager of MasterResource, won`t let me post at his self-proclaimed “free-market energy blog”, I put up a few thoughts at RealClimate, which I copy below (one typo fixed and link added below):


Allow me to stir the pot a bit, as it doesn`t appear that anyone has noticed Chip Knappenberger`s response to Gavin, in tbe form of his own climate parable, using the “Emperor`s new clothes” theme.

Waxman-Markey appears as the new clothes, with Chip apparently taking on the role of the bright and persistent voice of the insufficiently jaded little boy who can`t help but to see the truth, and bravely refuses to be cowed.

Some of the criticisms of W-M seem fair to me – after all, they manifest precisely the reasons that Jim Hansen has taken a strong stance in favor of more transparent and rebated carbon taxes over the pork and bureaucracy that comes with cap and trade.

1. But Chip is still failing to address the main premise of Gavin`s tragedy of the commons fisheries analogy: there is a commons problem that requires coordinated action (a multi-player, repeated Prisoner’s Dilemma), and the only way out requires initial measures at trust-building, with more effective measures to follow when the parties can agree on burden sharing and enforcement.

Thus Chip is simply perpetuating the problem that I have noted here:

“Unfortunately, what passes for discussion on climate change (and other environmental issues) is too often people talking past each other (frequently with all of the hallmarks of a tribal battle): some correctly see a looming commons problem that requires government regulation but ignore the risks of pork, partiality and wasted resources in the policies themselves, while others, not anxious for government to expand its regulatory purview, downplay or dismiss the resource problem and focus on the downsides of government action or the motives of those calling for government action (while ignoring those invested heavily in a status quo that is replete with moral hazard).

Capitalism, the destructive exploitation of the Amazon and the tragedy of the government-owned commons

2. Further, while Chip has good reason to criticize all of the pork that is loaded into the W-M hairshirt – there certain ARE plenty of corporate interests seeking to use climate policy to get sweet deals from government – it`s more than a bit coy of him to paint the critics of W-M as relative innocent truth-tellers, while somehow failing to note all of the sweet deals built into the status quo that fossil fuel firms, utilities, automakers and their investors have long enjoyed. (Not to mention that these interests have hardly been turned away from the W-M and other pork troughs.)

Chip`s convenient oversight might have something to do with the fact that the public advocacy firm he shares with Pat Michaels is funded by coal interests, as Marion Delgado points out in #677, and as I have previously discussed directly with Chip: Pat Michaels – scientist AND paid advocate. Correspondence with Chip Knappenberger.

It doesn`t end there, unfortunately, as Chip is posting on the “MasterResource” blog run by Rob Bradley, who is CEO of the coal-industry-funded Institute for Energy Research. For the sin of pointing out the political-favor-protection game that IER and MasterResource are engaged in, Rob Bradley has exercised his Constitutional right to ban me from the MasterResource blog (mid-conversation with, but without notice to, Chip, as it turns out).

So sure, let`s fight the pork as best we can, Chip, but let`s not ignore the fact since there are NO property rights in the atmosphere or climate, markets are not protecting it, but instead steadily producing an ever-growing tragedy of the commons. Care to acknowledge that, or to offer any suggestions?


Jim Hansen on Freeman Dyson on climate change

March 29th, 2009 No comments

I received the following in an email from NASA climate scientist James Hansen (whom I`ve mentioned a number of times), in connection with today`s New York Times Magazine article (“The Civil Heretic”) on Freeman Dyson, which is now making its way through the “skeptosphere”.  My short and unfair take on Dyson?:  Short Freeman Dyson: Yep, it`s warming; I LIKE vast uncontrolled experiments with climate, and who needs fish in the ocean anyway!

Dyson is rather critical of Hansen, but it`s not at all clear that he understand`s Hansen`s position.  But why attack Hansen, when Exxon  and its CEO Rex Tillerson are now explicitly pushing carbon taxes?  If any firm ought to understand fossil fuels – and the problems with government actions – it`s Exxon.  Hansen is a vocal scientist, but he represents no particular special interests.

In any case, Hansen`s mail is fairly brief, so I thought I`d just post it as if for all you open minds out there:  

            Tomorrow’s NY Times Magazine article (The Civil Heretic) on Freeman Dyson includes an unfortunate quote from me that may appear to be disparaging and ad hominem (something about bigger fish to fry).  It was a quick response to a reporter* who had been doggedly pursuing me for an interview that I did not want to give.  I accept responsibility for the sloppy wording and I will apologize to Freeman, who deserves much respect.

