Just as a quick self-advertisement to hopefully get traffic flowing…
My University runs a Weather and Climate blog here where I will be a frequent contributor, if anyone would like to add it to their list of reads (my posts specifically are here).
A lot of the articles will probably be on recent weather topics, but I will be posting exclusively on broader climate issues. They will not be very technical, as it is geared to be part of a newspaper blog, but hopefully people find it interesting, and of course any technical level is fair game in the comments.
This will act as replacement to my old WordPress blog, which I am putting to rest, but my old articles will still be up.
Ed Daviessays
I’m reading Robert Zubrin’s How to Live on Mars. Quite fun in parts but made me cringe a bit in others: particularly a short diversion on global warming (on Earth) which is basically the CO₂ is plant food argument. He does say, though, that the reduction of CO₂ in the atmosphere since the Eocene was due to the evolution and proliferation of grasses which I hadn’t heard before. Does this idea have any scientific basis?
[Response: I’m sure others can chime in, but this seems very odd. Most arguments for the secular trends in CO2 over the Cenozoic are tectonic in origin (i.e. rates of crustal formation, impact of the uplift of the Himalyas on chemical weathering etc.). – gavin]
This seems backwards. The long-term decline of CO2 lead to the wider spread distribution of C4 plants (a more evolved process), which are less sensitive to the CO2 content as C3 plants (i.e., the most primitive photosynthetic pathway in terrestrial plants). The long term evolution of CO2 is controlled by the balance of weathering vs. outgassing.
I would like to recommend Raymond Bradley’s new book ”Global Warming and Political Intimidation”. Bradley was one of the three scientists behind the hockey stick, and he tells the inside story of the political controversy in a straightforward and highly readable manner.
Ed Daviessays
Gavin, Hank, Chris, thanks; I thought the idea was weird. I’ll take the rest of the book with an even bigger pinch of salt (i.e., treat it as fiction).
I’d be interested in the experts views on this paper:
Katsman, C. A., and G. J. van Oldenborgh (2011), Tracing the upper ocean’s “missing heat”, Geophys. Res. Lett., 38,
“The analysis reveals that an 8-yr period without upper ocean warming is not exceptional. It is explained by increased radiation to space (45%), largely as a result of El Niño variability on decadal timescales, and by increased ocean warming at larger depths (35%), partly due to a decrease in the strength of the Atlantic meridional overturning circulation. Recently-observed changes in these two large-scale modes of climate variability point to an upcoming resumption of the upward trend in upper ocean heat content.”
I note that, despite BOEMRE’s statement that this has nothing to do with the previous investigation, Agent May states that he intends to ask ‘followup’ questions WRT that previous interview. Seems it’s not such a separate question after all.
Hunt Janinsays
What will be the impact on sea level rise, if any, on water now impounded in earth in dams, etc.?
MARodgersays
#13
The volume of fresh water in all rivers & lakes, if drained into the oceans, would raise sea levels by something like half a metre.
If by “dams, etc” you mean human-built reservoirs, the figure will be a lot smaller. There are some pretty big reservoirs in the world. The biggest (on the Zambezi River) would raise sea levels 0.5mm if it was full (and it quite often is). A quick Wikicalc yields a figure of 7.5mm rise for the top 46 reservoirs if full.
Paul Ssays
#13, Hunt Janin – Water now impounded in dams won’t have any effect on future sea level change. Chao et al. (2008)* estimate that sea level rise was reduced by about 3cm over the 20th Century, almost entirely after 1950, due to water being impounded in terrestrial reservoirs.
So if it was all released right now you would expect a quick 3cm rise.
The current rate of impoundment is something like 0.2mm/year, a fall from an average 0.55mm/yr since 1950. Again, that’s according to Chao et al. (2008). It’s possible this might pick up again due to large scale projects in developing countries (e.g. Three Gorges dam).
*Can’t find a non-paywall link but key figures are in this slideshow
Rick Baartmansays
Anyone here who is member of the APS, please help out by commenting on the “Physics Today” thread:
It’s an essay by Steven Corneliussen global warming science and the media.
[Response: I’m a member, but it’s not worth commenting in response to the political drivel being posted there after the article you link to. On the subject of APS though, it is interesting to note that APS has recently added a new “topical group” on climate physics. This is important because these topical groups are not something that APS members can just add on a whim. For example, a colleague of mine had to get quite hard to get the Quantum Information topical group to happen in APS. That, at least, should presumably be a non-political subject. This attests to the seriousness with which most physicists — and not withstanding e.g. Dyson — take the physics of climate.–eric]
catman306says
Here in NE Georgia, in the winter I heat with firewood and in the summer I survive the heat with a window A/C. I define spring and fall as the days when I need neither a fire or the A/C.
The number of spring/fall days is steadily diminishing, replaced by heating or cooling days. Climate change means fewer days when the temperature and weather are ‘just right’.
I think some metric of fair spring/fall days might be useful in explaining the full effect of human caused climate change to non-scientific people. Anyone without central HVAC could easily relate to this metric.
Among the intriguing items in the State of the Climate report was the observation that although recent SST rises have been fairly slight, and subject to the fluctuations from ENSO and other modifying influences, the temperature of lakes has been rising rather steeply, with a global average in the range of 0.4 C/decade. This is even faster than land surface temperatures in general, but I expect that the difference is due at least in part to the fact that the lake temperatures measurements have been nighttime measurements, and not subject to the diluting effects of insolation that has not been rising on average. The different rates of rise of SST and lake temperatures also presumably reflects the consequences of heat transfer to the deeper layers of the ocean.
