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hathawad at 03:08 AM on 15 September 2016There is no consensus
There definitely is a consensus that CO2 can increase temerature,
BUT NOBODY KNOWS BY HOW MUCH, that part is NOT consensus. According to believers the icecaps would have been long gone by now and we would be in knee deep water in Florida.
There is no consensus on CATASTROPHIC climate change.
Over the past 11,000 years the Earth has had temperatures above today's average temperature about 9 times. We are now at average temp according to this data: GISP2 below
During evolution, the CO2 was many thousands of ppm and man was definitely not around then and yet life was possible during this "catastrophic" CO2 level
Moderator Response:[RH] Shortened link. Please note that use of all caps is against our commenting policy.
[TD] Your comments are most appropriate on several other threads. Please read the following, and if you want to comment further on those topics do so on those threads, not this one:
"...the icecaps would have been long gone by now." You need to provide a reference for your claim. I'm unaware of anyone who has claimed that. For actual peer reviewed scientific projections of ice loss, type into the Search field at the top left of any page relevant terms such as ice, sea ice, land ice, and glacier, and choose from among the resulting hits. Here is one of those: Read the Intermediate tabbed pane of "How the IPCC is more likely to underestimate the climate response," scrolling down to the section on Arctic sea ice.
"...we would be in knee deep water in Florida." You need to provide a reference for your claim. I'm unaware of anyone who has claimed that. For actual peer reviewed scientific projections of sea level rise, type "sea level" into the Search field at the top left of any page, and choose from among the resulting hits. Here is one of those: "How much will sea levels rise in the 21st Century?" After you read the Basic tabbed pane there, read the Intermediate one.
"There is no consensus on catastrophic global warming." "Catastrophic" is too ambiguous a term; scientists' projections are much more specific. Read "Positives and negatives of global warming." After you read the Basic tabbed pane, read the Intermediate and then the Advanced.
"Over the past 11,000 years the Earth has had temperatures above today's average temperature about 9 times. We are now at average temp according to this data: GISP2 below." The GISP2 graph you linked has as its most recent data the year 1855. Not even 1955, but 1855. So it does not show anything like "today." Also, it reflects the temperature only from a single spot in Greenland, which is not at all representative of the entire Earth. Read "Most of the last 10,000 years were warmer." To learn about temperature indices that are representative of the entire Earth, and that go up to much closer to today, read "Real skepticism about the Marcott hockey stick." Then use the Search field to look for more posts about Marcott, and posts about PAGES 2K.
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Tom Curtis at 02:22 AM on 15 September 20162016 SkS Weekly Digest #37
Zoli @24, I don't know how big an issue you thought it to be, but AGW is one of the biggest, indeed probably the biggest policy issue facing humans today. That is because, while there is a reasonable chance of a soft landing* (climate sensitivity in the lower half of the probability range, damages at a given temperature in the lower half of expected range, rapid reduction in net global emisisons), there is a significant risk of absolutely catastrophic outcomes (climate sensitivity in the upper half of the PDF, damages in the upper half, and very limited reductions in net emissions). Thinking that the former makes AGW a non-issue is like thinking that Russian Roullette is safe because there is a five in six chance that you will not blow your brains out.
Second, the IPCC is fully aware of all the factors discussed here. The image you provide an URL for shows the outcomes of specified scenarios with prescribed emissions history, and concentrations calculated from those emissions history using carbon cycle models that take into account all the factors we discuss. Most of those scenarios do not achieve net zero emissions in this century, and hence show ongoing temperature increases. Remember, for CO2 concentrations to be drawn down naturally, CO2 emisions have to fall to less than 10% of their peak values - something that does not even occur in RCP 2.6 until late in the century, and not at all in the other scenarios this century. So, no. The IPCC are not "alarmists". Rather they are realistic and well informed.
(* Note: Even a soft landing will involve many individual climate caused catastrophes - just not a global catastrophe.
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ubrew12 at 01:53 AM on 15 September 2016BBC climate coverage is evolving, but too slowly
denisaf@9 said: "policies to reduce emissions can only slightly slow down this damaging process". If we managed to hold CO2 at today's 400ppm, by end of century the rise would be 2 C. If instead we get to 560ppm (BAU out to 2050), the rise will be 3 C. But that's the expected mean: there's a one-in-six chance the rise (after 560ppm) will be 4.5 C or higher. A 'roll of the dice' of a global extinction event, if we let CO2 get to 560ppm. So, depending on your tolerance for risk, 'policies to reduce emissions' seem prudent, to me.
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Zoli at 00:51 AM on 15 September 20162016 SkS Weekly Digest #37
@chriskoz
@Tom Curtis
Thank you. So climate change isn't that big issue as I thought.
And IPCC authors are alarmists because they didn't count the quick CO2 drop.
[img]http://i67.tinypic.com/vddces.jpg[/img]
Long term changes, page 1104
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chriskoz at 18:50 PM on 14 September 20162016 SkS Weekly Digest #37
scaddenp@21,
A typo crept into my comment@19.
I ment to show, that if you could have PVs that collect 200W peak power per m2 in AL, and jam-pack that site with such PVs, then your peak power output from that site would be (647ha = 6,470,000m2) * 200W = 1.3GW.
Obviously I see now, that 200W peak power is incorrect and not correct metric. With the more reasonable metric you pointed out (5kWh/m2/day) we and up with average insolation of just 200W over 24h. With 10% PV efficiency, the energy yield would then be 0.13GW averaged over 24h - 10 times less than planned nuke yield. Needless to say the yield would be intermittent, unlike nuke. With the best available commercial PVs approaching now 20%, the yield would still be five times less than nuke.
However I did not underestimate the cost of jam-packing that site with PVs. The latest estimate of PV cost is at $0.3 per 1W capacity.
So I the total cost of such project is $0.13Giga*0.30 = $39m
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chriskoz at 16:15 PM on 14 September 20162016 SkS Weekly Digest #37
Tom@20,
Thanks for your clarifications to what I agree.
