It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Thursday, September 2, 2010

Fifteen Years Ago

When I first started thinking and writing about anthropogenic climate change in the early nineties, I would have said things not dissimilar from what Tom Fuller said today at Watts':
The IPCC’s AR4, published in 2007, painted a future with global warming as a serious, multinational problem that we should face together. You may agree or disagree with their findings–I agree with most of it, not all.

But nowhere does the work of thousands of scientists in peer-reviewed literature say that we are doomed, that civilization is at risk, that there is no future for us.

...

Sea levels are not going to rise by 20 feet. Or 10. Or five. There is not going to be a climatic tipping point that pushes our planet into a spiral of ever-increasing temperatures. Global warming is not going to cause the extinction of half the species on this planet, or even 1%.

And it is long past time that respected members of the scientific community publicly acknowledge those facts and helped bring this debate back within the realm of reality.
I would have thought such a claim was reasonable then. After all, the problems are and were well within our technical capacity to solve, and surely now that the problems were demonstrated, with substantially accurate predictions and few misses, one might presume people would take vigorous action to avoid consequences of the type Fuller describes as "not going to" occur.

But fifteen years later, the matter looks very different. While the runaway greenhouse spiral still doesn't appear to be in the cards, sea level looks much more delicate than it did. Anthropogenic climate change is certainly already contributing to an extinction crisis. Severe events are increasing the extent of crop failures and human dislocation. How bad this gets depends primarily on whether and when we take the problem seriously. If we fail to take the problem seriously, there is no real ceiling on how bad it will get.

Now, I would have said that 15 years ago as well. Perhaps Fuller doesn't understand that there is no ceiling, no worst case. I would have thought people would not be as foolish as they have been of late. Maybe in fifteen more years Fuller will come around.

Oddly, in a way I hope he doesn't. I hope things really are not as bad as they look, but failing that, I hope we get a grip soon enough that the evidence remains, to the less expert, somewhat equivocal.
The best way to prove that a cataclysm is possible is to have one.
I'd rather not risk that sort of vindication.
Of course it's true that "nowhere does the work of thousands of scientists in peer-reviewed literature say that we are doomed, that civilization is at risk, that there is no future for us" and that nothing like that is explicitly in the IPCC. What journal would publish such a claim?

But when you look at the world with a 5 C different mean surface temperature in the past record, you see changes far more dramatic than those that have brought down civilizations and biomes in the past. Indeed, the shift is far greater than historical humanity has ever seen, except perhaps at a few exceptional isolated locations, which generally did not fare well in the process.

Oh, yeah, and five feet of sea level in this century looks like a not unreasonable bet; twenty feet in 400 years is something I'd give odds on if there were some way to collect. Again, I'd rather lose, though.

In any case, the important thing to understand is this:
We are not predicting what will happen.
We are deciding what will happen.
What is or isn't in the cards depends on what we decide to do or not to do, and on nothing else. It's not a scientific question, so IPCC can't take a position on it. The fact that they don't doesn't mean we are off the hook. It's a decision.

Do you want to risk the entire future rather than taking a small hit on your present comfort?

Apparently most people do. Or else they don't understand the situation very well.

77 comments:

Dirk said...

Ah, sounds like a variant of the precautionary principle. The burden falls on Fuller (and others of his ilk, I guess) to show that AGW and its secondary effects will not be harmful for the majority of the world then.

Maybe in fifteen more years Fuller will come around.

Based on his behavior on this blog and elsewhere, I highly doubt that it will happen at all, let alone in 15 years.

Dirk said...

This may be OT, so Mike, please delete if you opine that it's inappropriate.

Do you want to risk the entire future rather than taking a small hit on your present comfort?

Sometimes I wonder how many of the contrarian crowd have young children who will face the brunt of whatever happens.

If they do, what do they tell them when they start asking questions related to AGW impacts? That it's not happening? That it's happening but it's not caused by their hands? That it's (insert deity here)'s will?

I ask this as I've talked with some previously "skeptical" folks who have altered their view of AGW after taking on the mantle of parenthood, partly due to the question that Mike posits.

Steve Bloom said...

Dirk, the all-explaining "it's natural cycles" (non-)argument is very common.

Re Fuller, it may be as simple as "a man's got ta earn a livin'" (h/t Michael), and/or he could simply be (and odds are is) one of the majority who is unable to grasp the implications of accumulation. Add to that a probable resentment of being told what to think by boffins (an all too common syndrome among journalists, as we saw with the response to the recent "scandals"), and there you have it.

Lou Grinzo said...

This post reminds me of something I've intended to talk about for some time, namely the difference in how newcomers (not a reference to you Michael) adjust to their new knowledge of climate change or peak oil.

PO newbies tend to look at the hard facts, like the number of countries that are already post peak, Hubbert's famous prediction, etc., and panic. As they learn more their sense of urgency wanes; they realize how inefficiently we use oil, and how much low hanging fruit there is, for example.

ACC is largely the opposite learning curve. Initially people are very dismissive of the meaning of an increase of "only a couple of degrees", but as they learn more, their sense of urgency tends to rise dramatically.

I think this slow, rising ACC response is key to your question about the willingness of individuals to make a relatively small sacrifice now to prevent a staggering set of impacts far down the road.

