Warmth is, on the whole, a good thing when you are cold, a bad thing when you are hot. Generalizing to nations, the countries most likely to benefit by global warming are ones close to the poles. The habitable area of Canada, for example, is a narrow strip several thousand miles long bordered by the United States on one side, snow and ice on the other. A few degrees of warming would make it substantially wider, as well as making the currently inhabited parts a little more habitable.
Along similar lines, the countries most likely to lose by global warming are those where it is already too hot. India, for example. Which is why I was struck by a news story about the Prime Minister of Canada's plans to lecture the Prime Minister of India on the dangers of global warming.
Meanwhile, Putin has announced that he does not believe in AGW. My guess is that what that really means is that he is in favor of it. Russia is, after all, the only country in the world with a longer arctic boundary than Canada.
(Very low lying countries are also at risk from warming, but there are not many low enough to be seriously threatened by a meter of sea level rise, which is the upper bound of the current IPCC high emissions projection for 2100.)
58 comments:
35 million Canadians are a little better off; 1.25 billion Indians are worse off.
Sounds like a net benefit from manmade climate change, IFF one ignores the 35:1 ratio.
This argument best combined with endorsement of open borders and free trade.
There's no point to this kind of analysis unless it has a bearing on policy. And then only if (1) a policy change (e.g., reduce CO2 emissions by fiat) is adopted and enforced by major CO2-producing nations, and (2) a reduction in CO2 emissions actually affects global temperatures. The current warming trend (a trend that has stopped, unless you believe NOAA's pause-induced adjustments to the temperature record) is trivial by comparison with past warming trends (see http://wattsupwiththat.com/2015/11/29/climate-and-human-civilization-over-the-last-18000-years-2/, for example). The AGW hypothesis arises from an observational coincidence -- a relatively trivial rise in observed (though not rigorously measured) global temperatures and an (unsurprising) rise in man-made CO2 emissions from the 1970s to the 1990s. In view of the historic record, this is hardly enough to refute the null hypothesis that there is more than a trivial relationship between global temperature and CO2 emissions. In fact, there is evidence of a reverse relationship (i.e., higher temperatures -- due to natural variability -- leads to a greater atmospheric concentration of CO2). Further, the real "culprit" in AGW theory, as I understand it, is so-called greenhouse gases, of which CO2 is a minor component.
Further, the real "culprit" in AGW theory, as I understand it, is so-called greenhouse gases, of which CO2 is a minor component.
Please familiarize yourself with the science (which is not at WUWT) before making comments.
Anonymous:
Figuring out what the net effect of AGW is is hard. 1.25 billion Indians are worse off because of hotter summers, better off because doubling CO2 concentration increases the output of C3 crops, which includes most food crops, by 30% or so. I wouldn't be surprised if they are worse off on net, but I don't actually know.
But my point was not about whether AGW is a good or bad thing. It was about the fact that Trudeau's position is almost certainly inconsistent with the welfare of Canadians, driven by ideology. At least, I haven't heard him say "we Canadians have to keep AGW down for the sake of the people of India, even thought AGW would make us better off."
The Indian position is more complicated. The government may well believe that AGW is a bad thing--but also that it needs coal as a cheap source of electric power. Putin's position is as simple as Trudeau's--the difference being that Putin is willing to act on his national interest. He expects to benefit once from warming, a second time from using whatever is the least expensive source of power even if it produces CO2.
I think one needs to consider not only the interests of various countries in global warming (pro or con) but also the interests of various countries in the actions that might be needed in order to avoid it (pro or con).
Canada is a technologically-developed nation with a stable population, a stable per capita ecological footprint, and a "green" public image; it has little to lose (other than some oil revenue, which might be offset by technological revenue) from a global movement to reduce CO2 emissions. I'm sure there is internal debate about AGW within Canada, probably pitting the oil-producing regions and industries against everybody else.
India is a developing nation with a rapidly-growing population, a rapidly-growing per capita ecological footprint, and no particular investment in looking "green" or "sustainable". A global movement to reduce CO2 emissions, depending on the details, would substantially restrict its growth potential -- or at least deny it the easy growth path that Canada and the U.S. have already followed.
The U.S. has more in common with Canada than with India. The fault lines of the debate within the U.S. -- over even the existence of AGW, much less what to do about it -- are largely between people and industries that have a lot to lose from actions that would avoid AGW (coal, oil, automobiles, and the regions that produce them, as well as political groups opposed to governmental collective action) and those that don't (high-tech industries, densely-populated cities, and political groups that favor governmental collective action).
One might also see India as a strategic target for convincing in Trudeau's mind: _because_ India has so much to lose from GW (A or otherwise), it should be possible to persuade India's government to take AGW seriously, where it might be harder to persuade, say, Nepal.
In fact, to the extent that there's a regional split within the U.S., it's between the Northeast and Northwest (generally in favor of avoiding AGW, despite the benefits those areas would reap from warming) and the South (generally opposed to even discussing AGW, despite the costs those areas would incur from warming), analogous to the Canada/India difference.
Which suggests that people on both sides of the issue are weighing the costs and benefits of "doing something to avoid" AGW more heavily than the costs and benefits of global warming itself.
Look at borderline case of socialism fighting against Global warming in Norway. It is small cold country that practically lives on oil and gas.
Could the projected global warming result in Antarctica becoming habitable and colonizable? There's a possible interesting theme for an SF novel.
I though that the atmosphere near the equator was already pretty much opaque to heat and therefore AGW would only have very small temperature effects near the equator. That leaves the cooler countries and lower countries.
Well, Trudeau is basically a social democrat, right? His party's ideology as well that of the voters who vote for that party are anti AGW and would probably (at least vocally) support "saving the world" even at the cost to Canada.
Putin does not map well to the regular political spectrum because he is a quasi-dictator, but if one had to put him somewhere he is a traditionalist conservative. So again, his voters (however the elections are manipulated in Russia, they probably still play some role) would not be very happy to hear him preach about AGW.
I think that the primary interest of both politicians is to stay in power (a simpler task for Putin but he still cannot be entirely careless) and therefore to say whatever their electorate likes to hear, the actual interests of their countries are secondary.
I don't know about India, but I would expect the people there to have dozens of worries other than AGW to think about first, so global warming is probably politically not much of an issue. If your house is almost falling apart and I tell you that the stuff you used for insulation might be a pain in the back 50 years down the road, you are probably going to ignore me (regardless of whether I am right or not).
That's a very interesting point, David.
Another weird thing about that is that India is already doing far better than India on this metric. I checked the most obvious data source on this, and Canada is the 4th highest emitter in the world, on a per capita basis. India is 20th.
https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions
By any reasonable standard, India is already doing far better on this problem than Canada. I would be very interested in Mr. Troudeau's proposal for Canada getting anywhere close to India's performance on that metric.
