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funglestrumpet at 06:58 AM on 9 July 2012Climate change is simple: We do something or we’re screwed
One of the main problems with trying to convince the general public of the danger is the concentration on whether GW is AGW or not. They get hung up on that point and because they refuse to believe that we are to blame, they think we we cannot supply the solution. This is an easy position to adopt because it means no effort on their part and it helps them believe what their favourite colmnist has said in their daily/Sunday paper. Not only that, but it is happening very slowly in terms of human lifetimes, which is a deception, I know. However, if an asteroid were headed our way, would we just put our head between our knees and kiss our backsides goodbye, or would we try and do something? Even the general public would support action despite the fact that it is clearly not an asteroid of our making and the possible actions are far more limited than the current climate changes ones are. Also, even the thickest of newspaper columnists would support taking action in such circumstances. Well, having said that, there are a couple I can think of and a peer of the realm who would say it is nothing to worry about in order to get attention. So what am I recommending? Well, stop debating the 'A' in AGW. Take it as read that we are to blame and leave those who disagree to carry on the debate elsewhere, away from the mainstream. Push quantifying the precise long-term temperature effects of cutting GHG emissions within possible sensitivities to GHG (obviously narrowing the sensitivity band as sensitivity becomes more clearly constrained) and start a serious debate on alternative energy supply. In particular, lend support to Thorium nuclear reactors, which I believe the USA and China are now collaborating on. We simply cannot afford to take the 'If its nuclear, it must be dangerous and must not be used' approach. Not using it is damn dangerous if Mr Roberts is anywhere near correct in his prognosis. It would not hurt to start compiling a list of persons who we believe are against taking action for reasons that do not have a valid, ie not debunked, scientific foundation. The time might well arise when the only way to get some action is to get people facing charges of crimes against humanity. That might even shut up a certain attention seeking peer. Finally, David Roberts is correct when he says that we do not need to know the details in order to act. We know the science of the greenhouse effect and we know that we are pumping GHGs into the atmosphere. The dangers are clear and so too is the necessary action. -
llosmith at 06:43 AM on 9 July 2012Climate change is simple: We do something or we’re screwed
Composer99 @13: The link in 10 should read LINKModerator Response: [RH] Fixed link that was breaking page formatting. -
Kevin C at 06:15 AM on 9 July 2012Climate change is simple: We do something or we’re screwed
Clyde: Have you read the IPCC SREX, rather than second hand reports of its contents? The material on Disaster losses is quite concerning, especially given the current fragility of the global economy. -
curiousd at 05:49 AM on 9 July 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
Maybe I now know enough to make a slight correction to something someone told me(not sure who the someone was) here in one of many helpful answers to my questions. The recent pre print Hansen and Sato made available here states they determine a "fast feedback" response which includes CO2, water vapor feedback, sea ice, clouds, aerosols. The warming up of the entire ocean, (like the melting of Antarctica and Greenland)is longer term, on order of "100s of years" Someone - I think incorrectly - confused fast feedback response, which is a portion of the equilibrium response, with the "transient response". "Transient response" means you run a simulation to include continual addition of CO2, which, unfortunately, is what "really happens". Also, the warming up of the ocean is not included in either the fast feedback response or the transient response because it can take 1000 years for the ocean temperature to equilibriate with the surface?? Do I now have this right? -
Alexandre at 04:53 AM on 9 July 2012Roy's Risky Regression
Tom Curtis at 08:22 AM on 8 July, 2012 That's a great summary! Do you have any link with that information so I can keep it as a reference? -
Clyde at 04:30 AM on 9 July 2012Climate change is simple: We do something or we’re screwed
Paul Magnus 11 Even at the current rate of extreme events societies globally are going to collapse. We are just arriving at 1c. Not even there yet. The IPCC SREX report disagrees with your position. No strong evidence to support GW is causing "extreme" weather events. Read more here. -