I think the first serious moment of truth will come decades from now, when the rising temps, rising population, and random weather effects conspire to bring us a year when providing food aid to several countries that desperately need it can't be done by simply writing a check. What happens when helping other countries avoid mass starvation requires people in the US, the EU, Japan, etc., to literally eat less? Will that be the wake up call that finally drives home the seriousness of our situation?

There are times when I'm sure that if I had a time machine I wouldn't use it to go forward several decades to see how so many trends play out. I wouldn't want to see it.

Steve Bloom said...

I'd bet on sooner than that, Lou, and I think it will take the form a a major shift in ocean circulation (along with more of the atmospoheric effects we're already seeing).

slipr.com said...

I wonder if "how bad it will get" isn't a scientific question after all. Isn't that what the energy analysts at EIA (etc.) who are providing us with future emissions projections are, in essence, attempting to do?

Michael Tobis said...

It is an engineering question. I think the distinction is important.

Ron Broberg said...

Sea levels are not going to rise by 20 feet. Or 10. Or five.

Tom, what is your source for this? What time frame are you assuming?
How confident are you that there won't be 5 feet of SLR by 2100? Can you quantify your confidence?


Global warming is not going to cause the extinction of half the species on this planet, or even 1%.

Tom, what is your source for this? What time frame are you assuming?
How confident are you that AGW won't contribute to a 1% extinction by 2100? Can you quantify your confidence?

Steve Bloom said...

Could you expand on the point about engineering, Michael? Thanks.

Check this out! He's been hinting around at it, but now Kevin Trenberth directly attributes the Pakistan-Russia event to global warming. David Appell has the scoop.

Prediction: Fuller won't like it.

Steve Bloom said...

OT: Michael, I have a science question about the expansion of the tropics/atmosphere. This must be a negative feedback on tropospheric temps, but is it non-negligible?

Michael Tobis said...

The distinction between science and engineering is the distinction between what we study and what we control. The future of climate is under human control.

Not sure I understand the question.

Steve Bloom said...

Thanks for the clarification, Michael.

Re my question: I mean relative to what the Ts would have been had the troposphere not expanded. If my understanding is correct there would be some zonal differences with the main effect being in the tropics.

The answer to this is potentially valuable since it could serve to bring more attention to the expansion and its implications.

Michael Tobis said...

Are you talking about the expansion of the tropics poleward, or are you talking about the pressure surfaces going upward, or about the tropopause going upward? In any case, please take this offline if you want to pursue it.

Steve Bloom said...

Will do, thanks.

climatesight.org said...

He denounces projections of extinction and sea level rise pretty confidently. Does anyone take him seriously when he doesn't even include a statement of error?

Kate
http://climatesight.org

Steve Bloom said...

Fuller says a lot of things confidently, Kate. He's been challenged on important points of science and policy several times on this blog, and generally those episodes end with him emitting a cloud of ink and disappearing.

Over on his own blog he's obviously telling people what they want to hear, so I suppose one could say they take him seriously.

Michael Tobis said...

LOL "cloud of ink"!

Lovely. It could suffer from overuse but it's really excellent when apropos.

Steve Bloom said...

I picked up the phrase from James Annan, who used it in reference to RP Sr.'s behavior in the course of the infamous butterfly effect argument (also involving Gavin and William).

rab said...

Take heart. A lot of the deniers, now seeing they've lost the battle on the question of whether there is warming and whether it is anthro., have shifted to "the warming won't be catastrophic". Fuller is predicting nothing dramatic by 2100. He can be confident because this is outside his lifetime so he won't have to face his defeat.

David B. Benson said...

In case there was actually any rational doubt, the last time CO2 concentrations were so high was in the Miocene with sea levels many tens of meters higher than now, up to a maximum of ~80 meters.

Tom said...

Hi all. So, according to MT I'm just 15 years behind the times. Guess we'll see.

I stand by what I've written, and I've been pretty consistent, allowing for some learning and shifting of opinion based on that. I don't believe for one second that the Greenland ice cap, which survived much warmer temperatures than the IPCC project for this century, will lose anything more than a bit around the margins.

So I absolutely do not believe those saying that sea level rise will be more than the 18-59 cm projected in AR4.

I saw the 'species extinction' game played in the 70s, and it's the same game today. We have identified about 1.5 million species and we are guesstimating about the total. Those who came up with the original diversity loss estimates have admitted in print that they stuck their finger in the air and guessed. We have lost species due to habitat loss, predation and cetera, but the numbers are two orders of magnitude lower than predictions. Hence the sticking of fingers into the air. There is no extinction crisis at all. There are many species vulnerable to human expansion into their habitat, but so far they have coped.

As for a climatic tipping point, it seems like a scare story to me. I have seen no convincing evidence presented for it. I've seen climate scientists that are respected in this forum flat out say it will not happen.


So we always end up back at the same point. What is the sensitivity of this planet's atmosphere to a doubling of concentrations of CO2?

You think it's high. I think it's low. We disagree on this. I think that concern for humanity dictates that we help the poor, including providing energy availability, as our highest priority. I am happy to support a wide variety of 'no-regrets' policies while we conduct further research that may settle our disagreement.