Your posts always have very precise meaning, allowing easy and clear discussion, a benchmark of quality blog commenting.
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denisaf at 16:12 PM on 14 September 2016BBC climate coverage is evolving, but too slowly
I am an Australian physical scientist who has followed the debate about climate change due to emissions of industrial operations for decades. There is very little uncertainty about the hypothesis that irreversible atmospheric climate disruption and ocean acidification and warming is occurring. Comprehensive atmospheric and ocean measurements have backed the arguments of climatologists. The emerging global policies to reduce emissions can only slightly slow down this damaging process even if it these policies can be implemted as rapidly as physically possible. More emphasis should be placed on measures to adapt to the consequences, such as sea level rise, more severe storms, more droughts and more floods.
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scaddenp at 14:21 PM on 14 September 20162016 SkS Weekly Digest #37
I hectare is 10,000 m2, so I think your area is off by factor 10. Since solar incoming is 1367W/m2, I dont your solar panel is going to give you 200W/m2. NREL puts Alabama available solar input at 5kWh/m2/d
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Tom Curtis at 14:12 PM on 14 September 2016BBC climate coverage is evolving, but too slowly
nigelj @6, a lot that passes for climate denial consists of straighforward, and often ludicrous pseudo-science and/or conspiracy theories. If we had a news media that actually took seriously their duty to inform, these would not be presented in news and current affairs shows, and only presented in documentaries that fisk them. This is not different to who we would expect new media to treat numerology, astrology, 911 Trutherism and other various nonsenses given air by credulous people on the internet. Scientifically, thes include opinions that:
Humans are not the cause of the current rapid rise in CO2 levels;
CO2 forcing is not in the order of 3 - 4 W/m^2 per doubling;
The climate sensitivity per doubling is not greater than 1 C per doubling of CO2.
Of more interest are theories that the climate sensitivity is in the range of 1-3 C, which are not excluded by the IPCC. Likewise, for theories that increased global temperatures will be net beneficial up to about 2 C. Neither of these possibilities are excluded by the IPCC, given that they represent the lower half of the uncertainty range of IPCC estimates. The question that should be raised is why the proponents of these views are so much more certain about their conclusions; particularly given that they typically exclude large parts of the relevant evidence. In short, if those opinions are to be reasonably discussed, the framing should be an attempt to allow them to defend themselves against a charge of convenient dogmatism.
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Tom Curtis at 13:59 PM on 14 September 2016BBC climate coverage is evolving, but too slowly
Nate @5, in science, a consensus is commanded by observations. There are significant social aspects involved in how that comes about but science is a self correcting enterprise in which what drives the corrections are a determination to ensure theory matches obvservations by altering the theory where the two differ.
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Tom Curtis at 13:54 PM on 14 September 20162016 SkS Weekly Digest #37
chriskoz @17, CDIAC (or TJBlassing, at least) gives an exponential time constant for CH4 of 12.4 years, meaning it will take about sixty years for CH4 to drop to natural concentrations, following the cessation of all anthropogenic emissions (and ignoring changes in 'natural' emissions as a result of feedbacks on changes in temperature and/or precipitation). Just saying that it has a lifetime of 12.4 years (or 10 years) may mislead some into believing essentially all CH4 will be gone in about a decade, which is false.
Further, when you use CO2eq, particularly when using all anthropogenic forcings, aerosols also have a low exponential time constant so that the rapid fall in CO2eq concentration will be, at least roughly, balanced by a rise in CO2eq concentration due to the reduction in aerosol concentrations. That is not relevant in discussing Zoli's figure which is based on greenhouse gases only, but it is relevant when discussing the more appopriate European Environment Agency figure I discuss above. The initial relatively rapid fall in CO2 concentration, given zero net anthropogenic emissions still quickly reduces the CO2eq concentration in that scenario, and sustains your very important point.
As a side note, "long lived greenhouse gases" by convention are any greenhouse gas which does not condense out of the atmosphere, ie, any greenhouse gas other than H2O, which has an exponential time constant measured in hours.
r @19, peak generation capacity is probably not the best measure given that mean generation capacity of solar is significantly less than nuclear, and that even peak generation capacity requires cloud and haze free skies on only a few days in the year, and then only around noon. More typically, daily peaks will be 10% or more less than that, and will represent a minority of the days output. Fossil fuel and nuclear power unquestionably require less space than renewables for a given generation capacity. Your example, however, certainly provides andecdotal evidence that economically solar trumps nuclear.
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chriskoz at 13:09 PM on 14 September 20162016 SkS Weekly Digest #37
Interesting what's going on with nuclear in Alabama:
For sale: Multibillion-dollar, non-working nuclear power plant
I'm posting it here because there were discussions about advantages of nuke over renewables. Now the renewable ulitily company is placing a bid on this nuke site were $6b have been completely wasted.
I'm not going to argue about advantages of renewables over nuke, but I note that this 647ha site was meant to be generating 1.2GW of nuke power. If you covered such are with PV panels (this is what the prospective renewables buyer is likely to do) in the range of 10% efficiency, which is ~200W/m2, you will get 647,000,000*200W = 1.3GW of peak power. The same capacity as the ill-fated nuke, surely at the small fraction of the investment cost ($50m) and essentially free running to some 20y.
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Tom Curtis at 10:19 AM on 14 September 20162016 SkS Weekly Digest #37
Zoli @16, I will add a few points to Chriskoz's excellent response.
First, the estimate of CO2eq concentration you use is for greenhouse gas concentrations only. It does not incorporate all anthropogenic impacts on Global Mean Surface Temperature. Once you include the impact of other factors, in particular that of aersols, the CO2 eq emissions as of 2014 (ie, the most recent year for which data is available) was 440.6 ppmv CO2eq. For comparison, the 2014 value from your linked source was 481 ppmv CO2eq, with a most recent value (2015) of 485 ppmv CO2eq. I take it your 487 ppmv CO2eq represents an estimate of the additional increase in the half year since the end of 2015. Similarly estimating the approximate trend increase of for all anthropogenic factors gives 446 ppmv CO2eq, or 1.6 times the preindustrial average (compared to the GHG only estimate of 1.74 times the preindustrial average. Therefore the GHG only estimate is a substantial overestimate for estimating future climate impacts.
