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Comments 21301 to 21350:
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Tom Curtis at 21:50 PM on 2 February 2017CO2 lags temperature
poncholarp @519:
1) "The graph I was quoting .... ... not at a log offset..."
The graph plots CO2 and temperature against time. It does not plot correlation, and if you were to attempt to plot correlation, you would use a scatter plot. As it happens, the correlation between CO2 concentration and temperature is 0.888 +/- 0.037 using means of 1000 year bins of the data, with bins where one or both data sets had no representatives being excluded. (The results might differ with other means of dealing with the fact that the actual data do not have CO2 values and deuterium values on the same dates.) In contrast the correlation of CO2 forcing and temperature is 0.879 +/-0.038. Both are high, and while (as expected) the CO2 concentration has the higher correlation, both are within error of each other.
Note that we expect the correlation to be higher for concentration because temperature drives the changes in CO2 concentration, while CO2 forcing only partially drives the temperature over that period. In contrast, in the modern period, when it is known that temperature is not driving CO2 concentration, we expect CO2 forcing to correlate better with temperature than does CO2 concentration. And indeed, that is the case.
In any event the difference between CO2 concentration and CO2 forcing plotted against (in this case the Epica Dome C 800,000 year record) is scarcely noticable to the naked eye:
(Note, the data terminated 24,000 years BP for deuterium, but there was no data for CO2 in the 24,000 - 25,000 years BP bin, hence the first data point is for 25,000 years BP.)
2) "If you could accurately subtract..." What utter tripe, and you know it to be utter tripe because your conditional "If you could" shows that your conclusion that "...you would clearly see that warming trends have no correlation to co2" is simply made up. As it happens, they also have ice core records of methane and nitrous oxide, and you are simply wrong. Your made up "fact" is a fiction.
3) "Very impessive graph though that ... now further proves my point" I am very certain it does not, but cannot mount any argument because you have completely failed to provid evidence for this claim. Given that, it amounts to sloganeering.
4) "The bar graph you used implies that co2 is a warming driver... when, this is what is being debated in this thread ..."
Now, either you are attempting to criticize the standard theory of greenhouse gases and the LGM - which is that temperature responds to the log of CO2, and that CO2 was one of several relevant greenhouse gases, and that changes in albedo had slightly more effect than the combined effect of greenhouse gases. In that case I do not need to support the graph because it simply presents that theory you are trying to criticize - and shows that you have not accurately presented it.
Alternatively you are trying to refute a theory of your own concoction that no informed person believes, in which case who cares. I think, however, that you are trying to pass of the theory of your own concoction as that which climate scientists use, and pretend the refutation of your nonsense thereby refutes thousands of person/years of research.
Moderator Response:[PS] Both of you need to keep it civil. Take a deep breath, ignore provocation and stick to discussing the science.
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uncletimrob at 17:57 PM on 2 February 2017Global warming hiatus claims prebunked in 1980s and 1990s
@5 OPOF, I have great difficulty explaining this to people, I'm guessing because 30 years in some cases a significant fraction of their lives. Even people with some matematical training are happy to pick a couple of yeaars to prove their point but to ignore long term trends. Personally I hope that the models and trends are shown to be erroneous, but the evidence is stacked against that I believe.
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Doug Bostrom at 16:30 PM on 2 February 2017Global warming hiatus claims prebunked in 1980s and 1990s
A deep dive comes up with a fascinating report. Thanks for this; great stuff.
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One Planet Only Forever at 09:53 AM on 2 February 2017Global warming hiatus claims prebunked in 1980s and 1990s
The common practice for evaluating climate data has always been to look at a 30-year set of data (along with all the previous history that is available). That was always the way that the Canadian Building Code climate data for design was updated every 10 years, a new most recent 30 year set of data being the basis for location specific design values (along with the full history of data for each location).
An appropriate way to look at the trend of the data is the 30-year rolling average.
There has been no pause/hiatus in the 30-year riolling average. Evene the 40 year satellite data would show a fairly steady rise of the 10 years of 30-year rolling average.
Looking at shorter sets of data (or cherry-picking bits of detail from the historical record) is the only way to create the impression of justification for claims that warming due to increased CO2 is not continuing to occur, or the rate of warming has dramatically changed from a previous rate in a way that is inconsistent with the current best understanding of climate science.
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Tom Curtis at 09:52 AM on 2 February 20172017 SkS Weekly Climate Change & Global Warming Digest #4
In the humour department comes this paper refuting the science of global warming:
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chriskoz at 07:16 AM on 2 February 20172017 SkS Weekly Climate Change & Global Warming News Roundup #4
In case AUS federal politics are not on this site's radar, here's the rebirth of "clean coal" meme debunked here in the past:
Coal could get clean-energy subsidy under new Turnbull focus
The option of redirecting federal subsidies from exclusively renewable energy projects to encourage investment in new, coal-fired power generators, is among "several ideas" being considered as part of a wide review of policy.
my emphasis
So Turnbull will have directed the subsidies to coal power stations in a move embracing his predecessor (Abbott) slogan that "coal isgood for humanity". Sad but it was somewhat predictable: Turnbull revealed time and time since becoming PM, that science is not any guidance in his policy decisions.