So trot out dhogaza and his buds and let the name-calling begin.

Michael Tobis said...

Tom, first of all you missed the part where AR4 said 18-59 cm EXCLUSIVE of ice melt, right?

More to the point, on what do you base your "beliefs"? Do you not think that the opinion of those who have studied the problem in depth shoudl carry some weight?

You can't just go pulling numbers out of your, um, hat, you know. Is your opinion based on what your readers want to hear, or is there something behind it?

Steve Bloom said...

Fuller: "I don't believe for one second that the Greenland ice cap, which survived much warmer temperatures than the IPCC project for this century, will lose anything more than a bit around the margins."

Now, not too may years this was a widespread if not consensus belief in the field, but can Tom name even one glaciologist who currently thinks it's true?

As to sensitivity, we've been through that on this blog before and Fuller came up with bupkis to back up his assertion.

Re extinctions, this Encyclopedia of Earth article sums the situation up this way:

"Chiefly from analysis of the fossil record, there is considerable insight on the rate of speciation and extinction over an extended time frame, dating from roughly 545 million years before present until a time approximately 50,000 years before present; this interval is known as the Edenic Period, a span in which most of macroscopic life on Earth evolved and was significantly not influenced by the presence of humans. Furthermore, scientists have been able to deduce a background extinction rate for this period, which is a useful point of comparison for use by conservation biologists. The present rate of extinctions induced by humans appears to be running at approximately 10,000 times the background rate and is likely to be accelerating."

That seems clear enough.

Tom said...

There's something behind it. I haven't just been sitting around. I do read. I read peer-reviewed papers. I read what you and others post. I read magazines. I read articles. I watch lots of TED videos.

I read the IPCC reports, both the full reports and the SPMs. And yes, I did read their caveat on their SLR estimates. (FWIW, I think accumulation in SH will more than balance out loss in NH and as I wrote, I think Greenland will lose a little around the edges.)

I don't claim to be a scientist or to have a scientist's level of understanding. But what I have, I have, and I have worked on it.


Since we come to different conclusions, you can of course denigrate my efforts, both at autodidacticism and communication.


But I do take all this seriously. FWIW.

Steve Bloom said...

SH accumulation? What SH accumulation? Last time I checked even East Antarctica taken in isolation was losing mass, notwithstanding increasing snowfall.

Steve Bloom said...

And, BTW, re Greenland, if you can't find even one qualified scientist who agrees with you, then your view has nothing to do with science and everything to do with wishful thinking.

rustneversleeps said...

Tom sez: "I think accumulation in SH..."

What "accumulation" in the southern hemisphere would that be Tom? This? (Source.

And thanks for those insights on what you read to form your opinions... Odd. I am suddenly having a weird flashback...

Tom said...

Ah, Rust Never Sleeps. Well, let's start with 'How to Talk to A Climate Skeptic'.

Objection: Sure, sea ice is shrinking in the Arctic, but it is growing in the Antarctic. Sounds like natural fluctuations that balance out in the end.

Answer: Overall, it is true that sea ice in the Antarctic is increasing.

Around the peninsula, where there is a lot of warming [PDF], the ice is retreating. This is the area of the recent and dramatic Larsen B and Ross ice shelf breakups.

But the rest of the continent has not shown any clear warming or cooling and sea ice has increased over the last decade or so.

This is not actually a big surprise.

In fact, it is completely in line with model expectations that CO2-dominated forcing will have a disproportionately large effect in the north. The reasons lie in the much larger amount of land in the northern hemisphere and the fact that the ocean's thermal inertia and ability to mix delay any temperature signal from the ongoing absorption of heat."

Of course, you may argue that that is not scientific, or peer-reviewed, or whatever. (You might have them update it, then...)

So let's turn to that obscure document, IPCC AR4, Chapter 4, “Observations: Changes in Snow, Ice, and Frozen Ground” (p. 351):

An updated version of the analysis done by Comiso (2003), spanning the period from November 1978 through December 2005, is shown in Figure 4.8. The annual mean ice extent anomalies are shown. There is a significant decreasing trend in arctic sea ice extent of –33 ± 7.4 × 103 km2 yr–1 (equivalent to –2.7 ± 0.6% per decade), whereas the Antarctic results show a small positive trend of 5.6 ± 9.2 × 103 km2 yr–1 (0.47 ± 0.8% per decade).

Umm, do they count as peer-reviewed literature?

Tom said...

As for ice in the Antarctic land mass, In the March 25 2008 issue of EOS, there was a News item by Marco Tedesco titled “Updated 2008 Surface snowmelt Trends in Antarctica” (subscribers only). It reports the following:
Surface snowmelt in Antarctica in 2008, as derived from spaceborne passive microwave observations at 19.35 gigahertz, was 40% below the average of the period 1987–2007. The melting index (MI, a measure of where melting occurred and for how long) in 2008 was the second-smallest value in the 1987–2008 period, with 3,465,625 square kilometers times days (km2 × days) against the average value of 8,407,531 km2 × days (Figure 1a). Melt extent (ME, the extent of the area subject to melting) in 2008 set a new minimum with 297,500 square kilometers, against an average value of approximately 861,812 square kilometers.”

rustneversleeps said...

