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Comments 19001 to 19050:

19001. bvangerven at 00:43 AM on 19 June 2017
       Explainer: Dealing with the ‘loss and damage’ caused by climate change
       

       @4 chriskoz: I hear you.

       
       The Paris agreement is as weak as any agreement can be. That’s the reason even the fossil fuel industry supports it. Trump asked to renegotiate this agreement but it is hard to imagine an agreement that asks even less of its participants.

       
       The Paris agreement is entirely voluntary. Every country announces how much emission reduction they want to achieve, but this cannot be legally enforced, and if a country breaks his promise, it has no consequences.

       
       If a government official proposed to collect taxes in a similar manner he would be declared mad. Imagine that every citizen in the country can freely choose the amount of taxes he will pay. Nobody with half a healthy brain cell left thinks that this could work.
       But this is the scheme they have thought out to tackle the biggest problem of our time with ZERO margin to get it wrong.

       
       I do see one way out: appealing to the universal declaration of human rights. Global warming will threaten several human rights – among which the right to a livable environment for current and future generations. And therefore a government taking no or insufficient action can be legally sued and enforced to take action. On this subject I can recommend the book by the Dutch lawyer Roger Cox: “Revolution Justified”.

19002. chriskoz at 22:33 PM on 18 June 2017
       Explainer: Dealing with the ‘loss and damage’ caused by climate change
       

       bvangerven@3,

       I like your passion and honesty. so, Is there a positive answer to your quest?

       In current political situation, nope. At the international level, the AGW problem can be viewed as a typical tragedy of the commons (I know some poeple here don't like this term but I cannot use a better term to describe what I mean here) without any global regulation or incentive that historically was always needed in resolving similar problems. If the best we have so far (Paris accord) is so weak that the biggest polluter to date (US) can quit it at whim without any conseqences, it means we have practically nothing.

19003. bvangerven at 21:58 PM on 18 June 2017
       Explainer: Dealing with the ‘loss and damage’ caused by climate change
       

       For me, the most important question in the climate change debate is: who is going to pay for this ?

       
       Perhaps your reaction is: Shouldn’t we focus on choosing the best solution and implementing that solution, and let’s find out later who will pay the expenses ?

       
       But the point is: we are not reaching a solution BECAUSE this question isn’t answered.

       
       The viewpoint of scientists has shifted. First, they thought only about mitigation: what can be done to stop climate change ?
       Then it became acceptable to think about adaptation – which is already an acknowledgment of defeat – we can’t stop it anymore, how can we adapt ?
       Now, apparently, we are starting to contemplate the possibility (well, it is not just a possibility, it is already the daily reality) that we won’t be able to adapt, so there will be loss and damage to pay.
       And even geo-engineering, which scientists would deem unthinkable a decade ago has become a serious possibility . Geo-engineering is btw not the best term, because it wrongfully implies that it is a precise science with known outcomes. Climate interference is a better term: taking desperate measures, injecting sunlight reflecting aerosols into the atmosphere, hoping it will have no adverse effects we don’t know about. In reality, it is another way of playing russian roulette with the planet at stake.

       
       WHY are we contemplating one possibility after the other, one even more grotesque than the other ? Because the fundamental question: who is going to pay for this ? is not getting answered.

       
       Climate mitigation is by far the cheapest and least risky solution. Why does the world not choose to go for the best solution ? Because the bill is not always paid by the same stakeholders.

       
       Climate mitigation would largely be paid by the polluters.
       Climate adaptation would most likely have to be paid by the tax payers
       Loss and damage would be paid by the countries that suffer the most from climate change, either in the shape of money or in the shape of lost human lives and property.
       Geo-engineering ? That would be a giant perpetual bill that our generation leaves to future generations.

       
       And in such cases the bill tends to end up at the people with the least influence and the least power. That means: the developing countries and the future generations.

       
       The only way to get out of this deadlock is to say: no matter what, no matter which solution is chosen, the bill has to be paid by the polluters. It is the only logical decision, and the only fair decision.

       
       Once fossil fuel companies realize that the bill will end up on their desk anyway, they will quickly choose and support the cheapest option, which is climate mitigation.

       
       If we fail to let the polluters pay, I don’t believe we will succeed in avoiding catastrophic climate change.

19004. chriskoz at 21:57 PM on 18 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       Tom Curtis@68,

       The limitting factor of Ohm law in DC transmission is not the percentage of resistance Ohm losses in proportion to the transmitted power but the temperature rise of the conductors that results from the Ohm losses. It thought it was obvious in my previous post, that my examplary Ohm loss of 16,000 W/m was enormous and unrealistic. If not, I restate it here with an assertion that this Ohm loss does not magically "disapppear" into oblivion (as, incidentally FF interest groups would like them to "disappear" after burning into "trace gas only"), but must be dissipated as heat. So, imagine each metre of your transmission line becomes 16kW heater which is a very accurate model, what happens? The wire simply melts away. My lowest estimate (160 W/meter) that I deemed realistic will still rise the conductor T but likely not to the point of damage because such amount of heat can dissipate without signifficant rise in conductor temperature. The standards for maximum conductor temperature in emergency operation (up to 2h surge) is something like 90degC, while it must be even lower in continuous operation.

       Ohm losses are not the only losses in transmission. And those that I described in my examples are absolute physical limits. Practical losses will be higher due to menioned increase in T, ergo increase in conductor resistance. Ohm limits the amperage of your cable, to the practical limit of couple kA. Other losses like corona discharge limits the voltage of your line, current highest is 1.2MV. You can try to build higher towers/bigger insulators but only up to a point. The cable cannot be too thick (in my examples I used 5cm but 2cm is more realistic standard for aerial cables) because your tower would fall down under the weight and force of the stung up heavy cable.

       To see the practical limits of HVDC transmission in play look at its records here. Remember, each record is achieved by itself at the cost of lower than optimal (not shown in this Wiki summary) other parameters of the line. Now Desertec (or Dii as it's now known) wants to beat all of those records, including voltage and distance in one mega-project. The fact they failed confirms my opinion they wanted to build something too big that exceeds the limits of available technology.

       In your responses to me and Nigel, you're quoting their plans from 2012 at the latest, while I provided the link from 2013 explaining what happened:

       Siemens pulled out of the venture in November last year. In the same month, Dii failed to get the support of the financially-strapped Spanish government for a 500MW CSP demonstration project in Ouarzazate, Morocco, though the project is still going ahead.

       So it's worth quoting the the explanation form the head of Energy Policy in Spain. She said:

       At a very basic level, we are still missing lines and capacities for export, Spain is already struggling with its own excess renewables production – additional imports from third countries would certainly compound the problem,” she added. “It is difficult to argue that the EU needs the additional RES capacity,”

       In other words, the load balancing of local network with intermittent renewables is already a big problem, without dealing with concentrated energy transmission, which confirms my opinion. You are better off by producing and consuming your RES locally. Maybe "locally" means within EU itself with distances within the limits of current transmission technology. Maybe she would like Spain (where there is still plenty of sun) to become the "Sahara" of that project so that she be happy with production and export only (like I'm happy with my rooftop PV that need zero maintanance) and do not deal with complex logistics of transmission and load balancing of intermittent source.

       Dii is currently thinking its network can power African and Middle-Eastern nations, which is more realistic as transmission distances are shorter. Perhaps it did not abandon its dream of powering Europe from Sahara, but s of now, it is only a dream.