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robert test at 07:11 AM on 2 February 2017Global warming hiatus claims prebunked in 1980s and 1990s
Wonderful article. A few weeks ago I was having a conversation with someone I know who is a long-time AGW denier who frequently waffles on exactly the position he takes.
In that conversation he denied that anyone has claimed there was/is a pause in warming.
Ari Jokimäki observes that "apparently, the first claims of global warming hiatus after 1998 were made in 2006 by well-known climate change mitigation opponents."
Of course there is the distinction between the science literature and the popular literature.
I would like to see an attempt made to create a complete bibliography of the leading denier articles that claimed there was/is a pause in warming.
The historical record of this travesty should be preserved.
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nigelj at 07:06 AM on 2 February 2017Global warming hiatus claims prebunked in 1980s and 1990s
Excellent history. I find this pause issue pretty interesting, just as a lay person observer. I think a lot of this depends on how you define a hiatus or pause.
For example, I'm looking at the NASA Giss surface temperature record, and clearly there was a slowdown in surface temperatures from roughly 2002 - 2010, (just eye balling the graph)and there were also previous slowdowns like this. I see this as a slowdown or pause of at least some kind. I would suggest the general public see this as a pause, and it would be most unwise to say to them its not a pause, or you come across as claiming white is black. It's important not to let the denialist people spook you into making wild claims. Of course you can say with validity that this "pause" was not statistically significant.
I think it would be valid to say theres been no 'pause' in terms of the underlying greenhouse effect, or total energy accumulation, because that is what the evidence shows. But you should be specific that theres no pause in terms of energy accumulation, and not simply say there was no pause of any kind.
The real issue to me is what caused the pause in surface temperatures? The most likely explanation is natural variation or noise.
Given the greenhouse effect should in theory and assuming it is the only climate forcing agent, cause a straight line, it can only be natural variation. Foster and Rhamstorf subtracted all known natural cycles from the temperature record and were left with something getting near a straight line, reinforcing the natural variation theory. There was nothing to suggest something totally unknown was at play.
The sunspot cycle is known to be a factor that can supress or exaggerate temperatures for a period.
Ocean cycles clearly affect surface temperatures, because el nino and la nina years stand out. It appears there were a lot of la ninas and weak el ninos during the slow period, which suggests some sort of ocean process. My understanding is energy went into the deep oceans, and it's hard to measure this affect on temperatures at that depth, so hence the generally flat global temperatures.
Clearly the pause is now over, which suggests this ocean phenomenon has reversed and may be cyclical. But do we know for sure, could you get quite a long pause? It seems to me these ocean cycles are not well understood. However the ocean can't by definition act as some sort of heat sink forever, and that heat is going to come out, or alternatively the ocean would stop absorbing so much heat. Given the big jump in temperatures over the last three years it must be one or the other?
The IPCC back about 1990 also predicted slow periods of about 10 years, due to natural variation, and we have seen a slow period of about 6 - 10 years depending on what graph you look at. This prediction surely reinforces that the IPCC is a reliable authority. Rather than playing down the pause, I would highlight this. Don't let the denialists frame the debate and make the definitions.
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Tom Dayton at 05:49 AM on 2 February 2017Global warming hiatus claims prebunked in 1980s and 1990s
Alexandre, unfortunately there is a lot of confusion about this topic due to use of jargon and loose terminology rather than actual disagreements among scientists. I agree with Tamino (enter "pause" in the search field of his site) and others that there has been no hiatus/pause/slowdown in "the trend" of surface temperature, given that I and those other people define "the trend" to mean the "long term" trend in surface temperature. There is no doubt among those people that the surface temperature has, does, and always will vary around that long term trend, as "short term" trends that are too short to reasonably imply any change in the underlying long term trend.
Some scientists have investigated the causes of "the pause/hiatus/slowdown," unfortunately using those terms instead of being clear that they were discussing one of (or some of) those short term trends, not the underlying long term trend.
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Alexandre at 03:37 AM on 2 February 2017Global warming hiatus claims prebunked in 1980s and 1990s
Tamino claimed several times that the hiatus is statistically not even there (e.g. here). How does the SkS team weigh in in this issue?
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John Hartz at 01:26 AM on 2 February 2017Trump is copying the Bush censorship playbook. Scientists aren't standing for it
Recommended supplemental reading:
A new battle over politics and science could be brewing. And scientists are ready for it by Chris Mooney, Energy & Environment, Washington Post, Jan 31, 2017
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Ger at 22:49 PM on 1 February 2017We may be closer than we thought to dangerous climate thresholds
Rate of change: during 1950-1980 the average rate of change was around 0. Like if the than emitted fossil CO2 was in equilibrium with the nature. Nature, the sea, was in that period capable to absorp that amount of CO2. Currently It looks like the top layers of the oceans are satured so more CO2 stays in atmosphere, capturing more heat.