Ragweedsays
@15 (et al.) There was a special issue of BioSciene on Global-Scale Environmental Effects of Hydrological Alterations in 2000 that addressed some of the impoundment volumes, etc. I believe that an earlier paper of Chao et al. was included. I don’t seem to be able to access the issue, but I recall that in addition to the effect of water impounded by dams, there is also the issue of water released to the surface from underground aquifers. Apparently impoundment has lowered sea level by about 3cm, but total aquifer release has raised sea level by nearly the same amount, so it has been in balance.
I will have to find the issue, however to confirm the numbers.
David MWsays
Real Climate readers might be interested in these two rather depressing related comment pieces on The Guardian website on climate change and environmental protection more generally, and the US Republican Party – the first is by Raymond S. Bradley…
Can anyone help me out here? I’m interested to know what the current state of the science is regarding the possibility of a runaway greenhouse effect if we burn the unconventional fossil fuels (tar sands, shale gas etc.) in addition to the remaining coal, oil and gas reserves.
In his book “Storms of my Grandchildren”, James Hansen says he thinks it’s a dead certainty, but David Archer in “Global Warming Understanding the Forecast” reckons there’s not enough fossil fuel carbon on Earth (although it’s not clear if he’s considered the unconventional fossil fuels).
Has any modelling been done on this scenario?
Joe Cushleysays
Here’s one for the hall of mirrors from Roy Spencer… yeah, really “ironic” Roy…
UAH Global Temperature Update July, 2011: +0.37 deg. C
August 1st, 2011
How ironic..a “global warming denier” reporting on warmer temperatures ;)
The global average lower tropospheric temperature anomaly for July, 2011
Jon Psays
Gavin,
Please discuss Lake Powell and how wrong you were about it.
[Response: Sure. Please link to the quote where I said something wrong. – gavin]
But I’m not sure if anyone has done a thorough analysis of conventional and unconventional fuels. But it would be nice to see what the predictions might be.
Meowsays
@20: Chris Colose wrote a short note on the runaway greenhouse effect at Skeptical Science with some cites. His understanding is that TSI at earth’s orbit is too small for a runaway to take hold. This reasoning rests on the idea that an earth with much more atmospheric water vapor would have a larger albedo than today’s earth.
(found by putting the following string into the search box at the top right of this RC page, with the “site search” button selected; I skimmed the first few hits and gave you the one most concisely asking and answering that question)
The ReCaptcha AI oracle, in response, gave me these words:
fringes isideal
Patrick 027says
Re 25 Meow – I don’t think that’s the reason why. I remember the point was made that we don’t know exactly how cloud feedbacks behave when we get near a runaway water vapor situation.
I think the thing about a runaway water vapor situation is that CO2 wouldn’t have so much effect then (?). Of course it should take less TSI if you have more CO2 to get to the same temperature, but … well Chris Colose had some graphs that show how it would work (clouds excluded, as I recall) – maybe this was in hiw WordPress blog; I don’t remember.
PS a runaway water vapor situation doesn’t imply permanence. Turn the TSI down past some threshold and you have runaway water vapor feedback in the cooling direction. As opposed to (if I recall correctly – and I never read a whole lot about this) what had been thought about a snowball Earth with dry ice clouds in some conditions (but it turns out that dry ice clouds are effective greenhouse agents). But there isn’t a hysteresis in equilibria with runaway water vapor feedback, whereas there is (or is supposed to be) hysteresis in a the Snowball Earth – nonsnowball cycle, involving runaway ice albedo.
PS runaway feedback doesn’t take you to infinity – it just means that there is some range of conditions for which the climate has no stable equilibrium – it can’t come to rest there – climate sensitivity has to go past infinity at some point and could become negative (along an unstable equilbrium).
(Technically/hypothetically, you could have a climate sensitivity of x K/(W/m2) that is an average over tiny steps where the climate passes a bunch of tiny tipping points. For example, what if there were a set global temperature at which a given sufficiently small pocket of methane hydrate/clathrate destabilizes. You could then have little tiny runaways that wouldn’t be perceptible. But internal variability and the time it takes for each pocket to be released after the temperature threshold is crossed (?) may blur that out (PS on the small scale there are runaways all the time – I think cumulus convection has some of that).)
Patrick 027says
… that example of methane feedback is of course a non-Charney feedback.
Thomassays
I have read that grasses were a kind of productivity miracle. So I can easily imagine that the amount of soil carbon is higher with grasses than without. But I really doubt that is was sequestered in a time frame shorter than the silicate cycle equilibrium time, so I wouldn’t think it would be a factor.
Fred @18. Assuming measurements are made consistently over time, I wouldn’t expect much day/night variation on lake water temps. It is possible that changes in rivers, and shoreline vegetation along rivers might have a substantial impact. I don’t know what happen to water temp if a lake Eutropifies and gains a layer of floating lakeweed. My guess, lower evaporation, but possibly higher albedo.
barrysays
Kevin@12
I speculate that finding nothing wrong with the 2005 observational note on polar bears, the investigators combed through the records (hard files, computers) they took from Monnett and found a new line of inquiry – impropriety of management on a project about polar bears. The likeliest explanation for the changing allegations is that the Department of the Interior is trying to suppress certain research into polar bears. There is precedent.