19005. Digby Scorgie at 17:48 PM on 18 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Tom Curtis @8

       Thanks!

19006. jgnfld at 16:03 PM on 18 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       While it's obvious to most, "sceptics" like Giaever, and many others, totally miss the point when they talk about problems with measuring the global average temperature. What anomalies measure is trend at a location. The global set of anomalies is the global sample of trends not the global sample of temperatures. Nowhere in there is any attempt to measure global mean temperature, nor should there be. Sampling issues remain, but the issue is whether there is sufficient coverage to infer trends averaged globally not whether there is sufficient coverage to measure global average temperature. While more coverage is good, what reasons do we have to assume that unsampled areas are systematically different from already sampled areas in ways not already identified and corrected for (e.g., urbanization at sampling sites)? 

       Giaever's critique focuses on showing the difficulties involved in measuring a completely irrelevant variable.

19007. nigelj at 11:30 AM on 18 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       Tom Curtis @71, thanks I will read that later this week as its quite long.

       It's a much more plausible looking proposal. It will come down to costs and benefits.

       Everyone is looking for magic bullets, but there aren't any, just various options that might work for some countries and not others. The EU has a common policy on many things, so should be able to coordinate over electricity, and as spain and northern africa suit solar so well, its the obvious thing. It really just depends on how all costs stack up, and that is a huge calculation. But sunlight intensity, consistency and hours are so good in the Sahara its a big plus that could outweigh the cable costs.

       We are the opposite in my country, and have cloudy weather and are too far from any desert, but have great wind resources and geothermal.

       I think humanity is so used to traditional forms of energy, it's a big mindset change and confidence thing and this is probably more of an impediment than the actual technical issues. Unfortunately we are also becoming more reliant on electricity than ever, so this has come at a difficult time. 

19008. Tom Curtis at 09:49 AM on 18 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       nigelj @69, Desertec's proposal isn't for a single large facility in the middle of the Sahara, but for a large number of smaller facilities within the Sahara and parts of the Middle East.  That would be desirable if for no other reason than to extend the longitudinal extent of power production to minimize the need for storage.  The image I showed @28 above merely illustrates the proportion of the Sahara that would be needed to generate the relevant amounts of power, not a proposed site.

       Desertec provided this schematic of likely locations of sites:

       

       The idea would be a band of solar power sites across the Sahara just south of the Mediterainian, supplmented by a another band of fewer sites just north of the Sahel.  That would give mimimum typical transmission distances to Europe and Sub-Saharan Africa, and also give some latitudinal extent to avoid the impact of localized weather systems.

       Dii shows this map of current Dii projects:

       

       Their full 2012 proposal is here.

19009. nigelj at 09:11 AM on 18 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       Ah sorry Tom Curtis, I see you addressed some of that earlier above. Thank's by the way.

19010. nigelj at 09:02 AM on 18 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       Regarding 'desertec', I just wonder if the issue is really about the technology as such. I respect the various comments, for and against this and power losses and its rather intereresting.

       I think its really about relying on such a single huge centralised facility and single cable network. This would go for any type of very centalised facility.

       1) Yes the Sahara has incredibe sunlight hours and clouds rarely form because they can't, but it does get about 1 inch of rain a  year, usually torrential. One giant facility would still be offline for a few hours, and so would be particularly reliant on rather expensive and huge backup, unless people have to live with a few power cuts.

       2) Desertec is such huge reliance on one single facility, or group of facilities and, one gigantic cable network. This cable would become a huge target for terrorism, unless it was buried underground at enormous cost, and this creates other problems.

       Yes all systems can fail but having such a large system fail even if only a few hours would be a special kind of problem

       You probably need several desertecs spread, with their own cable networks.

       The ideal is solar on peoples roof tops, but this is reliant on breakthrough battery technology. You smart fellows want to be wealthy and earn a nobel prize, get into that.

19011. Tom Curtis at 08:37 AM on 18 June 2017
       Animal agriculture and eating meat are the biggest causes of global warming
       

       Theresab @8, this SKS page discusses the issue directly.  Essentially, deforrestation contributes more to global warming than does agriculture (18.2% vs 13.5%), but most deforrestation is driven by the lumber industry, not land clearing for agriculture.  From agriculture, the major contributors are agricultural soils (6%) and livestock and manure (5.1%).  All percentages are of global totals in CO2eq, from 2000 data.

       Crops require far less land area than does pasturing cattle.  Indeed, in general, you will require 10 times as much land area for animals as you will for plants for the same total food production.  That said, some area on which livestock is grazed is not suitable for cropping due to inadequate rainfall or other factors. 

19012. SteveAplin at 04:25 AM on 18 June 2017
       Tom Harris' Carleton University Climate Misinformation Class
       

       way late to the discussion, but since I live forty-five minutes by foot, fifteen by bike, and five by car from the institution in question (Carleton University) and am one of Tom Harris's fellow alumni, I feel compelled to jump in and say...

       His responses to the critiques offered hereare so weak and irrelevant he should be embarrassed.

       You know a denier has got nothing when he trots out the old "colorless, odorless gas" remark about CO2, as if it's only a pollutant if you can see and smell it. The same exact description applies to CO, the most reliable and prolific toxic killer of humans in human history, which is most definetly a pollutant.

       I have come to learn that when I hear the hooves of that old nag clattering on the pavement, I must expect little from the denier in the way of research and evidence and much in the way of irrelevant platitudes such as "plant food."

       It is a shame, because Harris's critique of the means by which we humans have begun our quest to reduce our dumping of carbonaceous garbage into our atmosphere is not so bad.

       He correctly identifies natural gas as the big beneficiary of efforts to reduce power-generation-related CO2.

       Natural gas, or methane (CH4), is, in all applications, a CO2 emitter almost as bad as coal. Quitting coal in favour of natural gas is like quitting whiskey in favour of wine — you're still a drunk.

       There's one and only one powergen option that keeps the lights on without CO2, and that's fission of uranium.

       Unfortunately, those who profess to care about reducing CO2 couldn't be less interested in promoting nuclear. They're too busy pushing proven non solutions like wind and solar.

       And who's the big beneficiary of that? 

       The natural gas industry.

       SKS editors — with all due respect, and I do most sincerely respect and admire you — it is high time you climbed off this renewable energy bandwagon. RE has failed in Germany, its biggest and most enthusiastic uptaker. Other than Brazil and my neighboring province of Quebec, just about every jurisdiction on earth that has a low grid electricity CO2 intensity per kilowatt-hou has at least some amount of nuclear. That's not a coincidence.

       Moderator Response:

       [DB] Nuclear power is wedge number 9 in the solutions to replacing fossil fuels.
       
       https://www.skepticalscience.com/solving-global-warming-not-easy-but-not-too-hard.html

19013. Theresab at 03:27 AM on 18 June 2017
       Animal agriculture and eating meat are the biggest causes of global warming
       

       OK, I have a question... So, supposedly not eating meat will reduce carbon emissions and help reduce global warming correct ? But so far it seems the main way animal agriculture contributes to global warming is through deforestation for feedcrops and pasture land. If more humans start eating plants instead of animals however, while the need for pastures and feed crop land will reduce, won't the need for farmland to grow all these in demand plants just increase ? For example the U.S is already unable to produce enough fruits and veggies to feed its citizens and relies on other countries as a supplement..if the decrease in land needed for animals doesn't match up to the increase in land needed for plant farming , won't this result in even more land cleared in other places to keep up with supply and demand (aka money to be made ? )

19014. chriskoz at 23:37 PM on 17 June 2017
       New research may resolve a climate ‘conundrum’ across the history of human civilization
       

       Nigelj@1,

       It's always better to look at the actual published source rather than dodgy 'skeptical' blog.