ranyl at 04:08 AM on 9 July 2012Climate change is simple: We do something or we’re screwed
How long is the lag in the system? For El Nino it seems about 6 months, for the sun it seems about 2 years, the Argus current takes 4-35 years to reach the North Atlantic, but what is the lag between CO2 forcing and heat realisation? Say it is only 20years for 80% warming like Hansen's suggests, then considering the rise in CO2 since 1990, 350ppm to 393ppm, or 35% or all humankind's CO2 emissions in the last 20 years, and the last 10 years has had low low sunspot activity, been shaded by the Asia smog and S02, with nitrogen fertilizes effects rducing warming further due to ozone formations from NO destroying methane and predominantly La Nina conditions and maybe things are sobering. And the man in the video never mention so much stuff as well, like waste, pollution, overexploitation, invasive alien's, methane re-rise, forest fires, the albedo accelerator that is kicking in terms of ice sheet surface, snow melt and sea ice loss. These weathee extremes are clearly serious and the last time USA hada major drought the whole economny sort of stopped, and let's face it the world's ecomony isn't that robust at present. How to do we get to 350ppm? And given paleo data that isn't that safe! Make the impossible possible he says? That would take a transformative scale change to all levels of society across the world. That seems impossible, unless everyone takes on board that environmental change is now and serious and is soemthign to do everything about otherwise the legacy we leave is civilization chaos which in past times has never been pretty. Adaptation is also needed to protct food and water security agaisnt the times. So a reasonable challenge, so like the man in the video says why isn't everyone making their primary drive to restore to 350ppm and to prepare for the changes to come? -
dagold at 03:29 AM on 9 July 2012Climate change is simple: We do something or we’re screwed
I watched Robert's talk with interest. We clearly need to build a 'critical mass' of support to pressure the extraordinarily reluctant politicians to even begin addressing the problem. The 'educational' approach Roberts takes is important. But I am wondering if old fashioned story telling approaches might also be key. I am crafting a potential TED video that combines my personal health story- 2 serious diseases, multiple hospitalizations and surgeries- culiminating in a liver donor liver transplant from my brother. It has it all!- my initial 7 year denial of the scientists and the consequences (ambulance, hospitals, surgeries), systems being pushed out of equilibrium, complete with graphs of upward sloping liver function tests ('Keeling Curves!'), tipping points crossed, and, finally, maturing to the stage of facing the information, making the hard choices-asking a family member to donate over half their liver- and (for me) coming out to the other side...all in analogy to climate change. (please see 'My Personal Story' on www.itsphysics.org for more of the story) Coming soon to a theater near you. -
Composer99 at 01:20 AM on 9 July 2012Climate change is simple: We do something or we’re screwed
Whomever can fix it: Tom Curtis' link @10 is broken.Moderator Response: TC: Fixed, and thanks for spotting it. -
Rob Painting at 18:49 PM on 8 July 2012It's the sun
Icyhot - in addition to Tom's comments, the beauty of the mainstream climate science view of atmospheric CO2 as Earth's thermostat - is that it has explanatory power. Turn up the CO2 and the Earth gets warmer, turn it down and the Earth cools. Aside from maybe one outstanding complication, the Miocene, this relationship holds true for hundreds of millions of years back in time. There are, of course, other control knobs on Earth's climate - such as the Milankovitch Cycles, but CO2 is very clearly the Big Kahuna. If, as you suggest, the Earth is moving closer to the sun, why then was it much warmer on Earth further back in time? -
villabolo at 15:57 PM on 8 July 2012Nil Illegitimi Carborundum
Giordano Hernandez I would have gone postal if all that vitriol were directed at me. Hang in there. -
Paul Magnus at 15:45 PM on 8 July 2012Climate change is simple: We do something or we’re screwed
Here is a good article on current rate of extreme events http://thinkprogress.org/climate/2012/07/07/511194/what-is-causing-the-climate-to-unravel/ -
Paul Magnus at 15:07 PM on 8 July 2012The GLOBAL global warming signal