            You might guess (correctly) that I was referring to the fact that contrarians are not the real problem – it is the vested interests who take advantage of the existence of contrarians.

            There is nothing wrong with having contrarian views, even from those who have little relevant expertise – indeed, good science continually questions assumptions and conclusions.  But the government needs to get its advice from the most authoritative sources, not from magazine articles.  In the United States the most authoritative source of information would be the National Academy of Sciences.

            The fact that the current administration in the United States has not asked for such advice, when combined with continued emanations about “cap and trade”, should be a source of great concern.  What I learned in visiting other countries is that most governments do not want to hear from their equivalent scientific bodies, probably because they fear the advice will be “stop building coal plants now!”  These governments are all guilty of greenwash, pretending that they are dealing with the climate problem via “goals” and “caps”, while they continue to build coal plants and even investigate unconventional fossil fuels and coal-to-liquids.

            I will send out something (“Worshiping the Temple of Doom”) on cap-and-trade soon.  It is incredible how governments resist the obvious (maybe not so incredible when lobbying budgets are examined, along with Washington’s revolving doors).  This is not rocket science.  If we want to move toward energy independence and solve the climate problem, we need to stop subsidizing fossil fuels with the public’s money and instead place a price on carbon emissions.

            My suggestion is Carbon Fee and 100% Dividend, with a meaningful starting price (on oil, gas and coal at the mine or port of entry) equivalent to $1/gallon gasoline ($115/ton CO2).  Based on 2007 fuel use, this would generate $670B/year – returned 100% to the public (monthly electronic deposit in bank accounts or debit cards), the dividend would be $3000 per adult legal resident, $9000/year per family with two or more children.  This is large enough to affect consumer product and life style choices, investments and innovations.  Of course all the other things (rules re vehicle, appliance and building efficiencies, smart electric grid, utility profit motives, etc.) are needed, but a rising carbon price is needed to make them work and move us most efficiently to the cleaner world beyond fossil fuels. 

Jim Hansen

*             The reporter left the impression that my conclusions are based mainly on climate models.  I always try to make clear that our conclusions are based on #1 Earth’s history, how it responded to forcings in the past, #2 observations of what is happening now, #3 models.  Here is the actual note that I sent to the reporter after hanging up on him:

 I looked up Freeman Dyson on Wikipedia, which describes his views on “global warming” as below.  If that is an accurate description of what he is saying now, it is actually quite reasonable (I had heard that he is just another contrarian).  However, this also indicates that he is under the mistaken impression that concern about global warming is based on climate models, which in reality play little role in our understanding — our understanding is based mainly on how the Earth responded to changes of boundary conditions in the past and on how it is responding to on-going changes.  

If this Wikipedia information is an accurate description of his position, then the only thing that I would like to say about him is that he should be careful not to offer public opinions about global warming unless he is willing to first take a serious look at the science.  His philosophy of science is spot-on, the open-mindedness, consistent with that of Feynman and the other greats, but if he is going to wander into something with major consequences for humanity and other life on the planet, then he should first do his homework — which he obviously has not done on global warming.  My concern is that the public may assume that he has — and, because of his other accomplishments, give his opinion more weight than it deserves.

      (emphasis added)      

Categories: carbon pricing, Exxon, Jim Hansen Tags:

Marlo Lewis/CEI at MasterResource: why a massive cap & trade program is much, much better than Jim Hansen’s simple rebated carbon tax idea. Or not.

March 3rd, 2009 2 comments

Marlo Lewis of CEI has a rather schizophrenic post up at Rob Bradley‘s MasterResource blog – one of my favorite “free market” fossil-fuel industry-funded sites (unlike the NRO’s “Planet Gore”, MasterResource actually allows comments!) – regarding the proposal by leading “alarmist” climate scientist Dr. James Hansen (of NASA and Columbia U.’s Earth Institute) that the federal government adopt a “tax and dividend” climate policy instead of a “cap and trade” approach.

Lewis notes that Hansen recently testified in front of the U.S. House Ways and Means Committee about Hansen’s “tax and dividend” proposal, but while Lewis calls Hansen’s per capita rebated carbon tax proposal “clever”, Lewis puzzlingly fails to compare Hansen’s proposal with the cap and trade alternative that the Obama administration supports and that Congress (and industry) appears to favor.  Instead we get some poorly grounded speculation about the effects of a carbon tax and complaints about the political viability of a transparent carbon tax – all of which points not only ignore the more opaque, rent-seeking prone and heavy-handed cap and trade alternative, but by implication suggests that those who prefer an opaque and back-room deal prone cap and trade approach have made the correct political calculation.