       The 'conundrum' Dana is talking about likely comes from (Liu et al 2014) where they state:

       A recent temperature reconstruction of global annual temperature shows Early Holocene warmth followed by a cooling trend through the Middle to Late Holocene [M13]. This global cooling is puzzling because it is opposite from the expected and simulated global warming trend due to the retreating ice sheets and rising atmospheric greenhouse gases. Our critical reexamination of this contradiction between the reconstructed cooling and the simulated warming points to potentially significant biases in both the seasonality of the proxy reconstruction and the climate sensitivity of current climate models.

       So L14 has already pointed out the possible M13 sesonal and hemispheric bias. They, hower, looked at SST reconstructon biases only. Look at Figure3 in L14: it has been known that N hemisphere models (3B) do match Marcott (3A) at least in sign.

       However, note that the total cooling shown by M13 from the peak of Holocene (ca 7ka BP) to the LIA dip, is some 0.5-0.6 degC only. Not 1.4C as the 'skeptical' blog clearly exaggerated. BTW, that latter graph is hardly readable with 4 plots superposed. The obliquity plot has nothing to do with the rest of the plots because Milankovic forcings do not have direct effect on global temperature, they only produce variations in Arctic temperatures. However 'skeptics' have superimposed and scaled the obliquity plot only to suggest to uninformed that obliquity is in direct correlation with temperature shown by M13, maybe to justify the bogus 'neo-glacial' label there. My 'uninformed' question would be then: why the obliquity is so different than T in the very first section of it labeled 'pre-boreal' (whatever that mysterious term means)? Logical answer: because the obliquity has nothing to do with this picture and does not belong there.

19015. Tom Curtis at 17:29 PM on 17 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       chriskoz @66, in reverse order:

       1)  Your estimated 160 W/meter with 100 lines represents a total loss of 160 MW over 1000 Km, or 0.04% of the total 400 GW at the point of origin.  Even the 16,000 W/m estimated with 10 lines, ie, 16 GW over the 1000 Km represents just 4% of the 400 GW at origin.  Both estimates are well below the 10% loss per 1000 Km from Desertec.  Therefore I do not see how your calculations show the project to be implausible.

       2)  Desertec and Dii still exist (the later's most recent function being on the first and second of this month).  What has changed is their strategy.  Because Europe already has an abundance of electricity supply, they changed from a strategy which prioritized delivering energy to Europe first, to one that prioritizes delivering energy in North Africa and the Middle East, with the idea that overtime interconnections with Europe will be established allowing desert solar to provide an increasing share of Europe's power.

       3)  The solar resource varies substantially by location.  Indeed, the difference between the solar resource in the North Sahara to that in France is approximately a factor of 2.  In Germany or Britain, the solar resource is approximately a third of that in North Africa:

       

       This is an annual average, so the problem will typically be even worse in winter.  Put another way, solar energy is generated 45% less efficiently in France than it would be if generated in the North Sahara and delivered over high voltage DC lines, allowing for both the difference in solar resource and transmission losses.

       Further, purely regional grids must relly heavilly on storage, probably battery storage to allow regular power delivery.  Storage increases costs by 50-80% for eight hour capability (Lazard 2016).  As the best strategy will come down to costs, the costs of transmission lines will have to be greater than the costs of 400 GW of solar generation for local solar plus storage to be competitive with desert solar in Europe.  Based on Lazard's LCOE for thin film photovoltaic (the cheapest form of solar), and this estimate of costs of transmission by distance, the cost of generation is much greater.

       

       (Cost is in millions of USD for 2000 MW line.)

       4)  Costs for transmission would increase linearly with distance, not exponentially.  Increasing interconnectivity within an area will increase costs at less than the rate of increase of area covered.

19016. Eclectic at 13:04 PM on 17 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       Chriskoz @66 , I am sure you are quite right about super-colossal solar energy collectors transmitting over very large distances.  My impression was that Tom Curtis was primarily demonstrating the solar collection area needed for national-level electric power generation, as being a small area really (when set against continental size).  "Relatively" small projects, delivering to a city 100 or 200 Km away, might be practicable with today's technology.  But colossal projects might be the go, if future-tech superconduction at hot temperatures ever becomes possible — but by that time, it's more likely that local collection of solar power from rooves/walls/roads/etc will be the preferred option (not to mention small-scale fusion generation! ).

       Still, we cannot live in the maybe-future.  Present-day technology is at the stage where (politics permitting) coal-fired plants can be phased out quickly, and gas-fired plants following soon after.

       As you say, Chriskoz, a distributed/dispersed power generation system is not only possible, but very desirable also from the perspective of high resilience against terrorist attacks & natural disasters.

19017. chriskoz at 11:49 AM on 17 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       Tom Curtis@30, Eclectic@31,

       (sorry for late reply, my workweek was busy)

       My skepticism about large scale projects concentrating the renewable power into high energy, together with long distance transmition infrastructure is high, utopian cost. The process of concentrating many small, intermittent, low energy sources into a reliable and sizeable commercial supply (of an order 100s MW) is by itself very difficult without buffering storage of adequate capacity and time. In case of solar source, that time is at least a daily cycle. Then, on top of that, the lengths of the interstate transmition increase as the sources in entire regions/states stop producing completely due to meteorological conditions (such as a recent freak overnight storm in SA) and the entire load must be transfered from other state. The transmition costs owithin such model grows exponentially with its size. You don't need to be an expert in technology to understand, in a philosofical sense, that concentrating a number of small energy sources (higher enthropy) into a single high energy (lower entropy) "super-grid" is a process going against a natural entropy flow, whereas existing electricity distribution models go with a natural entropy flow. So the cost of a new model implementation must be much higher.

       IMO, much more realistic is a distributed model where electricity is consummed as close to the source as possible, with high capacity storage and some transmition that balances intermittence within a given region only, e.g. when broken clouds or local storm overshadows PV panels in a given suburb. Anything on a scale of Desertec project rfered to by Tom is unfeasible.

       With regards to Desertec, in was conceived in 2007-8, and the Tom's link is dated June 22nd, 2009: a time when its plans were very operational. Fast forward just 5 years till 2013, and Desertec abandons Sahara dream due to its utopian costs. Now, were in 2017, and no comparable alternative project is beeing considered (it should be given AGW solution becomes most urgent) so the idea is pretty much dead. Some say, as noticed by Nigel elsewhere, there were huge political obstacles with host nations. But I even disregard those obstacles (biggesr obstacle in general is outright science denial by white nations' politicians) and think technical obstacles may heve been decisive.

       High-voltage direct current transmission technology has its disadvantages, and above all its limits. Disadvantages include difficulty in AC/DC conversion and higher cost of safety and maintenance. In particular High-voltage DC circuit breaker is expensive and difficult to build. Those problems limit the practical length and power capacity of existing HVDC lines to 1000km/couple GW. To have the entire Europe's electric power (400GW) delivered from 2000-3000km Sahara increases the scale of the enterprise by 1000times. And don't forget that energy losses in trnsmission increase with a square of power. Even the Ohm law becomes the hard limit on such scale.