Here we have the graph of ghg well, co2 emissions.( I am sure that total ghg emissions is going to be much steeper) we can see that there is a marked up tick around 1945. http://thinkprogress.org/wp-content/uploads/2012/07/chart751.png I think that that might correlate quite closely to the the up tick in sea level rise rate acceleration, The next surge will be soon and must be related to the albedo effect in the article and it's effect on Greenland ice sheets. What seems likely in the south is massive collapse and disintegration. So the ice going tthere will result in a jump in sea level rise rathere than a rapid increase in rate, -
Stephen Baines at 15:04 PM on 8 July 2012Murry Salby's Correlation Conundrum
DM. We're on the same page. The only rather academic difference is that I think conservation of mass is not a sufficient condition to argue that humans are the sole cause of the current increase in CO2. You also have to assume that removal processes do not distinguish between anthro and natural CO2 in the atmosphere. That assumption is implicit in the equations as you have presented them. Alternatively, one could characterize variations in atmospheric CO2 as a system of two distinct budget equations that track the anthropogenic CO2 and the natural CO2 in the atmosphere separately. One could then set the loss term for the anthro CO2 into one natural reservoir equal to anthropogenic emissions. In the other equation another natural reservoir could contribute CO2 to atmsophere while not interacting with the reservoir that serves as a sink for anthro CO2. Of course, in doing all that, one would be contradicting physical reality. Removal processes cannot distinguish between anthro and natural CO2 any more than my bank can discriminate between the dollars deposited as salary and those deposited from tax refunds once they are in my checking account. None of the evidence we have in hand suggests that atmospheric CO2 acts as anything other than single reservoir of well mixed gas with respect to loss processes. Still, I can't tell you how many people I meet are prone to think human derived CO2 must behave differently -- it's ingrained in their psyche. -
Marco at 15:01 PM on 8 July 2012Murry Salby's Correlation Conundrum
Dikran, I fully agree that the natural environment is still resulting in a net uptake. I was merely pointing out that some may still claim, even after they accept the "net" versus "absolute", that there is a net natural emitter that is larger than the anthropogenic contribution. Better have arguments for that available, or they have another few hours to spread that new confusion! -
Paul Magnus at 14:55 PM on 8 July 2012Climate change is simple: We do something or we’re screwed
@9 SW, I think we don't need much science to prove that 2c is way beyond the carrying capacity for global civilization. Even at the current rate of extreme events societies globally are going to collapse. We are just arriving at 1c. Not even there yet. Do you really think that another 1c is not going to be absolute mayhem? Then also add the accelerating sea level. Tusha. No need to even then address a 4c scenario. -
Tom Curtis at 13:55 PM on 8 July 2012It's the sun
Icyhot @976: If the Earth's orbit decayed by one inch per annum since 1750, it would be 6.65 meters closer to the Sun, on average than in 1750. Incoming solar radiation varies with the inverse square of distance. So, a decay of 6.65 meters in the approx 150 billion meters radius of the Earth's orbit would result in a 0.00000001 increase incoming solar radiation, or a forcing of 0.000000024 W/m^2. This is compared to the approx 1.8 W/m^2 forcing from increased CO2 over the same period. Therefore such a decay in the Earth's orbit would not have a detectable effect the Earth's climate (and probably would not be detectable to begin with). However, that is beside the point. There is, SFAIK, no evidence that the Earth's orbit is decaying. Indeed, if anything the solar tide on the Earth would cause the Earth's orbital distance to increase, just as the Lunar tide result in the measured increase in distance to the moon. The increase in distance, however, is very small so that there is no reason to think the Earth's orbit will increase or decay significantly at any time in the past or future several million years. -
Tom Curtis at 13:04 PM on 8 July 2012Climate change is simple: We do something or we’re screwed
Sceptical Wombat, the special report by the WGBU, Solving the Climate Dilemma: The budget approach, directly addresses the second point, and contains relevant discussion on the other two points. -
IcyHot at 13:02 PM on 8 July 2012It's the sun