Nor does Lewis make any mention of all of the support that carbon taxes have received, not only from economists, but from a wide range of others, including Exxon`s Rex Tillerson and various neocons, conservatives and libertarians (George Will, Congressman Bob Inglis, Jon Adler, Barbara Thoring, etc.), at least in comparison to cap and trade.

As a result, one is forced to wonder just whati it is that Lewis is trying to achieve – is he trying to sabotage a government-lite carbon policy, so that government-heavy policy is more likely to prevail?  If so, why?  Or does he really think that opposing EVERY carbon pricing policy is the most effective way to delay and/or influence ultimate policy outcomes?  I for one am confused.

My more extensive (and less high-level) comments to Marlo Lewis on his comment thread are copied below:

first, I’m afraid I don’t follow you on the science. We can’t stop our
still growing GHG releases on a dime, much less the short- to
medium-term feedbacks from water, methane and albedo changes, and
long-term will persist for centuries, and the water cycles, the oceans’
pH and world’s biota are changing noticeably and fairly rapidly, even
without significant further increases during the past decade – yet what
is it, precisely, about our ability to change our influence on the
system or to control responses that gives you comfort? Why do you seem
to think it is “conservative” for our nation and others to do nothing
in light of our remarkable and uncontrolled global climate experiment?

BTW, surely you are aware that Hansen has earlier offered extensive
information that paleoclimate records indicate that long-range climate
rsponse to a CO2 doubling is on the scale of 3 degrees C. Did you miss
that? Or were you more eager to say that Hansen’s reference to more
recent studies about facts some how implies that Hansen is “dissing”
models? What’s the point anyway, other than point-scoring – if facts
appear to indicate that long-term sensitivity is relatively high,
should we be ignoring that and placing our faith in models instead?
Should facts not further inform models, or policy-makers?

Second, while you note Hansen’s attack on cap & trade and his
“tax and dividend” proposal “quite clever”, you fail to offer any
opinion on the realative merits of these quite different proposals.
Instead, you offer some sniping criticisms of tax and dividend, as if
you are hoping that the consequence will be that the Obama
administration, Dems and rent-seekers generally will turn away from
climate policy altogether. But isn’t that nothing but wishful thinking,
and shouldn’t libertarians and others who prefer to avoid the
monstrosity of cap & trade be trying to encourage the efforts of
those whose proposals would be much less economically damaging? Isn’t
Hansen’s proposal far preferable over cap & trade, and the kind of
industrial planning that Jon Adler says is inevitable from the EPA
under EPA vs. Massachusetts without legislative action?

Exxon and a host of others (as noted at the blog posts linked at my
name) have come clearly down in favor of carbon taxes over cap &
trade; perhaps you may at some point care to favor us with your own
comparative views.

It seems to me that Hansen’s proposal is clearly preferable; it
could be easily implemented and monitored, would not involve large new
bureaucracies, would be much more transparent and less susceptible to
rent-seeking, would provide market signals on GHGs while having no
fiscal impact, would be grounded in the principle that the atmosphere
is owned by citizens and not government (or by corporations that are
given or purchase rights to emit GHGs), and, by being refunded per
capita to citizens would be generally progressive.

Third, as for your criticisms of Hansen’s proposal:

– carbon taxes will hit coal use more heavily than petroluem or
natural gas, so focussing first on “pain at the pump” smacks of
pandering, especially as revenue recycling may eliminate the pain

– older, dirtier coal plants are already uneconomic and generate
tremendous costs to health and property that are not costed to
producers or consumers; taxing carbon is a great way to end some of the
nonsense incentivized by the CAA. Your speculation about power supply
and electricity prices is nothing more than speculation, but oil and
gas-fired plants could be brought on line relatively quickly;

– as for the “green stimulus” effect, it is ironic that you fail to
see that the fact that “There is no guarantee people will use their
dividends to buy hybrid cars, energy-efficient appliances, or green
energy” is in fact an argument IN FAVOR of rebated carbon taxes as
opposed to cap and trade, as the first allows much greater economic
freedom and is thus more conducive to wealth creation. Further, not
only is dividending the tax proceeds a great way to make sure that the
government doesn’t have an even larger pot to dole out mandates,
subsidies and other goodies to favored industries, but the right could
trade its acceptance for such a tax for elimination of existing
subsidies to ethanol and solar.

– your point about labor productivity is fair, but it ignores the
social cost of carbon. Has forcing polluting industries for the ’60s on
benefitted society and improved productivity as a whole the whole? Or
is it simply more important to allow certain classes of producers and
consumers to profit while continuing to shift costs to others?

– as for “massive” transfers, this is all “would” and “could”
without any backing, and it completely ignores all of the massive
wealth transfers involved in the way we presently regulate power
generation and energy (and have refused to regulate GHGs). I’m happy to
have more information, but let’s not forget that the whole purpose is
to have a closer alignment between profits/benefits and social costs.


Rob Bradley cheers on coal, but are all those who want to better manage commons and environmental impacts "Malthusian" idiots, or only in the case of coal?

February 5th, 2009 No comments

Rob Bradley has a new post up at MasterResource, cheering on big (and now “clean”) coal, which has apparently received assurances from the Obama administration – after being bad-mouthed by NASA scientist Jim Hansen, Steven Chu and Obama himself – that, despite pressures from the “Malthusian anti-energy crusade” regarding climate change impacts, the recent massive TVA fly-ash spill and opposition to destructive mountaintop removal practices in Appalachia, coal will remain profitable during Obama’s term and central to US energy supplies.  Hooray!

But I wasn’t quite clear on all of Rob’s message, so I asked him a few questions in the comment thread:

Rob, are the John Badens, Terry Andersons, Bruce Yandles, Elinor Ostroms and others who want to find ways to manage our commons better – by improving ownership, incentives and pricing signals – also part of a[n evil] “Malthusian crusade”?

I just wanna make sure I know who to hate.

As for that big fly-ash breach/spill in Tennessee, I’m glad that you didn’t point out how this was a result of government ownership of TVA, with the added benefit that costs will be borne not only by direct and indirect victims, but by taxpayers as well. No sense in pointing out how government is so often in the way, particularly if it detracts from our “we hate enviros!” message. Last thing we ever want to do is to reach a shared understanding with enviros of the institutional underpinnings of problems, since that means our funders might lose some of their fairly purchased, government-given special privileges.

While it’s clear that “free-market” Rob cares little about whether the coal industry continues commercial activities that shift the environmental costs and risks (including potential costs arising from GHG emissions) to others, I forgot to ask Rob whether, as a hearty cheerleader for those poor coal underdogs, he also supports their position that the government should subsidize their change in business model by (a) having Uncle Sam pay the bulk of capital costs for IGCC (integrated gas combined cycle plant) [something like $1 billion for the first one with CCS], (b) giving them a further break (reduced royalties) on the sweet deals they already have for stripping coal from public lands and (c) – now that the federal government is getting into the busy of running the financial sector – making sure that power producers that want to use coal have easy access to credit, by twisting the arms of those uppity Wall Street financiers who with their fancy new “Carbon Principles” and “Enhanced Due Diligence” seem a bit too reluctant to extend credit for coal-fired power plants.

Here’s hoping Rob weighs in further.  I want to make sure I’m not messing up when I try to distinguish the “white hats” from the “black hats”.   From what I can tell so far, seeking to manipulate government policy for your own benefit is evil – as long as you’re not a coal firm, and we call the evil ones “Malthusians”.  Right?

Marlo Lewis/CEI laughs at the ice sheets and Gore; Lloyd’s and other insurers do not. Hmmm.

July 16th, 2008 No comments

Andy Revkin of the NYT recently posted at his “Dot Earth” blog an update by a scientist to the effect that apparently the increasing summer melt in Greenland is not markedly lubricating glacier flow.  While this doesn’t alter the fact that the Greenland melt (and outlet glaciers)continues to accelerate, it does abate some concerns that the thawing Greenland ice sheet could make a very rapid contribution to rising sea levels by more quickly offloading icebergs. 

To Marlo Lewis of CEI, this posed an irresistible opportunity to fire off a clever but skewed attack on Al Gore and on serious warnings raised by scientists about the possibility of ice sheet collapse.  Says Lewis:

The core issue for policymakers is not whether global warming is affecting the Greenland ice sheet (of course it is), nor even whether the Greenland is in negative mass balance and contributing to sea level rise (it is). Rather, the key question is whether half the ice sheet is in danger of breaking off and sliding into the sea, as Al Gore warned in An Inconvenient Truth.

In AIT, Gore presented as a serious scientific possibility the simultaneous crackup of the Greenland and West Antarctic ice sheets. That would raise sea levels 18 to 20 feet, with the consequence, Gore said, that 100 million people would “be displaced,” “forced to move,” and “have to be evacuated.”