I saw (sorry forgot reference) at another site that it takes a 30 years before the mixing of the deeper layers is back in (some sort of) equilibrium.
And lo and behold, around 2010 we see an even faster rate of heating up occur. Even if the heating is a 0.1 C (its more a 0.15~02) a year, after 13 more years we would be at 2.3 C already before (if nothing changes) we pick up another sprint in temperature rise)
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MA Rodger at 22:06 PM on 1 February 20172017 SkS Weekly Climate Change & Global Warming Digest #4
scaddenp @10.
Your graph is not unusual for SO2 graphs in that it stops at 2000. Coal-use has thankfully ceased its massive post-2000 rise and perhaps even peaked, as data from the BP 2016 review suggests.
The stat is mirrored in CDIAC CO2 emission data (2000 - 2,413Gt(C), 2015 - 4105Gt(C), down 2% on 2014).Thankfully, the post-2000 global SO2 emissions are not as dramatic as CO2 emissions, this graphic of SO2 from Klimont et al (2013) demonstrates.
And even more up-to-date is the NASA Global Sulfur Dioxide Monitoring Page which shows emissions 2005-14 from 500 locations around the globe and so allows analysis by latitude. It also splits emissions into electricity generation (totalling ~50%), smelters (~12%), FF (~12%), volcano (~25%). And it shows the monitored anthropogenic sources falling from 2007 (58 TgSO2) to 2014 (41 TgSO2). We can presumably expect this trend to continue for some years as SO2 emissions are further decoupled from coal use and coal-use hopefully also dropping substantially.
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poncholarpez at 20:24 PM on 1 February 2017CO2 lags temperature
Tom Curtis. The graph I was quoting in the OP isays it is a direct correlation to historical observed co2 v temp. They rise at the same rate, not at a log offset with an assumed modified result for proportion of co2 making up greenhouse gasses in the atmosphere. If you could accurately subtract other greenhouse gass portion of the temprature into that graph, then you would clearly see that warming trends have no correlation to co2. Very impessive graph though that combined with the feedback given, now further proves my point but in the upside spikes of the graph too. Thanks for that ;)
The bar graph you used implies that co2 is a warming driver under the greenhouse gasses group, when, this is what is being debated in this thtead, yet it is being taken as gospel that it is?? Furthermore, the bar graph you provided takes no account of water vapour as a greenhouse gass and takes no account of potential cloud cover conditions. Ill informed, nice try.
Moderator Response:[JH] Please keep it civil.
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scaddenp at 14:07 PM on 1 February 20172017 SkS Weekly Climate Change & Global Warming Digest #4
Tom, I was basing of this
which certainly to come from a published source.
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nigelj at 13:33 PM on 1 February 20172017 SkS Weekly Climate Change & Global Warming Digest #4
So coal causes some quantity of cooling through the global dimming effect. But as noted, it also causes warming, and on the best evidence we have this is the more powerful effect, although with some level of uncertainty.
However we cannot stop there. I read this recently so thought I would add it in. A recent study by the WHO has found air pollution, including particularly from coal, causes far more deaths than previously thought, as below.
www.who.int/mediacentre/news/releases/2014/air-pollution/en/
And coal mining remains a very hazardous occupation. We had a coal mine explode a few years back, killing dozens of people, despite all the modern technology, and health and safety rules.
And we are no longer in the Industrial Revolution with coal generating steam power or home heating. We now have other energy alternatives.
Things constantly evolve and change.
You have to consider the big picture, and the full range of evidence. Trump seems to struggle with that, as do his inner circle.
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Tom Curtis at 12:32 PM on 1 February 20172017 SkS Weekly Climate Change & Global Warming Digest #4
scaddenp @7, do you know that global dimming is reducing from a scientific study. My understanding was that as aerosols decreases in the developed world due to the introduction of scrubbers, it increased in the third world, and particularly in China due to their rapid industrialization. Because aerosols tend to be regional effects, it may be that global dimming as measured in the US, EU or Australia has fallen, but that globally it has remained the same or increased. I have made a quick skim of Wild 2012, and Wild 2016, and can see no definite conclusion on that point. Wild 2012 does illustrate the different trends in different regions (Figure 2).
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jbpawley at 11:48 AM on 1 February 2017Trump is copying the Bush censorship playbook. Scientists aren't standing for it
So, where is the URL of the WWW site for this March March? We need to support the organizers before they can be fired. And the need those cowering Deomocrats to get up and start leading!
Moderator Response:[JH] The url is embedded in the term, "March for Science." Click on it and you will be taken to the march's website.
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scaddenp at 11:38 AM on 1 February 20172017 SkS Weekly Climate Change & Global Warming Digest #4
But independent of Tom's comment - scrubbing technologies are reducing global dimming independently of the about of FF we burn. As far as I can tell, the models for zero emissions also nil the human aerosols.