Second, the IPCC AR5 does not give median or mean estimates of the Equilibrium Climate Sensitivity (ECS). From the estimates they do give, and a reasonable assumption about the shape of the Probability Density Function (PDF) of the ECS, it is possible to estimate that while the mean value is in the order of 3- 3.4 C, the median value (ie, the value such that we have a 50% chance of an ECS less than that) is in the order of 2.4-2.7 C. Therefore, based in the IPCC AR5, even at a CO2eq concentration of 600 ppmv, there is a 50/50 chance that we will not exceed a GMST of 2 C. (Based on mean values of the ECS, we need to keep CO2eq concentrations below 525 ppmv.)
I consider a 50/50 chance to be a "realistic chance", and also consider it a very realistic possibility that we will limit total CO2 emissions to double the 2014 increase over preindustrial values or less, ie, about 600 ppmv CO2eq. That by itself is sufficient to justify my claim.
I should note that this is little comfort to AGW deniers and those wanting a slow reduction in CO2 emissions. That is because, assuming a linear increase in damages with increase in temperure the relevant value of ECS is not the median, but the mean; and damages are likely to increase more than linearly with increased temperatures. That is why estimates of the emissions reduction task are based on values which are likely (66.6% probability) to keep GMST below 2 C, where the value minimum value which is likely to achieve that is just slightly higher than the mean estimate.
Third, based on a current CO2eq concentration of 446 ppmv, and a requirement to stabilize it at no higher than 525 ppmv by 2050, we can increase it by no more than 79 ppmv over 34 years, or in other words to limit the average increase over that period to 2.33 ppmv per annum, and with a current average increase 3.5 ppmv per year (approximately). If we reduce the increase on a linear basis, by 0.1 ppmv per annum, the average emissions over the 34 years will be about 1.8 ppmv, well below the threshold. That is clearly a physically, and technically feasible reduction program, although other reduction programs will probably be better. The reasons for pessimism, and they are reasons for grave pessimism, are entirely political. Will the leaders of the nations of the Earth have the collective will to pursue an emissions reduction program of that magnitude.
Finally, these are not my only reasons for my statement. I think it is more important that the ECS will not be achieved for many years after a stable CO2eq concentration is reached, and that with zero net emissions, the CO2eq concentration will be drawn down by the ocean fairly rapidly up to a limit. That limit is about 25% of the current CO2 concentration, which will be drawn down much more stably. That means if net emissions can be reduced to zero (and certainly not more than 5% of current values), CO2eq concentrations will fall rapidly such that by the time ECS is reached, the CO2eq concentration will result in a temperature rise approximately equal to the Transient Climat Response to the peak CO2eq concentration. That gives us significantly more leeway than calculations based on the ECS allow, as indicated by Chriskoz.
Note, again, the decision to drop down to zero net emissions is a political one, and it is far from clear that the politics will result in that decision. The approach favoured by many economists of putting a social price on CO2eq emissions and then allowing emissions to stabilize where they will will certainly result in ongoing emisisons. Indeed, it will likely result in ongoing emissions greater than 10% of peak emissions which would mean the eventual stable temperature will be in excess of that estimated from ECS, and would continue slowly rising into the future for as long as net emissions were greater than zero. However, if sensible policies are pursued, ie, any policy that secures measured reductions in global emissions, achieving net zero emissions by 2050, or net negative emissions at a slightly later date has a good chance of keeping GMST below 2 C (except in El Nino years), and a reasonable chance of keeping it below 1.5 C above preindustrial levels.
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nigelj at 08:06 AM on 14 September 2016BBC climate coverage is evolving, but too slowly
Many media including the BBC do indeed have this fake balance issue. I see a similar thing in media in my country of New Zealand, where there is broadly a 50 / 50 split in certain specific media between warmist articles (for want of a better word) and sceptical articles. This may create an impression with some people that climate scientists are equally divided in their views, which is not the case. Over 90% of climate scientists agree we are warming the climate, according to several different carefully conducted polls.
There seems little point having sceptical articles contesting generally well established elements of the science like "the greenhouse effect".
For other sceptical articles that discuss something that is in genuine doubt, perhaps the BBC should have an advisory at the top or bottom of the article that reads basically something like this : “Advisory to readers : The BBC advises that the IPCC has determined we are warming the climate, and over 90% of climate scientists agree we are warming the climate, according to published polls (then a list of the polls).
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chriskoz at 07:55 AM on 14 September 20162016 SkS Weekly Digest #37
Zoli@16,
You are wrong in thinking that the "GHGs equivalent of 487 ppm CO2" must stay in the atmosphere while Earth is warming in equilibrium (next 40+ years). The GHGs breakdown:
indicate that some 30% of the GHG forcing is from CH4, which increased since 1750 by about 1ppm. But CH4 has the lifetime of only 10y (the image is wrong in labeling CH4 as "long-lived") after which it oxidises to CO2. The forcing of the resulting 1ppm increase in CO2 is negligible compared to the existing CO2 forcing from 400/280 ppm. All we need to do is stop emitting CH4 and that part of forcing quickly goes to essntially zero.
Secondly, if CO2 emissions ceased today, it would not stay at 400 ppm forever but would slowly equilibrate with ocean reservoir over the next few decades or so, while the temperature is, hopefully still reaching the equillibrium. Read e.g. Archer 2005 for details. The bottom line is: current CO2 amount of 400ppm is not "locked". Only about 15-25% of the 400/280 in crease (i.e. 30-40ppm) will stay in the atmosphere for 100s thousand y (essentially forever).