… no hysteresis with runaway water vapor – of course that excludes things like biological feedbacks and abiotic CO2 feedback (if it got hot enough to decompose carbonate rocks, for example (?) (but then, upon cooling you’d presumably have some very rapid chemical weathering, so maybe …)), and H escape, etc.
Chris Snow, for a simple discussion of your question, see:
J.F. Kasting, T.P. Ackerman. “Climatic Consequences of Very High C02 Levels in Earth’s Early Atmosphere” Science 234: 1,383-1385 (1986)
Even at several tens of bars of CO2 you cannot generate a true runaway greenhouse, although you can surpass the modern day boiling point of 373 K. Even at constant 30% albedo this is true.
Meow,
The increase in albedo is a fundamental consequence of increased Rayleigh scattering in a moist atmosphere, and this acts as a negative feedback over the course of the moist greenhouse or runaway evolution (but as I said, CO2 does not generate a runaway greenhouse regardless, unless the net solar insolation is sufficiently high to prevent the planet from ever reaching radiative equilibrium over the timeframe of the oceans existence). The scattering is a bit less important around lower temperature stars, because their spectrums are red-shifted and thus the Rayeligh scattering is reduced (Rayleigh scattering favors shorter wavelengths, being inversely related to the fourth power of the wavelength).
The negative feedback is important though because another fate a planet can have, rather than transitioning into a true runaway, is to have a large quantity of ocean water lost by hydrogen escape even prior to a runaway. This occurs in a warm moist greenhouse even without a true runaway. If the albedo is fixed at 0.3, then the runaway can happen well before a significant fraction of the ocean is lost; however, if the albedo is free to increase with higher solar luminosity, then the oceans might slowly be lost to space, and enough time may pass to become depleted before a true runaway happens (see Abe et al 2011, Astrobiology).
Ron R.says
Ed Davies Aug 2011 at 5:01 PM:
He does say, though, that the reduction of CO₂ in the atmosphere since the Eocene was due to the evolution and proliferation of grasses which I hadn’t heard before. Does this idea have any scientific basis?
My understanding is that grasses did not become abundant until between 8 and 5.5 mya. Before 15 mya there is very little fossil evidence. Course, as with many things paleontological and archeological these dates often get pushed back with new discoveries. Thus grass phytoliths (or what appears to be) have been found in dinosaur coprolites. But at present I doubt that grasses were abundant enough pre middle to late Miocene to affect CO2.
This investigators’ interview with Monnett co-author J. Gleason is even more thuggish than the one with Monnett. It sounds as though they actually think Gleason and Monnett faked their observations. One, Eric May, talks of some anonymous math guy that has told him that Monnett and Gleason have made egregious errors. Quite McCarthyist.
Be warned: very long transcript
J Bowerssays
Call the cops, someone’s impersonating Lysenko! Are Gleason and Monnett being hounded for thought crime, or for not having supernatural powers to foresee how others use and cite their work? That transcript’s unbelievable.
gryposays
Professor Salby questions human v natural emission fingerprints. Seems to base this on measurements during Pinatubo and 98 el nino. ie warming causes soil emissions, isotope ratios are inconclusive?
[Response: Not yet listened to it, but there is nothing controversial in saying that ENSO and volcanoes cause responses in the carbon cycle – soil respiration, solubility etc. This is the biggest effect in the interannual variability of the CO2 rise (though it is irrelevant for the trend). – gavin]
Cool dudes: The denial of climate change among conservative white males in the United States
► Conservative white males are more likely than other Americans to report climate change denial.
► Conservative white males who self-report understanding global warming very well are even more likely.
► Climate change denial is an example of identity-protective cognition.
► System-justifying tendencies lead to climate change denial.
► Climate change denial increased from 2001 to 2010.
Ray Ladburysays
Alistair@38: ” Climate change denial increased from 2001 to 2010.”
Even as evidence mounted rapidly. Ladies and gentlemen, it is inescapable: Conservative white males have a negatively-sloped learning curve.
gryposays
Gavin,
Yeah, that’s why I thought I might have missed something. He seems to think he’s found something new, frequently saying the IPCC doesn’t know it, but without seeing what he is doing, I can’t make anything out of it.
#33–Chris, I think it might be useful to remind us what the criteria are for a “true runaway.”
Some of the scenarios that don’t qualify–significant loss of H2O, or T actually exceeding the boiling point, for example–are sufficiently dire in themselves, to say the least. Are any of these significantly more probable than the “true runaway” you tell us is impossible?
(I don’t want to overstress these–the threats to our food security and political stability under BAU are bad enough, and seem all too probable to be realized at this point. But I’m also a curious chap.)
wilisays
On the grasses issue, the important question to me is whether they could, even theoretically, play an important role in carbon sequestration.
Robert Murphysays
Listening some more to Salby’s address. He was asked about future temperature increases and projections of 4 degrees warming; if natural processes are driving temps, what was his projections – he said he didn’t do projections then said the following:
“Let me make one comment. What you’re really talking about is a 4 degree simulation, right? And that’s based on model runs that were done oh, in the late 90’s and early 2000’s for the last IPCC report. Now the conclusion of that was that the increased temperature that was observed, global temperature, in the 80’s and the 90’s was due to CO2. And that appears to have been a sucker-punch that the IPCC went for because no sooner – the ink hadn’t even dried on the report – that Mother Nature intervened and CO2 after the turn of the century continued to increase, in fact if anything, slightly faster, but global temperature didn’t. If anything, it decreased in the first decade of the 21st century. Now I’m confident the IPCC will come up with any explanation, in fact its already come up with several, but your extrapolation of 4 degrees presumes that you essentially have these model projections and that’s what they’re relying on and those model projections rely on “we know what CO2 is” since we’re responsible for CO2, since the human source is essentially what causes atmospheric CO2 to change, quote unquote, that we can extrapolate that. Well, doesn’t look like that works.”