       For example, 400GW delivered by say 1MV line means 400kA current. Standard 2cm aluminum wire has resistance of 50 microOhm/m. But say a thicker (harder to deploy and support) 5cm cable, resistance 10microOhm/m be used. The power loss by Ohm alone is I²*R = 400kA*400kA*10microOhm = 160,000M*10microW = absurd 1,600,000W per each metre of cable. Of course no one is going to use just one cable, but even if you repeat the above calculation for 10 cables, each carrying its share of 40kA, you end up with enormous power loss of 40*40*10 = 16,000W per metre each. To be realistic you need to have say 100 lines, 4GW each, which is 4kA per line, with Ohm losses just 4*4*10 = 160W per metre. That's just the hard physical limit. There are other limits like corona discharge, arcing on insulators or dialectric leakage in case of underwater cable, that also add to the heat production and stress on the cable material itself.

       From my calculations above, it'll clear that concentrating and long distance transmitting the renewable energy is an expensive business that quickly becomes too expensive and scaling it even higher to the point of Desertec level becomes utopia.

19018. One Planet Only Forever at 11:24 AM on 17 June 2017
       Explainer: Dealing with the ‘loss and damage’ caused by climate change
       

       The assistance to developing countries should include "Giving Away" Carbon-Free technology (no patent profit-taking), and providing "Free to the developing nation" research assistance to develop location specific carbon-free systems suited to the divesrtity of regional population requirements.

       We really need to all be in this together working to improve the future for all of humanity, as a robust diversity of humanity (not all Drinking Coca-Cola or Pepsi - I like Dr. Pepper). Anyone not interested in helping with that needs to have their life truly be "Of No Consequence - Living on their own for their own amusement in ways that have no impact on anyone else."

19019. Tom Curtis at 10:00 AM on 17 June 2017
       CO2 is plant food
       

       Hans @27, there are a large number of studies of carbon exchange in a variety of ecosystems and seas, many of which will also analyse the day/night (diurnal) cycle.  As examples, Leinweiber et al (2009) analyze the diurnal cycle in Santa Monica Harbour.  Friend et al (2007) compare model and observaltional values net ecosystem exchange of CO2 (NEE) across a variety of land based ecosystems, including the diurnal variation in NEE (Figure 5, bottom panel).  However, it is easier to just look at the gross fluxes from the IPCC AR5 Figure 6.1:

       

       The gross fluxes are are indicated by the large arrows.  Where the gross flux is two way, the net flux is indicated above the brackets.  Values inside the boxes are the total amount in the reservoir.  Black figures indicate preindustrial values, while red values indicate the change to the preindustrial value due to anthropogenic influence.

       Although the gross flux is what you appear to be interested in, it is the net flux that is the relevant comparison for anthropogenic emissions, given that the gross flux largely represents churning which does not alter atmospheric concentrations, except locally on a diurnal basis, and regionally on a seasonal basis.

19020. nigelj at 09:26 AM on 17 June 2017
       Explainer: Dealing with the ‘loss and damage’ caused by climate change
       

       Developed countries are the larger emitters per capita, and are a bigger contributor to more severe weather, so some compensation should be given by developed countries to developing countries. We have caused them some harm, and this is normally the basis for compensation and various laws. It's a just approach to the whole thing, but its unreasonable to expect it to be sort of huge money give away either. 

       But determing such things in international court cases would be a nightmare. The only winners would be lawyers and bureaucrats. No country is going to want to admit liability over this huge climate issue.

       Proving and quantifying liability over specific weather disasters will be very, very difficult for several reasons. It will be hard to get countries to agree on how much certainty you need to determine if a weather event is caused by climate change. It would be hard to determine levels of compensation, as there are no innocents, everyone is an emitter.

       It would seem that countries donating money as aid, or some sort of international aid fund might be the best solution, that recognises developed countries have some sort of duty to provide some extra help to developing countries. In fact if countries are severely hurt by extreme weather we often already help with international aid, and regardless of causation.

       Of course this would all require a determination of how much aid. But we could at least approximately quantify costs of climate change as a whole going forwards, and determine how much of this is caused by higher emitting countries. Levels of compensation will be a decision ultimately made by governments and populations, and some already give aid, but history indicates people are usually mostly willing to give some help through taxes or private donation or both.

       One thing about money given in aid or some form of international fund or insurance fund, as opposed to legal cases, is the use of that money can be monitored and controlled to some extent by the donors. Levels of aid money might also depend on whether developing countries are making efforts to curb their own emissions.

19021. Hans15731 at 08:48 AM on 17 June 2017
       CO2 is plant food
       

       I would like to know if there are measurements done showing the output of CO2 at night above seas, forests and grassy lands. If someone knows how many tons of CO2 is released at night and how much is absorbed by day.

       Also when plants die they release a lot of CO2 in the atmosphere, almost as much as they took in while they were growing and alive. One of the reasons I bring this up is to see what is the natural cycle and volume of CO2 going out and back into the atmosphere as we need some standard as to how nature processes CO2 .

19022. Curiousbev at 08:30 AM on 17 June 2017
       The Larsen C ice shelf collapse hammers home the reality of climate change
       

       As this is your first post, Skeptical Science respectfully reminds you to please follow our comments policy. Thank You! All this argument over nearly 50 years, and what have we done to adapt to the wilder weather? A simple blizzard can grind us to a halt just because we don't seem to have the sense to bury our power lines. Neanderthals managed to adapt to both warming and glaciation several times over a couple hundred thousand years. Today, power failures paralyze whole swaths of the country. Long term warming could indeed end us.  But ice is survivable. Our half -naked ancestors managed it. How can we deal with weather in the future if we cannot manage it today?

19023. nigelj at 07:08 AM on 17 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Ubrew12 @11, yes Giaver is like that.

       I recall Giaver complaining that the Antarctic or Arctic (I can't remember which) "only" had 10 weather stations, but he seems singularly unable to define exactly how many weather stations he want's, and why. It's like there would never be enough for him, and he is possibly saying "you cannot prove you have enough therefore, I'm going to say climate change is a fallacy". 

       In fact it's really hard to say exactly how many weather stations you ideally need globally. It's hard to quantify this.

       But the planet has thousands of weather stations through most countries, with gaps mainly in central africa. Even 10 in the Antaractic is obviously a lot better than just one or two, and they are reasonably dispersed.

       I suggest we intuitively know the thousands of weather stations across the planet that are at least reasonably widely dispersed, gives a good idea of global average temperatures that is pretty accurate, and accurate enough for our purposes. And its possible to look at areas with poor cover, and ask the question of whether it's likely temperatures in those areas whould be higher or lower, based on adjacent areas, and knowledge of their geography etc. We cant be 100% certain, but we can be pretty certain.

       Basically I feel people like Giaver are demanding 100% coverage and 100% certainty, yet as a scientist he should know things dont work like that and generally aren't possible. Maybe he has some hidden ideological agenda but I dont want to speculate. I just think he is being unreasonable.

19024. nigelj at 06:42 AM on 17 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Dfwlms @10 says:

       "What are the talents and experiences of the 3% of current, practicing climate scientists who do not endorse the consensus position of the US National Academy of Sciences? "

       Where are you going with that? Climate scientists all tend to have advanced degrees from what I have seen.

