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Tom Curtis at 12:06 PM on 9 July 2015Explainer: the models that help us predict climate change
Hick'ry, try here for a starter. The page explicitly explains CO2 lasers, so does not cover some of the important factors for atmospheric absorption, but covers the basics reasonably well. You will notice that of the three types of modes that allow CO2 to absorb or emit IR radiation, the most important in the atmosphere is the bending mode, that absorbs or emits radiation at 667 cm^-1.
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Tom Curtis at 11:52 AM on 9 July 20152015 SkS Weekly Digest #27
Michael Fitzgerald @10, the slope of the Stefan-Boltzmann function at 250 W/m^2 is 0.258 Degrees K per Watt/m^2. At 400 it is 0.181 Degrees K per Watt/m^2. Neither is λ. That is because λ includes not only the planck response (ie, the slope of the Stefan-Boltzmann function) but also the further effect of any feedbacks. These increase the temperature response by 1.5 to 4.5 times the base response, ie, increase λ to 0.39 to 1.16 K/W/m^2.
I used the value of the Planck responce at 250 W/m^2 for that calculation because forcings are calculated for the TOA (ie, near to the effective altitude of radiation to space where the temperature calculation does not include the greenhouse effect), and hence λ is defined for that altitude as well. We could calculate a climate sensitivity parameter for surface forcings but the values would differ from the more conventional calculation for the TOA.
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MIchael Fitzgerald at 11:07 AM on 9 July 20152015 SkS Weekly Digest #27
OK. But isn't ΔT/ΔF (λ) just the slope of the Stefan-Boltzmann relation at 255K? In your calculation, you added 150 W/m^2 of extra warming power to the 238 W/m^2 of solar power (255K). That being said, increasing 238 W/m^2 to 239 W/m^2 should only result in another 0.63 W/m^2 to the 150 W/m^2 of warming resulting in a surface temperature of 287.9 K which is 0.3C warmer, or 0.3C per W/m^2 and not 0.75C per W/m^2. Where does the extra 0.45C come from?
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Tom Curtis at 11:06 AM on 9 July 20152015 SkS Weekly Digest #27
MA Rodger @7, you appear to have taken the derivative of formula (1) @8, which gives (if I have done this correctly):
(3) dT/dF = 1/σ*0.25*(j*/σ)^-0.75
However, you express the relationship between σ and j* as a product rather than a ratio, and I am not sure how you derive the value 65 in your concluding sum which eliminates σ from the calculation. Could you clarrify.
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Hick'ry at 10:21 AM on 9 July 2015Explainer: the models that help us predict climate change
Can you point at a presentation on the CO2 infrared absorption process? Many thanks.
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L. Hamilton at 09:10 AM on 9 July 2015Climate denial linked to conspiratorial thinking in new study
But getting back to "Recurrent fury" ... it occurs to me that the "do you trust scientists for information about X?" questions we've been asking on surveys basically tap into the obverse. Who trusts scientists? People *not* inclined toward conspiracy thinking.
Moderator Response:Duplicate image removed.
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Tom Curtis at 08:57 AM on 9 July 2015Climate denial linked to conspiratorial thinking in new study
Michael Fitzgerald, I have responded to your questions here.
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Tom Curtis at 08:56 AM on 9 July 20152015 SkS Weekly Digest #27
Michael Fitzgerald from elsewhere asks "...what is the sensitivity as a function of temperature?"
The simplest response is that the sensivitity function is given by the Stephan-Boltzmann law, j* = σ * T4, where j* is the power in Watts per meter squared, σ is the Stefan Boltzmann constant, and T is the temperature, in this case the Global Mean Surface Temperature (GMST).
Transforming the equation to a formula for temperature, we have:
1) GMST = (j*/σ)^0.25
j* in turn is the sum of the effect of all forcings and all feedbacks. That is, it is the globally averaged insolation, times (1 - albedo) plus the total greenhouse effect. Putting those numbers in we have
GMST = ((0.25 * 1360 * (1 - 0.3) + 150)/σ)^0.25 = 287.6 K, or 14.46 C
Very clearly this is an approximation as I have ignored emissivity, which raises the temperature in degrees K by a degree or so (as the Earth is not a perfect black body at IR temperatures), and the uneven distribution of surface temperatures (which would lower it by approximately the same amount), but it is a pretty good estimate, as can be seen by comparison with the estimates from observations (14 C from HadCRUT4, 13.4 from GISSTEMP) and from models (CMIP5 mean of 13.7 C) which take far more detail into account (right section of graphs).
Using all known energy sources for the Earth's surface and the current total greenhouse effect (rather than that from the 1980's as used in the calculation above), the estimate absolute temperature using this formula comes out at 289.65 K, but again given the approximations involved that is quite good.
From your discussion with MA Rodger, it appears that you may be confusing the result of this equation with the Climate Sensitivity Factor, λ, which is defined such that the temperature response to a given forcing (ie, not including feedbacks) that perturbs the Earth's temperature from a prior quasi-equilibrium is:
2) ΔT = λ * ΔF
where ΔT is the change in temperature, λ is the climate sensitivity factor (having units of degrees C per W/m^2) ΔF is the change in forcing. This works as a linear approximation only for small perturbations relative to the total incoming energy plus total greenhouse effect. Further, it only works for conditions approximately like those currently existing. Clearly at very low temperatures λ would be much different from current values both because of the larger planck response to temperature (ie, the response based on the Stefan-Boltzmann law), and because many feedbacks that currently exist would not exist, or be very much weaker. For example, much below the freezing point of water there is no water vapour feedback and essentially no albedo feedback. More than a hundred degrees below the freezing point of water and there is essentially no greenhouse effect (because all of the CO2 would have precipitated out of the atmosphere), and so on. It follows that it is a mistake to try and apply formula (2) except in current conditions. However, in current conditions, λ is for all intents and purposes the "sensitivity as a function of temperature", and is approximately 0.75 which corresponds to a climate sensitivity of 2.8 C per doubling of CO2.
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MA Rodger at 07:00 AM on 9 July 20152015 SkS Weekly Digest #27
Michael FitzGerald @here.
You say @that3 "Your equation seems to assume that dT/dF is linear" but my equation is dT/dF = 0.25 x 65 x F^-0.75. How can that be linear?
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MA Rodger at 07:00 AM on 9 July 2015Climate denial linked to conspiratorial thinking in new study
Michael Fitzgerald @5.
The Weekly Digest is sort-of Open Topic thread. I'm surprised this is needing more than a single Q&A, but...
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MIchael Fitzgerald at 06:38 AM on 9 July 2015Climate denial linked to conspiratorial thinking in new study
Philippe,
Sure. Can you suggest an appropriate thread? I can't seem to find one. Might I suggest that one of your authors find a reference for sensitivity as a function of temperature, write an article about it and then we can have a place to discuss this. It seems to me that such a reference must exist somewhere, I just can't seem to find it and your authors should know more about what is out there then I do.
Thanks,
Michael
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tmbtx at 05:59 AM on 9 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
Ranyl - I still have some hope. Maybe that's just the part of my brain rationalizing the recent purchase of a home in Holland...
I'm not following though how switching to renewables will add to a carbon debt. Seems like it would be a net positive change.
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PhilippeChantreau at 05:43 AM on 9 July 2015Climate denial linked to conspiratorial thinking in new study
Gentlemen, this is kind of OT and should be taken to he appropriate thread, as usual.
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MIchael Fitzgerald at 05:37 AM on 9 July 2015Climate denial linked to conspiratorial thinking in new study
MA,
The zero feedback sensitivity I used is the slope of the Stefan-Boltzmann Law as this would precisely quantify the relationship between temperature and incremental input (forcing) for a planet with no GHG's or clouds in its atmoshere (i.e. no feedback). As for feedback, I don't even account for that at 1K, so the actual sensitivity at 1K must be even higher than 65C per W/m^2, making the situation even worse.
Your equation seems to assume that dT/dF is linear which can't be true based on the requirements of Stefan-Boltzmann. Back to the original question, where can I find a plot of the sensitivity as a function of temperature?
Perhaps a better way to pose the question would be that if the next W/m^2 of forcing increased the surface temperature by 0.8C what did the one before that do, the one before that and so on. If I just divide the current surface temperature of 288K by its Planck emissions of 390 W/m^2 I get 0.74 C per W/m^2, however the relationship between temperature and emissions is far from linear (its a T^4 relationship), so I would expect a sensitivity closer to the slope of Stefan-Boltzmann at 288K which is about 0.2C per W/m^2. -
MA Rodger at 05:16 AM on 9 July 2015Climate denial linked to conspiratorial thinking in new study
MIchael Fitzgerald @1.
I'm not sure what sensitivity function you're using. The Stefan-Boltzmann Law does yield a rise of 65°C for the first W/sq m (actually 64.8°C). At 239 W/sq m, it yields a temperature of 255 K or -18°C which is, of course below freezing, this being the temperature of the atmosphere up where it radiates out into space, theoretically.
Sensitivity (from the direct forcing alone) would presumably be 3.7 x dT/dF =3.7 x d/dF ((5.67e-8 x F)^0.25) = 3.7 x 0.25 x 65 x F^-0.75 = 0.99°C. However, do note this is the sensitivity without any feedback mechanisms. With feedbacks the sensitivity is put in the range 1.5 °C to 4.5 °C according to IPCC AR5.
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wili at 05:10 AM on 9 July 20152015 SkS Weekly News Roundup #27B
Something to include in next weeks news roundup?
www.esquire.com/news-politics/a36228/ballad-of-the-sad-climatologists-0815/
Includes interviews with Box, Mann, Schmidt, and Parmesan, and lots of interesting insights into their (and our) emotional responses to our predicament.
Moderator Response:[JH] I alerted my fellow SkS authors to the article yesterday and it will be included in the next posting of the Weekly News Roundup. I will also post a link to it on the SkS Facebook page. Thank you for bringing it to our attention.
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MIchael Fitzgerald at 04:01 AM on 9 July 2015Climate denial linked to conspiratorial thinking in new study
Something the deniers say that troubles me is that the first W/m^2 of forcing results in a temperature of about 65K for a sensitivity of 65C per W/m^2 and that the Stefan-Boltzmann Law requires more forcing as the temperature increases, thus the sensitivity must decrease as the temperature increases which is consistent with the stated sensitivity of 0.8C per W/m^2 at the current temperature.
The problem is that When I plot the sensitivity as a function of temperature starting at 65C per W/m^2 for the first W/m^2 ending at 0.8C per W/m^2 forcing at 239 W/m^2 (the total forcing from the Sun at the defined sensitivity) and integrate across all 239 W/m^2 of forcing, the surface temperature I end up with is higher than the boiling point of water. I simply can not find any reasonable function for the sensitivity as a function of temperature that produces the correct temperature based on the constraints on the sensitivity.
My question is what is the sensitivity as a function of temperature? I
haven't been able to find this in any of the literature. -
ranyl at 03:20 AM on 9 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
Howardlee and Tom C,
The ocean will take up CO2 from pulse but over a long time though, the graph is misleading, look at the X axis on those graphs and that is in a very hypothetical situation were CO2 releases just entirely stop into the atmosphere.
If we stopped all fossil fuel emissions tomorrow CO2 levels would still rise from land use, permafrost melting, forest fires (also not in IPCC) and the land sinks becoming acute sources as vegitation shifts and we have at least 0.5C warming to come, and in general warming tends to cause the releass CO2 in all the last Ice ages, most likely due to Southern Ocean linked mechanisms.
Then everyone talks about grand children when the climate right now is quite literally becoming very extreme everywhere, so the impacts are now not tomorrow or in several decades.
Then the question is how long does it take to get to equlibrium temperature?
Hansen and others say 80% in 100 years, and ~99% in 1000 years.
CO2 now ~400ppm.
Last CO2 400ppm was the early Pliocene and Miocene, 3-5C to 4-6C warmer respectively.
And people somehow claim we have a carbon budget; isn't this a debt situation?
And if this is a debt situation, isn't replacing all the power supply with renewables and cars with electricity merely going tp add to that debt.
That is if there is no CO2 budget, but a debt, then anything that requires CO2 emissions to make it is merely adding to the debt, even if it does slow the rate of debt accumulation in the long terms as fossil fuel usage is reduced. And at present all renewables carry a CO2 cost, and a significant biodiversity cost as well (mining rare earth metals, toxic wastes, mining steel, concrete, aluminium, solvents, etc,etc,etc), and soberingly we are in a rapid mass extinction and climate change is only just taking hold.
Hope, is there hope?
Unless we get CO2 below 350ppm by 2100, 2C is inevitable and considering the extremes we are already having how can that be at all safe?
How?
350ppm by 2100 given only 60% warming materialised gives 1.8C still.
A 2C rise is a 5-SD shift in the world's mean temperature (using natural variation for the last 2000 years), and that is like increasing the average height of men by 15inches, extremely extreme.
And it is becoming more and more apparent that in terms of weather there are other influences that are making things even more extreme that just a shift in temperature might be expected to produce, like Arctic rapid warming, the front ending of deluge events resulting in greater peaks of flow to exacerbate flash flooding and so on and on.
Therefore as the climate dramatically shifts before our eyes we pretend there is room to move.
And we locked into at least another 10 years of higher than 1990 emissions?
And there are things like, New York is unsustainably vulnerable to sea level rise and storm surge increase, yet is anyone saying lets move?
Florida?
Venice?
Shanghai?
Bangladesh?
Anyway lets hope the ocean do perform a miracle as Tom suggest for it is hard to see any other way out of this as even letting the mobile phon eis too great a sacrifice to anyone I've asked.
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Rob Honeycutt at 03:14 AM on 9 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Tom @63... That may be true in the northeast of China where it gets much colder than Chongqing, I'm not really sure. But if you look at early traditional homes in China, there is a cultural element that is very different from western culture.
Whereas westerners build their homes around a central fireplace, these courtyard style arrangements are found in some remarkably colder regions in China. The central courtyard is (obviously) open, and all the various rooms surrounding the courtyard are generally very open as well, with lattice work for window coverings and such. I think much of that carries through into the culture today.
The few rural homes I've visited in China were all very open. Even the kitchen, which is a room generally separated from the main living structure, still had no door and had open windows in the winter. It's just a big food prep room with a fire and one massive wok for cooking.
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ryland at 02:43 AM on 9 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
My apologies. In the interests of clarity I should have written "If someone you love dearly receives it the exact emotional cost to you is total emotional devastation.
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ryland at 02:41 AM on 9 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Tom Curtis @59 In response to your comment:
"Come to that, what is the exact emotional cost of an excessive dose of anaesthetics? Please elucidate"
If you receive such a dose the exact emotional cost is none as you'll be dead. If someone you love dearly receives it the exact emotional cost is total emotional devastation. I trust that elucidates sufficiently.
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howardlee at 01:55 AM on 9 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
Tom Curtis @ 8 - I was referring to the work of Zeebe & Zachos who were looking at the PETM compared to today. Most people estimate the rates of carbon release in the PETM were much slower than modern rates. But the recovery curve is broadly similar to Archer's figure you post. Here's a relevant figure:
Regarding strong ocean absorbtion continuing for centuries, I'm simply highlighting research that may not apply to us. In addition to the Randerson et al paper there are others reporting the same thing such as this, and this.
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Alexandre at 01:19 AM on 9 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
Sorry, on my post above I meant a warming of 20 ºC over land.
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Alexandre at 01:17 AM on 9 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
IPCC scenarios do not convey the full gravity of the situation. They are usually limited to 2100 and people tend to think that 4.9 ºC (projection for RCP8.5) is the worst that can happen, bad as it is.
It is plausible to assume that we're not leaving any fossil fuel underground. We are going to sell it and burn it to the last dollar, if we just continue our business-as-usual behavior. Try to talk seriously with any politician or executive of the fossil fuel industry about giving up available oil or coal.
If we burn it all, and considering long-term climate sensitivity, we'll eventually pour enough CO2 in the atmosphere to reach about 20 ºC over land (reference below). This pathway we're in is tantamount to destroying the planet we live in. That's not something people gather from reading the mild-mannered IPCC report.
Hansen 2013: Climate Sensitivity, Sea Level, and Atmospheric CO2
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howardlee at 01:08 AM on 9 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
tom Curtis @ 5 - OK I'll grant you nobody is talking of Venus-style, ocean-boiling runaway greenhouse. My point was that the paleo record shows several abrupt, strong global warming episodes.
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Tom Curtis at 23:54 PM on 8 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
howardlee @6, the consensus view on ocean uptake is represented schematically by David Archer thus:
From memory, this is for a 1000 Petagramme pulse of CO2. As you can see, the oceans keep on absorbing CO2 strongly for several hundred years after the pulse, eventually absorbing around 80% of CO2, before chemical weathering of different sorts eventually, and very slowly removes the rest (over hundreds of thousands of years).
The models showing this pattern have successfully retrodicted the decline in CO2 concentrations following the PETM, so it is highly unlikely that they will fail for the CO2 increase expected over the next few hundred years with BaU.
Yes, some scientists think differently, but they are a distinct minority. It makes no more sense to work on the assumption that they are right than it does to work on the assumption that that other distinct minority much loved by Anthony Watts are right.
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Tom Curtis at 23:35 PM on 8 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
howardlee @5, a runaway greenhouse effect is when the Climate Feedback Paramater, α, approaches zero. The Climate Feedback Parameter is defined by the IPCC:
"Formally, the Climate Feedback Parameter (α; units:
W m–2 °C–1) is defined as: α = (ΔQ – ΔF)/ΔT, where Q is the global mean radiative forcing, T is the global mean air surface temperature, F is the heat flux into the ocean and Δ represents a change with respect to an unperturbed climate."Here is one of the diagrams from the post to which I previously linked:
In this diagram, the difference between the green line (representing the OLR prior to any forcing) and the red line (representing the OLR after a forcing is applied) is the change in OLR required to reach a temperature equilibrium. As you will note, the y axis is in W/m^2, and the x axis in degrees K, meaning the instantanious slope of the blue line is the Climate Feedback Parameter for a given GMST. As the slope approaches zero, you require a larger and larger temperature response to achieve equilibrium until, eventually, the temperature response to achieve equilibrium is greater than that consistent with liquid water on the Earth's surface.
In simpler terms, the Cimate Feedback Parameter is the inverse of the Climate Sensitivity Parameter, λ, which is defined by the IPCC:
"The climate sensitivity parameter (units: °C (W m–2)–1) refers to the equilibrium change in the annual global mean surface temperature following a unit change in radiative forcing."
Fairly simply, as α approaches zero, λ approaches infinity. So, a runaway greenhouse effect is that condition in which, until the oceans boil dry, climate sensitivity is for all practical purposes infinite. Neither of the two posts you link to suggest evidence of this state, nor even use the term "runaway greenhouse effect".
With regard to the "long tail", I clearly discussed the long tail of climate sensitivity, ie, the extended tail of the Probability Density Function of climate sensitivity as estimated using some statistical methods. It has nothing to do with the long duration until equilibrium climate sensitivity is reached.
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howardlee at 23:34 PM on 8 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
I hate to add to the pessimism but there is evidence that the oceans, which have been "scrubbing" about 28% of our CO2 for us, will decline in their capacity to do this. In a recent study, Randerson et al showed that the ocean feedback will overtake the terrestrial feedback by the end of the century. This is because as the ocean warms it resists uptake of CO2, and a warming ocean reduces circulation, which diminishes the ability to refresh the saturated surface ocean with deeper water. A slowed biologic "pump" from sluggish, hot, acidifying oceans may also be a factor.
In other words, the oceans will effectively amplify our emissions in the coming decades, over and above all the worst case scenarios mentioned in this article.
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howardlee at 22:48 PM on 8 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
Tom Curtis @2. Paleoclimate indicates that at geologically short timescales the climate can in fact do the equivalent of a runaway greenhouse - for example the end-Permian, end-Triassic, Capitanian etc. When CO2 rates overwhelm the terrestial and surface ocean sinks the Earth can undergo rapid, lethal warming. For example see this post and this post.
The rock weathering thermostat does indeed prevent a runaway greenhouse over timescales of millions of years - but that doesn't prevent centuries-multi-millennia-length abrupt warming events which have happened several times in Earth's past.
On the long tail, again paleoclimate does indicate a very long tail of 10s to 100s of thousands of years for anthropogenic climate change. For an article on that topic see this post.
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tmbtx at 16:00 PM on 8 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
Tom - I specifically am referring to the behavior of the climate system. Even more specifically I'm referring to how gaps in the understanding seem to turn out a bit worse than best guesses. There is nothing strange about this as scientists are usually cautious in their conclusions and making guesses without sufficient study. I suppose finding that we won't likely turn into Venus is a good thing, but the geologic record seemed to make that pretty clear to begin with. Certainly there are good things in our response with regards to renewable energy, etc. I'm not saying we're all dead and that there's not hope (well not most days) but that the size of the problem seems to grow a bit with each incremental advance. Concluding that our supposed worse case scenario is a lot easier to reach than previously believed is consistent with that.
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John Hartz at 15:07 PM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
On a more positive note, I also recommend that everyone particpating in this thread take a gander at:
Study urges 10 climate actions to curb warming, lift GDP by Alister Doyle, Reuters. July 7, 2015
Doyle's article is a brief summary of the report, Seizing the Global Opportunity: Partnerships for Better Growth and a Better Climate, released by the Global Commission on the Economy and Climate.
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John Hartz at 14:55 PM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Tom Curtis:
I am aware that that the Chinese government has an aggressive policy of retrofitting scrubbers to still operational power stations, and of phasing out older, smaller coal fired power stations in favour of renewables. I also believe that they used to burn a lot of "brown coal" and are phasing that practice out. Per usual, you and I are pretty much in agreement on these matters.
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John Hartz at 14:50 PM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
In the context of our ongoing discussion, here's a "must read" article.
The most important climate story today is the global coal renaissance by Brad Plumer, Energy & Environment, Vox, July 7, 2015
The information presented in this article does not bode well for the future of human civilization as we know it. It seems that human beings place a higher value on their personal "creature comforts" than they do on maintaing a healthy planet.
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Tom Curtis at 14:16 PM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
John Hartz @64, my understanding is that the Chinese government have an aggressive policy of retrofitting scrubbers to still operational power stations, and of phasing out older, smaller coal fired power stations in favour of renewables. That is consistent with (2008) predictions that particulate polution from coal fired power plants would remain essentially static for China by 2010, and decline aftewards. Those predictions include a declining particulate pollution from coal fired power stations for Beijing.
A recent analysis of coal station emissions says:
"Reducing the emissions from the coal power sector has been a priority for the Chinese government over the last decade (Xu et al. 2013). Improvements have also been made by altering the load factor of the power plant (capacity of plant in use), boiler types, the use of scrubbers and the size of power plants. Larger thermal power plants with a capacity to produce over 300 MW have to a great extent replaced older smaller power plants, with their contribution to the overall thermal power capacity increasing from 48 to 73 % between 2005 and 2010 (NBS 2011; Xu et al. 2013). The majority (over 90 %) of the power plants today are also installed with pulverised-coal burners, instead of the fluidised-bed furnaces and stoker-fired boilers used in some of the remaining smaller power plants (Tian et al. 2012). This has resulted in a thermal efficiency amongst Chinese coal power plants that actually surpasses that found amongst US power plants (Xu et al. 2013), a claim that to a great extent can be verified by the shutting down of small inefficient power plants, reductions in power plants’ own use of electricity and improved technology (Xu et al. 2013). China’s Electricity Council (CEC 2013a) also reports that the ratio of Chinese coal power plants equipped with fluegas desulphurisation (FGD) units today is 90 % and that 98 % of all newly built power plants are installed with low-NOx burners (LNBs). Pollution control measures for particulate matter (PM), including dust collectors, wet FGD units, wet scrubbers and electrostatic precipitators (ESPs), are also being installed at an impressive rate (Zhao et al. 2010; Cai et al. 2013), resulting in a rapid overall improvement of the Chinese coal sector"
Given this, I am inclined to accept the peer reviewed source of my initial claim.
I will note that it does not necessarilly contradict your source in that NOx emissions have increased rapidly, and while they do not contribute to the particulate pollution shown in the image @60, it does contribute to acid rain, and of course, to anthropogenic global warming.
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John Hartz at 11:27 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
@Tom Curtis #60:
You state:
Note that (contrary to John Hartz) coal was only a factor in this pollution when used for domestic heating. Industrial, and particularly power station use burns coal at very high temperatures, with almost complete combustion and with significant deployment of scrubbers so is not a primary contributor; although petrol engines in cars are.
Your statement does not squre with the following:
"The Chinese capital has for many years suffered from serious air pollution. Primary sources of pollutants include exhaust emission from Beijing's more than five million motor vehicles, coal burning in neighbouring regions, dust storms from the north and local construction dust. A particularly severe smog engulfed the city for weeks in early 2013, elevating public awareness to unprecedented levels and prompting the government to roll out emergency measures."
Source: Beijing air pollution, Topics, South China Morning Post
It is my understanding that many of the coal-fired power plants built in China during the early years of its economic expansion were not equipped with any pollution control devices including scrubbers.
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Yail Bloor III at 11:21 AM on 8 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
Tom, I would agree that Earth not being susceptible to a runaway greenhouse effect is good news. However, it would not be necessary for Earth to have temperatures hot enough to burn us to ashes or pressures that would crush us to jelly and yet be entirely unsatisfactory for the continued existence of our species. My personal level of optimism would have to be described as "cautiously hopeful." Humans are a stubborn lot...perhaps they can shift that mule-headedness toward a more constructive purpose.
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Tom Curtis at 10:51 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Rob Honeycutt @62, I am only able to rely on my source:
"The reasons for haze-fog pollution formation are many, and the main reasons can be summarized as follows [26,27]:
(i)
The automobile exhaust is the main source of pollutants. In recent years, there are more and more cars in the cities in China and the components in automobile exhaust are the main components of the haze-fog;
(ii)
Secondary pollution from factories is also an important reason. There is much benzene and aldehydes in chemical pollution emissions, and they are important components of haze-fog;
(iii)
The relative humidity near the ground in the haze-fog areas is relatively high, and the ground has lots of dust, so particulate matter can easily form;
(iv)
Burning garbage and burning coal in winter for heating can also generate pollutants."(My emphasis)
China, however, is a big country with a lot of cultural divergence, so I differ to your more direct knowledge of customs in Chongquing without accepting that coal is not used for winter heating in other parts of China.
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Rob Honeycutt at 09:57 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Just as an interesting aside... 10-15 years ago I used to see this scene everywhere around Chongqing (where my wife's family lives). These lovely little bricks of black death were used primarily for cooking in rural homes. You see them much less now as more and more people are moving into high rise apartments in the cities where all the cooking is done on gas cooktops.
And no, no one would use these for heating homes because no one there heats their homes, even in below freezing weather. They just put on more cloths and wonder why the silly American is shivering. And if said American tries to close a window to stave off frostbite, the next family-member entering the room says, "It's stuffy in here, we need some fresh air!" and opens the window again. :-)
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Tom Curtis at 09:21 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
I should note, by the way, that ryland has only one drum to beat - that the third world (and in particular China and India) will not transition to a fully industrial economy except by the use of coal and other fossil fuels, and that therefore western attempts to curtail CO2 emissions are pointless. That point is only valid if he can categoricaly state exactly what policies with regard to greenhouse emissions both nations will pursue over the next two decades. Given the standard of evidence he has now indicated he considers appropriate; I suggest that he no longer be heard (on grounds of excessive repetition, and sloganeering) until he states categorically and exactly what the policies of those two nations will be, on an appropriate thread.
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Tom Curtis at 09:06 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
If I can take us back to ryland's claim @46 in response to John Hartz @43:
"Yes, I rather think I am ["...stating that you cannot form an opinion about air quality in Inida and China without personally observing and experiencing it"]. China is a very large country as indeed is India and it seems highly unlikely that there is uniform air quality over the entirety of either country. So when you ask ""At what cost to their respective environments, especially clean air?" the question is somewhat loosely worded. Do you mean the environment and air in the cities or in rural areas or in the mountains or on the coast?"
Again note the ridiculous standard, ie, that China (or India) must have "...uniform air quality over the entirety of either country" in order for us to form an opinion about the air quality in China. Transparently we can form an opinion about the average air quality in China (which by definition is uniform over the entire country). More importantly, we can form an opinion about the air quality in specific locations:
"There was continuous haze-fog weather in most parts of China, including Tibet and Xinjiang. The areas with serious haze-fog pollution included the Beijing and Tianjin areas, South Hebei Province, Northeast Henan Province, Western Shandong Province, Jiangsu Province, Anhui Province, Western Zhejiang Province, Northwest Fujian Province, Central Hunan Province, South Jiangxi Province, Central Hubei Province and the Northern Sichuan Basin Area. Southwest China became the only unpolluted land."
(Source)
Note that (contrary to John Hartz) coal was only a factor in this pollution when used for domestic heating. Industrial, and particularly power station use burns coal at very high temperatures, with almost complete combustion and with significant deployment of scrubbers so is not a primary contributor; although petrol engines in cars are.
We can also form a view as to the geographical extent of acid rain over China, to which coal is a major contributor:
ryland's response to John Hartz' statements on pollution in China consists entirely of empty rhetorical points, just as was his response in impacts (which was introduced to distract from the issue of pollution in China).
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Tom Curtis at 08:27 AM on 8 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
tmbtx @1, you do not consider the proof that the Earth cannot undergo a runaway greenhouse effect good news? Or the recent indications that climate sensitivity may not have a long tail? The later does not eliminate the risk of severe impacts from climate change, but it does largely eliminate the risk of extreme impacts, which is surely good news. If you are not finding any evidence of optimistic developments, you are relying to much on biased sources. There is good news out there, particularly in the technical development of low carbon technologies (renewable energy, electric transport).
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Tom Curtis at 08:11 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
ryland @58, what is the exact cost to the Earth's climate system of a meteor strike? Or the cost in GDP, or the cost in lives? Even when there is absolute certainty that a meteor will strike the Earth, there remains no certainty about impacts.
Come to that, what is the exact emotional cost of an excessive dose of anaesthetics? Please elucidate.
Your examples of certitude are transparently of a different category to the examples of the costs you ask questions about. Worse, you ask costs of an undefined quantity (how much coal will be burnt exactly, by which nations, and what steps to reduce or increase emissions by other nations)? Therefore you are clearly expecting an unrealistic level of certitude with regard to the impacts of emissions.