@Thomas:
The only greenhouse gas with more of an effect than CO2 at current atmospheric concentrations is water, which has an extremely short atmospheric lifetime that makes it impossible to directly budge its concentration either way. There are non-CO2 greenhouse gases that are increasing - methane, CFCs, a couple of others - but none of them have the raw forcing or the lifetime of CO2 (methane in the atmosphere decays over ~30 years, for example).
That's before any of the other things you've gotten horribly wrong, so I'm not sure why I'm bothering.
@David Friedman:
If CO2 increases significantly increased vegetation growth, we would expect to see larger seasonal swings in the CO2 data as time goes on (because more plants are growing in spring and dying in winter), and we would expect to see the airborne fraction of human CO2 emissions decrease (as plants are increasing the amount they retain). Neither of those things are evident in the data.
@J Oliver:
There's a larger effect at the poles, in winter, and at night for a lot of reasons (water vapour concentrations are smaller so the marginal effect of CO2 is larger, thermodynamics, etc.), but there are still significant warming effects at the equator. India has gotten ~0.6-0.8 C warmer since preindustrial, the global trend is ~0.85c.
@Daublin:
He's only recently been elected; the Harper government that was previously in power for ~9 years didn't take global warming seriously.
As far as the broad point this post is making goes: What was the excess mortality of the 2010 Russian heatwave? Moscow isn't exactly Arctic, but it did manage to hit 38c in July 2010, an anomaly of ~7.7c. Then there were a few wildfires. Wiki links to this article quoting Munich Re as saying 56,000 people died as a result of the heatwave and wildfires, but it doesn't exactly appear a reputable website.
How much do you think it'll cost, both in dollars and in lives, for significant fractions of the world's equatorial population to migrate to the poles?
"The Twilight Zone" The Midnight Sun
https://www.youtube.com/watch?v=AbQJDBQzgwM
One of the best twilight zone I've seen.
@James Picone, Thank you for the concrete data: India has gotten ~0.6-0.8 C warmer since preindustrial
"How much do you think it'll cost, both in dollars and in lives, for significant fractions of the world's equatorial population to migrate to the poles?"
Why would significant fractions of the world's equatorial population migrate to the poles?
For example, migration in the United States in the last decades has been from north to south since 1960:
U.S. population change, 1960-2000
If people have air conditioning, they don't seem to mind hot weather.
@Picone:
1. What is the source for your figure on warming in India?
2. We have lots of direct data on the effect of CO2 growth from greenhouse experiments.
Your indirect argument depends on the scale of the effect of the annual plant cycle on CO2. A little googling tells me that we have Mauna Loa data only since about 1960 and that the annual seasonal swing is about 5 ppm. Since 1960 CO2 concentration has increased from about 300 to 400. The greenhouse results for C3 crops show about a 30% increase with a doubling of CO2 concentration. If all vegetation was C3 we would expect less than a 10% increase from 1960 to the present which, on your argument, would increase the annual swing in CO2 by something less than .5 ppm.
Would you like to claim to have data good enough to reject a change on that scale? Would you like to point at it? Looking at the Manua Loa data for a single week I observe random fluctuations of about 3 ppm.
https://scripps.ucsd.edu/programs/keelingcurve/wp-content/plugins/sio-bluemoon/graphs/mlo_one_week.png
Or in other words, unless you can point me at an actual analysis of how much the annual CO2 swing has or has not changed since 1960 that is inconsistent with an increase in vegetation of the scale we might expect from increased CO2, I conclude that you are blowing smoke--making an argument that you cannot support but that sounds good.
One reason for that conclusion ...
You criticized me on Slate Star Codex for an argument I had not made. I pointed out that I had not made it, quoted a passage of my blog post on the subject which denied that argument, and asked you to either support your claim or retract it. Unless I have missed something, you have done neither.
I concluded that you are concerned less with whether what you say is true than if it supports your side of an argument. That's unfortunate--well informed people I disagree with who I can trust are a scarce and valuable asset.
@David
I admire your sharp mind and regularly read your books and blog. Why do you waste your time by examining data, arguments and etc. about clearly religious (nothing against religions in general) believe of climate warming, cooling or just change? I propose different argument that you are very qualified to make. Can you estimate devastation to Earth that will make dedication of resources to fight climate change? How many people will die because they will not have available resources? Birds and animals killed in order to reach this mirage of constant weather.
And most of the effects of global warming will be felt by yet unborn people. We could eliminate the problem, and at the same time save the snail darters and coral reefs, by putting a stop to the rampant breeding. All with significant savings on education.
Any needed workers we could get from India, what with all the people there fleeing heat and rising waters.
Speaking with your feet.
It is well documented that there has been a large geographical shift in the population of the United States from the northeast to the south and southwest during the past half century or so. While there are undoubtedly many reasons why people have / are doing this, one reason that is commonly cited is "a move to a warmer climate".
Thus, it seems to me, a great many people prefer a warmer world to a colder one … and have been willing to expend considerable effort and money to realize their preference. Perhaps there are a significant portion of the population who want a warmer world.
>700,000 people live year round in Alaska, far north of the so-called "habitable" zone of Canada. Ask most people up here and they would tell you it's quite habitable right now. In fact, you may be surprised to hear how many of them would prefer it stay cold here. Not that anyone cares much what happens in Alaska. So long as the oil keeps flowing.
@Mark Bahner:
Because David Friedman is discussing a hypothetical where equatorial regions lose land and polar regions gain land, so presumably people will need to move closer to the poles.
@David:
Before I get into the object-level, I'd like to make a meta point.
This will be the third time I tell you that I have, in fact, responded to the SSC post you made asking me to put up.
This is the first time I told you I have responded, dated Nov 28. You replied to this comment.
This is the second time I told you I have responded, also dated November 28th.
And this is the actual response, dated November 26th.
Are you feeling more charitable to John Cook mistakenly criticising an argument you didn't make yet? Because I rather think you should. You have, in a rather amusing way, managed to construct a perfect example of how easy it is for someone arguing in perfectly good faith to make a mistake.
On the object level: Finding a good, simple source for Indian temperature rise was a bit of a pain, this website is where I took the figure from. Search for "show an overall rise of about 0.6°C to 0.8°C in mean annual temperatures for India" to get to the spot where it makes that statement; it has a graph, and links back to this website, which is awful. No idea how to get the original data out of it.