So currently, the amount of "locked CO2" is 310-320 ppm only. Of course realistically, it will be more because of continued emissions and science denial by FF interest groups, but cetainly not yet as high as you claim (487ppm).
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Nate12674 at 07:42 AM on 14 September 2016BBC climate coverage is evolving, but too slowly
I think part of what Abloke said is worth discussing. He is putting down science consensus about a theory as being inferior to science facts. In my viw all science, whether observations, or theory, become accepted and established by consensus.
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Nick Palmer at 23:02 PM on 13 September 2016BBC climate coverage is evolving, but too slowly
ABloke. You haven't got a clue about the reality of the situation as you clearly don't know what you are talking about.
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Tom Curtis at 22:48 PM on 13 September 2016BBC climate coverage is evolving, but too slowly
To the moderators, I was surprised to see ABloke's comment get any positive thumbs on a reasonably educated forum. I was especially surprised to see that he got it so quickly. Consequently I ran a test and found I could give my own comment a thumbs up. I ask that the moderators remove that thumbs up, which was only done as a test, and remove also ABloke's if it was similarly underserved.
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Tom Curtis at 22:43 PM on 13 September 2016BBC climate coverage is evolving, but too slowly
I can only assume that ABloke writes frequently to the BBC complaining about the lack of coverage of phrenology, geocentrism, and hollow Earth theory, given his peculiar definition of "balance". Or is it perhaps only the pseudoscience he adheres to that he thinks deserves to have its public plausibility boosted by inaccurate reporting by the BBC.
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ABloke at 22:33 PM on 13 September 2016BBC climate coverage is evolving, but too slowly
If anything, the BBC have been rabid AGW alarmists with a 'the debate is over' slant on most if not all is 'climate/weather' related coverage.' If anything, they are becomimg slightly more balanced than in the past and certainly in the piece you refer to. The BBC is supposed to be balanced in all things and if anything, this report represents that balance. CO2 driven climate change is 'Theory' not a fact, and theory with very little to back it up, so they cant say C02 'does' cause climate change, no matter how much youy scream 'unequivocal scientific consensus' and '97%' because there is none and for the sake of balance, the BBC have to report as such. They cannot present things as scientific fact, when there is 'no' scientific fact to back it up. 'Consensus' just doesnt cut it.
Moderator Response:[JH] Pure undadulterated poppycock, i.e, sloganeering.
Sloganeering is prohibited by the SkS Comments Policy.
Please read the policy and adhere to it. If you do not, you will relinquish your privilege of posting comments on this site.
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Zoli at 19:26 PM on 13 September 20162016 SkS Weekly Digest #37
@Tom Curtis
"First, it is not clear that we are past the point where a realistic global emissions policy will prevent an average rise of temperatures above 2o C."
Why? As I understand we have accumulated GHGs equivalent of 487 ppm CO2 so far. http://www.esrl.noaa.gov/gmd/aggi/aggi.html
487/280 (pre industrial) =1,74
So we almost doubled the GHG amount.
Climate sensitivity estimates are about 2,5-3 Celsius.
0,74×3 = 2,22
0,74×2,5 = 1,85
So we achieved the requirements for 2 Celsius rise. The only question is the time the world needs to accumulate enough heat, melting ice etc.
There is a chance the climate sensitivity estimates or my simple calculations are wrong of course.
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Eclectic at 15:11 PM on 13 September 2016The Madhouse Effect, a review
Martin, I agree with Gws @5.
There is a vast number of things you can make a joke about. Even "gallows humour" jokes about Death/Taxes.
But jokingly denying Global Warming is uncomfortably close to denying wife-beating or denying genocide. It's poor taste. Just don't go there, unless you're a very very very clever humorist !
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chriskoz at 11:17 AM on 13 September 20162016 SkS Weekly Digest #37
It's worth noting that even though habitability of Earth by homo sapiens (as defined by Sherwood and Huber (2010) and promoted by Tom Curtis here) does not change much with even very pessimistic AGW scenarios, the life expectancy of all homo sapiens individuals will be curtailed severely, as Tom himself asserts:
Such temperatures will result in significant death tolls among the elderly
I would love to see the life expectancy metric quantified for various RPC scenarios & various regions, because this is far better metric of AGW direct impact on homo sapiens species, rather than Sherwood and Huber (2010) metric. However, I don't know if anyone tries such quantification; I guess there is not enough historical data for the very moderate warming so far and any data is hidden behind the influence of technology and improved hygiene which prolongs life expectancy.
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One Planet Only Forever at 09:24 AM on 13 September 20162016 SkS Weekly Digest #37
Tom Curtis@11,
The main point of my comment remains.
It is unacceptable for a current generation to impose any challenges on future generations. And it is even less than unacceptable for a portion of a current generation to be benefitiing at the expense of others in the current generation as well as at the expense of future genrations. This is a combination of depletion of non-renewable resources and acumulated impacts of human activity.
Also, the full understanding of the robustness of other life required to sustain human life will likely only become well understood when it is too late to reasonably mitigate the impacts and created challenges. The current generation is already faced with a many bigger challenges to mitigate because of the "lack of restraint and lack of concern for the future" of previous generations.
Moderator Response:[JH] You could do us a great service by rolling-up your comments into an article for posting on SkS.
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Bob Loblaw at 09:07 AM on 13 September 20162016 SkS Weekly Digest #37
For some reason, in Tom's comment 11, the link to the XKCD cartoon has extra junk at the start. This one should work. The cartoon is definitely worth it - thanks, Tom.
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Tom Curtis at 08:34 AM on 13 September 20162016 SkS Weekly Digest #37
Moderator inline @4, the only contact information for Coral Davenport that I can find is her twitter account. As I do not, and will forseeably, have a twitter account that does not help me. I would be quite happy, however, for somebody else with a twitter account (or other contact details) to advise her of this dicussion.