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Tom Curtis at 11:22 AM on 1 February 20172017 SkS Weekly Climate Change & Global Warming Digest #4
Ravenken @5, the particulate matter is soot, which contributes to global warming, and is accounted for in models as Black Carbon (BC). Coal or oil with high sulfur contents also release sulfur dioxide (an invisible gas). That reacts with components in the atmosphere to form sulfates, very small particles that reflect sunlight and also form cloud condensation nuclei. As a result of the latter, the presence of sulfates will result in more, but smaller water droplets in a cloud, which results in a greater cloud albedo, and reduced rainfall. The effects of sulfates are taken into account as the aersol direct effect (the albedo of sulfates), and the aerosol indirect effect (the impact on clouds by providing cloud condensation nuclei). Combined the consequences of these two effects is what is generally called global dimming. As both effects are taken into account in climate models, so also are the effects of global dimming. However, the uncertainty of the strength of the two effects is one of the largest uncertainties in climate science.
From the above, you should see that the impact of reduced aerosols from shutting down fossil fuel energy sources is taken into account in scenarios with rapid decarbonization of the economy.
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Ravenken at 11:06 AM on 1 February 20172017 SkS Weekly Climate Change & Global Warming Digest #4
scaddenp- thank you for getting back to me...
I'm still a little in the dark... what I am trying to get at is, as global society starts using less coal I thought that might decrease the amount of global dimming occuring from coal power plants... There might not be any dimming from coal plants (as my ignorance would attest) but I'm assuming there is... I get and understand the CO2 is going nowhere but I thought the particulate matter from coal plants contributed to global dimming...
I guess my first question is do coal plants contribute to global dimming. If so, how much... I appreciate your patience.
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Tom Curtis at 09:10 AM on 1 February 2017CO2 increase is natural, not human-caused
KalleH @21, you are quite correct that I intended to write "...determine the source of the [decrease] in atmospheric C14". Thankyou for picking up on my error.
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KalleH at 08:27 AM on 1 February 2017CO2 increase is natural, not human-caused
Tom -
In your post (29th November 2016, #19 above) you wrote:
That being said, it is a bad practise to relly on a single indicator in making these sorts of determinations. In fact there are at least 10 different lines of evidence that help us determine the source of the increase in atmospheric C14.
My understanding was that the levels (or actually ratio) of C14 were decreasing as they come from a fossil source. Am I wrong, or could you possibly have meant CO2?
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Haze at 21:08 PM on 31 January 2017Fact Check: Trump's Cabinet Picks on Human-Caused Global Warming
Apologies. Having written comment 1, I then scrolled down the page to see, much to my chagrin, the next item was "March for Science'. Good-o but as the 45th POTUS has dismissed other such marches do you thinkthere will be on going and varied protests? This is political I guess rather than science so if it is scrubbed then fair enough
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Haze at 20:53 PM on 31 January 2017Fact Check: Trump's Cabinet Picks on Human-Caused Global Warming
The outlook for the Paris Agreement and the funding of climate scientists doesn't look too good at the moment, if media reports are to be believed. It seems that the new administration may not be entirely convinced by the 97% consensus that humans are responsible for all of the global warming since 1950. If so what steps will/can climate scientists, particularly in the US but also in other locations, take to convince the new administration that climate change is dangerous? Presumably plans were put in place before Mr Trump was elected as it has been known for many months that his election was a possibility. Have any plans been made? If so will they be made public? If not will plans be made or will climate scentists vacate the field as it were?
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scaddenp at 09:27 AM on 31 January 20172017 SkS Weekly Climate Change & Global Warming Digest #4
Not common to see sealevel rise talked about in inches but I just found this image
based on this paper.
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scaddenp at 06:51 AM on 31 January 20172017 SkS Weekly Climate Change & Global Warming Digest #4
Ravenken, I cant comment on the forcing used to climate commitment papers but I would note a couple of things:
1/ Aerosols are increasing decoupled from CO2 emissions anyway thanks to scrubbing technologies and have been dropping since 1990s.
2/ If you look at the forcing strength, the heating from increased CO2 is rather stronger than aerosol cooling.
From this I would conclude the GHG concentration is most anthropogenic important factor affecting temperature.
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Ravenken at 06:23 AM on 31 January 20172017 SkS Weekly Climate Change & Global Warming Digest #4
I've got a question that I believe SS can best answer/direct me... do the modeled forecasts for temp from reduced CO2 also account for decreased solar dimming and thus more wamring?
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roycekimmons at 06:19 AM on 31 January 2017Global warming theory isn't falsifiable
This is an interesting topic that has recently been published on in the Public Understanding of Science journal by David Mercer. His analysis documents how Popper is invoked by those on both sides of the issue, and his analysis seems to be very illustrative of many of the arguments appearing in this thread. If you had not seen it, here's the link: http://journals.sagepub.com/doi/abs/10.1177/0963662516645040
Moderator Response:[PS] Link fixed. Please learn how to do this yourself with the link tool in the comments editor.