As far as CO2 fertilisation vs. the Keeling curve, grabbing *weekly* data is an amazingly terrible way of looking at the test I'm talking about. If you go here and click on 'interactive plot', you get a nice graph of the full dataset with a window you can slide around. Have a look at peaks and troughs for the annual cycle - it is easily consistent enough that a different of 0.5 ppm would be visible. There's also a nice graph of the annual cycle for the last two years, which shows neatly how the noise in the daily measurements pretty much vanishes if you average on a timescale of a week or longer. Early in the data, measured lowest-trough-to-next-peak, the annual cycle is ~7 ppm. Late in the data, measured the same way, it's more like 8 ppm. Of course, over that same period yearly average CO2 increase itself increased by ~.8 ppm, so this quick-and-dirty analysis suggests ~.2 ppm is the amount the carbon cycle can have expanded by.
Alternately, we could look at actual papers, like this one, which finds a significant increase in seasonal cycle mostly caused by more stuff growing in the North, so maybe I'm wrong and there is a detectable CO2 fertilisation effect, although I would cautiously note that plants don't live on CO2 alone, they also live on nitrogen, water, and a moderately predictable climate that doesn't throw out 7-degree anomalies too often.
Picone writes:
"And this is the actual response, dated November 26th."
I have just checked through all of your comments at that link. None of them responds to my request that you either retract or support the false claim you made about what argument I had made.
I think I have been sufficiently clear about what I wanted a response to so that it should have been obvious that it wasn't the earlier comment of mine to which you had responded. But just to make sure, here is the comment of mine that, so far as I can tell, you never responded to. If you in fact made a response to it, feel free to point me at it and I will be happy to apologize.
---
Picone writes:
“The takeaway here is that David Friedman is quite happy to commit the same ‘dishonesty’ he’s accusing Cook of, by conflating the category “Does not think climate change is principally human caused” and “Does not specifically indicate climate change is principally human caused in the abstract of their paper”.”
Would you like to support that claim? Where in what I have written, here or on my blog, did I make any assertion about how many people think climate change is principally human caused?
I quote from my original blog post:
“That Cook misrepresents the result of his own research does not tell us whether AGW or CAGW is true. It does not tell us if it is true that most climate scientists endorse AGW or CAGW.”
----
James Picone writes:
"Early in the data, measured lowest-trough-to-next-peak, the annual cycle is ~7 ppm. Late in the data, measured the same way, it's more like 8 ppm. Of course, over that same period yearly average CO2 increase itself increased by ~.8 ppm, so this quick-and-dirty analysis suggests ~.2 ppm is the amount the carbon cycle can have expanded by."
And I gave "less than .5 ppm" as the amount we would expect due to CO2 fertilization. You, on the other hand, offered as evidence against fertilization,
"If CO2 increases significantly increased vegetation growth, we would expect to see larger seasonal swings in the CO2 data as time goes on (because more plants are growing in spring and dying in winter), and we would expect to see the airborne fraction of human CO2 emissions decrease (as plants are increasing the amount they retain). Neither of those things are evident in the data."
I think you have now conceded that one of those things is evident in the data. Hence that you had not actually checked to see if your claim was true before making it.
I don't understand, by the way, your reason for using .2 rather than 1. Is your point that CO2 was a rising curve? That would increase the trough to peak calculation but decrease the peak to trough--did you check both? The fact that total CO2 concentration is larger at the end of the period shouldn't increase the size of the annual cycle, since that depends on how much carbon is being taken out and released by plants--an amount, not a percentage. Unless, of course, more CO2 results in more plant growth, which was what you claimed to offer evidence against.
P.S. to Picone:
If yearly average CO2 increased by .8 ppm, then the increase from trough to peak, half a year, due to that cause would be .4ppm. Subtract that out and you get an increase hypothetically due to CO2 fertilization of .6 ppm, or a little more than my estimate.
Am I misunderstanding you?
I looked for Picone's responses and they don't seem to say what he claims. Now, considering that his links just go to the SSC comment section and not directly to the comment in question (is there something wrong with links, the linking system, or my machine? I don't know) it's hard to verify that he's not just blowing smoke. I suggest quoting your response so that a trip to the SSC comments, armed with CTRL+F, would eliminate all doubt.
Having said that, I did read many of the comments and I find Picone's style mildly infuriating (mildly because why get upset over someone who argues dishonestly?). He continues to repeat, over objection, that the (paraphrasing) "real takeaway is that, hey, abstracts don't give all info and we can probably assume that more than 1.6% of the papers view human activity as the MAIN DRIVER of global warming" when that is, as was repeated, EXPLICITLY not what Friedman was arguing. Friedman was saying that the Cook paper misrepresented its findings and used statistical tomfoolery to do so.
It is not a reply to Friedman's charge of dishonesty to say that (paraphrasing) "even though the data they used in their paper does not support their conclusion, by their own standard and methodology, it is PROBABLY MAYBE LIKELY true to some extent anyway, so Friedman is the dishonest one." It's actually quite mind blowing.
I suggest, David, that you do your best to ignore people when they act this way. Whether they are on the payroll or just confused, it merely serves to take away time from honest research. You've just got to trust that the people who are reading the comments can see what the Picone's of the world are doing from their comments alone. Trying to refute them over and over when they are not making honest arguments (because they are incapable? trying to annoy you/waste your time?) is counterproductive.
Carry on!
Dear Anonymos,
The bit about 35/1 ratio only applies if we assume the Indians cannot move north.
This section in the comment is the response:
(quoting you):
"Would you like to support that claim? Where in what I have written, here or on my blog, did I make any assertion about how many people think climate change is principally human caused?"
Then I quote you as saying:
"97% of articles expressing an opinion on the cause of warming hold that humans are at least part of the cause, but only 1.6% hold that humans are the principal cause."
Then I add:
"Only 1.6% included explicit quantification /in their abstract/. That’s a different claim to “only 1.6% hold that humans are the principal cause”. Pedantic? Yep. Meaningless? Yep. Roughly the same scale as the complaint you have about Cook? By my lights, yes."
That was the response. The scare quotes around 'dishonesty' might make it more clear I don't think the category slippage you accuse Cook of is significant.
I concede that I was likely wrong about the growth in size of the annual cycle.
"don't understand, by the way, your reason for using .2 rather than 1. Is your point that CO2 was a rising curve? That would increase the trough to peak calculation but decrease the peak to trough--did you check both?"
I specifically noted that those numbers were trough-to-peak. I didn't check peak-to-trough; this was just spitballing numbers. The paper I linked to later is a bit more meaningful here.
"If yearly average CO2 increased by .8 ppm, then the increase from trough to peak, half a year, due to that cause would be .4ppm. Subtract that out and you get an increase hypothetically due to CO2 fertilization of .6 ppm, or a little more than my estimate."
Good point; that was a mistake. In my defence that was all worked out rather late at night in my timezone.
"Now, considering that his links just go to the SSC comment section..."
They go directly to the comments in question for me.
"He continues to repeat..."
That was not my argument. My argument is that the lack of papers in categories 5/6/7 is a /really big deal/, that categories 5/6/7 are wider than Friedman interprets, and that the set of things you have to believe to conclude that 1) anthropogenic warming has occurred since the preindustrial and 2) it is not the main warming influence over that period are either insane, ignorant, or contradictory; Cook is inferring 'agree main influence' from 'agree anthro warming' because of that, I argue the inference is legitimate.
"Whether they are on the payroll or just confused, it merely serves to take away time from honest research."
Your conspiracy theories are hilarious.
Keep in mind that your opinion of my intellectual honesty is likely similar to my opinion of Friedman's intellectual honesty. I'm not going to accuse Friedman of being paid for stunts like "looking at CO2 weekly data for a question that is seasonal", "calculating trends over a long period by taking the difference between the start and end points and dividing by the number of years difference" or "quoting the graph from Tol15 that is most convenient for his argument, and not quoting the other graph which is much less convenient", because that would be ridiculous.
I'm using my real name here. You certainly can't accuse me of trying to hide any affiliations I have. For what it's worth, I don't work in climate science or in a climate-science related field, I don't get paid for anything to do with climate science in any capacity, and nobody in my direct family gets paid for or works in climate either. I don't know about my extended family, but I wouldn't be surprised if it was true for them as well. About the only conflict of interest I can come up with is that I live in Australia, and we've had some entertainingly strong heatwaves, bushfires, and droughts over the last decade or two, and they've definitely been made worse/more common by the increase in temperatures over that period.
I notice that nobody has deigned to respond to the more significant problem with Friedman's argument, which I alluded to by mentioning the recentish Russian/European heatwave. Large anomalies kill, even if the absolute temperature isn't as high as it gets in some locations.
Hello David,
I just read that a second "pay per minute" cafe was opening here in Belgium, and remembered that you were surprised they were not more of them. Maybe this is starting to change. I'm not sure about the trigger though, except maybe that the resistance to change from customers is getting smaller these days (innovation is hip), and it is easier to market such "new" (for those not familiar with your readings ;) ) concepts through social media
Ps: sorry for being out of topic
I am now finding your reply, do not know why I did not find it before. Your link takes me to the whole SSC page, not your comment. So I apologize for accusing you of not responding.
Your defense of your claim, if I understand it, is that while only 1.6% of the abstracts hold that humans are the principal cause, it is possible that more than 1.6% of the articles do. What you wrote, however, and I objected to, was:
"The takeaway here is that David Friedman is quite happy to commit the same ‘dishonesty’ he’s accusing Cook of, by conflating the category “Does not think climate change is principally human caused” and “Does not specifically indicate climate change is principally human caused in the abstract of their paper.”
"Does not think." You have not yet shown that I at any point asserted that the authors of those papers did not think humans are the principal cause, which was your claim. Hence you have not yet provided any support for the claim I objected to. I am still waiting for you to either support it or retract it.
You have switched from your original claim to a different one--that I carelessly referred to "articles" when I should have referred to "abstracts." Do you think that my not specifying "abstracts" when the whole discussion is about abstracts is equivalent to John Cook claiming that 97% of the articles held that humans were the main cause of warming when his own article showed only 1.6% of the abstracts held that?
So far as your contortions to justify the statement in the second Cook paper, I remind you that what it said was:
""Cook et al. (2013) found that over 97% endorsed the view that the Earth is warming up and human emissions of greenhouse gases are the main cause.""
That is not the same as "found that 97% held that humans were one cause of warming and they must have believed that humans were the main cause because rejecting that makes no sense" which seems to be what you are now imagining he meant. I again point out that the example for category 2 was an abstract holding that greenhouse gases contribute to warming.
I remain disturbed by the contortions you are willing to go through to avoid recognizing deliberate dishonesty by someone on your side. I don't assume that you are being paid to take the position you do. In some ways it would be less disturbing if you were.
On the question of the effect of CO2 on plant growth, are you now agreeing that what you offered as evidence against is actually evidence for?
"I am now finding your reply, do not know why I did not find it before. Your link takes me to the whole SSC page, not your comment. So I apologize for accusing you of not responding."
That's quite strange. They definitely take me straight to the comment when I click them, and they have the comment anchor in the link.
Do you now acknowledge that it's entirely plausible that Cook might have made a good-faith mistake about the contents of your argument, now that you've witnessed yourself making a similar mistake first-hand?
"Your defense of your claim, if I understand it, is that while only 1.6% of the abstracts hold that humans are the principal cause, it is possible that more than 1.6% of the articles do. What you wrote, however, and I objected to, was:"
Broadly, yes. More specifically, you had 'category slippage', in which your not-intended-to-be-super-formal language could, if read unwarily, identify a different category to the ones that the paper, interpreted strictly, was about.
This is what you're saying Cook is doing, when he shifts from categories 2/3 to "main cause of warming".
And now you're being similarly pedantic with my wording! Pedantry all around; and approximately none of it carrying any actual meaning. Fine, if it'll assuage your honour, I retract that specific reading of what I claimed.
[More Cook13]
If you ask someone whether they think supply and demand influences prices, and then report that they think supply and demand is the principal component of prices, I don't think you have committed a major sin, and the link between "CO2 is an anthropogenic forcing" and "warming is 50% human" is much tighter than that. It's really, genuinely *this close* to just assuming that the people who responded can do maths.
I doubt you apply this level of rigour to papers with opinions closer to yours.
"On the question of the effect of CO2 on plant growth, are you now agreeing that what you offered as evidence against is actually evidence for?"
Quite possibly. It's surprisingly hard to find readable studies on the issue; the one I linked to is available on the web but uses very specialist language that I'm having trouble parsing; and it's only a single study. But it certainly looks like I was wrong and the seasonal cycle has gotten bigger, and if it has it's almost certainly partially due to CO2 fertilisation (If I'm interpreting that paper correctly, a significant chunk of it appears to be plants migrating north, as well). I would be surprised if that continues for long in the face of shifts in climate, and I think more frequent droughts/floods/heatwaves are going to limit the realised agricultural improvements, but it does look like it's there.
I note that you're still avoiding the argument I'm putting forward here that your post is wrong - there are significant negative effects in Russia from warming.
"I note that you're still avoiding the argument I'm putting forward here that your post is wrong - there are significant negative effects in Russia from warming"
How does that make my post wrong? I didn't say there were no negative effects. I didn't even say there were net positive effects, although I think it likely.
I expect there are some negative effects in Russia. My point was that both Russia and Canada are likely to have larger net positive effects than most places, in particular India. My guess in both cases is that "larger" in this case is "greater than zero." But, as I've been saying for years, we can't know what net effects are going to be, since there are both positive and negative effects spread out over a long period of time.
