A Few Things Ill Considered

Natural Emissions Dwarf Humans’

This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.


Objection:

According to the IPCC, 150 billion tonnes of carbon go into the atmosphere from natural processes every year. This is almost 30 times the amount of carbon humans emit. What difference will any reductions we try to do make?

Answer:

This is quite true that the natural fluxes in the carbon cycle are much larger than anthropogenic emissions. But in the natural process, for roughly the last 10K years until the industrial revolution, every gigatonne of carbon going into the atmosphere was balanced by one coming out. What we have done is to alter only one side of this cycle. We put approximately 6 gigatonnes of carbon into the air but, unlike nature, we are not taking any out.

Thankfully, nature is actually compensating in part for our emissions, because only about half of the CO2 we are emitting is staying in the air. Nevertheless, since we began burning fossil fuels in earnest over 150 years ago, the atmospheric concentration that was relatively stable for the previous several thousand years has now risen by over 35%. So whatever the total amounts going in and out on their own, humans have clearly upset the pre-existing balance and altered significantly an important part of the climate system.


This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.


“Natural Emissions Dwarf Human’s” was first published here, where you can still find the original comment thread. This updated version is also posted on the Grist website, where additional comments can be found, though the author, Coby Beck, does not monitor or respond there.

Comments

  1. #1 Brian D
    October 22, 2008

    Coby, which sources would you consider to be the more realistic example of human emissions? I’ve seen numbers ranging from 6 to 10 GtC/yr (I suspect land use changes are included in some of them while others may only mention fossil fuels, but I’ve been wrong on this before), and I’m trying to narrow down which ones I should cite when asked this. A citation would be useful, and I’m not having much consistent luck on Google Scholar.

  2. #2 coby
    October 22, 2008

    I’ve always used this as a primary source:

    http://cdiac.ornl.gov/trends/emis/meth_reg.html

  3. #3 J4zonian
    March 17, 2009

    Unless you mean one human is causing this problem, your title needs to say ” Humans’ ” instead of ” Human’s “.

    If you do mean one, please tell us his or her name (I’m betting it’s a guy, probably in the midwest, probably a big sports fan)so we can go to his house and straighten him out.

    Please correct your title, both here and where it’s referenced (the list of denier points, etc.)

  4. #4 coby
    March 17, 2009

    Thanks J4zonian, I have made the changes.

  5. #5 Adam Nieman
    December 4, 2009

    Carbon dioxide is potent stuff. There’s only a small amount in the atmosphere but it keeps us warm and allows plants to grow. Shift the CO2 budget just a bit and a significant amount of this potent stuff can build up.

    Here’s an illustration that shows the total quantity of carbon dioxide in the atmosphere (natural and anthropogenic) with the United Kingdom for scale: http://www.flickr.com/photos/carbonquilt/3987382740/

    Here’s a movie showing the total volume of carbon dioxide being emitted into the atmosphere in real-time (as it’s actually happening): http://carbonquilt.org/gallery/videos#video-o1vbtnExw_g (There are similar movies on the same page.)

  6. #6 Robert Raczyński
    January 17, 2010

    Please, don’t give me this Gore’s bullshit all over again… Nobody cosidering himself a reasonable man can deny our affecting the Earth’s climate, however, the proportions and relations seem inadequate… First, carbon dioxide is not the only one element of this puzzle – steam and methan have been produced and emited ever since life started here and before… In a geological scale we’re just a piece of nothing. I think the world will go round long after we spent the last dollar or euro to stop something we can’t change or even reduce and die of hunger feedeng all the “wise guys” to the very end…

  7. #7 dhogaza
    January 17, 2010

    In a geological scale we’re just a piece of nothing.

    Of course. So what? We’re focused on how climate will change in the next century or two, not over million-year geological timescales.

    In other words, you’ve raised a strawman.

    I think the world will go round long after we spent the last dollar or euro to stop something we can’t change or even reduce and die of hunger feedeng all the “wise guys” to the very end…

    Yes. No one claims that AGW will “destroy the world”. The claim is that over the next century, at least, if we do nothing there will be a significant *human* cost.

    If all we care about is the earth itself after humanity disappears, sure, AGW is no problem.

    Neither is nuclear war. Hey, let’s drop the big one, and see what happens!

  8. #8 skip
    January 17, 2010

    Forget it Dho.

    This guy’s a Walkaway Joe. He’s done his drive-by; we’ll never hear from him again.

  9. #9 Robert Raczyński
    January 18, 2010

    You bet! I’m not a native speaker of English so I might not have put myself clearly. What I meant was not to underestimate the significace of the process. Still, I strongly disagree with the statement that if we limit the CO2 emmission, we’ll solve the problem and live happily ever after. This is a topic for a longer discussion, but to convince “the sceptic” (usually not very bright or aware one) it is not enough to show him some charts and figures! People are bored with primitive eko-nazism or “intelectual” preaching. What they see is a total economical failure of ‘green technologies’! What do you propose for now? “Intelligent houses”? “electric cars”? No beef? Only underaged emos and hippies get hooked on it. Greetings to all Walkaway Joes, anyway…

  10. #10 Lachlan
    January 19, 2010

    Robert,

    You’re right that if we limit CO2 emissions, there will still be many environmental problems, but if we limit emissions, then we can avoid the particular problem of excess CO2.