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indianaclark at 03:43 AM on 31 January 2017CO2 is not a pollutant
If we can define pollution as the contamination of air, water, or soil by substances that are harmful to living organisms, most substances can fill-the-bill, especially when we consider high/low concentrations and temperatures. Plants that grow in areas that we don't want them will be considered as weeds. Carbon Dioxide that becomes too concentrated for our environment certainly should be considered a pollutant, but the question, and I think it is still unanswered scientifically, is what is that level? The dynamic complexity of the Earth's ecosystem suggests that when we begin tinkering with nature we may find ourselves creating additional problems for mankind that are currently unforseen.
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Montross515 at 23:55 PM on 30 January 20172017 SkS Weekly Climate Change & Global Warming Digest #4
If warming melts the polar caps the ocean goes up 100 or more feet. It hasn't gone up an inch yet, so why worry. 99% of everything in our solar system is in the Sun, so it controls and we don't understand it.
Moderator Response:[JH] Sloganeering snipped.
[PS]
Thank you for taking the time to share with us. Skeptical Science is a user forum wherein the science of climate change can be discussed from the standpoint of the science itself. Ideology and politics get checked at the keyboard.
Please take the time to review the Comments Policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter. To avoid sloganeering back your assertions with data/references to support your view.
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Digby Scorgie at 17:35 PM on 30 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
An additional thought on Kevin Anderson's lectures is that the shrinkage of 10% per year is in emissions. I have assumed that this equates to a similar shrinkage in economic activity — of the traditional type. My assumption might not be correct.
On the other hand, there really is a conflict between the 10% and 4% reductions. We need 10% to avoid 2o of warming, but the economists say we can't do more than 4%. Unfortunately 4% is not good enough — my understanding is that it is likely to lead to the dreaded 4o of warming.
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Digby Scorgie at 14:14 PM on 30 January 20172017 SkS Weekly Climate Change & Global Warming Digest #3
Tom Curtis @10
My cheeky response is: "I have no children (phew!)." My serious response is that there is a problem only if those who suffer by ignoring climate change also cause others to suffer as a result. Does this really apply in the case of one group of one country's farmers?
michael sweet @11
See serious response above.
RedBaron @12
You put the problem in an entirely different light. As usual it's a lot more complicated than one might first think.
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RedBaron at 13:52 PM on 30 January 20172017 SkS Weekly Climate Change & Global Warming News Roundup #4
The Fox Who Will Guard the Nation’s Henhouses (And Five Questions the Senate Should Ask Him) by Karen Perry Stillerman, Union of Concerned Scientists, Jan 24, 2017
I got a kick out of this one particularly because I used the exact same analogy 2 days ago! Excellent article!
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Digby Scorgie at 13:51 PM on 30 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
Further to my comment @9, I note that Kevin Anderson has been giving variations and updates of the same lecture for some years now. The relevant quotation for my comment is as follows:
"There is a widespread view that 4oC is incompatible with an organized global community, is beyond adaptation, is devastating to eco-systems, and is unlikely to be stable." Such warming is therefore to be avoided "at all costs".
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chriskoz at 13:21 PM on 30 January 20172017 SkS Weekly Climate Change & Global Warming News Roundup #4
Re: "21 kids are fighting Trump's attempts to delete federal climate websites".
The article is misleading. The "The "Juliana v United States" case was filed in and heard for the first time in Oregon in March 2016 well before the 2016 election campaign and even before T-man emerged as its frontrunner. The Obama administration (against whom the suit was filed) tried to dismiss it and failed according to this ruling. The latest ruling on the case by district judge Ann Aiken from Nov 10, 2016, allowing it to proceed, coincides with T-man election victory date but has nothing to do with T-man himself. The case would have proceeded unchanged had Clinton won the alection (I doubt judge Aiken's mind was influenced by that even in the yesterday of the ruling). Needless to mention that, T-man's "attempts to delete federal climate websites" is completely irrelevant to this case.
So, the article is very misleading, confusing the irrelevant events (the rise of an irresponsible conman to the POTUS office and his subsequent actions) with the Juliana v United States case which precedes these events.
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RedBaron at 02:49 AM on 30 January 20172017 SkS Weekly Climate Change & Global Warming Digest #3
Michael,
You are right that US farmers are businessmen. You are also right that farmers have pretty good long term records. You are right that farmers are aware of the impact climate change is causing their businesses. I never once met an American farmer who was an AGW denialist. And most American farmers are conservative Republicans too. Their influence is part of the reason for the "red state" heartland traditionally voting Republican.
So there is an opportunity with farmers to develop an AGW mitigation strategy that cooperates with the Republican party by including this demographic of Farmers and rural communities.
However, you will have to address a few things.
In 2012 the average age of farmers was 58.3 with over 20 times more farmers over age 75 as under 25. This has been growing steadily every year, as income:cost of living ratio has dropped. 52.2% of those farmers principle income off farm and only 46.1% of farmers with net positive income from farming. That means a full 63.9% of US farmers are operating at a loss and the only way they manage to avoid bankrupcy is off farm income. As if farming wasn't already a hard enough job!