Moderator Response:[JH] Try: coral.davenport@nytimes.com
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Tom Curtis at 08:20 AM on 13 September 20162016 SkS Weekly Digest #37
XKCD has an interesting cartoon on global warming, which is unfortunately too large to place here. Quote:
"[After setting your car on fire.] Listen, you car's temperature has changes before."
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Tom Curtis at 08:09 AM on 13 September 20162016 SkS Weekly Digest #37
OPOF @7, you need to draw a distinction between conditions under which humans can continue to live as a biological species; and those underwhich we can sustain our current population and civilization. If, biologically, only a million humans are able to continue ekeing out an existence near the polar caps, reduced to the state of hunter gatherers than Earth is still inhabitable by humans. Under those conditions, we know it is inhabitable because humans continue to inhabit it.
The level of ecological complexity needed to sustain such a life is minimal compared to that which exists today. All that is required is the existence of some prey animals, and some (perhaps wild) fruits for sustenance.
You also need to understand the type of robustness found in ecological systems. It is relatively easy to knock an ecological system out of kilter - to remove a key species so that a large number of other dependent species will also be lost with the result that the surviving system can sustain only a far more limited total number of species, and total biomass. But the ecosystem as a whole will survive (will predictably survive) the loss of 90% or more of species. We know that because it has happened at the Permian mass extinction. More importantly, we know that because the most difficult factor any living thing has to deal with in its environment is other living things. The range of nearly all plants could be greatly extended were it not for the competition of other plants more suited to particular conditions. Likewise with animals. The effect of a mass extinction, consequently, is to remove the most fearsome impediments to survival of the surviving species. That loss of competition itself allows the survival of species not specifically dependent on particular other species for survival.
That last condition is most easilly met by generalists - those species not adapted to any particular condition but found across a wide range of conditions across the planet. Among these, preeminent among large animals are humans.
So, except for two caveats, humans will survive the coming ecological collapse. I say the coming collapse because if global warming does not do it (and temperature increases of 4 C may well bring it about), species transfer by trade will; and if not that over fishing will. The two caveats are that global mean surface temperatures do not rise by more than 10 C, and that we do not spark intense enough wars as a result of the collapse so as to exterminate ourselves. Even if we do that later, after a few years the Earth will be uninhabited by humans, but still habitable.
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nigelj at 08:07 AM on 13 September 20162016 SkS Weekly Digest #37
One Planet Only @7
You seem to make the point that too many people are putting their selfish short term concerns and personal benefit above the concerns and rights of future generations. I agree with this, and it’s not a viable long term plan for the planet.
Part of the reason is just selfishness. However part of the reason may be how we process information. Humans are evolved to be good at processing information on short term risks, but struggle to get to grips with long term risks, especially complicated ones. There is some psychological research on this, and I can't remember where, but probably easily googled. There is thus a temptation to just ignore the long term future as being too hard to contemplate.
Of course experts and long term thinkers have tried to do the job for us. The Stern report looks at long term issues and costs of climate change and costs of mitigation, and shows that reducing emissions can be done at an affordable cost to society. However the media have suspiciously avoided much discussion of this research, and it is dismissed by climate sceptics with a wave of their imperious hands. What a surprise.
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nigelj at 07:49 AM on 13 September 20162016 SkS Weekly Digest #37
Tom Curtis @ 2 and 4.
All your points are well made, and seem technically correct to me, and are informative for a non climate scientist like me. I agree it's important people are accurate in descriptions, and avoid hyperbole.
However you might be falling into your own trap in one regard. You make the valid point that too much concentration on the 2 degree limit and unproven claims that its been breached, gives climate sceptics an excuse to claim its too late to do anything.
However you then give a description of research that heat stress only becomes a problem at 35 degrees or more at 100% humidity and this requires 7 - 10 degrees of warming. This in turn gives the climate sceptics breathing space, as they would argue we will never hit such large temperature increases!
I also recall India has just had a massive, record setting, extended and dangerous heatwave with temperatures of 35 - 50 degrees. This may not be at 100% humidity, and as concerning as the definition in the Sherwood research, but its still very stressful. The last IPCC report stated that theres already evidence of increasing heatwaves, so this is already a problem in some regions.
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The Madhouse Effect, a review
Martin @4: That is an interesting anecdote. Were you onboard with the joke you made, or were you actually just uninformed at the time, trying to make conversation?
If this had happened to me (atmospheric scientist) back then, I would have tried to "convince" you as well; if it happened to me today, in the US, I would shut up and maybe try to move away from this (joking) person.
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One Planet Only Forever at 01:00 AM on 13 September 20162016 SkS Weekly Digest #37
Tom,
A scientific assessment of the regional temperature change that "human beings" could live with is, like all such science, just the evaluation of a bit of the whole.
Human survivability is actually only able to be properly assessed on the whole, not by a bit. That means that the survivability of the robust diversity of life which human beings are only a part of needs to be understood.
That is a much more complex matter to figure out. It would seem likely to only be well understood when it becomes apparant that the warming was too much too fast, when it is too late to practically mitigate the created and unavoidably obvious damage done.
It would seem that the practical sustainability of human life as a sustainable part of the robust diversity of all life far into the future on this amazing planet could be challenged by a significantly lower amount of temperature change than the change that 'Human Beings evaluated in isolation of other life' could tolerate. And any created challenge for future generations deserves to be acknowedged as a fundamentally unacceptable thing for a previous generation to do to a future generation (it is fundamantally unjust to consider the opportunity perceived to be lost by a portion of a current generation to be able to be balanced against the challenges created for future generations - as percieved by those in the current generation who would be giving up their opportunity for more personal benefit).
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John Hartz at 23:38 PM on 12 September 20162016 SkS Weekly Digest #37
Manmade climate change is already directly impacting humans in ways we are just now beginning to understand...
Blame Global Warming for Your Bad Attixtude by Eric Roston, Bloomberg News, Sep 8, 2016
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chriskoz at 18:50 PM on 12 September 20162016 SkS Weekly Digest #37
Tom@4,
Now I undesrtand that you really mean homo sapiens uninhabitability threshold be 7-12oC based on Sherwood and Huber (2010). It's higher than I imagined previously & I thought it (erroneously) be a typo. Thanks for your explanation.