Hello Ladies and Gentlemen. What is the truth to the assertion/hypothesis that the Earth's orbit is degrading by approximately 1 inch per year. I am at a loss for the location of the publication that provided this information. I do find it curious. Have any of you interested parties read about or researched this hypothesis? Although I find myself wondering about the validity of the assertion/hypothesis, it would seem to be a logical,if not complete cause of warming. What would the effects of increased or decreased solar flare activity have on the Earth with this hypothesis. An interesting point for further investigation. -
Sceptical Wombat at 12:29 PM on 8 July 2012Climate change is simple: We do something or we’re screwed
One of the problems with cross postings like this is that SKS's usual policy of justifying everything by references to the peer reviewed literature goes by the board. This is a pity and I think detracts from the quality of your site. Could anyone give me some references to justify the following: 2 degrees Celsius would be unbearable We have to start reducing emissions in 5 to 10 years We are on target to reach 4 degrees by the end of the century I'm not saying that the evidence is not there - I would like to be able to refer to it. -
newcrusader at 11:04 AM on 8 July 2012Climate change is simple: We do something or we’re screwed
The heat across most of the eastern US (east of the Rockies to the Atlantic coast) has been historic. I know so many people that 'believe in global warming' but know so little about what is really happening. I have been looked at as 'alarmist' 'obsessive' discussing to others about the dire danger we are in. Now I am gloating - my attitude is simply...'I told you so' 'you snickered' at me and thought I was a 'radical environmentalist' trying to destroy the 'American way of life'. With C02 levels this high ( though this is in the pipeline) We are seeing Carbon in the atmosphere from 1990- or before before when C02 had passed 350ppm. As the decade progresses that warming in the pipeline will rear its ugly head. Is the climate beginning to unravel quicker then many thought? Perhaps- but there is really little time left to stop the worst outcomes that climate change will bring to us. -
Tom Curtis at 08:46 AM on 8 July 2012Climate change is simple: We do something or we’re screwed
Sphaerica @2, uncertainty is often misinterpreted. Fake "skeptics" think that if the science is uncertain, the future will be less bad than scientists predict; but of course it may be much worse. On the other hand, we are only almost "out of time" if the scientist's predictions are accurate and not overestimating the problem. While the low side uncertainty exists, it is always too soon to say too late. (And while the high side uncertainty exists, it is never correct to say that we have time to spare.) This is also on top of Chris G @1, with whom I agree. One point that needs to be mentioned, however, is too late for what? Assuming scientists central projections are accurate: We are already too late to avoid a collision (zero damage from climate change), and passed that point around 1990. We are not yet too late to avoid the collision writing of our car, but if we don't brake now a our car is toast. If we don't mind the radiator being concentened into the rear fender, we still have time to spare. In this situation, policy settings around the world are for steady acceleration. -
sol6966 at 08:45 AM on 8 July 2012Roy's Risky Regression
Rob, Stephen & Tom Thanks Sol -
Tom Curtis at 08:22 AM on 8 July 2012Roy's Risky Regression
sol @18: Declining C14 ratio indicates old, hence fossil fuel or volcanic (ie, not oceanic outgasing or deforestation; Declining C13 ration indicates organic, hence not volcanic; Declining O2 concentration indicate combustion, hence not volcanic; Measured CO2 emissions from all (surface and beneath the sea) volcanoes are 1 hundredth of antrhopogenic CO2 emissions; hence not volcanic; Partial pressure of CO2 in the ocean is increasing, hence not oceanic outgassing; Known changes in biomass too small by a factor of 10, hence not deforestation; and as the icing on the cake, The start of the growth in CO2 concentration coincides with the start of the industrial revolution, hence anthropogenic; and Increase in CO2 concentration over the long term almost exactly correlates (corr.: 0.998; R^2: 0.997) with cumulative anthropogenic emissions:
(Source)
and finally,
Annual CO2 concentration growth is less than Annual CO2 emissions, hence anthropogenic.
In all, six independent lines of evidence preclude a volcanic source for the increased CO2; five independent lines of evidence preclude a source from the non-fossil biosphere; and three lines of evidence are only consistent with an anthropogenic source.