Of course, that was transparent in your original statement, even without clarrification, which called for a certainty so absolute it risked no rebutal ("categorically state") and admitted of error bars so small as to be inconsequential ("exactly"). Indeed, you ask for a level of certainty that is not even found in tracking airpaths until after the event (think turbulence, pilot error); meteor strikes (which are often only predicted in terms or probabilities, and are never predicted precisely as to location on Earth); or the precise dose of anasthaetics (which varies between people).
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ryland at 07:47 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
I have no idea where you got the idea I "insist that the computation of the costs of burning fossil fuels must be done with near absolute certainty". What I actually wrote was "As for the cost to the Earth's climate system of their burning coal again, I don't know and I'm not sure that anyone can categorically state exactly what that cost is."
You appear to have taken it that I mean financial cost. I don't. I mean exactly what I wrote namely cost to the Eath''s climate system. For example it is said that increasing the global temperature by >2C will lead to climate change evidenced by longer and more severe drought. more flooding, increased incidence of hurricanes, increased sea levels, glacier loss etc. This is what I mean by cost to the Earth'scliate system. As I said, "I don't know and I'm not sure that anyone can categorically state exactly what that cost is."
On reflection perhaps what that cost will be would have been better
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tmbtx at 06:19 AM on 8 July 2015Carbon cycle feedbacks and the worst-case greenhouse gas pathway
This is what happens when there's little upside and large downside in the uncertainties - the more things are refined the greater chance that they're worse than previously thought. I can't recall any time there was a new discovery or refinement that made the situation look a bit more optimistic than pessimistic.
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John Hartz at 05:49 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Ryland:
I specifically chose the compution of GDP because it is used by governments, finacial institutions, investors, and others as input into making major policy decisions that have major fiscal impacts. Why then do you insist that the computation of the costs of burning fossil fuels must be done with near absolute certainty when the computation of GDP is not?
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ryland at 04:48 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Thanks Michael Sweet. In future I will remember your advice and in future will put links in instead of just the URL.
John Hartz. First thanks for your very gracious comment at 55. I'm not surprised you did not consider my examples were appropriate. But let's take theadministration of anaesthetics. If you get it wrong your patient may die or become brain damaged. I guess that is only a personal tragedy confined to the patient and the immediate family but I would argue it is more significant than determining the GDP. Let us say you come in for, let us say, a heart bypass, and I give you too much anaesthetic so you are not revived. To you and your family that is of a lot more significance than calculating the GDP. I would also contend that tracking the course of a meteor that could destroy the earth is orders of magnitude more important than calculating the GDP especially as calculations of GDP are not always accurate. If the meteor is likely to hit the earth there are means to divert its course such as the use of explosives that destroy the meteor.
In fact I cannot see that determining the GDP is anyhwere near as significan t as any of the examples I gave. But then , I would say that wouldn't I?
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John Hartz at 03:18 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Ryland:
If I have misrepresented your modus operandi, I aplogize.
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michael sweet at 03:10 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
Ryland,
Thank you for giving your links. To clean them up, go to the insert section of the comments box. Highlight the words you want to be linked and then click on the chain icon. A box will appear where you can copy the URL you want to link to. After you do it once it is easy.
The moderators start to complain you are sloganeering when you only give your opinions and do not link sources. In a scientific discussion you want to present data to be convincing, not go into your personal philosophy. You will get less moderator complaints when you cite links.
Once you have linked a source, it is not necessary to refer to that link again. If you continue to refer to the same source that is repetition and is also considered sloganeering. If everyone has cited their sources the conversation has run its course. Readers can then decide which argument they thought was stornger.
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John Hartz at 03:09 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
@ryland #51:
You state:
As for examples of high bar of certitude. How about diagnosis of a fatal disease that cannot be cured? How about determining the track of a meteor that may hit the earth? How about determining the correct amount of anaesthetic to give to a patient prior to and during major surgery? How about determining the flight paths of passenger aircraft converging on a busy airport. :
Thank you for the examples. Unfortunately, they are not in the same category as is computing the costs of fossil fuel emissions. More comparable might be the computation of national GDPs. Do you believe the compution of national GDPs should be done with a high bar of certitude?
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ryland at 02:53 AM on 8 July 20152015 SkS News Bulletin #6: Pope Francis & Climate Change
John Hartz @50 with regard to your comment "you pull the victim card and then depart the scene" please note my reply at 51. I clearly have not departed the scene. Your comment at 50 is rather puzzlig as I don't remember it being there when I wrote my comment (@51) in answer to your comment @49. If I had seen it I would have responded to it in my comment above. I really cannot understand how I missed it.
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