It’s worse than I thought. No wonder Curry loves it, “If Salby’s analysis holds up, this could revolutionize AGW science.”
[Response: It’s on a par with “If I was a bird, I could fly!”. Both propositions are true but neither has any relevance to the real world. – gavin]
Paul Ssays
On Professor Salby,
His talk moves on from annual cycle and ENSO/volcano-induced fluctuations to extrapolations of temperature-CO2 connections back over the whole surface temperature record, concluding that temperature is driving CO2 changes:
“The correspondence to observed changes in CO2 on timescales of a couple of years, over the satellite era and, to the degree seen, even over the 20th Century makes it difficult not to conclude that sources involved in changes of CO2 on short timescales are also involved in its change on long timescales.”
“…future atmpospheric CO2 is only marginally predictable and in significant part not controllable. That means changes in human emission will not be tracked by changes of atmospheric CO2. They never have been.”
Though I think the main thing he’s excited about is his finding that changes in carbon isotopic ratios (12c/13c) correlate with natural fluctuations. He suggests this means the ratio changes cannot be used as a fingerprint for detecting changes in atmospheric CO2 by human emissions.
Msays
“Salby is claiming that most of the rise in CO2 is due to natural causes, not human emissions of fossil fuels. Uh huh.”
And Judith Curry is doing her best, “oh, this is a good talk, it sounds like it might be plausible, but I won’t make any statements that can be used against me when it turns out this is just ridiculous” impression (as far as I can tell, the only skeptic arguments she has been willing to disown is the “sky dragon” book).
I often use “the rise of CO2 might be natural” meme as a way to determine when someone lacks all ability to determine reality from fiction. Judith Curry has really jumped the shark…
-M
My attempt to quote Salby: “the popularized view is that CO2 is driving the bus… the reality is the opposite, climate is at the wheel and CO2 is at the back of the bus … the observed behavior reveals that much as we might like it … we can’t predict CO2” “emission from natural sources is integral to observed changes in CO2, but its contribution has not been recognized… therefore, future atmospheric CO2 is only marginally predictable and not controllable… future concentrations will not be tracked by changes in emissions of CO2, and they never have been”
He also drops random stuff about the medieval warm period and recent warming just being a rebound from the little ice age. Talk of “the science” stimulates his gag reflex, because “discourse gets to the truth”. “Excluding discourse isn’t science, its advocacy – so pick up your phone and call Canberra! … anyone who think the science of this complex system is settled, is in fantasia”.
I have to say that his talk stimulates my own gag reflex…
Msays
Salby: “I don’t believe that the CO2 in the ice cores is 50,000 year old CO2”
[Response: He’s right. Some of it is 800,000 years old. – gavin]
Robert Murphysays
More Salby:
“The correspondence to observed changes of Co2 on timescales of a couple of years over the satellite era and to the degree seen even over the 20th century, makes it difficult not to conclude that sources involved in changes of Co2 on short timescales are also involved in its change on long timescales. The popularized view has been that CO2 is driving the bus and climate is along for the ride. The observed behavior reveals just the reverse. Climate is at the wheel, and to a significant degree, CO2 is at the back of the bus. Climate projections rely on an ability to predict CO2; it’s the one thing believed to be known, because of the presumption we control it. Namely, future atmospheric CO2 is determined entirely by human emission. That’s what is specified in climate models which then predict how climate will respond, in so-called climate scenarios.
The observed behavior reveals that, much as we might like it, the real world doesn’t work that way. Net emission includes a substantial contribution from natural sources; if you don’t control CO2, you can’t predict it, and if you can’t predict CO2, you can hardly predict how climate will respond.”
Mike Pollardsays
Does Salby mention any interaction with Colin Prentice in the podcast? They are at the same institution and Prentice seems to have solid credentials regarding CO2 (his bio states ”I was chief author of the chapter “Carbon cycle and atmospheric carbon dioxide” in the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).”) If I was Salby I’d want to run what I had past Prentice who would seem to be ideal for a critical appraisal of work on the atmospheric carbon dioxide.
No Unforced Variations for August, sorry, but this seems worth a look.
Himalayan glaciers shrinking
Spatially heterogeneous wastage of Himalayan glaciers. Fujita (2011), PNAS.
Just as a quick self-advertisement to hopefully get traffic flowing…
My University runs a Weather and Climate blog here where I will be a frequent contributor, if anyone would like to add it to their list of reads (my posts specifically are here).
A lot of the articles will probably be on recent weather topics, but I will be posting exclusively on broader climate issues. They will not be very technical, as it is geared to be part of a newspaper blog, but hopefully people find it interesting, and of course any technical level is fair game in the comments.
This will act as replacement to my old WordPress blog, which I am putting to rest, but my old articles will still be up.
I’m reading Robert Zubrin’s How to Live on Mars. Quite fun in parts but made me cringe a bit in others: particularly a short diversion on global warming (on Earth) which is basically the CO₂ is plant food argument. He does say, though, that the reduction of CO₂ in the atmosphere since the Eocene was due to the evolution and proliferation of grasses which I hadn’t heard before. Does this idea have any scientific basis?