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DSL at 08:22 AM on 8 July 2012Climate change is simple: We do something or we’re screwed
If George Monbiot (or, rather, Leonardo Maugeri) is right, the worst may have gotten much worse: http://www.monbiot.com/2012/07/02/false-summit/. -
Chris G at 06:57 AM on 8 July 2012Climate change is simple: We do something or we’re screwed
...nothing to be done about it anyway, ... as though we are already committed to the worst that could possibly happen, which I would like to think is not the case. -
Chris G at 06:53 AM on 8 July 2012Climate change is simple: We do something or we’re screwed
Hi Sphaerica, If you put it that way, OK. It bothers me when people say that there is nothing to be done about it anyway, and the 'out of time' concept can be used (abused?) as leverage by them. I do not wish to give them any leverage. -
Dikran Marsupial at 06:34 AM on 8 July 2012Murry Salby's Correlation Conundrum
Stephen Baines wrote "Strictly speaking, I'm sure one could construct a mathematical budget that could reconcile a natural source with a CO2 increase less than human emissions." No, this is not possible, without contravening conservation of mass. The increase cannot be less than human emissions without the natural environment as a whole taking in more CO2 than it emits. It is important not to confuse the cause of the rise with the source of the molecules actually in the atmosphere (yes, I know that sounds odd). There are vast exchange fluxes that swap CO2 from the oceans/terrestrial biosphere and atmosphere each year, so anthropogenic CO2 only lasts on average about 4-5years in the atmosphere. However the exchange is a straight swap, so it doesn't have any effect on the amount of CO2 in the atmosphere. In my paper I have a simulation of a very basic model of the carbon cycle that shows that even though the rise is 100% anthropogenic, only a small percentage of the excess in the atmosphere consists of CO2 of directly anthropogenic origin; this is a result of the exchange fluxes. -
Dikran Marsupial at 06:29 AM on 8 July 2012Murry Salby's Correlation Conundrum
@Marco, even if some part of the natural environment had become a stronger emitter of CO2, and some other part a greater CO2 sink, the mass balance analysis still tells us that the natural environment is a net carbon sink, in which case how can it be causing the rise while taking more CO2 out of the atmosphere than it puts in? I think part of the problem is that the mass balance argument is so simple some find it hard to accept that it proves unequivocally that the rise is anthropogenic, but it does. -
Dikran Marsupial at 06:26 AM on 8 July 2012Murry Salby's Correlation Conundrum
@oarobin The mass balance argument is sufficient as it proves that natural emissions must be smaller than natural uptake, and hence the net action of the natural environment is opposing the rise in atmospheric CO2. "that is another possibility is that all Ea is taken up by the environment which also emits excess carbon equal to C'." There is no physical mechanism by which the natural environment could preferentially take up all of anthropogenic emissions. However, even if it could, in order to have conservation of mass natural emissions would still have to be less than natural uptake, in order for the observed rise to be less than anthropogenic emissions. Bart has frequently tried to dismiss the mass balance argument as being static rather than dynamic, however this simply isn't true. Figure 1 is the results of the mass balance argument, not that the net environmental sink has inter-annual variability and is gradually strengthening over time. One wonders how this is possible in a static analysis. Essentially introducing a time index variable is an attempt at obfuscation. The key result is that conservation of mass tells us that: En - Un = C' - Ea This is true for any time, i.e. En(t) - Un(t) = C'(t) - Ea(t) so if at any time the right hand side is negative, we know the left hand side is as well. You don't need a more complicated model, the only reason Bart intrduces it is to avoid discussion of the mass balance argument. -
Dikran Marsupial at 06:09 AM on 8 July 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