       And what would it matter? Having a poor qualification does not mean you are wrong, and having an exceptional qualification does not prove your assertions to be correct. This is the "argument from authority" fallacy as below. Qualifications are worthy of our respect, but they do not prove an argument or theory to be true or false, and only experiment and so on can prove that.

       en.wikiquote.org/wiki/Argument_from_authority

        

       "Historically, minority opinions about controversial subjects have often eventually prevailed while the majority opinions were found to be without merit."

       Sometimes this has been the case. Please quantify and prove what you mean by "often". 

       And what is your point? Its like you are implying some theories have been wrong in the past therefore climate science is by definition wrong. This is a pretty illogical claim, if you are making it. The scientific consensus has been wrong on some things, but that does not mean it is wrong on everything. All we can really say is scepticism has its place - but obviously has to be based on something compelling.

       And what is your alternative to scientific theory and consensus? Should the public just listen to whoever shouts loudest?

       I can at least say the large consensus views of physics and biology of this and last century have proven to be very durable, eg evolution, quantum theory, plate techtonics  etc.

       Some smaller consensus positions have proven to be only partly correct, eg dangers of saturated fats. In fact consensus positions sometimes evolve, rather than radically and completely change.

       "For example, apparently a significant percentage of legitimate scientists believed the "Piltdown Man" hoax for over 40 years: "

       That was a long time ago, when anthropology was in its infancy.   More modern scientific theories are much better scrutinised than piltdown man, because science itself has progressed, we have more scientists in the planet, communication systems have improved, science education has spread, and so on.

19025. Philippe Chantreau at 06:02 AM on 17 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       dfwlms @ 10. The experience, talent and expertise of the researchers involved is completely irrelevant. First, one would have to quantify these according to objective criteria, an undertaking in its own right.

       Regardless of their "ranking" in these matters, they are only still 3%. Most people choosing the consensus as their favorite denmial target attempts to depict it as a consensus of opinion, while it is in fact a consensus of research results. 97% of scientists actively researching climate find that their research supports the current model of Earth climate and the influence of greenhouse gases, that's what matters.

19026. ubrew12 at 03:27 AM on 17 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       nigelj@3 said: "Giaever is... a highly accomplished physicist... not... a climate expert"   I've noticed Giaever also committed a fallacy I've started calling 'heads I win, tails you lose'.  In this case, no amount of temperature sensors covering the Earth, carefully adjusted to remove local effects like the urban heat island effect, and integrated together on an area basis will satisfy Dr Giaever that the climate scientists have done an adequate job calculating Earth's temperature... Tails You Lose.   A few minutes later, Dr Giaever casually points to a single temperature sensor, at the South Pole, which has cooled in recent decades, and declares this proves his point about Earth not warming... Heads I Win.

       As Donald Trump would say: "There's a real winner!"

19027. dfwlms at 02:04 AM on 17 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       What are the talents and experiences of the 3% of current, practicing climate scientists who do not endorse the consensus position of the US National Academy of Sciences? Historically, minority opinions about controversial subjects have often eventually prevailed while the majority opinions were found to be without merit. For example, apparently a significant percentage of legitimate scientists believed the "Piltdown Man" hoax for over 40 years: https://en.wikipedia.org/wiki/Piltdown_Man

       Moderator Response:

       [DB]  Sloganeering and off-topic snipped.

19028. trstyles at 00:51 AM on 17 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       It's a safe bet that virtually all physicists accept stochastic approaches like the "Monte Carlo Method" to studying the subatomic realm, because they have been undeniably successful in making discoveries that are backed up by experimental evidence. I sometimes wonder however, whether many in the physical sciences do not yearn, deep down, for the deterministic universe of pre-quantum days. One that does not require the troubling concept of randomness.

       For example, some of you may have encounterd an individual with a good grasp of meteorology who nonetheless finds climatology rather difficult to understand and essentially untrustworthy. Common misunderstandings of climate science occur to some extent because it is possible to negotiate a successful career in physics or engineering without the need for probability theory and statistical methods, let alone an understanding of complex global systems. In fact it is possible for the stochastically squeamish to earn an advanced degree without taking courses that addresses complexity of the sort the so called "soft" sciences routinely deal with.

       The days when a university education was comprehensive and initiated a lifelong process of keeping up with all fields of "Natural Science" are past (l-o-n-g past). Specialization is now essential, but the limitations of specialization require trust in the professionalism of other scientists. Unfortunately trust has all but evaporated in large segments of society. The concept of Professionalism itself is diminished by confusing it with obnoxious forms of elitism.

       By the way, I hope is not overly "political" to point out that the current mess we find ourselves in is an example of science applied by persons ignorant of how complex systems operate. We are literally witnessing uncontrolled "blowback" caused by unscrupulous social engineers who abused behavioral science. They employed sophisticated propaganda in pursuit of a certain limited result...... and got far more than they ever bargained for.

       I hope it was more. I'm not quite prepared to view our opponents in this debate(?) as being that derranged. Not yet.

19029. Tom Curtis at 13:33 PM on 16 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Digby Scorgie @5, Annan and Hargraves (2013) find a temperature difference between the preindustrial and the Last Glacial Maximum of 4.0 +/- 0.8^o C.  The IPCC AR5 show a range of estimates as follows (Table 5.2):

       4.4–7.2; Single-EMIC ensemble with microfossil-
       assemblage derived tropical Atlantic SST; Schneider von Deimling et al. (2006)
       4.6–8.3; Single-EMIC ensemble with multi-proxy derived tropical SST;
       Holden et al. (2010a)
       1.7–3.7; Single-EMIC ensemble with global multi-proxy data; Schmittner et al. (2011)
       3.9–4.6; Multi-proxy; Shakun et al. (2012), for the interval 17.5–9.5 ka
       3.4–4.6; Multi-AOGCM ensemble with global multi-proxy data; Annan and Hargreaves (2013)
       3.1–5.9; Multi-AOGCM ensemble; PMIP2 and PMIP3/CMIP5

       The same table shows the East Antarctic temperature difference to be 7-10^o C.  Any graph which shows a lesser temperature range using the Vostock ice core data has scaled the temperature to reflect the difference between the polar and global temperature.

       In any event, that suggests the NAS is claiming LGM temperatures 4-5^o C below preindustrial temperatures, and hence 5-6^o C below current temperatures.

19030. nigelj at 13:09 PM on 16 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Evan @5, yes you would think Dr Giaver would realise small changes can have substantial effects, depending on the issue and context. He is an expert in  semiconductors, and these devices can amplify small currents into larger currents,so if anyone should appreciate this he should.

       However he might be thinking that these devices can also work with and remain stable with small fluctuations  in power supply voltage (I emphasise very small, I was investigating this to see if a smartphone power supply could work with my older spare mobile phone), and so thinks of the planet in those terms.

       However clearly humans have become adapted to a stable climate and face several degrees of change and this has to have consequences, and we know this from basic biology and the potential pressure on our infrastructure, communities, cities and agriculture.

       People see things from their learned perspectives, understandably enough, and I probably have my own biases.  He is probably applying analogies from his own specialist field, and has reaced a sceptical and flawed conclusion.