Source: USDA-NASS, Census of Agriculture
This has caused a steady stream of farms to fail since 1970. In fact the financial stability of the small to medium family farm continues to decline, forcing 1/2 of the farmers in the whole country out of business and the remaining farms have doubled in size.
Also, Ag’s % GDP has fallen from 6.8% to .7% GDP. Available arable land has fallen from 189,244,000 hectares in 1969 to a minimum value of 151,669,300 in 2011 due to extensive land degradation and land use change. We are producing about 1 ton of food for every 100 tons of top soil lost. The % of the US publics food dollar that reaches the farmer is at an all time record low.
As razor thin as farm margins are, in order to effectively recruit this demographic you must first teach the farmer how to disconnect his operation from fossil fuel inputs. Right now lowering the price of oil can mean the difference between a profit and losing the farm.
"When farmers view soil health not as an abstract virtue, but as a real asset, it revolutionizes the way they farm and radically reduces their dependence on inputs to produce food and fiber." -USDA
It is one of the reasons for the huge push by the USDA NRCS & SARE to teach farmers how to wean themselves off Haber process nitrogen and mined phosphorus. A push that Trump right now has on hold with the gag order on the USDA! And worse, Trump appointed an industrial Ag guy.
Trump picks Sonny Perdue for agriculture secretary
So don't expect any improvement this 4 years. The fox is in charge of the hen house.
See the real power isn't really the farmers. They are between a rock and a hard place. The real power lies in the industrial giants supporting the farmers and taking that huge cut of the food dollar. As long as the US farmer is dependant on them, they really have no choice at all. And by themselves, there are far too few to worry about, and are typically safely ignored as a voting demographic. As long as the real power at the USDA is using the "mushroom" strategy, expect no help from farmers, no matter how scientifically and economically sound it might be.
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michael sweet at 23:15 PM on 29 January 20172017 SkS Weekly Climate Change & Global Warming Digest #3
Digby Scorgie,
Farmers are a powerful lobbying force in the USA. Most farmers are rich businessmen. If they were serious about climate change their voice would be heard. Their failure is one of the major effects of climate change. Farmers keep long term weather records for their locations. They are aware of the changes climate change is causing for their businesses.
If farmers were to take a strong stand on AGW the Repubilcans would have to listen. The factor holding back their concern is completely political. If they can be reached it would comletely change the political debate. That change would benefit all of us (as Tom states).
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Tom Curtis at 20:59 PM on 29 January 20172017 SkS Weekly Climate Change & Global Warming Digest #3
Digby Scorgie @9, because my children will also be adversly effected by those consequences. As will billions of others.
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Eclectic at 13:26 PM on 29 January 2017CO2 lags temperature
Tom Curtis @517
Thanks for your courteous and prompt reply, especially in view of your workload. I had been innocently picturing that each of the recent set of glaciations followed a very standardized path, without much variation. There was an earlier SkS article that linked to a paper showing the Milankovitch orbital fluctuations of the past half-million years, and indicating that in the coming few dozen millennia we would experience a relatively low-eccentricity of orbit, which might have a damping effect on the approach of the next glaciation. But as you say, Holocene humanity (and its increasing population) would be a more likely explanation for the Holocene's "abnormality".
Thanks once again, Tom. And if it's not being too saccharine of me, I'd like to thank you on behalf of all visitors and participants at SkS. You are a scientific powerhouse in the SkS comments columns.
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Digby Scorgie at 12:31 PM on 29 January 20172017 SkS Weekly Climate Change & Global Warming Digest #3
michael sweet @8
I don't understand the need to persuade people of the reality of climate change, even if their livelihood depends on it. If they refuse to accept reality, let them suffer the consequences.
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michael sweet at 11:00 AM on 29 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
Driving By,
We do not need to wait 75 years to start movng cities. Already parts of New York and New Orleans have not been rebuilt. Those people moved inalnd. Miami Beach is currently spending hundreds of millions of dollars in a futile effort to hold back the sea. They will eventually have to give up and move. In Tampa Bay, where I live, $175 billion dollars of real estate is at risk from the next hurricane.
If the next major hurricane strikes Galveston (or any other major city at risk) the Federal Government will likely stop subsidizing insurance. When that happens homes in the low areas will no longer be worth anything. People will start to move. Recently the New York Times claimed houses threatened by sea level rise have not increased as much in value as safer houses.
This Zillow report claims 1.9 million homes in the USA will be flooded by 6 feet of sea level rise. On the East Coast a substantial number of those would be flooded in a big storm now. When investors realize the risks they are taking what will happen to the coastal housing market? A hurricane does not have to strike me, if Fort Lauderdale gets hit (39,000 homes at risk from 6 feet of flooding, a big hurricane can have over ten feet of storm tide) our insurance will go up.
I am 58 but I expect to see coastal property values tank in my lifetime.
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Digby Scorgie at 10:25 AM on 29 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
According to Kevin Anderson of the Tyndall Centre, a likely warming of four degrees by the end of the century under business as usual will result in a planet incompatible with an "organized" society. He didn't use the term "civilized" because he didn't think we currently have a civilized global society!