Oh, come off it, Tom. Sea ice has nothing to do with sea level rise.

Please allay my suspicion that you are not just hopelessly confused by telling me that this was just a "change the subject" tactic on your part, and not an attempt at an actual answer.

rustneversleeps said...

Tom, is "square kilometers" a measure of mass?

Tom said...

And, "As opposed to the doom and gloom predictions of recent ice melt features in the western section of Antarctica, a recent study shows ice is thickening in Eastern Antarctica.
A study covering Eastern Antarctica shows continued growth in the ice mass of a region four times larger than the Western Antarctic area which is showing signs of ice reduction.
The head of the Australian glaciology program ,Antarctic Division, Dr. Ian Allison stated:

"Sea ice conditions have remained stable in Antarctica generally,"
Also mentioned was the difference in the size of the areas involved. One section of Eastern Antarctica is the Ross Sea region, which by itself has more than made up for the loss of ice in Western Antarctica."

Now, Rust Never Sleeps, we can throw cites back and forth all day. I am sure that there are papers out there saying that Antarctic ice extent, or mass, or volume, or snowflakes, is decreasing. And I can go out there and find other papers that say it is increasing.

But we would be fighting over weather, not climate science.

Tom said...

From physorg:

"From 1992 to 2003, Curt Davis, MU professor of electrical and computer engineering, and his team of researchers observed 7.1 million kilometers of the ice sheet, using satellites to measure changes in elevation. They discovered that the ice sheet's interior was gaining mass by about 45 billion tons per year, which was enough to slow sea level rise by .12 millimeters per year. The interior of the ice sheet is the only large terrestrial ice body that is likely gaining mass rather than losing it, Davis said.
"Many recent studies have focused on coastal ice sheet losses and their contributions to sea level rise," Davis said. "This study suggests that the interior areas of the ice sheet also can play an important role. In particular, the East Antarctic ice sheet is the largest in the world and contains enough mass to raise sea level by more than 50 meters. Thus, only small changes in its interior can have a significant affect on sea level."
The study, funded by NASA's Cryospheric Processes Program and the National Science Foundation's Antarctic Glaciology Program, suggests that increased precipitation was the likely cause of the gain. This was based on comparisons with precipitation model predictions over the same period of time. The most recent U.N. Intergovernmental Panel on Climate Change reported that Antarctica would gain mass due to increased precipitation in a warming climate. However, the study made no direct link to global warming."

For what it's worth, I said over a year ago that ice was increasing in the Antarctic, just as predicted by climate science many years ago, and that it did not disprove or call into question the fundamentals of climate science.

Steve Bloom said...

Fuller, you need to make an effort to a) not confuse sea ice and ice sheet mass and b) cite current results. Instead we get a Gish Gallop. Not too respectable.

Steve Bloom said...

Just for the record, a simple search (Antarctica+GRACE+mass+loss) finds the results that Fuller somehow missed. Yes, it's GRACE the gravity satellite(s). Now, had Fuller been paying attention, he would have known that the problem with altimeters is that while they track ice sheet thickness well, they don't track ice loss at the edges of ice sheets very well. GRACE accounts for the package. Summing up, the ice sheets are indeed accumulating mass due to increased snowfall, but losing even more (and at an accelerating pace) at the edges.
(Note: The Greenland ice sheet is experiencing significant and increasing surface melt during the summer. The Antarctic ice sheets are too high and cold for this to occur.)

I won't hold my breath waiting for Fuller to admit his error.

Tom said...

Bloom, there's a reason I don't respond to your bleatings. You're really not very nice. However, just this once, I call your attention to Nature Geoscience November 22, 2009, where Chen et al use Grace measurements to note ice mass loss in East Antarctica of 57 GT/year, plus... or... minus... 52 GT/year.

Could we please wait a bit before we panic?

Tom said...

And, guess the source (and date for bonus points...) "Two-thirds of Antarctica is a high, cold desert. Known as East Antarctica, this section has an average altitude of about 2 kilometer (1.2 miles), higher than the American Colorado Plateau. There is a continent about the size of Australia underneath all this ice; the ice sheet sitting on top averages at a little over 2 kilometer (1.2 miles) thick. If all of this ice melted, it would raise global sea level by about 60 meter (197 feet). But little, if any, surface warming is occurring over East Antarctica. Radar and laser-based satellite data show a little mass loss at the edges of East Antarctica, which is being partly offset by accumulation of snow in the interior, although a very recent result from the NASA/German Aerospace Center's Gravity Recovery and Climate Experiment (Grace) suggests that since 2006 there has been more ice loss from East Antarctica than previously thought 5. Overall, not much is going on in East Antarctica -- yet."

Tom said...

"While Wu et al. report that both Greenland and Antarctica are losing ice-mass, they are doing so at a much lower rate than previous estimates and that both are gaining ice in their interiors. “The mass loss in Greenland is concentrated along the coastal areas, and is particularly heavy in the west, and in the southeast with the large Kangerdlugssuaq and Helheim glaciers,” they state. “In contrast, the interior of Greenland shows significant positive mass balance.”