19031. ubrew12 at 12:46 PM on 16 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Digby Scorgie@5:  I've been wondering myself.  This graph says an 'ice age' (actually: glacial period) is about 4F to 8F colder than preindustrial.  

       

       8F is 4.5 C, so maybe that's what NAS means.  But I've been calling, in my personal correspondence, that an 'ice age' is, on average, 6F colder than preindustrial (average of 4F and 8F).  6F is about 3 C.  

       It's important to call attention not to the overall rise, but to the rise rate.  For example, the rise from the last glacial period was 3 C to preindustrial.  However, it took 10,000 years to accomplish.  That's a rise rate of 0.03 C/century, for one of the most radical natural climate changes recorded in prehistory (or, at least, the last 420,000 years).  By way of comparison, the rise rate in the 20th century was 25 times that value.  Natural?  I don't think so.  Worse: if the last 25 years is any guide about the 21st century, then this centuries rise rate is 75 times that natural value.  The people (Trump etc) who keep calling this climate change an example of 'natural' change, really need to explain why we are currently rising at a rate 75 times what a Milankovich Cycle would demand of Earth, naturally.

19032. Digby Scorgie at 11:56 AM on 16 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       I note that the NAS states that global temperatures were 4 to 5 degrees lower during the last ice age than "now".  But we've warmed about one degree since the start of the Industrial Age.  So does that mean that Ice-Age temperatures were actually 5 to 6 degrees lower than the pre-industrial temperatures?  Or is that really 4 to 5 degrees lower than pre-industrial?

19033. BBHY at 10:35 AM on 16 June 2017
       The Larsen C ice shelf collapse hammers home the reality of climate change
       

       Larsen B was bad news. Larsen C is very bad news. Now, there is evidence of the West Antarctic Ice Sheet surface melting. Horrendously bad news. 

19034. Evan at 09:54 AM on 16 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       nigelj@3. What is also surprising about Dr. Giaever's comment that 0.8C warming is only about 0.3% of 288K ("From 1880 to 2015, the temperature has increased from 288 K [degrees Kelvin] to 288.8 K - 0.3 percent. I think the temperature has been amazingly stable."), is that any kind of trained engineer, scientist, or technical person knows that the scale you use depends on the question being asked. To do such simple math is really surprising, because just from the consideration of ice melting, a much more logical reference point is 0C, and not 0K. Relative to 0C a warming of 0.8C from 15C to 15.8C is something to worry about. But on the other hand, not even James Hansen has made a big deal of 0.8C warming, if that was what we were limited to. Apparently Giaever also does not realize that we are talking about warming of 2-4C. If you are ice, that is a really big deal.

       He should know this. But this is why we need to look for consensus opinioins, because such simple oversights get caught in a group of experts.

19035. nigelj at 07:48 AM on 16 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Here is a perfect example of so called experts. Dr Gaiver has a mechanical engineering degree, plus a PHd in physics (something to do with semiconductor electronics) and has a nobel prize for physics, so clearly a bright guy with scientific credentials.

       He is also a well known climate sceptic. But he has never studied climate, and based much of his scepticism on one days worth of google searches on climate denial websites. His sceptical views are also on issues that have long since been genuinely debunked. Yet because he has a phd he gets peoples attention, and gets endlessly quoted by sceptics  (although selectively on what he says) even though his phd is not even remotely connected to the climate.

       Read his bio on wikipedia and also this article:

       www.snopes.com/2015/07/08/nobel-ivar-giaever-obama-climate-change/

       "Shortly after Dr. Giaever delivered his speech, his comments about President Obama began appearing on conservative web sites, cited as proof that global warming is a “hoax” and a “conspiracy.” However, Dr. Giaever (a physicist, not a climatologist) has given the same type of global warming speech in the same setting before, and by his own admission he doesn’t know much about the subject:

       I am not really terribly interested in global warming. Like most physicists I don’t think much about it. But in 2008 I was in a panel here about global warming and I had to learn something about it. And I spent a day or so — half a day maybe on Google, and I was horrified by what I learned. And I’m going to try to explain to you why that was the case.
       Skeptical Science noted of Dr. Giaever back in 2012 that:

       While Giaever is certainly a highly accomplished physicist, that does not automatically make him a climate expert as well. As Giaever himself has admitted, he has spent very little time researching the subject, and it shows. He simply bounces from one climate myth to the next, demonstrating a lack of understanding of Climate Science 101, and then insults the entire scientific field by comparing it to a religion."

19036. nigelj at 06:54 AM on 16 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Yes  clearly you need to ask the real experts, namely climate research scientists. Science has become so specialised these days, in fact all occupations have, and simply hiving a chemistry or physics degree isn't going to be able to tell you what's really happening with climate.

       In fact I would go further. It appears to me as an educated lay person, that the case that we are warming the climate rests on quite a wide range of evidence, unlike other theories which might rely on more limited labortatory experiments. This is because we cannot put the entire planet in a laboratory, so inferences and deductions are made from laboratory tests of carbon dioxide, paleo climate research, observations of changes in the atmosphere, modelling etc. Its very complex, and a monumental global exercise in research.

       The important point is it's hard for even one expert to see the full picture, and thus draw accurate conclusions. So only bodies of scientists like the IPCC or science academies can really get their heads around the full picture, and what it means. This means the consensus is particularly significant. This review by committee may be frustrating, but it is the only way of comprehending the full nature of the issue.

       And yes, the sceptical community are spreading doubt, but refuse to come up with a valid alternative theory, or anything convincing on climate sensitivity. It just seems they are driven by political ideology, vested interests and anger, because if they were really sincere, they would put all cards on the table,

19037. Jonas at 06:24 AM on 16 June 2017
       Anti-vaccers, climate change deniers, and anti-GMO activists are all the same
       

       I hereby withdraw my donations and support from SkS.

       Monsato GMO "research" is Science Denial,
       and if Science Denial is promoted even here: .. good bye.
       There is plenty of good Climate Science Work here,
       but I do not accept industry lobbying and will not pay for
       and promote this site any more (I did it hundreds of times).

       Just an example:
       "The court documents included Monsanto’s internal emails and email traffic between the company and federal regulators. The records suggested that Monsanto had ghostwritten research that was later attributed to academics and indicated that a senior official at the Environmental Protection Agency had worked to quash a review of Roundup’s main ingredient, glyphosate, that was to have been conducted by the United States Department of Health and Human Services."
       https://www.nytimes.com/2017/03/14/business/monsanto-roundup-safety-lawsuit.html?_r=0

       Another example:
       « Monsanto papers » : la guerre du géant des pesticides contre la science
       http://www.lemonde.fr/planete/article/2017/06/01/monsanto-operation-intoxication_5136915_3244.html

        

       Moderator Response:

       [PS] Monsanto => GMO. GMO != Monsanto.

       Constructive criticism of the article with evidence that anti-GMO sentiment is not based on the logic flaws outlined in the article is welcome. Better than throwing the toys out of the cot.

19038. nigelj at 06:20 AM on 16 June 2017
       New research may resolve a climate ‘conundrum’ across the history of human civilization
       

       Johnboy @3, the graph in my link  only goes back about 12,000 years, so only shows some of the warming since the last ice age ended.