[Response: I’m sure others can chime in, but this seems very odd. Most arguments for the secular trends in CO2 over the Cenozoic are tectonic in origin (i.e. rates of crustal formation, impact of the uplift of the Himalyas on chemical weathering etc.). – gavin]
> CO2 … grasses
Good info here on the various thoughts about this over the past few decades: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2745.2007.01323.x/full
Ed,
This seems backwards. The long-term decline of CO2 lead to the wider spread distribution of C4 plants (a more evolved process), which are less sensitive to the CO2 content as C3 plants (i.e., the most primitive photosynthetic pathway in terrestrial plants). The long term evolution of CO2 is controlled by the balance of weathering vs. outgassing.
Arab News, of all places, has the latest on Charles Monnett:
http://arabnews.com/lifestyle/science_technology/article481649.ece
My take here:
http://bigcitylib.blogspot.com/2011/08/charles-monnett-and-polar-bears.html
@ 6 BCL
The full letter to Monnett can be downloaded HERE (H/T Gavin’s Pussycat).
Here’s the irony: US government department criticised for failing to collect oil revenues. That’s a possible billions, not just a few grand. BTW, ever heard of the USGS cartographer Ian Thomas?
I would like to recommend Raymond Bradley’s new book ”Global Warming and Political Intimidation”. Bradley was one of the three scientists behind the hockey stick, and he tells the inside story of the political controversy in a straightforward and highly readable manner.
Gavin, Hank, Chris, thanks; I thought the idea was weird. I’ll take the rest of the book with an even bigger pinch of salt (i.e., treat it as fiction).
Good article by Raymond Bradley in the Guardian on Romney and the Republicans.
I’d be interested in the experts views on this paper:
Katsman, C. A., and G. J. van Oldenborgh (2011), Tracing the upper ocean’s “missing heat”, Geophys. Res. Lett., 38,
“The analysis reveals that an 8-yr period without upper ocean warming is not exceptional. It is explained by increased radiation to space (45%), largely as a result of El Niño variability on decadal timescales, and by increased ocean warming at larger depths (35%), partly due to a decrease in the strength of the Atlantic meridional overturning circulation. Recently-observed changes in these two large-scale modes of climate variability point to an upcoming resumption of the upward trend in upper ocean heat content.”
#7–
I note that, despite BOEMRE’s statement that this has nothing to do with the previous investigation, Agent May states that he intends to ask ‘followup’ questions WRT that previous interview. Seems it’s not such a separate question after all.
What will be the impact on sea level rise, if any, on water now impounded in earth in dams, etc.?
#13
The volume of fresh water in all rivers & lakes, if drained into the oceans, would raise sea levels by something like half a metre.
If by “dams, etc” you mean human-built reservoirs, the figure will be a lot smaller. There are some pretty big reservoirs in the world. The biggest (on the Zambezi River) would raise sea levels 0.5mm if it was full (and it quite often is). A quick Wikicalc yields a figure of 7.5mm rise for the top 46 reservoirs if full.
#13, Hunt Janin – Water now impounded in dams won’t have any effect on future sea level change. Chao et al. (2008)* estimate that sea level rise was reduced by about 3cm over the 20th Century, almost entirely after 1950, due to water being impounded in terrestrial reservoirs.
So if it was all released right now you would expect a quick 3cm rise.
The current rate of impoundment is something like 0.2mm/year, a fall from an average 0.55mm/yr since 1950. Again, that’s according to Chao et al. (2008). It’s possible this might pick up again due to large scale projects in developing countries (e.g. Three Gorges dam).
*Can’t find a non-paywall link but key figures are in this slideshow
Anyone here who is member of the APS, please help out by commenting on the “Physics Today” thread:
http://is.gd/s8ryff
It’s an essay by Steven Corneliussen global warming science and the media.
[Response: I’m a member, but it’s not worth commenting in response to the political drivel being posted there after the article you link to. On the subject of APS though, it is interesting to note that APS has recently added a new “topical group” on climate physics. This is important because these topical groups are not something that APS members can just add on a whim. For example, a colleague of mine had to get quite hard to get the Quantum Information topical group to happen in APS. That, at least, should presumably be a non-political subject. This attests to the seriousness with which most physicists — and not withstanding e.g. Dyson — take the physics of climate.–eric]
Here in NE Georgia, in the winter I heat with firewood and in the summer I survive the heat with a window A/C. I define spring and fall as the days when I need neither a fire or the A/C.
The number of spring/fall days is steadily diminishing, replaced by heating or cooling days. Climate change means fewer days when the temperature and weather are ‘just right’.
I think some metric of fair spring/fall days might be useful in explaining the full effect of human caused climate change to non-scientific people. Anyone without central HVAC could easily relate to this metric.
Among the intriguing items in the State of the Climate report was the observation that although recent SST rises have been fairly slight, and subject to the fluctuations from ENSO and other modifying influences, the temperature of lakes has been rising rather steeply, with a global average in the range of 0.4 C/decade. This is even faster than land surface temperatures in general, but I expect that the difference is due at least in part to the fact that the lake temperatures measurements have been nighttime measurements, and not subject to the diluting effects of insolation that has not been rising on average. The different rates of rise of SST and lake temperatures also presumably reflects the consequences of heat transfer to the deeper layers of the ocean.