@angusmac As IIRC I mentioned in an earlier post, it is unreasonable to specify any percentage as being a reasonable error range without an anlysis of the physics of the problem. In this case, even if the model physics were perfect and the model had inifinite spatial and temporal resolution, it would only be reasonable to expect the projection to be within the range of effects that can arise due to internal climate variability (a.k.a. weather noise, unforced response etc.). The best estimate we have of this is the spread of the model runs, if the observations fall within the spread of the model runs then the model is as accurate as it can claim to be. As I said, the spread of Hansen's model runs, had he the computational power at the time to have run them, is unlikely to be smaller than those of the current generation of models. At the end of the day, given the state of knowledge available at the time, Hansen's projections do a pretty good job. If you disagree, and want to perform a solid scientific/statistical evaluation of the model, then download the code, adjust for the differences in the estimated and observed forcings etc., and generate some model runs and see if the observations lie within the spread. As I said, rules of thumb are all very well, but they are no substitute for getting to grips with the physics. -
Bob Lacatena at 05:58 AM on 8 July 2012Climate change is simple: We do something or we’re screwed
Chris G, In your analogy, there is a point, however gray and fuzzy it may be, at which the electric shock becomes unbearable, a point at which you would never, ever consider putting up with that much pain. That is the point Dave Roberts is talking about. That is what he means by "out of time." If we wait too much longer before taking action, the price and the suffering will be way, way beyond anything we would ever choose to endure. -
Chris G at 05:18 AM on 8 July 2012Climate change is simple: We do something or we’re screwed
I have a slight objection to the phrasing of the problem as being out of time or not. As long as we don't hit a tipping point which would make any effort on our part moot, the damages are not binary, they are analog. Or, put another way, it is not like tossing a coin, you win or you lose; it is more like electric shock. A very little hurts a little, the more you apply, the more it hurts, and there is no real upper limit to the pain, until you are dead. It is never a bad idea to slow down the car even if you think you may crash anyway. I do not think that Dave Roberts says we are out of time. Out of time would imply that we are already committed to hitting a tipping point that would overwhelm anything we might try to do, and he specifically says that he doesn't think that is very likely, at present. An interesting talk. Not much new there, but he has reached most of the same conclusions I have, but then, we all have to watch out for our own confirmation biases. -
Stephen Baines at 03:55 AM on 8 July 2012Nil Illegitimi Carborundum
Stephen Baines, USA -
Stephen Baines at 03:51 AM on 8 July 2012Roy's Risky Regression
Exactamundo. -
Stephen Baines at 03:42 AM on 8 July 2012Murry Salby's Correlation Conundrum
Oarabin Strictly speaking, I'm sure one could construct a mathematical budget that could reconcile a natural source with a CO2 increase less than human emissions. But to be relevant such a budget should be realistic from a biophysical and chemical point of view, and it must be consistent with data in hand on reservoir sizes, stable isotopes etc. To summarize then, for a natural source to be responsible for the recent CO2 increase 1) The anthropogenic CO2 to be taken up almost exclusively by natural sinks, while the natural CO2 remains in the atmosphere. I can think of no mechanism that could cause that to be true. 2) The source must be terrestrial (because surface acidification of the ocean indicates net uptake of atmsopheric CO2 while C isotopes and atmspheric oxygen trends are inconsistent with oceanic outgassing) 3) The net loss from this terrestrial source must amount to >40% of living terrestrial biomass (!!!) or >15% of soil organic carbon. It would have to be much larger as there should be some compensatory uptake by other reservoirs, and release from the mystery reservoir does not seem to be reaching some limit. 4) That source must look like very old plant carbon interms of isotopic composition. 5) Atmospheric oxygen must be consumed in rough proportion to release. That's a pretty hard list of requirements to satisfy, and I don't think you even can get past #1, which is why the budget approach has power. Then again, why look for an alternative explanation when we already have an explanation in hand that is consistent with everything we know about the carbon cycle? -
sol6966 at 02:54 AM on 8 July 2012Roy's Risky Regression
Stephen Baines @ 16 Thanks. So a relative decrease in C14 = old and a relative increase in C12 = plant Therefore, if the rise were due to volcanoes then C14 would still decline but C12 would stay relatively constant. Sorry for dragging this off-topic -
philipm at 02:43 AM on 8 July 2012Nil Illegitimi Carborundum