The recent Science study exposes Gore’s doomsday scenario (or half of it, anyway) as unscientific. …

Gore and his allies seek the political power to reprogram the U.S. and global economies. To justify this risky experiment, they depict global warming as a “planetary emergency, a crisis threatening the survival of civilization and the habitability of the Earth.” They claim to speak for the “consensus of scientists,” but what they actually present is science fiction. No child should go to bed worrying about a 20-foot wall of water sweeping across the globe. Neither should the child’s parents.

(emphasis added)

With this, Marlo deftly misstates the core issue for policy makers, distracts us from what scientists have long stated are the much greater risks posed in Antarctica, shifts our attention from the risks that our unmanaged activities are posing to the risks that Al Gore (and others who believe policy changes are needed) is posing and raises a strawman disaster scenario.  With slick work like this, maybe the folks backing Gore’s climate publicity campaign should consider making substantial contributions that could bring CEI over to his side!

Allow me to elaborate a bit (based on comments I posted on the same Dot Earth thread).

1.  ML:  “the key question is whether half the ice sheet is in danger of breaking off and sliding into the sea, as Al Gore warned”

I strongly disagree. The chief question is whether the existing and growing GHG forcing and albedo feedbacks will COMMIT us to a rapid pulse of ice sheet melting on scales that we can see in the paleo record: several meters per century for a few centuries (for forcings smaller than the BAU scenario). This possibility was noted back in 1978, and all we’ve seen since then is an accelerating expansion of melt areas and mass loss.  If such a melt pulse is in the cards, related questions are how to deal with the rising sea levels (both the continued shift of cities and infrastructure and the related losses, costs and upheaval) and whether mitigation efforts can head off or materially slow such a melting.

Presumably Lewis is aware, as Jim Hansen and other climate scientists have been making this point frequently, that the models of ice loss reviewed by the IPCC simply don’t include the mechanisms for such actual, rapid ice loss, and so probably underproject the loss that we are likely to see this century.  In fact, as well, we have seen net mass loss in the West Antarctic Ice Sheet (WAIS) due to melting and calving, despite expectations in the IPCC that increased snowfalls brought by warming temperatures would result in WAIS gaining mass.

2.  ML:  “In AIT, Gore presented as a serious scientific possibility the simultaneous crackup of the Greenland and West Antarctic ice sheets. That would raise sea levels 18 to 20 feet, with the consequence, Gore said, that 100 million people would “be displaced,” “forced to move,” and “have to be evacuated.” The recent Science study exposes Gore’s doomsday scenario (or half of it, anyway) as unscientific.”

If Gore referred to a rapid loss of the Greenland Ice Sheet, he was not reflecting scientists’ concerns (other than the concern for a geologically rapid melting over centuries), because Greenland’s ice is all on land and cannot simply collapse into the ocean.  However, that is NOT true of the WAIS, which is not walled in, much of it sits on land that is actually below sea level and can quickly lose mass into the sea, and is at present held back only floating ice sheets that are now rapidly crumbling.  There is significant scientific literature on this point, and a significant increase in alarm just over the past few years.  The WAIS is now referred to as an “awakening giant”.  Gore is right that scientists are concerned that the WAIS may rapidly lose mass into the sea – rather quickly raising sea levels by 12 to 18 feet – that scientists believe that human activities have kicked off a number of changes in Antarctica, and that scientists believe AGW may also initiate and accelerate the collapse of the WAIS.

It is a puzzle that Lewis does not mention these concerns, as he appears to be well aware of them.  In own his paper criticizing AIT, Lewis specifically noted that the process of retreat in glaciers such as WAIS whose base is below sea level, once initiated, “cannot be stopped”.  Lewis quoted one scientific paper as follows:

“Increased pressure at these greater depths lowers the melting point of this ice, increasing the melting efficiency of the warmer water. Rapid melting results.”

“Retreating glaciers lengthen the distance warmer water must travel from any sill to the grounding line, and eventually tidewater glaciers retreat to beds above sea level. This might limit the retreat in Greenland but will save neither West Antarctica, nor the equally large subglacial basin in East Antarctica where submarine beds extend to the center of the ice sheet.”

Here are links to just a few of the discussions by scientists of WAIS:

3.  ML:  “Gore and his allies seek the political power to reprogram the U.S. and global economies. To justify this risky experiment, they depict global warming as a “planetary emergency, a crisis threatening the survival of civilization and the habitability of the Earth.”