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Tom Curtis at 17:56 PM on 12 September 20162016 SkS Weekly Digest #37
chriskoz @3, Sherwood and Huber (2010) (SkS discussion here) state:
"Peak heat stress, quantified by the wetbulb temperature TW , is surprisingly similar across diverse climates today. TW never exceeds 31 °C. Any exceedence of 35 °C for extended periods should induce hyperthermia in humans and other mammals, as dissipation of metabolic heat becomes impossible. While this never happens now, it would begin to occur with global-mean warming of about 7 °C, calling the habitability of some regions into question. With 11–12 °C warming, such regions would spread to encompass the majority of the human population as currently distributed. Eventual warmings of 12 °C are possible from fossil fuel burning."
Their estimates of regions effected are based on areas that have at least one five hour period with Tw (wet bulb temperature) equal to or greater than 35 C in a year. They are slightly pessamistic about the survivability of such temperatures, given that mine workers routinely work 10 hour or longer shifts with Tw up to 32.5 C. Wet bulb temperatures of 35 C are survivable with no work, no sunlight, plenty of hydration, and cooler conditions after the five hours. That is, provided you are healthy and acclimatized. Such temperatures will result in significant death tolls among the elderly, but do not necessarilly render the areas uninhabitable.
As the extent of such 35plus Tw areas increases, however, the prospect of Tw significantly greater than 35 C, or extending through most of any given 24 hour period increased, and that will render the areas uninhabitable for practical purposes, and certainly by 12 C, large portions of the Earth's surface will be uninhabitable in the summer (or for the tropics, spring and autumn) seasons. 10 C represents a convenient intermediate benchmark to express this idea more simply. If you want to insist on the 7 C value, however, I will not object - but there is no basis for a claim of uninhabitability at 4 C.
Note, even at 12 C, a significant part of the Earth will remain inhabitable, and much more of it on a seasonal basis; which by it self is sufficient to refute Coral Davenport's claim.
Moderator Response:[JH] Coral Davenport is a journalist for one of the world's most influential newspapers. Therefore, it would be extremely beneficial if you could communicate your concerns to her. The more journalists know about the science of climate change, the better off we will all be.
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chriskoz at 14:37 PM on 12 September 20162016 SkS Weekly Digest #37
Tom Curtis@2
At around 10o C above preindustrial temperatures, part of the tropics will become uninhabitable to humans without specific protection...
You made a typo, that is important to explicitly corrrect here. Should be "around 4o C" I think.
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Tom Curtis at 09:17 AM on 12 September 20162016 SkS Weekly Digest #37
In the video, at 4:08 , Coral Davenport says (with ums, ahs and other redundancies and interjections excluded):
"The specific marker that a lot of scientists and scientific institutions have put forth is the warming atmosphere beyond 3.7 degrees farenheight [2o C] on average. That is the point at which a lot of scientists say we will be irrevocably locked in to a future of these climate impacts, and we're at the point right now where scientists say a lot of that is already baked in. There was a point in the climate debate when it was about how do we keep from getting there. At this point, in terms of the emissions that are already out in atmosphere, and the rate of emissions being produced today, scientists are saying we are probably set to go past that tipping point, and the debate is really about how do you keep it from getting far, far worse. How to you keep the planet inhabitable by humans."
That is inaccurate on several counts. First, it is not clear that we are past the point where a realistic global emissions policy will prevent an average rise of temperatures above 2o C. We may be past the point were the political process will get us a policy that will achieve that, but we should distinguish what is technically feasible and what is simply a matter of inertia and unwillingness to treat the issue with sufficient seriousness by politicians internationally, lest we justify the inertia of the policians based on that inertia itself.
Second, neither 2o C nor 1.5o C (which a substantial body of scientists believe is the relevant limit) is a known tipping point. Nor are either the point where it is known with certainty that there will be significant harmful impacts from global warming. Rather, both are reasonable estimates of the temperature beyond which it is likely the impacts of global warming will by significantly harmful, and likely that we will may pass any tipping points. If we keep below those thresholds, on the other hand, it is most likely that we will not have passed any tipping points, and that harms will be small relative to the range of climate impacts from a stationary climate (ie, on in which temperatures have not been rising).
Third, however, and most significantly, there is no possibility that the emission of fossil fuels and cement will bring the planet to a point at which it is uninhabitable by humans. That is not great news. At around 10o C above preindustrial temperatures, part of the tropics will become uninhabitable to humans without specific protection (cooling suites, or significant respites in air conditioned areas for significant periods, etc) for several weeks a year on average. That is a circumstance well worth avoiding. Somewhere between 4o C and 10o C we will pass a point where the burden of global warming is likely to bring about a collapse of our civilization, with a consequent loss of life in the billions due to the collapse of global trade. But the debate is not, or should not be about these outer limits which we will explore only if we do effectively nothing about AGW (something that would require a reversal of current policy and technical trends). Rather, it is about how close to the 2o C (or 1.5o C) we can keep the rise, and how quickly can be bring global temperatures back below those limits, given that we overshoot.
Coral Davenport is wrong to suggest that human inhabibility is in anyway a plausible consequence of global warming (except as restricted to specific areas at the outer limits of potentical temperature increase); and wrong also to suggest that once we go past 2o C the debate is suddenly about keeping below a much higher limit that essentially lets poluters of the hook.
Moderator Response:[JH] Please share your oncerns with Coral Davenport. Climate change is one of her beats.
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jimspy at 08:22 AM on 12 September 2016Researching climate change communication at George Mason University
Congratulations, John, and welcome to the "other" colonies.
As to Vegemite, you may wish to latch on to our native sandwich spread delicacy: Nutella! It's equally nauseating, so you should feel right at home!