Bottom line on the new work is that ice-mass loss has been overestimated by previous studies. “These findings confirm the ongoing shrinkage of the polar ice sheets,” state Bromwich and Nicolas. “However, and most importantly, the newly estimated ice-sheet mass losses represent less than half of other recent GRACE-based estimates for the same time interval: −230 ± 33 Gt yr−1 for Greenland2 and −132 ± 26 Gt yr−1 for West Antarctica.” According to Wu et al. “We conclude that a significant revision of the present estimates of glacial isostatic adjustments and land–ocean water exchange is required.”

rustneversleeps said...

So, your evidence that the southern hemisphere is accumulating ice is a paper entitled "Accelerated Antarctic ice loss from satellite gravity measurements"? That concludes that "In agreement with an independent earlier assessment, we estimate a total loss of 190 +/- 77 Gt /yr"? That, even for East Antartica, concludes a loss of mass? That states: "Our new estimate (190 +/- 77 Gt /yr) agrees well with a recent result (196 +/- 92 Gt /yr) using InSAR mass fluxes in 2006, combined with snowfall estimates from a regional atmospheric climate model4. Acceleration of ice loss in recent years over the entire continent is thus indicated by these two independent studies."?

That's your reference in support your hunch that accumulating Southern Hemisphere ice will offset losses from Greenland?

Time for a beer...

rustneversleeps said...

Tom, you are citing sources that state that the Southern Hemisphere is losing ice mass.

You state: "And, guess the source (and date for bonus points...)".

It's NASA, early this year. Here's what they say in that same article: "Gravity data collected from space using NASA's Grace satellite show that Antarctica has been losing more than a hundred cubic kilometers (24 cubic miles) of ice each year since 2002. The latest data reveal that Antarctica is losing ice at an accelerating rate, too."

They also say, in the same paragraph: "One new paper, which states there’s less surface melting recently than in past years, has been cited as "proof" that there’s no global warming. Other evidence that the amount of sea ice around Antarctica seems to be increasing slightly is being used in the same way. But both of these data points are misleading."

Do those two points ring a bell? They should. Because they are exactly the same points you made upthread, including the exact same paper. And you cite this NASA source as support for your viewpoint?

Look, it's losing ice mass, ok?

Bartender? Make it a double.

NewYork said...

The view from the scientific community is a much more optimistic one in some sense, compared with the dominant view in certain political realms. If the recent rapid rise in global mean temperature was mostly natural, it implies that we can do very little about it (barring some severely risky geoengineering strategy) and we could in fact be in the process of being doomed by some natural climate event, not entirely different from an asteroid collision. But the science gives us hope. It says that we can limit the temperature rise from human activities, and likely keep our planet's climate livable for humanity for tens of thousands of years, before the next glaciation. And if a glaciation does become a threat, we know one proven way to combat it.

Fuller still doesn't get the sea level rise thing, even after a lengthy discussion at Kloor's site, still confusing projections over this century with the longer term. And where he gets his proclamations on instinctions is anyone's guess. It appears to amount to nothing more than "sticking one's finger in the air and guessing".

I see further that Fuller confuses sea ice (little implication for sea level) with ice sheets (big implication for sea level). Media outlets have done the same. If we recall...

The Australian's War on Science 37

On ice sheets:

Allison: ... In East Antarctica there might be a slight increase due to increased snowfall. ... on average West Antarctica is losing more ice that the East is gaining

There's some uncertainty over east Antarctic observations, though.

East Antarctica is now losing ice

About the only thing Fuller gets right is:

"I don't claim to be a scientist or to have a scientist's level of understanding."

Tom said...

It's been losing tiny amounts of ice mass for 3 years--so small it's extremely hard to measure. (100 cubic kilometers is literally an asterisk.) After growing for a much longer time--and remember that other measurements indicate it is still growing.

If GRACE turns out to be right and if it lasts for 30 years, then you have something to talk about.

For now, it's still weather.

Tom said...

instinctions. I like that... I'll bet David Brin could do something like that. I didn't confuse sea ice with land ice--read both posts.

As for extinctions, read up on it a bit. You'll see.

Tom said...

I will once again note, as I have on other subjects here and in other weblogs, that every time--every time--new measurement methodology is introduced, it has had a very disquieting effect on those paying obsessive attention to specific statistical measurements.

What on earth would you all be talking about if we didn't have satellites? Or if we hadn't loaded on some tools that could localize gravity differences?

Steve Bloom said...

Fuller, you claim to be calling my attention to a link I provided to you? How peculiar.

Here's the big picture point: It's very bad news that we're seeing any melt trend in the ice sheets, especially considering that the edge loss has to be large enough to overcome the increased snow accumulation. These losses were not expected; just a few years ago glaciologists assumed that it would take many centuries for the ice sheets to show significant mass loss. Recent paleoclimate results also show that at least the WAIS and GIS are prone to collapse under the sort of stress we've already put on them. So now, the big question is one of how fast the loss will accelerate, not whether it will. Since you seem to doubt that the loss can accelerate on a time-scale that people now living will care about, reading this interview of a leading glaciologist may clarify the situation for you.

Tom said...

The other thing with new measurement tools is they sometimes take time to get the bugs out, which you are happy to note when it comes to UAH.