Certainly there are risks associated with the climate strategy being offered by Mr. Gore, as well as with any kind of climate strategy – including doing nothing.  We should certainly evaluate the comparative benerfits, costs and risks of all policy options.  But Mr. Lewis instead offers us loaded statements.  There are equally honest ways to rephrase these loaded statements.  For fun, I offer the following to Mr. Lewis:

“You and your allies (fuel producers and consumers) seek to use political power to protect the benefits accruing to you as a result of the failure of market economies to require you to bear the full costs and risks generated by your economic activities, so that you reap gains while shifting those costs and risks to others. To justify continuing with this risky experiment with the Earth’s climate, you depict Gore as being on an unhinged, yet hypocritical and cunning Jeremiad, downplay the risks that even Exxon says merit present action, and paint everyone who agrees with them – from the world’s scientific bodies and major investors to Pope Benedict – as part of a cabal or cult of irrational believers or as malevolent man-haters out to poison our precious bodily fluids/destroy the market system itself, while you decline to straightforwardly address obvious externalities, risks or policy options.”

Just how seriously does Mr. Lewis want us to take him?

4. ML:  “They claim to speak for the “consensus of scientists,” but what they actually present is science fiction. No child should go to bed worrying about a 20-foot wall of water sweeping across the globe.”

I’ve seen no reference by Gore or other “alarmists” to a “20-foot wall of water” – that appears to be a boogeyman only of Mr. Lewis’s imaginings.  However, it is clear that scientists are indeed very concerned about a fairly rapid collapse of the WAIS.  This is NOT “science fiction”, as Mr. Lewis would have it.

And maybe Mr. Lewis doesn’t want to worry about it, but Lloyd’s of London certainly is, and is recommending that others worry about it too.  A recent report by Lloyd’s on various climate change risks concluded the following regarding the WAIS and Greenland:

It is our view that there are clear and worrying trends in the behaviour of component parts of the Greenland and Antarctic Ice Sheet, with the WAIS in particular showing anomalous behaviour. Meaningful predictions of the likelihood of rapid, catastrophic ice discharge, ice sheet collapse or lake outbursts in the near future are impossible. However, an increase in instability, with a resultant impact on sea level within our lifetime, is a credible risk.

Insurers and other commercial institutions sensitive to these risks should keep a close watch on future developments and be prepared to revise their strategies regularly.

The rest of the report also offers useful analyses.  But who wants to read this kind of stuff?  Thanks, Mario, for distracting us.


PS:  More on ice sheet risks below from Jim Hansen: 80623.pdf

“West Antarctic and Greenland ice sheets are vulnerable to even small additional warming. These two-mile-thick behemoths respond slowly at first, but if disintegration gets well underway it will become unstoppable. Debate among scientists is only about how much sea level would rise by a given date. In my opinion, if emissions follow a business-as-usual scenario, sea level rise of at least two meters is likely this century. Hundreds of millions of people would become refugees. No stable shoreline would be reestablished in any time frame that humanity can conceive.”
“Present-day observations of Greenland and Antarctica show increasing surface melt [35], loss of buttressing ice shelves [36], accelerating ice streams [37], and increasing overall mass loss [38]. These rapid changes do not occur in existing ice sheet models, which are missing critical physics of ice sheet disintegration [39]. Sea level changes of several meters per century occur in the paleoclimate record [32, 33], in response to forcings slower and weaker than the present human-made forcing. It seems likely that large ice sheet response will occur within centuries, if human-made forcings continue to increase. Once ice sheet disintegration is underway, decadal changes of sea level may be substantial.

“Equilibrium sea level rise for today’s 385 ppm CO2 is at least several meters, judging from paleoclimate history [19, 32-34]. Accelerating mass losses from Greenland [74] and West Antarctica [75] heighten concerns about ice sheet stability.” df
“One thing that the paleoclimate record shows us is that ice sheet disintegration and sea level rise are usually much more rapid than the opposite process of ice sheet growth and sea level fall. This is reasonable because ice sheet disintegration is a wet process with many positive feedbacks, so it can proceed more rapidly than ice sheet growth, which is limited by the snowfall rate in cold, usually dry, places. At the end of the last ice age sea level rose more than 100 m in less than 10,000 years, thus more than 1 m per century on average. At times during this deglaciation, sea level rose as fast as 4-5 m per century.”

“The first principle is that you must not fool yourself – and you are the easiest person to fool.”
Richard Feynman