    Regarding our insignificance, think of a tiny rudder steering a large boat. If the rudder is pointing straight, then the water places a huge drag on both sides of the ship, and it goes straight. If the rudder points left, this “piece of nothing” causes an imbalance in the drag, which causes the whole ship to change course. Similarly, our small emissions can cause big changes in the balance.

    Regarding “economic” failure of green technology, note that many are only “uneconomic” if the cost of pollution (and resource depletion) are not considered. It is hard to make direct connections between the economic effect of severe weather events (floods, droughts, storms) and a particular “ungreen technology”, but the economic cost of these indirect consequences is nonetheless very high, if the scientists are right.

  11. #11 michael
    January 19, 2010

    Hey Lachlan,
    I understand the comparison you’re making, but the “science” on the effect of a rudder on a ship is not disputed.
    The science, dear Dhogaza, on the effect of dropping nuclear weapons on cities and the environment is not disputed, nor
    is the effect of tiny, insignificant viruses and bacteria. (as you have mentioned before)

    The fact is that a small (perhaps also insignificant) number of people stand to make incredible amounts of money out of Carbon Trading. They seem to be the ones creating their market out of the disputed science.

  12. #12 mandas
    January 19, 2010

    michael
    You are confusing carbon trading etc with climate change.

    Carbon trading is a proposed mechanism to use market forces to reduce CO2 emissions. It may or may not work. In any case, it is a political and economic argument and there are probably many ‘right’ answers depending on your own political and economic circumstances.

    On the other hand, climate change is a scientific argument. The simple fact that anthropogenic factors are influencing climate cannot be reasonably disputed. Note I said reasonably. Just because there are many who wish to dispute it does not make their position correct.

    So if you want to have an opinion on carbon trading go ahead. But if you want to have an opnion on climate change you need to base it on science, not on politics.

  13. #13 crakar24
    January 19, 2010

    I dont agree Mandas i think the two (ETS and AGW) are joined at the hip.

    For example when the CSIRO make this scientific statement in Sept 2009

    “September 2009: A three-year collaboration between the Bureau of Meteorology and CSIRO has confirmed what many scientists long suspected: that the 13-year drought is not just a natural dry stretch but a shift related to climate change.”

    KRudd then climbs up on his soap box and preaches the need for an ETS with the obligatory statement “the science in settled”.

    But then when one of the lead authors of the study has this to say

    “Jan 2010: One of the report’s co-authors, hydrologist David Post, told The Canberra Times there was ”no evidence” linking drought to climate change in eastern Australia, including the Murray-Darling Basin”

    The KRudd needs to climb down of the soap box.

    Of course that idiot Green politician Brown (the irony)is now calling the CSIRO a bunch of sceptics and caving in to political pressure. What pressure? From Abbott? (if i have anything thing to thank Skip for it would be the knowledge he has shared of narratives).

    http://joannenova.com.au/2010/01/droughts-might-not-be-due-to-carbon-dioxide-says-csiro/#more-6109

  14. #14 mandas
    January 19, 2010

    crakar
    As I have said repeatedly, you should not rely on blog posts or newspaper articles for your information. The link you gave me is to a newspaper article, and hence I will actually wait until I have read the paper before I make any sort of informed comment. However, if you are going to rely on these sorts of sources, you may wish to read the whole thing before you comment. Have a look at the last couple of paragraphs where the scientist says the glaciers are temporarily growing because of increased moisture from warming oceans (note – warming oceans), and the temporary increase is about to be overtaken by melting due to increased temperatures. However, none of what is written in the article is proof or evidence of anything. If you have the paper, read it and then tell us what it says.

    And I’m not sure what you don’t understand about the difference between climate change and an ETS. And ETS is simply a political and economic mechanism to deal with climate change. You can accept the truth of climate change but still think an ETS is a bad idea – a lot of people do. And I’m pretty confident the PM was talking about an ETS long before September 2009. I also seem to recall it was Coalition policy at the last election – and I am pretty sure (without any direct evidence except your obvious hatred for the PM) that you voted for the Coalition.

    And to be quite frank, I am getting sick of clicking on your links of ‘proof’ of things, only to discover that it is a link to a web blog of a denialist or similar. The link that the CSIRO has doubts about climate change etc is a joke. Joanne Nova??? Is that your proof? I am not doing your research for you on this one. Find the paper, then find the dissenting view by David Post – then we will talk.

  15. #15 skip
    January 20, 2010

    At least he didn’t plagiarize it.

    Crakar is being true to his word on that so for so let’s celebrate some progress.

  16. #16 mandas
    January 20, 2010

    crakar
    I apologise, I lied to you. I said I wasn’t going to do your research for you on this one, but my curiosity was peaked so I hunted around and guess what?? I found the study referred to. Here is a link:
    http://www.clw.csiro.au/publications/waterforahealthycountry/tassy/

    What is absolutely hilarious is what the study is really all about. Have a read and see for yourself! It’s part of a wider set of studies on water use sustainability in the Murray-Darling, Western Australia and Tasmania.