With regard to the link, what browser are you using? I'm using Firefox.
"Do you now acknowledge that it's entirely plausible that Cook might have made a good-faith mistake about the contents of your argument, now that you've witnessed yourself making a similar mistake first-hand?"
No. My mistake was not finding something. His "mistake" was asserting that I had made an argument I had not made and entirely ignoring the argument I had made. Since, after more than a year of discussing my argument with people who support him, I have not yet found any plausible defense of his claim in the second paper, the obvious explanation is that he knows he lied, having done so deliberately, and is counting on some people reading his response who did not read what he is responding to.
It's possible that he simply assumed I had made the same argument as some other critic, but replying to my argument without reading it is irresponsible, and replying by accusing me of dishonesty is more than irresponsible. Indeed, it is the sort of behavior one would expect of someone who is interested in the effect of what he says, not whether it is true.
My accusation of you was made to you, repeatedly, with the opportunity for you to rebut it, as you partially did—you did have a response that I missed, although that response failed to support your claim. He made no similar attempt, did not respond with a comment on my blog as he easily could have.
"Broadly, yes. More specifically, you had 'category slippage', in which your not-intended-to-be-super-formal language could, if read unwarily, identify a different category to the ones that the paper, interpreted strictly, was about.
Again, your claim that I objected to was not about articles vs abstracts but about beliefs of authors vs abstracts. You keep ignoring that. Where have I ever said or implied that only 1.6% of the authors believed that humans were the main cause? If I didn't say that, your claim about me was false. Why are you unwilling to admit that? You keep trying to change the subject.
"This is what you're saying Cook is doing, when he shifts from categories 2/3 to "main cause of warming"."
No. Category 1 was about the main cause of warming. Categories 2 and 3 were not. It isn't a slippage of language to claim that a paper holding that greenhouse gases contribute to warming asserts that humans are the main cause of warming. It's a falsehood. And, given the way Cook 2013 was written, pretty clearly a deliberate one. I don't think you ever offered an explanation of why only the summed figure for categories 1-3 was given and not the individual ones--when the individual figures would have shown that the strongest category represented a tiny fraction of the total. That being the category he was going, in another paper, to claim represented all of it.
If you were stupid I would find your defenses of Cook more plausible, but you are obviously bright, and pooling 1.6% with two larger numbers to give 97%, then reporting the 97% and not the 1.6%, is a standard example of how to mislead with statistics. The second paper didn't say "97% of papers held that humans cause warming," which would be roughly the fuzzy language used in Cook et. al. 2013. It was quite explicit about "main cause" and what that meant.
"the link between "CO2 is an anthropogenic forcing" and "warming is 50% human" is much tighter than that. It's really, genuinely *this close* to just assuming that the people who responded can do maths."
Nonsense. There was a period of about thirty years in midcentury when global temperatures were constant to falling, despite increasing CO2. That makes it obvious that there are other causes of comparable strength, so the question of how much warming when was anthropogenic is an empirical question, not doing math. Papers that said humans were the main cause of warming were in category 1, and we know how many there were. Papers that did not say humans were the main cause of warming did not say humans were the main cause of warming, and claiming they did say that is a lie. How many authors believed it we don't know, at least from Cook et. al. 2013. But we do know how many abstracts said it, at least according to the authors of that paper.
I remain disturbed by either your ability to persuade yourself that 2+2=5—more precisely that 1.6%=97%—when doing so is necessary to avoid admitting that a prominent figure on your side of the argument is dishonest, or your unwillingness to admit the fact in print. I can't tell which it is.
James Picone: "There are non-CO2 greenhouse gases that are increasing - methane, CFCs, a couple of others - but none of them have the raw forcing or the lifetime of CO2 (methane in the atmosphere decays over ~30 years, for example)."
[Part 1/2]
The above statement is inaccurate and misleading. First of all, there’s no such thing called lifetime of CO2 or of any other gas, but of its particles. You probably meant the “half life” or the average residence time (or average “lifetime”). Atmospheric methane “decays”, but not in 30 years, it starts “decaying” as soon as it’s emitted into the atmosphere. Likewise, CO2 also “decays” (e.g., it’s turned into organic matter by photosynthetic organisms), with the difference that the residence time of CO2 is much shorter than that of methane:
«Individual carbon dioxide molecules have a short life time of around 5 years in the atmosphere.» [It should read “average life time”]
http//www.skepticalscience.com/co2-residence-time.htm
The average residence time is actually closer to 4 years. You may prefer to make the calculation yourself:
(page 471)
«Figure 6.1 | Simplified schematic of the global carbon cycle.
http://climatechange2013.org/images/report/WG1AR5_Chapter06_FINAL.pdf
Atmosphere [stock]: (589 + 240) Pg C * 3.67 Pg CO2/Pg C = 3042.43 Pg CO2
Total respiration and fire [source]: (107.2 + 11.6) Pg C/yr * 3.67 Pg CO2/Pg C = 435.996 Pg CO2/yr
Ocean-atmosphere flux [source]: (60.7 + 17.7) Pg C/yr * 3.67 Pg CO2/Pg C = 287.728 Pg CO2/yr
Fossil fuels (coal, oil, gas) cement production [source]: 7.8 Pg C/yr * 3.67 Pg CO2/Pg C = 28.626 Pg CO2/yr
Net land use change [source]: 1.1 Pg C/yr * 3.67 Pg CO2/Pg C = 4.037 Pg CO2/yr
Freshwater outglassing [source]:1.0 Pg C/yr * 3.67 Pg CO2/Pg C = 3.67 Pg CO2/yr
Volcanism [source]: 0.1 Pg C/yr * 3.67 Pg CO2/Pg C = 0.367 Pg CO2/yr
Gross photosynthesis [sink]: (108.9 + 14.1) Pg C/yr * 3.67 Pg CO2/Pg C = 451.41 Pg CO2/yr
Atmosphere-ocean flux [sink]: (60 + 20) Pg C/yr * 3.67 Pg CO2/Pg C = 293.6 Pg CO2/yr
Rock weathering [sink]: 0.3 Pg C/yr * 3.67 Pg CO2/Pg C = 1.101 Pg CO2/yr
Total CO2 inflow [sources]:
(435.996+287.728+28.626+4.037+3.67+0.367) Pg CO2/yr = 760.424 Pg CO2/yr
Total CO2 outflow [sinks]:
(451.41+293.6+1.101) Pg CO2/yr = 746.111 Pg CO2/yr
Average residence time CO2: 3042.43 Pg CO2 / 746.111 Pg CO2/yr ≈ 4.08 yr
James Picone: "There are non-CO2 greenhouse gases that are increasing - methane, CFCs, a couple of others - but none of them have the raw forcing or the lifetime of CO2 (methane in the atmosphere decays over ~30 years, for example)."