@15 (et al.) There was a special issue of BioSciene on Global-Scale Environmental Effects of Hydrological Alterations in 2000 that addressed some of the impoundment volumes, etc. I believe that an earlier paper of Chao et al. was included. I don’t seem to be able to access the issue, but I recall that in addition to the effect of water impounded by dams, there is also the issue of water released to the surface from underground aquifers. Apparently impoundment has lowered sea level by about 3cm, but total aquifer release has raised sea level by nearly the same amount, so it has been in balance.
I will have to find the issue, however to confirm the numbers.
Real Climate readers might be interested in these two rather depressing related comment pieces on The Guardian website on climate change and environmental protection more generally, and the US Republican Party – the first is by Raymond S. Bradley…
http://www.guardian.co.uk/environment/2011/aug/03/global-warming-republicans
http://www.guardian.co.uk/commentisfree/cifamerica/2011/aug/03/epa-republicans-tea-party
Can anyone help me out here? I’m interested to know what the current state of the science is regarding the possibility of a runaway greenhouse effect if we burn the unconventional fossil fuels (tar sands, shale gas etc.) in addition to the remaining coal, oil and gas reserves.
In his book “Storms of my Grandchildren”, James Hansen says he thinks it’s a dead certainty, but David Archer in “Global Warming Understanding the Forecast” reckons there’s not enough fossil fuel carbon on Earth (although it’s not clear if he’s considered the unconventional fossil fuels).
Has any modelling been done on this scenario?
Here’s one for the hall of mirrors from Roy Spencer… yeah, really “ironic” Roy…
UAH Global Temperature Update July, 2011: +0.37 deg. C
August 1st, 2011
How ironic..a “global warming denier” reporting on warmer temperatures ;)
The global average lower tropospheric temperature anomaly for July, 2011
Gavin,
Please discuss Lake Powell and how wrong you were about it.
[Response: Sure. Please link to the quote where I said something wrong. – gavin]
@20. Chris, Kharecha and Hansen published on peak oil in 2008 http://pubs.giss.nasa.gov/abs/kh02000x.html
But I’m not sure if anyone has done a thorough analysis of conventional and unconventional fuels. But it would be nice to see what the predictions might be.
@20: Chris Colose wrote a short note on the runaway greenhouse effect at Skeptical Science with some cites. His understanding is that TSI at earth’s orbit is too small for a runaway to take hold. This reasoning rests on the idea that an earth with much more atmospheric water vapor would have a larger albedo than today’s earth.
CAPTCHA: front onionese. Hmm, time for dinner!
For Chris Snow: see the previous question and answer here:
https://www.realclimate.org/?comments_popup=6371#comment-199095
(found by putting the following string into the search box at the top right of this RC page, with the “site search” button selected; I skimmed the first few hits and gave you the one most concisely asking and answering that question)
“james+hansen”+”storms+of+my+grandchildren”+”dead+certainty”
The ReCaptcha AI oracle, in response, gave me these words:
fringes isideal
Re 25 Meow – I don’t think that’s the reason why. I remember the point was made that we don’t know exactly how cloud feedbacks behave when we get near a runaway water vapor situation.
I think the thing about a runaway water vapor situation is that CO2 wouldn’t have so much effect then (?). Of course it should take less TSI if you have more CO2 to get to the same temperature, but … well Chris Colose had some graphs that show how it would work (clouds excluded, as I recall) – maybe this was in hiw WordPress blog; I don’t remember.
PS a runaway water vapor situation doesn’t imply permanence. Turn the TSI down past some threshold and you have runaway water vapor feedback in the cooling direction. As opposed to (if I recall correctly – and I never read a whole lot about this) what had been thought about a snowball Earth with dry ice clouds in some conditions (but it turns out that dry ice clouds are effective greenhouse agents). But there isn’t a hysteresis in equilibria with runaway water vapor feedback, whereas there is (or is supposed to be) hysteresis in a the Snowball Earth – nonsnowball cycle, involving runaway ice albedo.
PS runaway feedback doesn’t take you to infinity – it just means that there is some range of conditions for which the climate has no stable equilibrium – it can’t come to rest there – climate sensitivity has to go past infinity at some point and could become negative (along an unstable equilbrium).
(Technically/hypothetically, you could have a climate sensitivity of x K/(W/m2) that is an average over tiny steps where the climate passes a bunch of tiny tipping points. For example, what if there were a set global temperature at which a given sufficiently small pocket of methane hydrate/clathrate destabilizes. You could then have little tiny runaways that wouldn’t be perceptible. But internal variability and the time it takes for each pocket to be released after the temperature threshold is crossed (?) may blur that out (PS on the small scale there are runaways all the time – I think cumulus convection has some of that).)
… that example of methane feedback is of course a non-Charney feedback.
I have read that grasses were a kind of productivity miracle. So I can easily imagine that the amount of soil carbon is higher with grasses than without. But I really doubt that is was sequestered in a time frame shorter than the silicate cycle equilibrium time, so I wouldn’t think it would be a factor.
Fred @18. Assuming measurements are made consistently over time, I wouldn’t expect much day/night variation on lake water temps. It is possible that changes in rivers, and shoreline vegetation along rivers might have a substantial impact. I don’t know what happen to water temp if a lake Eutropifies and gains a layer of floating lakeweed. My guess, lower evaporation, but possibly higher albedo.