       The last ice age ended about 20, 000 years ago and there is about 5 degrees of warming coming out of the ice age. Refer in the following article from RC. Scroll down to figure 4.  This also shows 20th century temperatures spliced on.

       www.realclimate.org/index.php/archives/2013/09/paleoclimate-the-end-of-the-holocene/

       I'm no expert, and stand to be corrected if my interpretations are wrong, but the link in my post appears correct, and RC is a very reliable website run by climate scientists.

19039. Rob Honeycutt at 04:11 AM on 16 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       An added comment on too's points 4-5:

       Research pretty clearly shows that consensus is important relative to the general public accepting climate change. Consensus isn't used to prove anything scientifically. Consensus is a way for non-experts to evaluate what is most likely to be correct and accurate. 

       No one expects anything to be proved by consensus. Consensus is a result not a method.

19040. ubrew12 at 03:46 AM on 16 June 2017
       SkS Analogy 8 - I'll take the specialist
       

       Excellent analogy.  I have a similar analogy regarding eyesight.  It occurred to me that the climate debate can be simplified to determining just one number: the ECS (equilibrium climate sensitivity to doubled CO2).  If the ECS is greater than 2 C, then we need to take action.  If it is less than 2 C, then we can relax.  

       Can the public use its science-eyes to 'see' the ECS?  No.  The public's right eye definitely sees something: Climate science has been calculating the same ECS for over a century, and today converges on this average value, 3 C, from at least twenty different directions.  But there is a problem.  The public cannot trust what it's right eye sees because an entire fossil-funded doubt-industry has dedicated itself to throwing shade at the Climate scientists.  

       The public is thus blind in its right eye.  To make policy, however, it still needs to 'see' the ECS.  Lets ask the left eye, the eye of the Skeptics.  What do Skeptics 'see' for ECS, and can they please show their work?  But, there's a problem: the left eye is closed.  It turns out the only purpose of the left eye is to invent reasons why the right eye can't be trusted, not to see anything on its own.  There will always be a reason why they cannot calculate the ECS, or cannot show their work, but 'just know', intuitively, that ECS is less than 2 C  (Rarely someone like Christopher Monckton will calculate ECS, and show his work, and people will find the error in that work usually on the same day).

       Thus the public is blind in both eyes.  One eye cannot be trusted, and the other eye is closed.  So, until our vision improves, we'll just stumble along blindly in the same direction, hoping for the best.  Which is the entire reason a powerful industry funded the left eye in the first place.

19041. Johnboy at 02:34 AM on 16 June 2017
       New research may resolve a climate ‘conundrum’ across the history of human civilization
       

       I apologize but i need help. I'm confused about the temperature changes over the Holocene since the end of the last ice age (or glaciation period). It appears that this piece and the plot provided by nigelj depict a warming of 1.5°C or so. Plots I've seen from ice core data over the last 400k years appears to me to show about an 8-10°C warming. (which actually does seem like an awful lot). Using that range,  I've been trying to impress my denialist friends that the earth had warmed at about 1°C per 1000 years, whereas now it's warming that much in just a century or so due to human driven climate change, 10 times as fast. 

       What am I missing here? This climate scientist wannabe would appreciate your help.

19042. dfwlms at 00:21 AM on 16 June 2017
       New research may resolve a climate ‘conundrum’ across the history of human civilization
       

       Based on many of the posted comments, one might conclude that the word "Skeptical" in the website title doesn't imply skepticism about scientific proclamations. So, one may wonder what the adjective is meant to imply.

       Moderator Response:

       [JH] Sloganeering snipped. 

       The explanatory statement appearing directly under Skeptical Science in the header of each page of this website reads as follows:

       Getting skeptical about global warming skepticism

19043. MA Rodger at 19:13 PM on 15 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       too @56.
       The position you set out for yourself is in part difficult to grasp.

       Your third point seems to be saying that you have doubts about AGW. The IPCC use of the word "likely" to mean 66% to 100% certain and “very likely” to mean 90% to 100%. Is it thus correct to consider your doubts as being 33% to 10% (ie no-less-than-10% as you appear unable to sign up to “very likely”)?
       With this in mind, my own position would be that AGW is “virtually certain” and I consider the UN IPCC rather pulls its punches when it sets out its assessment by stating “It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century” (that is 95%-100% certain) and that “Global surface temperature change for the end of the 21st century is … likely to exceed 2°C for ... RCP8.5." (ie RCP8.5 = unmitigated BAU).

       At your fourth point, you say the scientific consensus on AGW refers to your Point 3. Are you saying the scientific consensus applies only to AGW being “likely”? And then at your fifth point you say you don't see the scientific consensus on the likely-or-actual existence of AGW “proves this”. What is the “this” you refer to?

       Unlike Digby Scorgie @63, I will venture beyond point 5 (but unlike nigelj @58, not beyond point 9).

       Your sixth & seventh points are a matched pair. Obviously it would be a tiny bit lacking to prove some great calamity is about to occur if that knowledge is not used to prevent the calamity in some way. I would suggest that it is questionable whether it is useful to consider there being a 'solution' to AGW. Surely it is more a matter of how much AGW is sensibly acceptable and how much sensibly preventable.
       Your eighth point is entirely controversial. You are saying that you do not truly believe that a debate on the likelihood of AGW being the result of CO2 is “legitimate”. Do you then consider the work of the UN IPCC and its attribution of climate change quoted above to be “illegitimate”? Perhaps you need to chose a different word.

       This leads to your ninth point where you believe that it is “legitimate” to debate policy response to AGW even when there is evidently significant dispute that AGW even exists! How can such debate not become bogged down in the dispute over the exisetence of AGW?

       I would add that the [PS] Response @50 strongly asserts that there are “two sides” with a policy debate. I would agree. The Paris agreement had/has “sides” which could be divided into “two”. The UK Climate Change Act 2008 has “sides”. An individual country could be seen as having “sides” in AGW policy debates. And within the IPCC process there are also discernable “sides”. But to ascribe the confusion of all national and international policy decisions/non-decisions as collectively having “sides” is many steps too far for me.

       That said, there exists in particular circumstances “sides” whose positions and  whose impact on policymaking is worthy of discussion, but such discussion would require an understanding of where you are coming from. As I set out here, that is not yet nearly clear enough.

19044. Digby Scorgie at 11:50 AM on 15 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       too @56

       I got no further than your point (5).  Fossil fuels contribute about two-thirds of warming.  The consensus on this is based on hard data.  In essence, the ratio of atmospheric carbon 13 to carbon 12 is decreasing.  For the full story behind this you'll find an article on the topic at RealClimate.org.

       Moderator Response:

       [PS] read it carefully. I am not aware of anyone seriously considering that "consensus" = "proof". Proof belongs in maths not science.

19045. Tom Curtis at 09:59 AM on 15 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       michael sweet @61, Rhodes et al (2017) with regard to solar:

       "Capacity factor values for utility and residential-scale solar PV plants were calculated using the capacity factor maps found in Drury et al. (2013). Because these maps were at a finer granularity than county-level, the average value per county was calculated. Utility-scale PV was assumed to be single-axis tracking and residential PV was assumed to be south-facing fixed-tilt at the local latitude (see Figs. 46, 47). Capacity factor values for solar CSP were calculated using NREL's System Advisory Model (SAM) (NREL, 2015). Weather data from over 1000 locations across the US were used with the SAM model of a generic concentrating solar plant with 6 h of thermal energy storage. The resulting capacity factors for the plants were then used to give each county in the US a CSP capacity factor based on similar meteorological conditions (Fig. 48)."