[Part 2/2]
As for the average residence time of methane:
«Methane (CH4) is a very effective greenhouse gas. While its atmospheric concentration is much less than that of carbon dioxide, methane is 20 times more effective at trapping infrared radiation! The atmospheric residence time of methane is approximately 8 years. Residence time is the average time it takes for a molecule to be removed, so in this case for every molecule of methane that goes into the atmosphere it stays there for 8 years until it is removed by some process.»
http://www.soest.hawaii.edu/mguidry/Unnamed_Site_2/Chapter%202/Chapter2C2.html
This time seems to be accurate. This is the calculation using the data from the same previous source:
(page 474)
«Figure 6.2 | Schematic of the global cycle of CH4.»
http://climatechange2013.org/images/report/WG1AR5_Chapter06_FINAL.pdf
Atmosphere [stock]: (1984 + 2970) ± 45 Tg CH4 = 4954 ± 45 Tg CH4
Wetlands [source]: 177—288 Tg CH4/yr
Fossil fuels [source]: 85—105 Tg CH4/yr
Livestock [source]: 87—94 Tg CH4/yr
Landfills and waste [source]: 67—90 Tg CH4/yr
Geological sources [source]: 33—75 Tg CH4/yr
Rice cultivation [source]: 33—40 Tg CH4/yr
Biomass burning [source]: 32—39 Tg CH4/yr
Freshwaters [source]: 8—73 Tg CH4/yr
Termites [source]: 2—22 Tg CH4/yr
Hydrates [source]: 2—9 Tg CH4/yr
Tropospheric OH [sink]: 454—617 Tg CH4/yr
Stratospheric OH [sink]: 16—84 Tg CH4/yr
Tropospheric CL [sink]: 13—37 Tg CH4/yr
Oxidations in soils [sink]: 9—47 Tg CH4/yr
Total CO2 inflow [sources]:
Lower limit: (177+85+87+67+33+33+32+8+2+2) Tg CH4/yr = 526 Tg CH4/yr
Upper limit: (288+105+94+90+75+40+39+73+22+9) Tg CH4/yr = 835 Tg CH4/yr
Total CO2 outflow [sinks]:
Lower limit: (454+16+13+9) Tg CH4/yr = 492 Tg CH4/yr
Upper limit: (617+84+37+47) Tg CH4/yr = 785 Tg CH4/yr
Average residence time CH4 [lower limit]: (4954 - 45) Tg CH4 / 785 Tg CH4/yr ≈ 6.25 yr
Average residence time CH4 [upper limit]: (4954 + 45) Tg CH4 / 492 Tg CH4/yr ≈ 10.16 yr
Thus, the average residence time of methane in the atmosphere is about twice as long as that of carbon dioxide.
On negative effects:
The point is that there are very obvious, very significant negatives, even for cold countries. Large anomalies tend to lead to deaths, even with low absolute temperatures. Any comparative advantage for Russia or Canada is going to be nontrivial to calculate, because while less deaths in winter is great and all, the larger warming effect at the poles is going to lead to very intense heatwaves compared to the ones we get in warm countries (on anomaly basis). Which of those wins out depends on things like how many more wildfires they're going to see, for example.
On the link:
I'm using Pale Moon, which is a Firefox fork.
On Cook:
I'm still kind of baffled that you take Cook making a mistake about which argument you made as evidence of mendacity. The blog post he was posting on made the argument he attributes to you, just after quoting your blog post. This is not a difficult slip of the brain to understand. And he's seen that argument so, so many times. Say you have no idea who Scott Alexander is, and you run into a blog post that links to Scott's anti-libertarian FAQ, quotes a little bit of it, and then says "Plus, who would pay for the roads?". Do you seriously think that there's no chance you might accidentally misidentify who-would-pay-for-the-roads to Scott?
More Cook:
I think the fundamental disagreement here might actually be on how strong the evidence for ~100% of the warming since preindustrial being anthropogenic is. Do you concede that if the evidence is as strong as I think it is, then Cook's inference is defensible?
When I say it's "assuming that they can do maths", I don't exactly mean "2+2 = 4 => climate change", I mean that given certain common knowledge that can be attributed to people writing climate change papers, the ability to add up forcings makes it immediately obvious that it's gotta be almost 100% anthropogenic. There's no trend at best for any of the known natural forcings (TSI, vulcanism being the big ones), and there's some evidence for negative trend (that is, the natural forcings should be making things cooler). Total heat content of the entire system is increasing, which makes it immediately obvious that it can't be natural variation - not over that timescale, not that large an effect. The only significant changes in forcing over that period are both anthropogenic - aerosols and greenhouse gases. This is not a difficult calculation.
Have you considered the possibility that the reason you don't see people-who-think-climate-change-is-a-problem agreeing with you about Cook is because of some fundamental difference in thought about the evidence, like the argument I'm outlining above, rather than an entire group of people, including rather a lot of scientists, being fundamentally dishonest?
@Zephyr:
I was referring to how long a 'spike' in methane concentrations would persist in the atmosphere vs a 'spike' in CO2 concentrations, not the atmospheric residence time of a single molecule. That is, if we release X methane at time t, at what time does methane concentration return to its previous value?
I don't mean ~30 years to be anything like a hard number. This realclimate post has some schematic diagrams of modelling of methane release that kinda show what I'm getting at - methane breaks down quite fast, in a geological sense, and CO2 does not, so the lifetime of a pulse of methane is governed more by how long it takes it to react away (partially into CO2), and the lifetime of a pulse of CO2 depends on how long it takes for other sinks in the carbon cycle to equilibrate.
"Do you concede that if the evidence is as strong as I think it is, then Cook's inference is defensible?"
No. What Cook wrote was:
"Cook et al. (2013) found that over 97% endorsed the view that the Earth is warming up and human emissions of greenhouse gases are the main cause."
Suppose he had written "Cook et al. (2013) found that 2+2=4."
That would have been a lie. It's true that 2+2=4, but Cook et. al. (2013) didn't find it.
If he had written "found that 97% of the abstracts endorsed the view that 2+2=4" he would also have been lying.
Similarly here. I'm not interested in arguing about how many climate scientists believe what. I'm arguing about whether Cook lied about the contents of an article of which he was the lead author. That's the fact you keep trying to evade.
His statement isn't a statement about how many people believe what. It's a statement about what the paper found in the abstracts examined. What the paper found in the abstracts examined was that 1.6% (of the abstracts expressing an opinion on the causation of warming) endorsed the view that Earth is warming and human emissions of greenhouse gases are the main cause. Representing that as 97% is a lie.