Another thought: why are the scumbags' emails "redacted"? They choose to make threatening statements using a non-secure channel. A fair number look to me to have potential for criminal prosecution. They deserve to be exposed. -
philipm at 02:35 AM on 8 July 2012Nil Illegitimi Carborundum
Happy to add my name: Philip Machanick, South Africa You may also want to sign my pro-scientist petition. -
Stephen Baines at 02:29 AM on 8 July 2012Roy's Risky Regression
DM @8 Ugg... Well, that Spencer comment is a classic case of poisoning the well, and does not reflect well on his intentions. You do not judge the merit of an argument by its tone, but its content and you cannot assess content by ignoring everything else we know about a suject. The "strength and vehemence" of the objections to his ideas largely reflects frustration at Spencers unwillingness to engage in rational discourse through peer reviewed channels. To his credit, he did not dismiss "well-reasoned" objections as politically motivated. I think your approach here and in several posts on this issue are safe by his standards! The Salby comment is fine as it is. Of course, by ignoring evidence accumulated over a century of research on the issue, he is essentially doing exactly what he warns against. How is holding your hands over your ears less distructive to discourse than telling someone to shutup? The fact that he has not responded to you also hoists him by his petard. -
Stephen Baines at 02:10 AM on 8 July 2012Roy's Risky Regression
Sol, The volcanic carbon and the fossil plant carbon are both depleted in C14, because the carbon is so old the radioactive C14 has decayed. Plant carbon is depleted in a different isotope, C-13, for a different reason, because plants accumulate C-12 preferentially over the heavier C-13 during photosynthesis. During the recent increase in atmospheric CO2, C14:C12 and C13:C12 ratios have both declined. Together, these two patterns indicate that the CO2 added to the atmosphere is 1) old and 2) derived from plants. Thus, the source must be fossil plant material, ie fossil fuels. The increases also agree with what is expected based on known emission rates and natural exchange rates, although the C-14 has been complicated by addition atomic bomb testing in the 60s. You are correct that the observation that O2 has declined in proportion to increasing CO2 is one more line of evidence that oxidation of organic material. There are so many consistent lines of evidence that it still beggars belief that people question the anthropogenic source of the recent CO2 increase. -
M.L. at 00:28 AM on 8 July 2012Nil Illegitimi Carborundum
You are a hero and vital to the continued security, if not the existence, of humankind and countless other species. Thank you. M.L., Canada -
sol6966 at 00:24 AM on 8 July 2012Roy's Risky Regression
Rob Painting @ 13 Thanks for your comment. Why would carbon from volcanic activity be less depleted of c14 than fossil fuel carbon? -
jimnaylor at 22:59 PM on 7 July 2012Nil Illegitimi Carborundum
Jim Naylor, USA -
Tom Curtis at 22:33 PM on 7 July 2012Murry Salby's Correlation Conundrum
oarabin @20: Let Un(t+1)= En(t)+3.5*Ea; Let En(t+1)=En(t)+3*Ea This satisfies the conditions of the argument that you describe. However, even in this case atmospheric CO2 concentrations would decrease if it where not for anthropogenic emissions. Ergo, this argument as framed does not rebut mass balance argument. However, if we introduce the factor that the increase in Un is caused by Ea, then absent the increase in En, anthropogenic emissions would indirectly cause a reduction of atmospheric CO2. Alternatively, and more probably, increase in C' causes an increase in Un which drives C' towards an equilibrium value. A sufficiently large and rapid response in Un could have restricted C' to an increase one years anthropogenic emissions. In this case (only), a concurrent and coincidental rapid increase in En could be the cause of the increase in atmospheric CO2. However, an increase in concentration from natural sources would drive an increase Un as well. Therefore the increase in En must be orders of magnitude larger than the increase in En to overwhelm the tendency to return to equilibrium. As antrhopogenic emissions are 100 times larger than natural emissions (excluding equilibrium exchanges), that means the rate of increase of natural emissions must be many orders of magnitude larger than their initial (and measured) rates. In other words, the mass balance argument is an inductive argument (its conclusion could be false with true premises); but the probability of its leading to a false conclusion is very remote. What is more, if it where invalid the consequences would be immediately obvious as noted by Marco. Quite apart from that, as has been pointed out other measurements have also confirmed the mass balance argument. -