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pjmattheis at 05:10 AM on 12 September 20162016 SkS Weekly Digest #37
The cartoon of the week has layers of meaning - I have a CO2 monitor, and know how to use it, but I do not have a bell jar like the one pictured. However, a lone person in a standard SUV, with windows closed and no other ventilation, will quickly drive CO2 levels to 3-5 times outdoor 400+ppm. At those levels, cognitive function is heavily impacted, and in no good way. For a human with extended time in such an environment, "CO2 as plant food" gains new meaning, since vegetative brain function may be all thats left. This might could explain some of the crazy...
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Martin Gisser at 23:11 PM on 11 September 2016The Madhouse Effect, a review
We need more of this. Not only for the comic relief. Jokes are often more effective than dry fact based communication. Very Serious Persons dont like to look silly.
(Me I got convinced of the seriousness of the threat 20y ago when I met an atmospheric scientist on a bus: I made a denialist joke, but he didnt find it funny. Instead his jaw dropped. Within a fraction of a second the expression on his face told me, this is dead serious stuff.)
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Terry11 at 14:47 PM on 11 September 2016Tom Harris' Carleton University Climate Misinformation Class
Correction regarding Tom Harris' background.
Mr. Harris was not removed from Carleton Umiversity. He left after four terms. Owing to the fact there was such an uproar about the course subject matter when it was found to contain a number of errors and exaggerations (according to a CASS report) and some Carleton professors described the course as a "a source of embarrassment to the institution", it was mistakenly believed to be true. -
Digby Scorgie at 14:38 PM on 11 September 2016Range anxiety? Today's electric cars can cover vast majority of daily U.S. driving needs
michael sweet @33
Pardon my pessimism. All right, I'll concede that all the solutions for decarbonizing the global economy are known. They just need to be implemented on a world-wide scale. Does that sound better?!
We are therefore in a race. On the one hand we have to transition to a zero-carbon economy. On the other hand, the climate is changing for the worse at an ever-increasing rate. There are two possible outcomes. In the first scenario we transition to a zero-carbon economy in time to avoid the worst climatic effects. In the second scenario the climatic changes are too fast and disrupt our economic transition, which leads to a collapse of our global civilization; a few local civilizations are left struggling on here and there.
Which scenario is the most likely? The problem with the first scenario is that an enormous amount of social inertia has to be overcome even before we can implement the necessary changes. This is the main reason for my scepticism. But like any science-minded person I will change my mind if the situation changes.
As a postscript I'd like to add that, while I'm pessimistic, I still think it is essential that we fight like hell to change our attitude to the economy. It simply must be decarbonized. But I'm a tired old man. Please forgive me if I just sit back and watch what happens.
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nigelj at 08:38 AM on 11 September 2016Conservative media bias is inflating American climate denial and polarization
Eclectic @23
I would say the media is tilted towards the sceptics by a good 45 degrees minimum!
I agree with your comments on the Murdoch press. They present pure, one sided propaganda that is quite misleading. That’s being polite about it.
However even the so called liberal media or "in the middle" media is tilted towards the sceptics. The liberal media in my country goes at great pains to give sceptics 50% of column space on climate change opinion articles, even though sceptical climate scientists are in a minority. This is important because this false balance creates an impression with the public that scientific opinion is split 50 / 50 when it isn't!
Of course sceptics should get some space in the media, because of freedom of speech and balance, but they are over represented.
I just want to back to the Murdoch press and conservative leaning media like Fox. It is obvious I dislike their views on climate change, and other matters, however I'm also a strong supporter of freedom of speech. What really annoys me about their climate sceptical commentary is how misleading it is. You have talked about this.
Another example is an article I read in the conservative leaning media highlighting a paper on low climate sensitivity, without mentioning these papers are in a minority, and are based on a very risky set of assumptions on the so called pause. It all creates an impression that the science community has moved on and that climate sensitivity is now accepted as being low, when this is absolutely not the case.
If the "warmists" misrepresented research like this, the media as a whole would roast them alive, figuratively speaking. Warmists look at the weight of evidence, and the most thorough research papers.
I’m just interested in the truth about climate change. I’m 100% sure we have a big problem, but I’m open minded. It would be good if there was some alternative explanation that recent warming is natural, but there isn’t one that I can see which only leaves the greenhouse effect. I have a decent general education.
So if I can see this why can’t the conservative media? As I have said previously I think its a combination of things to do with selfishness, vested interests, dislike of big government, and a conservative tendency towards fixed beliefs based somewhat on emotive reactions. It’s like the conservative media have made a decision to distrust the science as its “inconvenient” to them for all these reasons, and have decided to declare war on climate science, and a war where the ends justify the means. It’s gone crazy.
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PaulS8950 at 05:51 AM on 11 September 2016Researching climate change communication at George Mason University
Welcome to Mason, John! Those of us in Atmospheric, Oceanic and Earth Sciences (and our Climate Dynamics PhD) have a long history contributing to WCRP, IPCC, Clivar, etc. Although I have just gone emeritus, I look forward to helping out in any ways that I can.
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StBarnabas at 05:44 AM on 11 September 2016Researching climate change communication at George Mason University
Many congrats John. I thoroughly enjoyed my time doing my PhD at the Harvard Smithsonian though that was back when Carter was president. I'm sure you will have a great time. We had an interesting discussion one night about how much you could make if you perjured your scientific integrety. This was long before the diagraced Wille Soon joined.
I'm sure you will find it great the DC area is wonderful, but the traffic is worse than it was in the '70s!
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shastatodd at 04:06 AM on 11 September 2016The Madhouse Effect, a review
talk about a madhouse! i am a narcissist. i consume resources and create pollution to enable my non-negotiable lifestyle! this behavior supports drilling, fracking, fossil fuel transportation by rail, truck or pipeline (including on native lands)... and agw.