Do you disagree? Do you want to claim that an abstract saying that greenhouse gases contribute to warming is saying they are the main cause? The question isn't what the author believed, it's what the abstract said.
I do not consider it possible that reasonable people cannot distinguish between "X is true" and "my paper found that 97% of abstracts endorsed X." I do, unfortunately, consider it possible that many people put tribal loyalty above truth, whether by lying to other people or to themselves. It's a pattern I have observed over and over again on both sides of the climate argument online.
So far as your argument that it has to be almost 100%, it's wrong. I posted a link a while back to a published journal article offering evidence that global temperature reflects the sum of AGW plus a cyclic pattern, attributed to exchanges of heat between atmosphere and ocean, with a period of about seventy years. If that's right, then for the rising part of the cycle warming is due in roughly equal amounts to AGW and the cycle.
Climate is a complicated system. If the IPCC had an adequate model it would produce a single projection instead of lots of them, and the projection would be reasonably accurate. I think it quite likely that the main cause of warming is AGW, but it isn't certain.
Total heat content of the system may be increasing, but what we are measuring is not the heat content of the system. We have halfway decent data on ocean heat content only for the end of the period, and even that doesn't go all the way down. The heat capacity of the ocean is very large, and we can't say on theoretical grounds how the division of total heat between ocean and atmosphere+surface varies over time.
But all of this is irrelevant to the central point, which is that Cook's claim was about what the abstracts examined said, and only 1.6% of them said something equivalent to main cause. You know that, whether or not you are willing to admit it.
And you never have responded to the question of why, if it was an innocent error, the original paper lumped the 1.6% category in with two categories representing weaker claims, and only reported the 97% sum. I do not believe that you are sufficiently naive not to recognize the implications of that choice.
At only a slight tangent, have you read Orwell's "Politics and the English Language?" I think it's relevant.
http://www.orwell.ru/library/essays/politics/english/e_polit/
On the question of the effect of climate change on plant growth, an article published in the Proceedings of the National Academy:
"Using a unique dataset of tree biomass collected over the past 22 years from 55 temperate forest plots with known land-use histories and stand ages ranging from 5 to 250 years, we found that recent biomass accumulation greatly exceeded the expected growth caused by natural recovery."
http://www.pnas.org/content/107/8/3611.abstract
The argument is not "Cook is correct; therefore the statement was fine". The argument is "You can legitimately infer 'main cause of warming' from the statements in cat 2/3, because other positions are not tenable". That is, the argument is that Cook did find 97% consensus on main-cause-of-warming, and that that is an inference from 97% being in categories 1-3.
Again, I think the Real Story of Cook13 was how few papers are in categories 5-7, and I think that if Cook was trying to do something devious and underhanded, raising the money to make the paper open access, setting up a website where you can rate papers yourself, publishing the raw data, doing a secondary survey of scientists, and publishing that raw data, is a very strange way to go about it. These are not the actions of someone trying to be deliberately deceptive. They are the actions of somebody who thinks they're correct and is trying to be open about what they're doing.
Could you refresh your memory on exactly which paper you're referring to re: natural cycles? Nuccitelli et al. 2012 is perhaps of interest here: link, which included this figure, based on Church 2011 and Levitus 2012.
That graph makes the claim that >50% of increase in surface temperature heat content is due to land/ocean heat exchange look a little ridiculous. That's the kind of data that I'm talking about when I conclude that anthro contributions to recent heating are almost certainly 100%ish.
The idea that heat exchange with oceanic depths lower than those included in that figure resolve the problem is similarly ridiculous. Heat exchange from that depth to the actual abyss is not even of the same order of magnitude; and I'd be surprised if you didn't realise that.
(Plus, arguably 'global warming' means the increase in total heat content of the system, not specifically surface temperature.)
IPCC projections differ on forcing evolution, not on the kinds of facts about the climate system I'm talking about. If you're referring to all of the CMIP bundle of models, I think you're being fooled by weather.
I would argue that the models are pretty accurate. They're certainly better than the naive projection would have been. In my experience most of the demonstrations that they're not doing okay only work because of deliberately poor baseline selection; try comparing trends, which makes that less of a problem. I've linked to SkS' article comparing FAR/SAR/TAR/AR4 projections to reality to you before.
I haven't read that essay of Orwell's. Got it open in a tab now.
"The argument is "You can legitimately infer 'main cause of warming' from the statements in cat 2/3, because other positions are not tenable"."
This seems to be completely at odds with the paper itself, based on these descriptions from the paper:
Cat 1: Explicitly states that humans are the primary cause of recent global warming
Cat 2: Explicitly states humans are causing global warming or refers to anthropogenic global warming/climate change as a known fact
Cat 3: Implies humans are causing global warming. E.g., research assumes greenhouse gas missions cause warming without explicitly stating humans are the cause
as well as these descriptions from the data file used in the paper:
Cat 1: 1,Explicitly endorses and quantifies AGW as 50+%
Cat 2: 2,Explicitly endorses but does not quantify or minimise
Cat 3: 3,Implicitly endorses AGW without minimising it
I don't see how inferring "humans main cause for all 3 categories" can be legitimized based on these very specific categorizations of endorsement.
-excel
@Anonymous:
The position "humans cause global warming, but it's <50%" is not tenable. Therefore, papers in cat 2/3, with high probability, do not take that position.
Papers in cat 5/6/7 either implicitly or explicitly don't allow for that inference - perhaps because they argue that in addition to human warming there has been significant natural variability (i.e., cat 5).
The 'middle position' of "warming happened, anthro, but I refuse to estimate how much" is similarly silly because of how untenable the <50% position is.
"The position "humans cause global warming, but it's <50%" is not tenable. Therefore, papers in cat 2/3, with high probability, do not take that position."
Why is it "not tenable"?
-excel
@Anonymous:
To quote myself from earlier:
"When I say it's "assuming that they can do maths", I don't exactly mean "2+2 = 4 => climate change", I mean that given certain common knowledge that can be attributed to people writing climate change papers, the ability to add up forcings makes it immediately obvious that it's gotta be almost 100% anthropogenic. There's no trend at best for any of the known natural forcings (TSI, vulcanism being the big ones), and there's some evidence for negative trend (that is, the natural forcings should be making things cooler). Total heat content of the entire system is increasing, which makes it immediately obvious that it can't be natural variation - not over that timescale, not that large an effect. The only significant changes in forcing over that period are both anthropogenic - aerosols and greenhouse gases. This is not a difficult calculation."
Alternately, AR4 chapter 9 lists some pretty good reasons.
@James Picone
"When I say it's "assuming that they can do maths", I don't exactly mean "2+2 = 4 => climate change", I mean that given certain common knowledge that can be attributed to people writing climate change papers, the ability to add up forcings makes it immediately obvious that it's gotta be almost 100% anthropogenic. There's no trend at best for any of the known natural forcings (TSI, vulcanism being the big ones), and there's some evidence for negative trend (that is, the natural forcings should be making things cooler)."
Going by the temperature records the evidence seems to be for a positive trend, pre-industrialism. Which negative trends are we talking about?
"Total heat content of the entire system is increasing, which makes it immediately obvious that it can't be natural variation - not over that timescale, not that large an effect."
This is an assumption. A rather large one.
"The only significant changes in forcing over that period are both anthropogenic - aerosols and greenhouse gases. This is not a difficult calculation."
The calculation may or may not be simple, but it seems to rely on large assumptions and some claims that contradict the historical record.
-excel
"Going by the temperature records the evidence seems to be for a positive trend, pre-industrialism. Which negative trends are we talking about?"
TSI.
LIA bounce stuff is very much done before instrumental records. Not a factor for present warming. And it's TSI, which certainly isn't in a warming direction since records began.
Note that I don't claim there's a significant negative trend, only that if there is a trend it is negative.
"This is an assumption. A rather large one."
Over here we call it "The second law of thermodynamics"
"The calculation may or may not be simple, but it seems to rely on large assumptions and some claims that contradict the historical record."
This IPCC AR4 chapter contains observationally-based ECS estimates if you want the complex version. Remember we've got 1.9 W/m**2 of CO2 forcing (alone) over preindustrial, assuming 280 ppm for preind. That heat has to go somewhere.
"LIA bounce stuff is very much done before instrumental records. Not a factor for present warming. And it's TSI, which certainly isn't in a warming direction since records began."
That's an interesting claim. What made that "bounce" stuff stop?
"Note that I don't claim there's a significant negative trend, only that if there is a trend it is negative."
K.
"Over here we call it "The second law of thermodynamics"
Pithy, but contentless.
"This IPCC AR4 chapter contains observationally-based ECS estimates if you want the complex version. Remember we've got 1.9 W/m**2 of CO2 forcing (alone) over preindustrial, assuming 280 ppm for preind. That heat has to go somewhere."
Doesn't really seem to address the problem.
"That's an interesting claim. What made that "bounce" stuff stop?"
More accurate: What made that bounce /start/?
Global average surface temperature is not a bouncing ball. It reacts to forcings. It got cold because of a negative forcing (likely reduced TSI). It got warm again when that negative forcing went away/went positive (TSI caught up).
There is, to the best of my knowledge, no evidence of TSI or other forcing changes on the same order of magnitude as the ~1.9W/m**2 of CO2 forcing over the surface temperature record.
Here is some proxy data for TSI over the last several centuries. SkS has a graph of that data. It's clear that there's a trend since the LIA, and that's almost certainly one of the factors that caused it.
There's no trend in TSI since instrumental records began, and if there is a trend it's negative. I linked you to the satellite data for it above. Additionally, the gap between the lowest value on that TSI graph and the highest value is less than the CO2 forcing since preindustrial! And that's before albedo!
"Pithy, but contentless."
Plenty of content. Total heat content of the entire system is measurably increasing. Looking at that and going "Well maybe it's internal variability. Over several decade timescales" falls afoul of conservation of energy. It's the same reason we know climate isn't a random walk - because physics doesn't work that way.
"Doesn't really seem to address the problem."
Sure it does. Do you know of any forcing of equivalent size?
@James Picone
You argue that any paper in categories 2 and 3 must have been implicitly in category 1 because to not be would be untenable. But how tenable are categories 5/6/7, which also involve rejecting the claim that warming is primarily human caused? You consider the positions that these categories refer to to be untenable too - right?
If so, why bother doing this aggregation work at all - why not just declare that 100% of climate scientists hold the position "global warming is real and humans are the principal cause", as this can be determined by a simple assessment of what is and isn't tenable?
@James Picone:
"More accurate: What made that bounce /start/ ? "
No, I think the "What made the bounce stop" question is of bigger interest, and even "did the bounce stop".
"Plenty of content."
No.
"Looking at that and going "Well maybe it's internal variability. Over several decade timescales" falls afoul of conservation of energy."
Another interesting claim, but with little to support it.
"Sure it does."
No, it doesn't.
@First anon:
I'm saying that things that are not cat 5/6/7 in their abstract are vanishingly unlikely to reject anthro >50%. This is different from saying cat 5/6/7 doesn't exist. If an abstract took the position that anthro <50%, either implicitly or explicitly.
If people think their paper is support for Weird Thing, they put that in their abstract. Papers on galactic rotation curves will say when they don't mesh with relativity, for example. It's an interesting result.
@Second anon:
Let me put it this way: the measured difference in forcings between the bottom of the little ice age and today is less than forcing value we expect for the CO2 we've emitted over preindustrial. I linked to proxy TSI data, there's a .75 W/m**2 difference between the lowest value on the graph and the highest value. We've increased CO2 from preindustrial 280 ppm to ~400 ppm. Forcing due to CO2 is 5.35 * ln(C/C0) W/m**2, or ~1.9 W/m**2 for CO2 emitted to date. This is before feedbacks; before any of that; and it's a pretty uncontroversial value. If you think the greenhouse effect doesn't exist, or CO2 is saturated and so can't have any effect, or some similar far-end denial position, now would be a good time to actually bring it up instead of snarking.
Notice that 1.9 W/m**2 is ~2.5 times as large as 0.75 W/m**2.
@James Picone:
"the measured difference in forcings between the bottom of the little ice age and today is less than forcing value we expect for the CO2 we've emitted over preindustrial."
Interesting choice of words.
"This is before feedbacks; before any of that; and it's a pretty uncontroversial value. If you think the greenhouse effect doesn't exist, or CO2 is saturated and so can't have any effect, or some similar far-end denial position"
Also interesting choice of words, given that the concept of CO2 saturation (or indeed any gas saturation) is pretty uncontroversial, but you've chosen to describe it as a far-end denial position.
-excel
"Interesting choice of words."
Directly measuring a forcing is decidedly nontrivial. Are you disputing the 3.7 W/m**2 figure for forcing for doubled CO2? Are you disputing that we have raised CO2 from roughly 280 ppm to roughly 400 ppm? If you don't dispute those, is there any particular reason you're making potshots?
"Also interesting choice of words, given that the concept of CO2 saturation (or indeed any gas saturation) is pretty uncontroversial, but you've chosen to describe it as a far-end denial position."
CO2 is saturated and so can't have any effect. Compound phrase. The last bit is very important.
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