"As the weight of covering ice varies, the underlying surface rock can be pushed down or rise up, buoyed by the magma that the crust floats on. This would obviously impact efforts to measure the height of terrain, including glaciers. Compensating for the rise and fall of bedrock is termed glacial isostatic adjustment, and it can have a significant impact on estimated ice-mass losses. Changes in the spatial distribution of the atmospheric and oceanic masses can also enter into the picture. Correctly assessing these different factors is the key to accurately calculating ice-sheet mass balance. Xiaoping Wu and colleagues have proposed a new method for untangling these factors from GRACE measurements. In a News and Views commentary on the work by Wu et al., David H. Bromwich and Julien P. Nicolas sum up the problem:

The atmospheric and oceanic contributions are commonly derived from global reanalyses or other global climate models that assimilate observations. However, the contribution from glacial isostatic adjustment is more difficult to evaluate because the Earth’s mantle is viscoelastic and therefore responds to changes in surface loading with a long delay. Indeed, the variations of the mass and extent of the ice sheets since the Last Glacial Maximum, about 20,000 years ago, continue to affect present-day changes in bedrock elevation. Assessments of the glacial isostatic adjustment typically rely on deglaciation models—which simulate the evolution of the ice sheets since the Last Glacial Maximum—together with assumptions about the viscosity profile of the mantle. Much is still unknown regarding the history of the ice sheets, and even less is known about the behaviour of the mantle in response to loading and unloading.


The method used by Wu et al., in “Simultaneous estimation of global present-day water transport and glacial isostatic adjustment,” estimates ice-mass changes and glacial isostatic adjustment simultaneously, instead of estimating the latter separately from deglaciation models as had been done before. The problem is expressed in terms of a single matrix equation, with the observed surface-height changes decomposed into their different contributions. The equation is then solved for ice-mass changes using matrix inversion. While the glacial isostatic adjustment that results is not directly generated by deglaciation models, the inversion method still requires a first-guess estimate to begin the calculations."

I would imagine there will be some fine tuning of those first guess estimates.

So maybe Dirk is right in his first comment about it taking 15 years for me to come around. We'll see.

I think that climate theory is correct here, and that the Antarctic is gaining ice (maybe not every year, or even every decade), and will continue to do so until a higher level of temperature warming occurs.

It's your book(s). Read it/them.

Steve Bloom said...

We'd be talking about the rapid loss of all the other glaciers (remember them?) and worrying about the status of the ice sheets.

And yes, you did confuse sea ice with ice sheets.

Steve Bloom said...

Sigh. As I said above, find just one glaciologist who thinks they're not losing mass.

BTW, you're confused when you say that the isostatic adjustment has to do with the instrument. It doesn't. The altimeters have lots of adjustment issues, similar to A/MSU.

Steve Bloom said...

Oh, and to what "climate theory" could you possibly be referring? The problem with the ice sheets all along has been the lack of a dynamical theory. Observation and paleo studies have informed us to a great degree, but those aren't theory.

Why are you so happy to just make stuff up?

Tom said...

Okay, Bloom, my parting shot. It is established theory that the Antarctic would gain ice until global warming got more severe. Talk about making stuff up. Do you remember upthread?

"Answer: Overall, it is true that sea ice in the Antarctic is increasing.

Around the peninsula, where there is a lot of warming [PDF], the ice is retreating. This is the area of the recent and dramatic Larsen B and Ross ice shelf breakups.

But the rest of the continent has not shown any clear warming or cooling and sea ice has increased over the last decade or so.

This is not actually a big surprise.

In fact, it is completely in line with model expectations that CO2-dominated forcing will have a disproportionately large effect in the north. The reasons lie in the much larger amount of land in the northern hemisphere and the fact that the ocean's thermal inertia and ability to mix delay any temperature signal from the ongoing absorption of heat."

As for 'one glaciologist,' again, upthread I referred to one: "The head of the Australian glaciology program ,Antarctic Division, Dr. Ian Allison stated:

"Sea ice conditions have remained stable in Antarctica generally,"
Also mentioned was the difference in the size of the areas involved. One section of Eastern Antarctica is the Ross Sea region, which by itself has more than made up for the loss of ice in Western Antarctica."

And again upthread, you have totally ignored what the IPCC said about Antarctic ice:

"
An updated version of the analysis done by Comiso (2003), spanning the period from November 1978 through December 2005, is shown in Figure 4.8. The annual mean ice extent anomalies are shown. There is a significant decreasing trend in arctic sea ice extent of –33 ± 7.4 × 103 km2 yr–1 (equivalent to –2.7 ± 0.6% per decade), whereas the Antarctic results show a small positive trend of 5.6 ± 9.2 × 103 km2 yr–1 (0.47 ± 0.8% per decade)."

So, increasing ice is part of established climate change theory. Check.
You get a glaciologist. Check.
You get what the IPCC says about Antarctic ice. Check.

But a new gravimeter using a first guess analysis is supposed to make us wet our pants? Sorry.

You get all arrogant and really stupid and you don't read what other people write. Which is why I have no need to engage with you. At all.

NewYork said...

Steve Bloom: "And yes, you [Fuller] did confuse sea ice with ice sheets."

And remarkably, Fuller still does. This is quite a display.