    And here is a REAL news item about the study, rather than an idiotic denialist blogger spin:
    http://www.abc.net.au/rural/news/content/201001/s2795899.htm

    I will accept a grovelling apology – but I am sure one won’t be forthcoming.

  17. #17 mandas
    January 21, 2010

    crakar
    I just bumped this thread back to the recent posts lists so you can see the information re the CSIRO.
    I am having a fun coversation over at Jo Nova’s website as well – thank’s for that link. She doesn’t check her sources or facts either, and is VERY easy to call out.

  18. #18 crakar24
    January 21, 2010

    Firstly to Skip,

    Thanks for that i will once again take this as a compliment if that is OK.

    To Mandas,

    Thanks for the link, as yet i have not read the study but i will in due course. Just to keep things moving along are you saying the report says “global warming is causing or will cause drought in Tasmania” or words to that effect?

    If so then why would a co author say this “At this stage, we’d prefer to say we’re talking about natural variability. The science is not sufficiently advanced to say it’s climate change, one way or the other. The jury is still out on that” Dr Post said.

    http://www.canberratimes.com.au/news/local/news/general/jury-still-out-on-climate-change-csiro/1728307.aspx

    Note the words “the science is not sufficiently advanced”. We then get a verbal tirade of bullshit from Idiot Brown accusing the CSIRO of all sorts of things, because why? Because Post told the truth? He stated that at this point in time rainfall variability can be attributed to natural causes and for this he gets it in the neck from idiot Brown.

    Sorry Mandas but i do not see why i owe you an apology.

    If there is no need to reduce emissions is there a need for an ETS? No

    If we need to reduce emissions do we need an ETS? Yes, the reason why is because the Gov knows no other way.

    By the way in regards to my voting history i generally do not vote for Lib or Labor, i am one of the unfortunate ones that live in Mayo. So i had a choice between Downer and no one. Labor did not even bother putting up a candidate.

    So i voted for Skippy the kangaroo, then Downer quit and we had candidates for the by election that no one had ever heard of so i voted for Skippy again old habits and all that.

    For the senate i voted for an independant because i liked his “take no shit” attitude. Something sadly lacking in todays current crop of jokers.

    I am glad you like Jo’s site i will have a look at your posts.

  19. #19 crakar24
    January 21, 2010

    I read your posts Mandas, dont be too disheartened, it may take you awhile to find your feet. Once you have done this you will find the art of dodging peanuts can be quite easy and also a lot of fun (at times).

  20. #20 mandas
    January 21, 2010

    crakar
    No, I am not saying the report says that global warming is causing the drought in Tasmania. The report says nothing about climate change because it is not about climate change. The report is about examining water use and sustainability in Tasmania – that’s it! It uses a number of scenarios to predict water use and requirements, including wetter, drier, and current conditions. It makes no comment on what may be more likely and makes no predictions about whether climate change exists or what causes it. That is why the whole newspaper article is a crock.

    The reason you owe an apology (not to me but to everyone here) is because you linked (in post #13) about a study on the Murray Darling basin which concludes that the drought is probably related to climate change (and the CSIRO study DOES conclude that for the Murray Darling), then tried to deny the credibility of that report by claiming that one of the authors of the report (Dr David Post) came to a different conclusion. The problem is that Dr Post was not one of the authors of the study on the Murray Darling basin. He was the project leader of a completely different study on water sustainability in Tasmania and the two studies are not the same.

    If you did your research (as I keep saying over and over again), you would have discovered that Dr Post accepts the facts of anthropogenic climate change, but stops short of attributing the current drought in Tasmania to climate change, because the evidence is not overwhelming. His views are perfectly consistent with those of a proper scientist who wants evidence before drawing a conclusion. He was probably asked whether the drought (in Tasmania) was caused by climate change, and he responded properly saying that the jury was still out. He did not say that rainfall variations can be attributed to natural causes – he just said, quite plainly, that he could not confirm it either way (‘the jury is still out’).

    Finally, I neither know nor care what Bob Brown had to say on the issue, and I can’t confirm it because there is nothing on their website. But anyone who thinks the CSIRO does not accept climate change as fact is an idiot.

  21. #21 crakar24
    January 21, 2010

    Re post 13,

    Facts as i see them,

    I claimed that AGW and ETS are joined at the hip.

    In support of this i quoted a study from the CSIRO which claimed AGW was the cause of droughts is SE Australia

    I then said KRudd would have used this study to push his ETS from his soap box.

    I then produced a quote from Post which says that there is no evidence of AGW but natural variability (in Tassie).

    And then produced another quote from Idiot Brown squealing like a pig.

    Now the point of all this was to show that when the CSIRO say AGW did it they are carried through the streets on the shoulders of politicians pushing the great green tax, but when the CSIRO say things like no evidence here of AGW they are spat on and abused by the very same. