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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Recommended supplementary reading...

Video interview of Ian Plimer at Sky News falsely claims that a new study announces an incoming ice age, partly based on an incorrect Daily Mail headline, Edited by Nikki Forrester, Article Review, Climate Feedback, Jan 20, 2021

Bob Loblaw at 11:17 AM on 2 February 2021

A Climate Bet Impossible to Lose

Johnny's point about "raw data" raises an important issue. What is "raw" data? When does data processing start?

For the satellite data, what is being measured is actually microwave emissions form the atmosphere, and it take a lot of modellig to derive "temperature" from that data. Rob's post has some good links in the "Selection of data sets" paragraphs that explain much more.

Pretty much any environmental variable has some sort of processing that needs to be carried out. Even something as simple as the regular temperature measurements aren't that "raw":

In the "olden days" (and probably still at some community-based volunteer observing stations), a liquid-in-glass thermometer was used. The "raw" data is the length of liquid in a tube, and the model used to transform that into temperature involves the temperature-dependence of liquid volume.
Most current system measure temperture electronically, where the resistance of some material (either platinum or a semicondutor material) is measured. It is then transformed into temperature using models that relate the electrical properties of materials to temperature.

Both of these still just give you the temperature of the thermometer, not the air, so the temperature measurement system has to try to make sure the thermometer is at air temperature, usually using a Steveson Screen or some other form of ventilated radiation screen.

That gives you local air temperature, and then you need to make sure that your local temperature is telling you the information you need at a regional scale. There is a good series of posts here on how temperature measurements taken for the purpose of weather observations are used to estimate global temperature changes:

https://skepticalscience.com/OfAveragesAndAnomalies_pt_1A.html

Everything in science has "models" involved at some point. Some are simple and extremely well-defined. Others are complex and involve considerably more uncertainty.

Rob Honeycutt at 10:02 AM on 2 February 2021

A Climate Bet Impossible to Lose

Johnny... That's a very interesting point, and one that I will absolutely remember in the future.

Johnny Vector at 08:49 AM on 2 February 2021

A Climate Bet Impossible to Lose

Speaking as a satellite systems engineer, please don't refer to that second graph as "raw data". That is already at least a "Level 1" product. Level 0 is raw data, right from the sensors. I build astrophysics instruments, so I don't know for sure that the graphed data is L1; I strongly suspect it's Level 2, which has had even more processing done to it.

I mention this not for the sake of pedantry, but because it's worth pointing out always that any satellite numbers in Kelvins have already undergone a large amount of processing. The only numbers that come down in Kelvins are the internal temperatures of the satellite itself. (Okay, even those probably are downlinked in A/D counts, but the conversion to Kelvin is usually a simple linear calibration.)

Anyway, I think it's worth avoiding the term "raw data" when referring to anything that's already been heavily processed based on a model, especially when there are two models whose outputs are outside each others' one-sigma error bars.

bvangerven at 07:30 AM on 2 February 2021

A Climate Bet Impossible to Lose

Interesting ...

I can 't figure out whether climate change deniers genuinely believe that the earth is not warming. But now I am starting to believe that some of them are sincere, even though they are wrong. I think it is called "emotional investment". As they have invested years, even decades of their life defending the denier position, admitting their mistake now would be admitting they have wasted years.

Humans are a social species. Of course, believing falsehoods is not a clever survival strategy. But being loyal to the group you belong to – sometimes by agreeing with what everyone in your group claims to be true – IS a valuable survival strategy. You have a better chance of survival in a group than on your own. But that also means that such people cannot be persuaded by logical arguments or by facts.

Bob Loblaw at 07:29 AM on 2 February 2021

A Climate Bet Impossible to Lose

Leprechauns? No way. It's pirates.

https://pastafarians.org.au/pastafarianism/pirates-and-global-warming/

...but a nice piece on an interesting bet, Rob. As you said, it was a pretty sure bet. I think the "coolists" were out on a Snipe Hunt looking for support for their viewpoint.

I think your cheating was the result of using physics instead of fizzicks to predict what would happen.

It's the kind of bet I wish we would lose, but that will take a bit of time.

Rob Honeycutt at 05:57 AM on 2 February 2021

A Climate Bet Impossible to Lose

Ah, luck of the Irish, I say. :-)

Philippe Chantreau at 05:20 AM on 2 February 2021

A Climate Bet Impossible to Lose

You cheated. Ocean cycles were rebooted in the middle and then commandos of invisible leprechauns were lighting fires everywhere to heat up things. I'm pretty sure I saw it on FaceBook. It's all a hoax.

Rob Honeycutt at 03:10 AM on 2 February 2021

Veganism is the best way to reduce carbon emissions

Guilhem... You're going to have to show me where the IPCC makes such a statement because I'm not finding it.

Eclectic at 00:15 AM on 2 February 2021

Veganism is the best way to reduce carbon emissions

Guilhem , there is much in what you say. But essentially your line of argument fails the test of practicality & timeliness, if you are pursuing a primary goal of halting the current rapid global warming. And I need hardly point out to you that AGW is heading toward colossal damage to the biosphere, with resultant cruelty to all animals not just the domesticated species used by omnivorous humans.

Stabilizing the present-day climate must take precedence. Eliminating fossil fuels is a goal reasonably possible over 30 - 50 years. In effect : in two generations of humans.

But achieving a Vegan or merely vegetarian diet worldwide, will take far more time than two generations. Can I cite a scientific study to support this contention - no - but your own knowledge of human nature & history will surely admit the truth of it. Guilhem, there is simply not the luxury of time to achieve your "Vegan ASAP" goal. Other goals must take moral priority over your desired Vegan revolution.

To aim simultaneously at AGW correction and Veganism, is to attach an iron ball & chain to the ankle of the Anti-AGW movement.

Guilhem , doubtless you have many worthy aims in this life. But if you wish to be more successful than Napoleon was, then you had best conquer one enemy at a time. And choose wisely your first enemy ~ and move fast, before your other enemies wake up and combine against you.

Guilhem_S at 17:41 PM on 1 February 2021

Veganism is the best way to reduce carbon emissions

Actually the 5.8% figure only account for enteric fermentation and manure management. The whole livestock sector account for 15% of GHGE (about 8Gigaton CO2) as stated by the UN, Lancet Countdown, IPCC report on land use etc (see source in the comment above) and many more reputable institutions

I hope the rest of the message is considered valid and worth being added in a way or another (to correct the current article maybe?) as you only mention this single figure in a comment that is 5 pages long

Rob Honeycutt at 13:15 PM on 1 February 2021

Veganism is the best way to reduce carbon emissions

Guilhem...

Perhaps you need to widen your scope.

Livestock only accounts for about 5.8% of all GHG emissions. That's important, but there are many other larger sources.

Bigbrother at 10:11 AM on 1 February 2021

Climate's changed before

It's time the scientists admit they really don't know what they are doing.

Moderator Response:

[TD] You must be more specific in your comments. Future comments like this one will be deleted without warning.

Bigbrother at 09:29 AM on 1 February 2021

2021 SkS Weekly Climate Change & Global Warming News Roundup #5

so, was Planet of Humans wrong about the fallacy of biomass and solar and wind? They could be less carbon neutral than what they are replacing.

Moderator Response:

[TD] Yes, that pseudo-documentary is wrong. See this post.

Guilhem_S at 07:13 AM on 1 February 2021

Veganism is the best way to reduce carbon emissions

Hi all, I appreciate when people take time to debunk climate hoax, however I think this particular article is misleading, to say the least, and need major updates. It is both in the name of the truth in science, especially related to climate change, and the credibility of your page that I’m writing this very comprehensive exhaustive feedback on the many flaws I’ve identified.

We know that land use and food production are major actors in climate change. The argument for veganism from an environmental perspective is oftenly that animal agriculture is a big contributor to climate change and shifting toward a plant based diet is better for the environment. Most people would agree that Veganism isn't the single best solution to climate change, and that -for instance- collective suicide might probably be better, as well as a totalitarian regime imposing a zero carbon lifestyle. From an individual perspective, a non vegan eating a single slice of pork ham a year but living car and plane free is probably doing better for the environment than a vegan doing a Bali - New-York plane round trip every year. With these arguments in mind, “veganism isn’t the best way to reduce carbon footprint” is a no brainer. That being said, it is true that some animal right activists overestimate the impact that veganism can have so I understand why you wish to clarify to them that it is not as black and white as they wish it to be. However globally the impact of animal agriculture is hugely underestimated (see for instance https://www.nature.com/articles/s41558-018-0354-z) and by trying to debunk a very marginal argument (‘veganism is the single best way to reduce carbon footprint’), you end up downplaying the power that one have by shifting to a plant-based or even vegan diet. This kind of attitude might actually increase the total carbon footprint, or at least minimize the carbon mitigation of people’s action by discarding a sector on which people can have a huge impact which is widely unknown from the general public.

First, the livestock sector accounts for 65% of the food sector GHGE while only providing 18% of the world's calories. And while most of the food fed to animal is non-edible (in dry weight), meat production is still globally inefficient (it takes about 3kg of edible dry plant to produce 1kg of meat https://www.sciencedirect.com/science/article/abs/pii/S2211912416300013). Because the livestock sector is about 15% of all anthropogenic emissions as calculated from many LCA, notably by the FAO (http://www.fao.org/gleam/results/en/), it is a huge source of potential mitigations.

To get a first idea of what are the order of magnitude we’re talking about, governmental official French figures are as follows : An average omnivorous diet emits 2,8 tons of equivalent CO2 per year, about half of which is coming from animal products (meat, dairy and eggs). A diet with ruminant at every meal emits 6 tons of CO2 per year. A vegan diet can emit as low as 0.6 tons and is the least carbon intensive diet. To achieve Paris agreement on climate change we need an individual carbon footprint of 2 tons or less of CO2 per person per year, which is impossible to achieve on a cheese or meat-based diet. [1]. A vegan meal is, on average 0.8kg of CO2 [2], a egg-based meal is on average 2kg of CO2 [3], a cheese/pork/chicken based-meal is 5.4kg of CO2 [4] and a ruminant based meal is 25.2kg of CO2 [5]. According to the french national agency for climate transition, a vegan meal emits 2.5 to 31.5 times less CO2eq than any other meal and there is no reason that this figure should be much different in other countries. If anything, French carbon impact of animal products -especially ruminant- should be lower than in other countries such as Brazil. These kinds of figures appear nowhere in your article while they could provide useful insight to readers as to what are the best food sources to fight climate change.
[1] https://nosgestesclimat.fr/simulateur/bilan
[2] https://nosgestesclimat.fr/documentation/alimentation/plats/v%C3%A9g%C3%A9talien
[3] https://nosgestesclimat.fr/documentation/alimentation/plats/v%C3%A9g%C3%A9tarien
[4] https://nosgestesclimat.fr/documentation/alimentation/plats/viande-1
[5] https://nosgestesclimat.fr/documentation/alimentation/plats/viande-2

“Although veganism does have the potential to reduce GHG emissions associated with diet, it is important to consider other sectors that are also part of the problem.” → One might ask why we should consider other sectors when it is this one we are debating. This kind of “whataboutism” argument can be used to discard every policy on reducing carbon footprint.

Insisting on what people perceive (to be feasible, to be environmentally friendly, etc.) instead of what is factually positive for the environment is misleading. If you claim to answer the complex question of limiting the worst for the climate you cannot rely on people’s opinion. I know just as much as you that major societal and individual change are required to achieve climate goals and prevent the worst scenario. Claiming that veganism isn’t good because some people really want to eat meat as a main argument is unbelievable on a website such as yours and by trying to debunk such a minor myth in our society (PETA's claim), you perpetuate more dangerous myths (such that grass fed ruminants are carbon friendly). Because the myth that does currently more damage is that local, organic, grass fed animal are better for the environment you should reverse the debunking and show that actually, intensive exported plant food are way more carbon friendly (and that “organic” isn’t really doing much, except increasing the demand for land by decreasing the productivity)

When you’re pointing at non-vegan related issues such as food waste to dismiss the major changes that could be brought, you’re obscuring the debate further. When we talk about change, we have to think about counterfactual scenarios: the question is not ‘is veganism with a lot of fruit imported by plane wasted good?’ but ‘is veganism good, all things else being equal ?’. Otherwise it might sound like a strawman.

On the Kim et al. (2019) paper, I don’t know how you manage to distort the results that much in the process of trying to make veganism look bad. The paper is clear: the vegan diet is the less carbon intensive in all country studied (97% to be correct), only the low-food-chain diet is slightly above, but not statistically significantly different, from vegan diet*. The argument you make about vegetarianism has not his place here if you want to discuss Veganism. What the paper is saying is that it’s better to be ⅔ vegan than 100% vegetarian because dairy products have a massive impact so it doesn’t compensate for the ⅓ of omnivorism remaining. Therefore, your conclusion “there are arguments that a flexitarian diet with moderate amounts of meat is better than a vegetarian diet that cuts out meat completely, showing that stopping meat intake completely does not necessarily reduce dietary GHG emissions and cannot be assumed to do so in a vegan diet.” is a fallacious non-sequitur : vegan diet is better than both flexitarian and vegetarian diet (as shown by the very study you’re citing) because it eliminate both meat AND dairy which both are very carbon intensive. I can’t believe you haven’t seen that and I really wish I was able to assume you’ve made an honest mistake but I barely can. Such mistakes, always in the disadvantage of veganism, and repeated, seriously undermine the ideological neutrality of the author on these questions.
(*Please note that the low food chain diet is a diet where 90% of animal proteins are replaced with pulses, so we could say it’s a 90% vegan diet. That’s why it’s not statistically significantly different from vegan diet).

The vegan diet doesn’t lead to a higher consumption of fruit: because vegan doesn’t eat meat, cheese and eggs which are the main source of protein, fat and calories, we should expect vegan to eat protein and fat sources instead such as legumes, beans and nuts or oil. Increasing fruit consumption is within the nutritional guidelines of every country which have one. For these reasons, the whole paragraph appears as a non-sequitur. At best, the argument is very weak and it is on you to show that the eventual additional portion of fruit due to veganism (and not due to healthier lifestyle as vegans also usually have healthier lifestyle, but uniquely due to veganism, which its very existence is one of your unproven assumption) will increase carbon emission so much that it will cancel out the 8Gigaton of CO2 mitigation from quitting animal agriculture. I think because of the assumption it relies on, both the waste and plane-transported food fruits are not a valid argument

Speaking about the food waste, which is another issue a priori unrelated to and independent from veganism, there’s a paper titled “The opportunity cost of animal based diets exceeds all food losses” [https://www.pnas.org/content/115/15/3804]. The title is pretty straightforward: in the US, after adjusting for various nutrient density, the adoption of a vegan diet could feed 300 millions more people while the total elimination of all waste along the whole food production line (which is impossible) could only feed 100 millions more people. Once again, just like the “Vegetarian vs. vegan” paragraph, I don’t understand how you can try to use an unrelated issue to make veganism look bad but still fail.

As a reminder, the biggest meta-study on food impact shows that only 0.16% of the food on the planet is transported by plane [https://ourworldindata.org/food-transport-by-mode]. It is questionable to mention it only here, when talking about veganism. The main impact of the vast majority of food is on-farm emission, as shown by the same meta-study on 38000 farm in 119 countries [https://ourworldindata.org/food-choice-vs-eating-local] eating 100% local would only reduce emission by 5-10% whereas eating vegan can divide by several time the carbon footprint of diet.

The argument of carbon sequestration by grazing livestock, a favorite of the industry, have been proven wrong for a long time, as the methane and nitrous oxide emission from ruminant far exceed the best sequestration possible. See for instance this review of the literature (and note the discrepancy between figure from the academic domain and claim from outsider unpublished in journal such as Savory) [https://tabledebates.org/sites/default/files/2020-10/fcrn_gnc_report.pdf]. Also, wild ruminants could do the same job and it would be vegan, as grazing pasture doesn’t require either killing nor exploiting them. Many wild ruminants still exist, preceded humanity and very likely will still exist if humanity disappears.

You might want to update the carbon impact of a vegan diet because Scarborough and Berners-Lee are not really in agreement with current research. Current research from Poore and Nemecek [https://science.sciencemag.org/content/360/6392/987], of the BMJ paper by Springmann [https://www.bmj.com/content/370/bmj.m2322] show that a vegan diet emits several times less (>50% less) CO2 than conventional diet. The official French figure show that a vegan diet can emit 4 times less CO2 than the current diet. You might as well check out the IPCC report on land use showing that a vegan diet could prevent the emission of 8 Gigaton of equivalent CO2 per year, showing a massive reduction (roughly 20% of all current anthropogenic emission https://www.ipcc.ch/srccl/chapter/chapter-5/). A recent Science paper also showed that shifting toward a plant-based diet (EAT Lancet which is about 70% less white meat and 95% less red meat than current French diet) and other food change are mandatory to reach climate agreement [https://science.sciencemag.org/content/370/6517/705]. The Kim paper of 2019 you’ve cited above shows a global reduction of 70% GHGE (why did you choose to not mention it ?). In the light of these various paper, it seems strange that you choose to show only to moderate-impact paper.

The latest Lancet Countdown report shows that animal agriculture emits about 55% of the carbon footprint of food production (including the feed) while providing only 18% of the world's calories. What is really shocking to me is that 95% of the animal farming carbon footprint comes from ruminants which represent a tiny minority of the number of animals killed and meat consumed. How can you suggest that eating lamb or beef is sustainable in any way ? For an outsider it looks like you’ve internalized the rhetorics of the industry and are really detached from the reality of the current research. [https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32290-X/fulltext]

The occurrence of cowspiracy appears as you have something against this movie and seems to alter your neutrality. There are ways to criticize some element of cowspiracy (such as the Goodland paper and the 51% figure) without making such a poor quality argument against veganism as a whole.

I would like to add few points that you have eluded about the impact a vegan diet can have: it can do much more to the planet than just ‘reducing GHG emissions associated with diet’. It can, for instance, lower potential health crises by reducing zoonotic emergence risk (70% of new diseases are zoonotic https://royalsocietypublishing.org/doi/10.1098/rstb.2001.0888). Land which are not used could be left to the wild, and with the natural reforestation of pasture we could sequester up to 700 Gigatons of CO2, making the climate goal of +1.5°C by 2100 feasible at 66% as shown by this Nature Sustainability article of 2020 [https://www.nature.com/articles/s41893-020-00603-4]. In countries where the meat consumption is high, it could drastically reduce the disease burden and total mortality, according to this BMJ paper, it could reduce total mortality of several tenth of % [https://www.bmj.com/content/370/bmj.m2322]. Note that this article also explored the carbon impact and showed a vegan diet emit globally 80% less CO2 than what we are currently doing (and is of course the least carbon intensive of all diet studied)

I hope I have achieved to make you realise how this page may sound to an outsider who knows the figure, and I have provided you with many up-to-date research sources.

Please make an impartial page to properly inform about the climate impact of food and the huge potential of plant based, vegetarian but especially vegan diet to mitigate climate crisis. As you’re part of the Pro-Truth Pledge i’m sure you will take this matter seriously. I would be more than happy to help to write something about it if you want, or to answer any of your questions.

Thank you for your considerations,
Guilhem

Philippe Chantreau at 06:20 AM on 31 January 2021

Refining the remaining 1.5C ‘carbon budget’

We're already pretty much a one degree and nowhere near equilibrium for current CO2 levels. The probability that warming would not exceed 1.5 degrees is likely lower than what is outlined in this article. The probability that emissions will stabilize by 2050 to levels that will allow for the atmospheric fraction to stop increasing is close enough to zero to be negligible. We should prepare for 2 degrees as minimum. The 2050 and after generations are going to have an interesting world to live in...

One Planet Only Forever at 09:05 AM on 30 January 2021

Case study - identifying myths and fallacies in Climate Science (Mis)Information Briefs

Bob Loblaw @4,

When I got my MBA decades ago the professor of the Marketing course prefaced the course by telling us how the science of marketing could be abused to fool people, but that we were to avoid trying to benefit from the tactic because it would only temporarily be successful.

Tragically, misleading marketing only being able to temporarily succeed has been all that is needed by Political Parties inclined to cheat that way, success on election day (or the short period of election days).

More tragically, there continues to be a lack of effective measures to discourage or penalize misleading political marketing.

Social Democracy (pursuing truer democracy through the correction of developed injustice and inequity) and the international pursuit of constantly improved understanding of how to reduce harm and be more helpful to Others, especially to help future generations are important parts of the solution. Those guiding principles are the basis of Agenda 21 and the Sustainable Development Goals which focus on limiting the harm done by fossil fuel use because limiting the harm of climate change makes it easier to achieve almost every other SDG objective.

nigelj at 06:24 AM on 30 January 2021

Case study - identifying myths and fallacies in Climate Science (Mis)Information Briefs

BaerbelW @3, yes I have read it thanks. I have posted a link to it in a response to someone over on the Realclimate website.

Philippe Chantreau at 05:05 AM on 30 January 2021

2021 SkS Weekly Climate Change & Global Warming Digest #4

Thanks for the links, the Nature review is very interesting.

Bob Loblaw at 01:07 AM on 30 January 2021

Case study - identifying myths and fallacies in Climate Science (Mis)Information Briefs

"Winning the argument" also has a lot in common with "making the sale".

There is an entire industry out there whose sole purpose is to convince people that they need something they previously didn't know they needed. And probably things they don't actually need.

The psychological tricks used in the marketing business are being applied in the political arena, and in general by anyone wanting to shape public opinion. For sales, there are "Truth in advertising" regulations and possibilities of criminal prosecution (at least in Canada, where I live), but that doesn't apply to so much of our social discourse.

A "well-informed public" is our best protection, but too much is done to make sure the public is not well-informed.

The mantra of this dishonesty is "you can fool all of the people some of the time, and you can fool some of the people all of the time, and that's enough."

BaerbelW at 21:51 PM on 29 January 2021

Case study - identifying myths and fallacies in Climate Science (Mis)Information Briefs

nigelj @ 2

I really hope that John Cook's Cranky Uncle game can help with this general and widespread issue! Have you seen the Teachers' Guide he published yesterday?
https://crankyuncle.com/teachers-guide-to-cranky-uncle/

nigelj at 16:43 PM on 29 January 2021

Case study - identifying myths and fallacies in Climate Science (Mis)Information Briefs

The reason these misinformation campaigns that use logical fallacies manage to fool so many people might be as simple as logic not being taught in school. It wasn't taught when I went to school in the 1970s and 1980s, but by pure chance I stumbled across a book on logic and fallacies when quite young. However there is probably more to it. Many people just dont think terribly logically.

Some people use logical fallacies as a matter of course, because to them its all about winning the argument by fair means or foul. It becomes ingrained in them.

John Hartz at 14:38 PM on 29 January 2021

2021 SkS Weekly Climate Change & Global Warming Digest #4

Boava et al (2021) is also the focus of:

Climate crisis: world is at its hottest for at least 12,000 years – study by Damian Carrington, Environment, The Guardian, Jan 27, 2021

Daniel Bailey at 11:22 AM on 29 January 2021

2021 SkS Weekly Climate Change & Global Warming Digest #4

Nature has a review of the Bova article, here.

MA Rodger at 09:05 AM on 29 January 2021

2021 SkS Weekly Climate Change & Global Warming Digest #4

Phillippe Chantreau @1,

Bova et al (2021) 'Seasonal origin of the thermal maxima at the Holocene and the last interglacial' certainly looks to have made some interesting and important findings but as you say it is paywalled. There is a graphic attached to this Rutgers press release which is perhaps a little clearer than the thumb-nails attached to the paywalled paper.

Philippe Chantreau at 05:03 AM on 29 January 2021

2021 SkS Weekly Climate Change & Global Warming Digest #4

Suggestion for upcoming digest: Seasonal origin of the thermal maxima at the Holocene and the last interglacial

Unfortunately behind paywall, but seems to elucidate a discrepancy between data and modeling in paleoclimate.

babelsguy at 02:44 AM on 29 January 2021

The SCIARA Project – Interactive Time Travel into the Climate Future

@doug_bostrom, thank you for the kind exchange. I very much appreciate it.

Recruitment is wide open, and every particpant needs to go through some socio-demographic screening.

Otherwise we could never select representative samples or measure representativity in the first place.

Of course, we will make sure that this data and the behavioural data from the experiments cannot be connected to individual user accounts by simply stealing our database. ;-)

Bob Loblaw at 00:07 AM on 29 January 2021

Case study - identifying myths and fallacies in Climate Science (Mis)Information Briefs

Thanks for the effort that the team puts into this.

It is so sad that the misinformation campaigns use such old, tired myths over and over and over and over again.

It is so sad that they manage to fool so many people with them.

Doug Bostrom at 06:14 AM on 27 January 2021

The SCIARA Project – Interactive Time Travel into the Climate Future

And just to clarify, I'm all for this project. It's surely going to be useful. Keen to see the outcome be useful input for politicians and policy formulation.

Doug Bostrom at 06:06 AM on 27 January 2021

The SCIARA Project – Interactive Time Travel into the Climate Future

Thanks very much for taking the time to elaborate, babelsguy.

I'm not surprised to hear confirmed your most common "FAQ." :-)

It seems as though the nut of the challenge lies in "3," that being the axle on which validity and hence utility of results will spin.

Is it the case that participation will be fully open to all comers, regardless of directed recruitment? I suppose a fairly detailed intake survey will be helpful, to successfully apply "7" and especially if participation is wide open.

babelsguy at 23:54 PM on 26 January 2021

The SCIARA Project – Interactive Time Travel into the Climate Future

Dear doug_bostrom, the question of self-selection bias is always about the first one we are asked. ;-)

There will be two contexts in which a SCIARA simulation can run:

Awareness building only: Then the self-selection is much less relevant because in this context, the simulation is not supposed to yield statistically relevant output; it's all about exploring and understanding of climate change itself, which can happen without problem even if all participants are extremely biased towards, say, strong climate mitigation action.
My only requirement would be to show the participants how representative a sample the simulation is running with, so they are not misled to believe that the outcome is "the truth".
Decision support: In this context, representativity is key.
There are several levels on which we can work to improve representativity:

Measuring: We must know know how representative a sample is in terms of the sum of the least "distances" between members of a perfectly representative sample and the actually used members of the real sample in multidimensional space.
Statistical adjustment: If we know how representative the real sample is, we can (within tight limits) change the so-called population weight of all participants when extrapolating to the full reference population.
The application of this technique is limited by the effects of skewed social dynamics if some population groups are strongly over- or underrepresented, as communication between participants cannot be statistically corrected.
Recruitment: Ideally, we recruit a sample that is as representative as possible in the first place. This can be achieved by partnering with organisations of all areas of civil life and adressing their members and supporters.
Common interest: While climate change aware people might be easier to interest in our simulations, all citizens should be interested in what the future holds for them, as both climate change and mitigation measures will happen in any case, no matter what their position on climate change is.
Desire to be heard and seen: SCIARA opens up a new communication channel between citizens and policy makers: "I show you what the social consequences of your proposed climate change mitigation measure would be instead of just telling you!". We expect people from all of the political spectrum to take part in our simulations so that their standpoint, values and needs are fairly represented.
Strict open-endedness and neutrality: While SCIARA's purpose is to contribute to faster, more effective and more socially viable action against climate change, we are non-partisan, commited to no ideology, do not try to sell any particular solution. We try to run our simulations as free from experimentor bias as possible.
Over-recruiting: If we have a large pool of registered participants to choose from, we can select a (more) representative sub-sample to take part in a simulation.
Citzen Science approach: By integrating participants into the scientific process along the lines of the emerging discipline of Citizen Science, we foster more buy-in and more trust into our platform and the simulation process.

michael sweet at 23:05 PM on 26 January 2021

Skeptical Science New Research for Week #3, 2021

Carbon brief referred to an article in Science Advances:
In the abstract they claim that they have developed a new method of assessing climate models and their results. They claim:

“Our results suggest that using an unconstrained multimodel ensemble is no longer the best choice for global mean temperature projections and that the lower end of previous estimates of 21st century warming can now be excluded.”

If this claim is correct that seems to eliminate the possibility of limiting warming to 1.5C. What do people here think about this article? Does anyone have a link to comments from scientists on this topic?

I also posted this note on the RealClimate unforced variations thread. That thread has degenerated into mostly commentors insulting each other so I do not think I will get a reasoned reply there. It makes me appreciate more and more the job the moderators at SkS do to keep the conversation under control. Thank you to all the moderators who keep the conversation on topic.

Tom Dayton at 11:32 AM on 26 January 2021

There's no empirical evidence

gzzm2013: In the left margin above the login area, there is a button labeled Interactive History of Climate Science. Click that.

Moderator Response:

[DB] Sadly, gzzm2013 has recused themselves from further participation here.

Tom Dayton at 10:24 AM on 26 January 2021

There's no empirical evidence

gzzm2013, here are explanations of greenhouse effect causality:

gzzm2013 at 09:29 AM on 26 January 2021

There's no empirical evidence

Dayton @407 that is a correlations, no proof of causality.

Dayton @408 yes the oxidation of carbohydrates produces CO2 gas.

Doug Bostrom at 04:32 AM on 26 January 2021

The SCIARA Project – Interactive Time Travel into the Climate Future

A fascinating effort to exploit new capabilities to produce policy guidance. We're bound to learn something of interest from this project.

I'm wondering how players will be selected for participation, or if they will select themselves.

If self-selected, how will simulation results account for self-selection bias?

It may be (is probably?) the case that fully self-selected participants will more or less converge on a population with proclivities not faithfully reflective of information, attitudes and beliefs of a more complete sample of the general population.

As well, drop-outs during the course of the game could result in a further distillation of users more divergent from the general population.

The resulting group of participants may feature unusual levels of information on various details of climate change, climate solutions. As well, they may not be reflective of general atittudes toward and acceptance of policy interventions, necessities for lifestyle changes etc.

If indicators for paths forward assessed by participation of such an unrepresentative subsample are then applied to the general population in the form of policy, incentives etc., there is a strong chance that misalignment due to the original self-selection will become visible, with acceptance and support projected by the game not mirrored in the real world.

I suspect that consumers of iinformation provided by the game in the political and policy realms will be aware of this risk.

How will self-selection be controlled for?

For readers wanting to learn more about the limitations of previous efforts mentioned by Daniel, a nice example is The Climate Action Simulation, Rooney-Varga et al, 2019 (open access). As is often the case, the supporting citations in this paper are of great value as a means of gaining at least a tenuous foothold on this domain, as valuable in their own way as the actual investigation described.