Kevin@12
I speculate that finding nothing wrong with the 2005 observational note on polar bears, the investigators combed through the records (hard files, computers) they took from Monnett and found a new line of inquiry – impropriety of management on a project about polar bears. The likeliest explanation for the changing allegations is that the Department of the Interior is trying to suppress certain research into polar bears. There is precedent.
http://www.ofcomswindlecomplaint.net/emails/USAdministrationPolarBearMemo.pdf
… no hysteresis with runaway water vapor – of course that excludes things like biological feedbacks and abiotic CO2 feedback (if it got hot enough to decompose carbonate rocks, for example (?) (but then, upon cooling you’d presumably have some very rapid chemical weathering, so maybe …)), and H escape, etc.
Since the sea ice is getting a little long in the tooth, hope you don’t mind if I link my sea ice predictions here: http://aperfectstormcometh.blogspot.com/2011/08/current-state-of-arctic-sea-ice-arctic.html
Chris Snow, for a simple discussion of your question, see:
J.F. Kasting, T.P. Ackerman. “Climatic Consequences of Very High C02 Levels in Earth’s Early Atmosphere” Science 234: 1,383-1385 (1986)
Even at several tens of bars of CO2 you cannot generate a true runaway greenhouse, although you can surpass the modern day boiling point of 373 K. Even at constant 30% albedo this is true.
Meow,
The increase in albedo is a fundamental consequence of increased Rayleigh scattering in a moist atmosphere, and this acts as a negative feedback over the course of the moist greenhouse or runaway evolution (but as I said, CO2 does not generate a runaway greenhouse regardless, unless the net solar insolation is sufficiently high to prevent the planet from ever reaching radiative equilibrium over the timeframe of the oceans existence). The scattering is a bit less important around lower temperature stars, because their spectrums are red-shifted and thus the Rayeligh scattering is reduced (Rayleigh scattering favors shorter wavelengths, being inversely related to the fourth power of the wavelength).
The negative feedback is important though because another fate a planet can have, rather than transitioning into a true runaway, is to have a large quantity of ocean water lost by hydrogen escape even prior to a runaway. This occurs in a warm moist greenhouse even without a true runaway. If the albedo is fixed at 0.3, then the runaway can happen well before a significant fraction of the ocean is lost; however, if the albedo is free to increase with higher solar luminosity, then the oceans might slowly be lost to space, and enough time may pass to become depleted before a true runaway happens (see Abe et al 2011, Astrobiology).
Ed Davies Aug 2011 at 5:01 PM:
He does say, though, that the reduction of CO₂ in the atmosphere since the Eocene was due to the evolution and proliferation of grasses which I hadn’t heard before. Does this idea have any scientific basis?
My understanding is that grasses did not become abundant until between 8 and 5.5 mya. Before 15 mya there is very little fossil evidence. Course, as with many things paleontological and archeological these dates often get pushed back with new discoveries. Thus grass phytoliths (or what appears to be) have been found in dinosaur coprolites. But at present I doubt that grasses were abundant enough pre middle to late Miocene to affect CO2.
Caroline Stromberg is the relevant expert.
http://www.guardian.co.uk/environment/2011/jul/29/transcript-jeffrey-gleason
This investigators’ interview with Monnett co-author J. Gleason is even more thuggish than the one with Monnett. It sounds as though they actually think Gleason and Monnett faked their observations. One, Eric May, talks of some anonymous math guy that has told him that Monnett and Gleason have made egregious errors. Quite McCarthyist.
Be warned: very long transcript
Call the cops, someone’s impersonating Lysenko! Are Gleason and Monnett being hounded for thought crime, or for not having supernatural powers to foresee how others use and cite their work? That transcript’s unbelievable.
Professor Salby questions human v natural emission fingerprints. Seems to base this on measurements during Pinatubo and 98 el nino. ie warming causes soil emissions, isotope ratios are inconclusive?
http://judithcurry.com/2011/08/04/carbon-cycle-questions
[Response: Not yet listened to it, but there is nothing controversial in saying that ENSO and volcanoes cause responses in the carbon cycle – soil respiration, solubility etc. This is the biggest effect in the interannual variability of the CO2 rise (though it is irrelevant for the trend). – gavin]
Here’s some light relief from the social sciences (sorry if it’s already been discussed)
http://www.sciencedirect.com/science/article/pii/S095937801100104X
Cool dudes: The denial of climate change among conservative white males in the United States
► Conservative white males are more likely than other Americans to report climate change denial.
► Conservative white males who self-report understanding global warming very well are even more likely.
► Climate change denial is an example of identity-protective cognition.
► System-justifying tendencies lead to climate change denial.
► Climate change denial increased from 2001 to 2010.
Alistair@38: ” Climate change denial increased from 2001 to 2010.”
Even as evidence mounted rapidly. Ladies and gentlemen, it is inescapable: Conservative white males have a negatively-sloped learning curve.
Gavin,
Yeah, that’s why I thought I might have missed something. He seems to think he’s found something new, frequently saying the IPCC doesn’t know it, but without seeing what he is doing, I can’t make anything out of it.
#30–
What a great link! Thanks. I guess it’s not shocking anymore, but it should be.
Salby is claiming that most of the rise in CO2 is due to natural causes, not human emissions of fossil fuels. Uh huh.
[Response: If he is really claiming that, he is very wrong. I’ll try and listen to the podcast. – gavin]
#33–Chris, I think it might be useful to remind us what the criteria are for a “true runaway.”
Some of the scenarios that don’t qualify–significant loss of H2O, or T actually exceeding the boiling point, for example–are sufficiently dire in themselves, to say the least. Are any of these significantly more probable than the “true runaway” you tell us is impossible?