He also reckons that, taking carbon budgets into account, we'd have to shrink the global economy by 10% a year to avoid more than two degrees of warming. The economists, on the other hand, say that 4% is the most that can be contemplated, else global civilzation will collapse.
I conclude from the foregoing argument that we either collapse global civilzation now in exchange for a habitable planet or we do nothing and collapse civilization later when the planet becomes barely habitable. If the argument is valid, civilization collapses in both cases.
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Tom Curtis at 09:02 AM on 29 January 2017Temp record is unreliable
Eclectic @403, I have responded here.
Moderator Response:[PS] Thanks for your consideration in keeping conversation ontopic. Most appreciated.
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Tom Curtis at 09:01 AM on 29 January 2017CO2 lags temperature
Eclectic asks elsewhere, with regard to the relative attribution to albedo and ghg contributions to the glacial to interglacial cooling as shown in Hansen and Sato:
"May I ask you whether the warming-phase figures are similar — or whether the CO2/albedo relationship is asymmetric regarding the actual causation of progressive warming as the planet exits a glacial age (i.e. whether CO2 plays a larger role in the ultimate root cause of the rapid 3-degree warming which terminates the typical glacial age) ?"
The graph I showed represents the change in radiative forcing and temperatures between the Last Glacial Maximum and the Holocene, ie, over a warming phase. However, it takes the difference in the values between the two times, and the relative contribution may (indeed, probably) differs at different stages in the process, or by small amounts for different glacial to interglacial (warming) or interglacial to glacial (cooling) transitions.
Based on Shakun et al (2012), durring the earliest phase of the most recent glacial to interglacial transition, albedo effects were probably more important than GHG effects, but that means at some stage the GHG effects would have been more important than the albedo effects than is shown in the Hansen and Sato graph. Otherwise the cumulative effect would not be that shown in their graph.
Likewise, from the long lag in the previous glacial to interglacial shown in the first graph in the OP, albedo effects were probably more important in the early stages of that transition, with GHG effects becoming more important later on with cumulative contribution from Eemian to LGM likely to approximate to those shown in Hansen and Sato. That said, lags vary substantially between different transitions, and sometimes though not often CO2 changes precede temperature responses (eg, 325000 years ago in the Vostock graph) - so the exact relative contribution and timing of the contribution must also vary. In general, however:
1) Milankovitch effects trigger the temperature response;
2) Albedo effects seem to follow closely on the Milankovitch effects; and
3) GHG effects seem to lag on both, and to lag more in cooling transistions than in warming transitions.
As to GHG being unimportant, consider this smoothed version of the Vostock graph:
The smoothing makes clear that the current interglacial is unusual in to respects. First, in prior interglacials temperatues have declined quite rapidly after the maximum has reached (in geological terms), before dropping through the floor once some threshold is reached. In contrast, in the Holocene, they have remained near constant. Second, in prior interglacials, have also declined (though not as rapidly as temperature initially in the Eemian at least). In contrast, in the Holocene the CO2 concentrations started to decline, and then rose by about 20 ppmv, against the temperature trend. There is substantial reason to believe that the CO2 increase was due to agricultural practises of preindustrial humans; and that the flat temperatures of the Holocene are due to the temperature increase from the rising CO2 countering the temperature decrease from the known increase in albedo over the same period (due to Milankovitch factors). (Known increase in albedo because the Arctic was ice free 8000 years ago, and reached a Holocene maximum in sea ice extent in the 19th century.) The Holocene climate and CO2 record would not have been possible if CO2 had no effect. Of course, there is far better evidence of the effect of CO2 than this, and I do not expect anybody unwilling to be convinced by that other evidence to be convinced by this. But it does illustrate that their go to evidence also refutes their case.
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Tom Curtis at 07:59 AM on 29 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
DrivingBy @2, "the public" is not a set with constant composition. Specifically, overtime the number of people born before any specific year tends to decrease, while the number born after that year tend to increase. And for those born after 1990, typically their minds are not made up (and they accept global warming science in a far higher proportion than more elderly demographics). Further, not all those who are older have opinions set in stone. Particular events significantly effect opinions on the matter, and consequently the willingness to take action. I expect future temperature increases, and key events such as the first year with zero ice at the North Pole (for instance) to result in significant changes in acceptance of the science. Within 20 to 30 years, due to the change of generations, and increasing warming, AGW denial will become as popular as flat earthism. The only problem is that may be 5 to 25 years too late.
Regardless, it is definitely worthwhile to continue making the case for AGW because:
1) We need to have the case out their for those just coming into adulthood to have a chance to learn;
2) The better we present the case, the more rapidly trigger events will shift the range of opinions; and (perhaps most importantly)
3) If we stop presenting the case for AGW science, that will not stop the deniers from presenting the case for AGW pseudoscience. As a result, if we stop, we can expect acceptance of the science to decline over time, not increase.