bill4344 at 19:57 PM on 7 July 2012Roy's Risky Regression
Alexandre @ 2. Further to Dana's reply, the connoisseur of 'how far will they' go may also enjoy Tim Curtin's '[CO2 and H2O] do not [trap heat] because they cannot, given the 2nd Law. Remember that photons are largely a fiction as they have no mass.' Well, that would also explain how they've escaped the Higgs Boson! Here, (comments page 6), June 23, 12.42pm (post NG's takeover ScienceBlogs no longer features permalinks, sadly.) -
CBDunkerson at 19:49 PM on 7 July 2012Murry Salby's Correlation Conundrum
Oarobin & Marco, it really does not matter whether natural emissions and/or uptake are changing over time. That has no impact on the mass balance argument. We know that the rate at which humans are releasing fossil fuel carbon into the atmosphere is GREATER than the rate that carbon is accumulating in the atmosphere. Pick a year for the past few decades... there is sufficient data to calculate both of those values and show that human emissions have consistently exceeded atmospheric accumulations. Ergo, we also know that for that time period natural carbon sequestration has exceeded natural carbon emission and the atmospheric increase has been due to human emissions. Could the accumulation of human emissions in the atmosphere be causing the natural absorption and emission values to change? Absolutely. In fact, they definitely are changing. That just doesn't impact the mass balance argument at all. If the mass of human emissions is greater than the mass of atmospheric accumulation then human emissions ARE responsible for the atmospheric accumulation. The only options for 'defeating' the mass balance argument are; 1 - Disprove (or deny) the data showing that humans have been emitting CO2 at a greater rate than the atmosphere has been accumulating it for decades. 2 - Invalidate the law of conservation of mass. 3 - Introduce a new variable... e.g. carbon emissions from aliens. -
Marco at 19:14 PM on 7 July 2012Murry Salby's Correlation Conundrum
Rob and oarobin - in principle it is possible that one natural source has increased its emissions, whereas another has increased its uptake. For example, it is possible that the oceans are a net emitter with this net emission being larger than the anthropogenic emissions. However, that requires an ENORMOUS net uptake from another source, such as the biosphere. We know, however, that this is not plausible: the biosphere would have had to take up hundreds of gigatons of CO2 in the last decade alone. Moreover, we should not have seen a decrease in ocean pH in that case. But how about the reverse situation? That is, the biosphere being the net emitter, larger than that of the anthropogenic emissions? It is possible that the oceans take up this much CO2. However, the biosphere would have had to decrease with several hundreds of gigatons of CO2 in the last decade alone. This should have been directly visible. Now, imagine that this net loss must have been sustained over several decades (at the very, very least since 1959): we must have observed such an enormous decrease in the biosphere (hundreds of gigatons of C, thousands of gigatons of CO2). -
Rob Painting at 18:48 PM on 7 July 2012Roy's Risky Regression
Sol - the 3 carbon isotope ratios tell us that the increase in atmospheric CO2 is due to fossil fuel emissions. Carbon 14 forms in the upper atmosphere due to bombardment by cosmic rays (high energy particles from distant, but powerful, stars). This isotope is radioactive so it emits and loses energy over time. Its half-life is about 6000 years. Fossil fuels are depleted in Carbon 14 because they formed over hundreds of millions of years underground. Burn fossil fuels and we should see a decline in the ratio of Carbon 14 in the atmosphere relative to the two other isotopes. This is what is observed. Plants favour the lighter Carbon 12 over Carbon 13 because it is energetically more efficient. Fossil fuels are made of dead organic matter, therefore a fossil fuel source should see an increase in the relative concentration of Carbon 12. Once again, this is observed. So that discounts volcanoes as a source. And most critically of all we actually have detailed inventories of the coal, oil, natural gas etc that we are burning and these match the observations too. -
Rob Painting at 18:30 PM on 7 July 2012Murry Salby's Correlation Conundrum
oarobin - so in essence that claim is that some mysterious mechanism absorbs all of human carbon emissions, and that natural emissions increase to compensate for this. I am curious as to how this mystery mechanism is able to identify and target only human carbon emissions, and more importantly, why?
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