(I don’t want to overstress these–the threats to our food security and political stability under BAU are bad enough, and seem all too probable to be realized at this point. But I’m also a curious chap.)
On the grasses issue, the important question to me is whether they could, even theoretically, play an important role in carbon sequestration.
Listening some more to Salby’s address. He was asked about future temperature increases and projections of 4 degrees warming; if natural processes are driving temps, what was his projections – he said he didn’t do projections then said the following:
“Let me make one comment. What you’re really talking about is a 4 degree simulation, right? And that’s based on model runs that were done oh, in the late 90’s and early 2000’s for the last IPCC report. Now the conclusion of that was that the increased temperature that was observed, global temperature, in the 80’s and the 90’s was due to CO2. And that appears to have been a sucker-punch that the IPCC went for because no sooner – the ink hadn’t even dried on the report – that Mother Nature intervened and CO2 after the turn of the century continued to increase, in fact if anything, slightly faster, but global temperature didn’t. If anything, it decreased in the first decade of the 21st century. Now I’m confident the IPCC will come up with any explanation, in fact its already come up with several, but your extrapolation of 4 degrees presumes that you essentially have these model projections and that’s what they’re relying on and those model projections rely on “we know what CO2 is” since we’re responsible for CO2, since the human source is essentially what causes atmospheric CO2 to change, quote unquote, that we can extrapolate that. Well, doesn’t look like that works.”
It’s worse than I thought. No wonder Curry loves it, “If Salby’s analysis holds up, this could revolutionize AGW science.”
[Response: It’s on a par with “If I was a bird, I could fly!”. Both propositions are true but neither has any relevance to the real world. – gavin]
On Professor Salby,
His talk moves on from annual cycle and ENSO/volcano-induced fluctuations to extrapolations of temperature-CO2 connections back over the whole surface temperature record, concluding that temperature is driving CO2 changes:
“The correspondence to observed changes in CO2 on timescales of a couple of years, over the satellite era and, to the degree seen, even over the 20th Century makes it difficult not to conclude that sources involved in changes of CO2 on short timescales are also involved in its change on long timescales.”
“…future atmpospheric CO2 is only marginally predictable and in significant part not controllable. That means changes in human emission will not be tracked by changes of atmospheric CO2. They never have been.”
Though I think the main thing he’s excited about is his finding that changes in carbon isotopic ratios (12c/13c) correlate with natural fluctuations. He suggests this means the ratio changes cannot be used as a fingerprint for detecting changes in atmospheric CO2 by human emissions.
“Salby is claiming that most of the rise in CO2 is due to natural causes, not human emissions of fossil fuels. Uh huh.”
And Judith Curry is doing her best, “oh, this is a good talk, it sounds like it might be plausible, but I won’t make any statements that can be used against me when it turns out this is just ridiculous” impression (as far as I can tell, the only skeptic arguments she has been willing to disown is the “sky dragon” book).
I often use “the rise of CO2 might be natural” meme as a way to determine when someone lacks all ability to determine reality from fiction. Judith Curry has really jumped the shark…
-M
My attempt to quote Salby: “the popularized view is that CO2 is driving the bus… the reality is the opposite, climate is at the wheel and CO2 is at the back of the bus … the observed behavior reveals that much as we might like it … we can’t predict CO2” “emission from natural sources is integral to observed changes in CO2, but its contribution has not been recognized… therefore, future atmospheric CO2 is only marginally predictable and not controllable… future concentrations will not be tracked by changes in emissions of CO2, and they never have been”
He also drops random stuff about the medieval warm period and recent warming just being a rebound from the little ice age. Talk of “the science” stimulates his gag reflex, because “discourse gets to the truth”. “Excluding discourse isn’t science, its advocacy – so pick up your phone and call Canberra! … anyone who think the science of this complex system is settled, is in fantasia”.
I have to say that his talk stimulates my own gag reflex…
Salby: “I don’t believe that the CO2 in the ice cores is 50,000 year old CO2”
[Response: He’s right. Some of it is 800,000 years old. – gavin]
More Salby:
“The correspondence to observed changes of Co2 on timescales of a couple of years over the satellite era and to the degree seen even over the 20th century, makes it difficult not to conclude that sources involved in changes of Co2 on short timescales are also involved in its change on long timescales. The popularized view has been that CO2 is driving the bus and climate is along for the ride. The observed behavior reveals just the reverse. Climate is at the wheel, and to a significant degree, CO2 is at the back of the bus. Climate projections rely on an ability to predict CO2; it’s the one thing believed to be known, because of the presumption we control it. Namely, future atmospheric CO2 is determined entirely by human emission. That’s what is specified in climate models which then predict how climate will respond, in so-called climate scenarios.
The observed behavior reveals that, much as we might like it, the real world doesn’t work that way. Net emission includes a substantial contribution from natural sources; if you don’t control CO2, you can’t predict it, and if you can’t predict CO2, you can hardly predict how climate will respond.”
Does Salby mention any interaction with Colin Prentice in the podcast? They are at the same institution and Prentice seems to have solid credentials regarding CO2 (his bio states ”I was chief author of the chapter “Carbon cycle and atmospheric carbon dioxide” in the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).”) If I was Salby I’d want to run what I had past Prentice who would seem to be ideal for a critical appraisal of work on the atmospheric carbon dioxide.
http://web.science.mq.edu.au/intranet/directory/listing/person.htm?id=cprentic