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Tom Curtis at 07:48 AM on 29 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
Richard @5, with regard to point 1, the IPCC AR4 stated:
"An assessment based on AOGCM projections, probabilistic methods, EMICs, a simple model tuned to the AOGCM responses, as well as coupled climate carbon cycle models, suggests that for non-mitigation scenarios, the future increase in global mean SAT is likely to fall within –40 to +60% of the multi-model AOGCM mean warming simulated for a given scenario. The greater uncertainty at higher values results in part from uncertainties in the carbon cycle feedbacks. The multi-model mean SAT warming and associated uncertainty ranges for 2090 to 2099 relative to 1980 to 1999 are B1: +1.8°C (1.1°C to 2.9°C), B2: +2.4°C (1.4°C to 3.8°C), A1B: +2.8°C (1.7°C to 4.4°C), A1T: 2.4°C (1.4°C to 3.8°C), A2: +3.4°C (2.0°C to 5.4°C) and A1FI: +4.0°C (2.4°C to 6.4°C). It is not appropriate to compare the lowest and highest values across these ranges against the single range given in the TAR, because the TAR range resulted only from projections using an SCM and covered all SRES scenarios, whereas here a number of different and independent modelling approaches are combined to estimate ranges for the six illustrative scenarios separately. Additionally, in contrast to the TAR, carbon cycle uncertainties are now included in these ranges. These uncertainty ranges include only anthropogenically forced changes."
Since then the IPCC AR5 has stated:
"Global mean temperatures will continue to rise over the 21st
century if greenhouse gas (GHG) emissions continue unabated.
Under the assumptions of the concentration-driven RCPs, global mean surface temperatures for 2081–2100, relative to 1986–2005 will likely1 be in the 5 to 95% range of the CMIP5 models; 0.3°C to 1.7°C (RCP2.6), 1.1°C to 2.6°C (RCP4.5), 1.4°C to 3.1°C (RCP6.0), 2.6°C to 4.8°C (RCP8.5). Global temperatures averaged over the period 2081– 2100 are projected to likely exceed 1.5°C above 1850-1900 for RCP4.5,
RCP6.0 and RCP8.5 (high confidence), are likely to exceed 2°C above 1850-1900 for RCP6.0 and RCP8.5 (high confidence) and are more likely than not to exceed 2°C for RCP4.5 (medium confidence). Temperature change above 2°C under RCP2.6 is unlikely (medium confidence). Warming above 4°C by 2081–2100 is unlikely in all RCPs (high confidence) except for RCP8.5, where it is about as likely as not (medium confidence)."So, the 1.1 C has support as the lower end of the range of the low emission scenario in both reports, but the AR4 assessement has a higher upper end projection for at least one scenario, while the AR5 upper end projection for its highest emmission scenario is only 4.8 C.
With regard to 2, the increase in atmospheric CO2 due to CO2 emissions falls to about 25% of total emissions over a couple of centuries, and then very slowly declines to zero over hundreds of thousands of years. Given that the atmospheric component currently represents about 45% of emitted CO2 (including from Land Use Change), that means we could expect a further 55% reduction from the current atmospheric increase (ie, from 400 to 330 ppmv) over the next couple of hundred years if we ceased all emissions now. The 25% figure is a rough estimate, and varies depending on the total CO2 emissions, with a greater increase with greater total emissions. If we were to continue to emit at BAU rates for a century or too, it would climb towards 40%.
With regard to point 3, Matthews and Caldiera (2008), Matthews and Solomon (2013) have shown that on the cessation of all emissions, Global Mean Surface Temperature remains approximately constant over time. This is shown in a graph from Steve Easterbrook's blog (which appears to come from a talk by Matthews, but Easterbrook is not specific):
As can be seen, to have a reasonable chance at keeping temperatures below a 1.5C limit, we need to reduce emissions sufficiently fast to keep a constant concentration. We would need almost as fast a reduction to keep it below 2C. But whenever we achieve zero emissions, temperatures thereafter will remain near constant for centuries as the draw down in emissions approximately cancels the slow increase to equilibrium temperatures.
As a side note, while global means surface temperatures will remain approximately constant, global mean land temperatures will cool slightly while ocean surface temperatures will increase.
I take the above to also answer your other two points.
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scaddenp at 05:52 AM on 29 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
Richard, try this post which discussed Hare and Meinshausen 2006.
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Richard13791 at 04:24 AM on 29 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
Some observations:
1. Average global temperatures are predicted to rise by 2100 by from 1.1 to 5.4 deg C. (Is this accurate?)2. Once CO2 gets into the atmosphere most of it stays there for a very long time (perhaps centuries), and presumably continues to contribute to rising temperatures while it is there.
3. To set a lower boundary on the problem, let’s say that ALL new human-produced CO2 and methane added to the atmosphere is reduced to ZERO starting tomorrow. Using current models, what is then the predicted change in average global temperature in 2100?
4. Are my statements/assumptions accurate?
5. Has anyone run the simulation I describe in (3)?
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DrivingBy at 03:02 AM on 29 January 2017Joint Statements on Climate Change from National Academies of Science Around the World
More typos... An edit function would be much appreciated!
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