Steve Bloom said...

Hmm, he mixed up sea ice and sheet ice yet again. Imagine that.

Also, Fuller, do note that the most recent AR4 results are now well over four years old, and that GRACE results are subsequent to that. FYI lots of stuff in the AR4 is out of date by now.

Re the respective satellite instruments, I wrote what I did having read up somewhat on the issues. You didn't.

Tom said...

Tuco Juan Maria Pacific Ramirez:

"Hooray for General Lee! God is on our side because he hates Yankees!"

Slap. Slap.

MWNN: "God is on their side, because he hates idiots."

You don't know what side you are on. You don't know what side I am on. You don't know how to read. You don't know how to write.

No wonder your political position is doing so well, with such sterling advocates.

I'll have to leave it at that, I'm afraid, and miss the usual round of namecalling. Do enjoy.

Steve Bloom said...
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Steve Bloom said...
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NewYork said...

I'm just wondering at this point if Tom Fuller actually knows the difference between sea ice and ice sheets and how changes in each affect sea level. I really don't think one needs to be a scientist to grasp these concepts, especially when explained. Since I don't think Fuller is an idiot, I suspect that acknowledging that sea ice plays a very small role in sea level changes would be a slippery slope towards admitting that (gasp!) he was wrong. Can't have that!

I find most contrarian types happen to share such traits, which is why they still "believe" they way they do after decades of more and more evidence.

Steve Bloom said...
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Michael Tobis said...

Steve, lay off the ad homs. Either Fuller is right or he is wrong. That's all that concerns us.

Tom, you are wrong, because you listen to people who are wrong.

Antarctic sea ice is not strong evidence. The Antarctic margin is softening and melting, and this is likely to be accelerating. There is no real cap on how fast the West Antarctic can disintegrate, and the most vulnerable point has retreated from the ledge where it was pinned.

Accumulation in the interior is not enough to affect the sea level picture very much; the Antarctic interior is still a high desert.

"I call your attention to Nature Geoscience November 22, 2009, where Chen et al use Grace measurements to note ice mass loss in East Antarctica of 57 GT/year, plus... or... minus... 52 GT/year."

So you are betting on an extreme end of that range, then?

Measurement isn't everything. We know more about how ice sheets fail than we used to. The West Antarctic is unstable and probably tipped. The main issue is how long the failure will take.

Michael Tobis said...

Steve: "The problem with the ice sheets all along has been the lack of a dynamical theory."

There has been considerable progress in the last 15 years, both observationally and theoretically.

Steve Bloom said...

Progress, yes, but unless I've really missed something, not enough to allow development of a model with useful predictive skill, right?

Michael Tobis said...

I have my doubts that we'll be able to calibrate them before the sea level rise really kicks in, but I know some very smart people who are working hard at it, so I'd hate to say no.

Tom said...

Michael, when you see a value with a margin of error that's 90% of the value, doesn't that make you want to wait for another orbit?

Steve Bloom said...

Michael, point taken, but for the record Fuller called me stupid, a remark which you chose to leave in place.

Steve Bloom said...

Fuller doesn't get it again. But a little more since Micahel didn't provide much context:

Our short-term concerns are about the WAIS and GIS, both of which are showing quite bad signs of mass loss. The WAIS is particularly worrying since unlike the GIS it has no geographic constraints on a collapse. See that link I provided above for why glaciologists think it's probably already tipped (at least for the portions grounded below sea level => ~3.5 meters SLR).

Regarding the EAIS, what's alarming isn't the precise trend so much as the detection of significant loss at the edges (remembering that the accumulation being balanced is considerable). This was entirely unexpected. The EAIS isn't nearly so ephemeral as the WAIS, but it has undergone major loss episodes in the past under forcing scenarios far less severe than what we're subjecting it to now. Note that in the mid-Miocene (~15 mya), the last time CO2 levels were the same as at present, the EAIS disappeared almost entirely, with only a relect ice cap surviving in the mountains.

I'll remind you again that you can consult the Copenhagen Diagnosis for an almost up-to-date consensus assessment of this stuff.

Michael Tobis said...

Steve, yup, but since the conversation took off from there before I had a chance to prune it, what could I do?

Besides, to be honest, I'm harder on my friends.

Michael Tobis said...

Tom: "Michael, when you see a value with a margin of error that's 90% of the value, doesn't that make you want to wait for another orbit?"

Since the value in question can be positive or negative, the result says basically "there's no way we could get this measurement if there were accretion here", which NB was not formerly the case.

How could you possibly interpret such a thing as a null result? Maybe it is because you are working backwards from the answer you want?

Some people wake up every morning wondering "is there any way I could possibly be wrong?" Other people wake up wondering "is there any way I could possible be right?"

The first group is more interesting, because it contributes to understanding, not to posturing. The methodology of the first group is called "science". The second group may be called "lawyers".

Arguments between scientists and lawyers usually turn out badly for the scientists. That is unfortunate, not just for the scientists, but for everybody else.

Journalists think themselves judges in these debates. They get confused because they don't know where the "burden of proof" lies. Maybe it would be a good idea to think about what it means to "prove" something.

Tom said...

Michael, long before I was a journalist I worked for the US Navy in radar, communications technology and cryptographics, repairing and maintaining a wide variety of equipment.

I am not asking for a legal standard of proof on GRACE gravimeter measurements of Antarctic ice.

But GRACE is new. The measurements are new. They use a variety of assumptions and inferences from models, if the article I read is correct.

When a figure comes back with a 90% margin of error from new equipment with new assumptions, it is not being lawyerly to say let's wait a while before we say that the climate science that predicts ice accumulation in the Antarctic, bolstered by other measurements, should not be promptly thrown in the garbage.

You're being deliberately obtuse here.

Michael Tobis said...

No, the number could be negative or positive. "90%" is not a useful way of looking at it.

If a temperature measurement says 3 C +/- 3.0 and another one (at another place or time) says 30 C +/- 5.0, which is the better measurement?

Suppose Grace came back 20 +/- 50 GT. What would the "percentage error" be? Or 0 +/- 50 GT.

"They use a variety of assumptions and inferences from models, if the article I read is correct."

Yeh. It's called science. Sheesh. No models, no science. No science, no civilization. Is that the plan?

Tom said...

Michael, you have to work pretty hard to misunderstand and mischaracterize what I'm saying.

I'm not saying throw out the models. I'm not saying don't use inferences. I'm saying:

1. New machine--satellite bound gravimeter.
2. First pass out the gate.
3. Using 'first guess' estimates for initial conditions.
4. Using other inferences for boundaries from models that may not be perfect.
5. Data comes back with very wide error margins.
6. Normal science says, lots to learn here, let's look at what we've got and design the second such experiment.

And anyone reading what I wrote would understand that. And you know I'm right.

It may be frustrating for you because you think it delays grounds for immediate action, and it may frustrate you that you're hearing this from someone who doesn't agree with you on the urgency of dramatic action.

But I'm right, and you know it.

dhogaza said...

No, Tom, you've been flogging this "uncertainty is 90% of the value" nonsense.

Michael:

"If a temperature measurement says 3 C +/- 3.0.."

Perhaps a clearer way to make the point is to ask Tom what happens to this "uncertainty is 100% of the value" argument if you write it as 276K +/- 3K ...

Tom:

"5. Data comes back with very wide error margins."

But not so wide as to rule out our being able to determine if mass is increasing or decreasing.

Steve Bloom said...

This is bold talk coming from a guy who didn't even know about GRACE until yesterday, and was also (and from the sound of it may still be) confused about sheet ice vs. sea ice.

BTW, Tom, where do you get the idea that GRACE would need to account for PGR but altimeters would not?

David B. Benson said...

Tom Fuller seems to have missed the point I made yesterday.

Sea levels are going to go way, way,
way, way, way
up.

Got it now?

Steve Bloom said...

In the opening paragraphs of a recent post over at his blog, Fuller exhibits the same confusion about sea ice and sheet ice:

"There are a lot of people obsessively watching the retreat of Arctic ice as we approach summer's end. More of it melts every summer and some scientists believe that Arctic ice will disappear each summer as global warming continues.

"Should we care? What would it affect? The answer seems to be, not much--unless you're a polar bear that uses the ice to rest on as it navigates and hunts around the polar ice cap. To humans, it wouldn't really make much of a difference. It might lead to commercial exploitation of an environmentally sensitive region. Some of the indigenous peoples inhabiting the area would have to put up with more development. Really, that's about it. Not trying to minimize it, but there are worse fates imaginable.

"On the other hand, nobody talks very much about melting permafrost. Watching frozen mud melt may be as boring as it sounds. At any rate, it can't compete with the visuals of glaciers calving and icebergs falling into the sea, natural as they actually are."

I'm not trying to pile on extra blame here, since it was posted a couple of days prior to this one, but having misinformed his readers will he now have the integrity to make a correction?

If anyone cares, the rest of the post is basically blaming the messengers for the lack of public understanding of the permafrost threat.

rab said...

Tom Fuller: "I don't claim to be a scientist or to have a scientist's level of understanding."

Then he makes scientifically questionable claims and says: "And you [scientists] know I'm right."

Look, it's a waste of time engaging this guy.

Michael Tobis said...

rab, but

" A researcher could be doing really important work on global warming, and then somebody writes a column in a national newspaper that completely undermines what they’re saying. But the scientist doesn’t think the column is important—it’s just some nincompoop writing a column—so they don’t take that writer to task in the way they should. It’s a case of saying, “How do we make a difference?” We certainly don’t make a difference by just moaning over coffee the next day."

rab said...

Re newspapers, I completely agree. (BTW, your latest post is right on; I quote it on my FB!)
OTOH, blogs, while good for plotting strategy and sharing info, are mostly preaching to converts.

dhogaza said...

"hould we care? What would it affect? The answer seems to be, not much--unless you're a polar bear that uses the ice to rest on as it navigates and hunts around the polar ice cap. To humans, it wouldn't really make much of a difference. It might lead to commercial exploitation of an environmentally sensitive region. Some of the indigenous peoples inhabiting the area would have to put up with more development. Really, that's about it. Not trying to minimize it..."

Not trying to minimize it but ... "not much" is a minimizing statement.

He can't even write a single paragraph without lying ...