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michael sweet at 01:06 AM on 11 September 2016Range anxiety? Today's electric cars can cover vast majority of daily U.S. driving needs
Digby,
I think you are being needlessly negative. It will be more difficult to make some products fossil fuel carbon free than others. So what if steel requires carbon? As Scaddenp and Tom Curtis point out above, biochar will make steel as good as fossil fuels. This would remove carbon from the atmosphere when making steel using electric arc furnaces using renewable energy. This techology has already been developed.
Once you have jet fuel from seawater , you can make any other hydrocarbon you want. Ocean freighters can burn jet fuel in their current engines without any modifications (Jacobson prefers hydrogen). Cost is estimated at US$3-6 per gallon (US$.75-1.5 per liter), less than gasoline in many European countries today. Plastics can also be made through this process using CO2 from the atmosphere (the Navy apparently found it was cheaper to get the CO2 from the ocean than from the air). I have seen articles that use plant based feedstock to manufacture plastic also.
There is no question that it will be a big job to convert our entire economy to a new source of energy. On the other hand, there is no doubt that fossil fuels will run out in 200 or 300 years even if we burn all the carbon in the ground. Do you expect our decendants to live in caves and revert to stone tools after all the carbon is gone?? I do not know anyone who has suggested that will happen We all expect them to figure out a new source of energy. We have that source availabe to us right now, it is wind and solar.
Currently business uses fossil fuels because they are the cheapest. Wind and solar have very recently become the cheapest source of electricity. As they are built out they will be able to replace fossil fuels for industrial heat and other uses. The best path forward is to convert the easiest energy first to renewables: electricity. Then you start to work on the harder processes.
Jacobson has demonstrated that there are multiple ways to get to fossil fuel free economies. There are multiple technologies for all of the objections that you have raised. I like the idea of jet fuel from sea water. Jacobson likes hydrogen power (with the hydrogen generated by electrolysis from renewable power). In 30 years we will see which tenchnologies win out. I doubt anyone today can predict exactly which technologies will be most successful. Just 10 years ago no-one thought that wind and solar would be as cheap as they are today.
Once renewable energy dominates the electricity market it will start to penetrate other markets. An example of this is the manufacture of aluminum in Iceland using renewable electricity from geothermal energy. Iceland is cutting into the market for Alminum made with coal electricity from Australia. Don't expect industrial manufacture of hydrogen (or jet fuel) until the electricity market has gone mostly renewable.
It is difficult to keep a positive face on in response to political stupidity, especially in the USA. It seems to me that we have no other choice, if we lose hope why should we build out renewables? The sooner we go full bore on renewables the less damage we will have to deal with. If we built wind generators like tanks were built during WWII we would emit much less CO2 in a decade.
The great positive is that renewable energy is now cheaper than fossil fuels!! Ten years ago it looked like the only way to get widespread acceptance of renewables was if the government heavily taxed fossil fuels. Those taxes have always been a political long shot. Now renewables compete without subsidy in many locations. And the price of renewables continues to go down! Walmart, Costco and Ikea are putting solar panels on top of their stores! Other major companies are loooking at solar because they save so much money.
As renewables gain market share it will become easier to raise taxes (or lower subsidies) on fossil fuels. Already the coal companies in the USA are going bankrupt!! Coal power plants are shutting down. There is discussion of making coal companies pay fair fees to mine on public land. As more wind and solar are built out it will become uneconomic to frak for gas. Unfortunately, nuclear was the most expensive power and is being eliminated along with coal. The response must be to build out renewable energy faster.
It is difficult to respond to a post like yours that lists multiple questions about many technologies. If you separate your questions into smaller chunks it is much easier to have a discussion.
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moreover at 23:01 PM on 10 September 2016The Madhouse Effect, a review
Regarding "Mann's unfortunate first hand experience" - I actually preordered the book from the organisation which was initially founded to help defend Dr. Mann (here's the article), namely the Climate Science Legal Defense Fund (CSLDF). (A signed copy is available, too).
I'm indebted to them myself when I was dealing with oil/gas industry threats over publizing a presentation by Dr. Kevin Trenberth. They gave me sound legal advice.
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Eclectic at 20:24 PM on 10 September 2016Conservative media bias is inflating American climate denial and polarization
Nigelj @22 , the playing field is more than just "tilted" by the sensationalism-and-controversy tendencies of innocently (and inappropriately) "balanced" or "equal time" reporting by the media.
The Murdoch press [most particularly] engages in active forcing of the denier messages. Op-Eds of gross falsehood in the WSJ (far too grossly false, to pass as editorial failure of supervision). And the use of a spurious "expert" to completely misrepresent and misreport the considered consensus of thousands of true experts (in a recent case). Many other cases could be mentioned. We are not talking of mild "spin", but of heavy-handed propaganda combined with suppression of truth.
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Digby Scorgie at 17:42 PM on 10 September 2016Range anxiety? Today's electric cars can cover vast majority of daily U.S. driving needs
michael sweet @31
I'd like to think one can still manufacture all of today's products, including EVs, in a zero-carbon economy. I've also read about Jacobson's work, but let me put it this way: I'm sceptical! And then you get comments such as Jim Eager's that some products can never be carbon-free. What do you say to that, Michael?
I've read about such things as electric-arc furnaces, carbon-absorbing cement, and alternatives to jet fuel. I looked at a shipping website and discovered that the shipping people are also concerned about their fossil-fuel habit and would like to kick it, but find it difficult. I know fossil fuel is needed for plastics, and I assume this doesn't mean having to burn the stuff.
Regarding jet fuel, for example, I read about a US experiment where ammonia was used to power both a helicopter and an aircraft. Ammonia can be manufactured using renewable sources of electricity, which makes it carbon-free. Then I was told (at SkS) that more-advanced synthetic fuels are being investigated, presumably different from biofuels. So there are hints of a solution but there remain intractable difficulties with transport. By contrast, generating electricity using renewable sources is simple.
So, to sum up, I'm sceptical that we can really decarbonize the global economy. I'll believe it when I see it. And finally, I think it's all theoretical anyway. Climate change will clobber us first.
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