MA Rodger at 21:07 PM on 25 January 2021

There's no empirical evidence

gzzm2013 @410,

You complain that your comments are suffering deletion. However, most can still be read by those logged-in and we are not missing much. You do however request a better explanation of the greenhouse effect and also argue that the term 'greenhouse' is not appropriate. I have responded to these comments on a more appropriate thread.

MA Rodger at 21:03 PM on 25 January 2021

CO2 is not the only driver of climate

gzzm2013,

Your request for an answer you can understand on the subject of CO2 as a greenhouse gas have fallen fowl of moderation. While I have already presented an answer for you above @62, perhaps a more detailed explanation would assist you, something which Einstein's 6-year-old could grasp. You also elsewhere insist that the mechanisms of an actual greenhouse and the planet's greenhouse effect are fundamentally different. I will also address the falacy within that argument.

The graph presented @62 shows three traces, Ts, Tmin and a raggedy one inbetween.

Ts is the radation we would expect from a planet with a temperature of +15ºC but no greenhouse effect, +15ºC being the average temperature as the Earth's surface. The raggedy line is a trace of the actual radiation from Earth. The raggedy trace is important as the area beneath it represents the energy radiated out into space. It is what cools the planet.

If the area below the raggedy trace does not equal the area below a similar trace of incoming absorbed radiation from the sun, the temperature of Earth will change until they do become equal.

The size of the Earth's greenhouse effect is represented by the area between Ts and the raggedy trace. About a quarter of that area is the big bite out of the raggedy trace at Wavenumber 666. That big bite is caused by CO2.

So imagine there was no CO2 and the big bite was absent. The area under the raggedy trace is now bigger and no-longer equals to the area under the solar heating trace. So the raggedy trace would become lower as Earth cools to make them equal again. (And a cooler Earth will have a lower Ts trace as well.)

And what makes CO2 even more important than providing directly a quarter of the Earth's greenhouse is that the other three-quarters is down to water vapour in the atmosphere. A cooler planet cannot support the same amount of water vapour in its atmosphere. This increases the height of the raggedy trace along much of its length again making the area underneath unequal to the solar heating trace. The planet thus has to cool even more to put them back in balance, which again reduces the level of water vapour in the atmosphere causing yet more planetary cooling. The upshot is that without CO2 in Earth's atmosphere, the temperature becomes so low that the greenhouse effect pretty-much disappears. That is the power of CO2 in our atmosphere.

And run it the other way by increasing the level of CO2 in the atmosphere, the big bite becomes bigger and Earth has to warm up to shed the extra heat caused by the CO2-enhanced greenhouse.

...

You also argue elsewhere that an actual greenhouse works by preventing convection while the greenhouse-effect works radiatively. You suggest that this difference in operation, one convection the other radiative, makes the term 'greenhouse' inappropriate for a planetry 'greenhouse' effect. Your argument is not actually well-founded.

Both a greenhouse and the 'greenhouse' effect rely on radiative effects to operate. The incoming solar radiation freely passes through the glass/atmosphere while outgoing radiation of a longer wavelength is unable to pass freely back out.

The greenhouse does also require the glass to prevent the heated air within causing convection and so dissipating the elevated solar warming. The atmosphere also acts to generally prevent convection. Of the two, a greenhouse is atually more leaky than the atmosphere which has a very gentle upward convection process (outside serious storms etc which in the grand scheme of things are quite rare). On average it takes over a week for a packet of air to rise the 12km to the top of the troposphere.

gzzm2013 at 12:06 PM on 25 January 2021

There's no empirical evidence

It is hard to discuss when my comments are deleted entirely.

So I will leave this echo chamber for now, and hopefully my unanswered questions to the claims made are left for the record.

Moderator Response:

[DB] Moderation complaints snipped.

Philippe Chantreau at 07:12 AM on 25 January 2021

There's no empirical evidence

Gzzzm2013,

The fact that you feel you can be sentencious and pontificate on such obvious elements as the atmosphere being transparent to solar light reveals that you have not done anywhere near enough reading to form an informed opinion that will hold any value. Everyone who contributes here is well aware of everything you just said. I could be pedant and add that temperature decreases with altitude up until you hit the tropopause, then things get a little more complicated.

And incidentally, both albedo (which you hint at without naming it) and aerosols have been studied extensively. They are the subject of an entire body of scientific litterature, and are an examined item of denial at SkS: It's aerosols

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