       That is, with respect to each county, they used average insolation and meteorological data for that county to determine solar capacity.  In contrast, Lazard (2016) state, with regard to solar:

       "Low end represents single-axis tracking system. High end represents fixed-tilt design. Assumes 30 MW system in a high insolation jurisdiction (e.g., Southwest U.S.). Does not account for differences in heat coefficients within technologies, balance-of-system costs or other potential factors which may differ across select solar technologies or more specific geographies."

       That is, they assume the best case regional insolation available within the US across the entire US, making their solar costs to those in low insolation, high cloud regions equivalent to those in high insolation, low cloud regions. 

       Rhodes et al state with regard to wind:

       " Capacity factor values for on-shore wind were obtained from 3Tier at a 5 km×5 km resolution (3Tier, 2015) and were averaged at the county level. Wind capacity factors would be higher and thus the LCOE lower if the best locations in each county (rather than merely average conditions) were chosen for siting the wind turbine.  The capacity factor values were for a generic turbine with a hub height of 80 m (Fig. 45)."

       That is, they use the average wind speed across specific counties rather than for the entire country.  Lazard does not give that information, but are likely to have followed their practise with solar, by using the best case region for determining costs across the US.  Lazard also do not give information on tower height, with increased tower height reducing costs.

       With regard to these methodological choices, it is not the case that each county in the US generates its own power.  With a sufficient distribution system, it would make sense for nearly all utility solar in the USA to be located in the SW, and even more sense for a substantial portion to be located in Mexico.  It would similarly make sense for onshore wind to be located in the mid-west which has the highest wind capacity factors.  Rhodes et al, however, adress the issue of more local generation forced on suppliers by current distribution capacity and state based marketing regulations.  It also provides information as to the best location of energy sources within a national distribution grid, if such should be sufficiently developed.

       With regard to nuclear, Lazard states:

       "Key sensitivities examined included fuel costs and tax subsidies.  Other factors would also have a potentially significant effect on the results contained herein, but have not been examined in the scope of this current analysis.  These additional factors, among others, could include: capacity value vs. energy value; stranded costs related to distributed generation or otherwise; network upgrade, transmission or congestion costs; integration costs; and costs of complying with various environmental regulations (e.g., carbon emissions offsets, emissions control systems).  The analysis also does not address potential social and environmental externalities, including, for example, the social costs and rate consequences for those who cannot afford distribution generation solutions, as well as the long-term residual and societal consequences of various conventional generation technologies that are difficult to measure (e.g., nuclear waste disposal, environmental impacts, etc.)."

       Given that the US already has several operating nuclear plants, not taking into account the cost of stranded assets will inflate the relative cost of no longer using nuclear power.  I think you will find that Rhodes et al only show nuclear as being the cheapest option where such nuclear power plants are already operational, and not always there.

       For what it is worth, Rhodes et al show levelized costs by county showing, Min-Max, (Mean) in dollars per MWh as:

       Nuclear: 120-190 (124)

       NG (Combined Cycle): 40-230 (111)

       Onshore Wind: 40-1090 (155)

       Solar PV (Utility): 90-270 (199)

       The the low end county costs are therefore commensurate with those from Lazard, consistent with their different methodologies.  The exception is for Solar PV, where the difference may be due to Rhodes et al using a 2013 paper for information on county level capacity factors.

19046. nigelj at 07:40 AM on 15 June 2017
       New research may resolve a climate ‘conundrum’ across the history of human civilization
       

       Good  article, that resolves a long standing mystery. It shows the considerable power of climate models, but this message will be lost on the sceptics.

       The following graph may be useful, and was posted on RC some time ago. It covers the last 12,000 years and includes the temperature data from Marcott, plus various model temperature estimates, plus CO2 levels, all on the same graph, so the divergence is clear. Be warned, it appears to be from a sceptics blog, but does appear accurate. 

       tofspot.blogspot.co.nz/2017/06/a-glance-at-holocene.html

19047. Susan Anderson at 04:56 AM on 15 June 2017
       The Larsen C ice shelf collapse hammers home the reality of climate change
       

       Thanks, that's some nice additional information. I think the caption should be fixed above. Also, here is a more recent and specific item: A Crack in an Antarctic Ice Shelf Is 8 Miles From Creating an Iceberg the Size of Delaware. They're confused over there, so busy providing clickbait on Trump and "balancing" in Opinion that there is not enough front page coverage of some of their potential for excellent climate reporting.

19048. michael sweet at 04:52 AM on 15 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       Tom Curtis at 34 and 36,

       While the paper that you linked was recent and detailed, I wonder about many of their conclusions.  

       This table from Lazard (not peer reviewed but up to date)

       (source: CleanTechnica) shows wind and utility solar as cheaper than fossil fuels annd nuclear.

       Westinghouse has declared bankruptcy because of their comittment building the nuclear reactors in the USA and Toshiba looks like it will also go under.  The nuclear builds in Europe are far behind schedule and way over budget also.  In the USA nulcear plants are closing because the O&M costs are more than wind and solar including the mortgage on wind and solar (nuclear has paid off their mortgages).  I wonder how Rhodes et al can find nulcear economic anywhere considering this.

       In their analysis, Rhodes et al used the average wind speed over the entire county to estimate the efficiency of wind power.  In almost all counties there are locations where the wind is much better than the county average so they are strongly underestimating the wind potential (they discusss this problem in their paper).  

       While Rhodes et al have some interesting data, I think their analysis is just a first try.  With more data and analysis their method will probably be useful, but the first pass is incomplete.  

       I am not expert in these matters so perhaps I make a mistake.  Energy analysis are very complicated.  Because Lazard appears to use actual prices and is more up to date, it seems to me that that data is more accurate.  Energy prices change rapidly so data from a few years ago is often not accurate.

19049. michael sweet at 04:25 AM on 15 June 2017
       2017 SkS Weekly Climate Change & Global Warming News Roundup #23
       

       Too,

       This SkS post discusses Jacobson's plan to use 100% renewable energy to power the entire economy (the entire economy, not just electricity).  He shows this will be cheaper than using fossil fuels.  He shows in other papers that there are enough materials (like steel and rare earth metals) to build out the wind generators and solar panels needed.  He shows in other papers that renewables can generate 100% of all power used as reliably as fossil fuels.  His group gives a lot more data by state (in the USA) and for most other coutries in the world on their web site the solutions project (a good name since you want a solution.  You will have to consider that the cost of wind and solar have decreased dramatically since those papers were written so the cost for Wind and solar will be less than he projects.

       Moderator Response:

       [PS] Jakobson's group have paper in press discussing path to 100% renewables for 139 countries.

19050. Wol at 04:12 AM on 15 June 2017
       The Trump Effect - Making Lemonade from Lemons
       

       One thing that's worried me for some time is the lack of a date in the rebuttal listings.

       Given that one of the ways that deniers attempt to win arguments is to cherrypick data, relying on an out-of date rebuttal can inadvertently lose the discussion.

       It would be a big job to make sure each is actually up to current knowledge, but useful.

       Moderator Response:

       [JH] Your concern about the currency of the SkS rebuttal articles is shared by the SkS author team. If you, and others, would like to help out in the task of updating the articles, please send us a note using the the "Contact Us" button on the bottom of this webpage. 

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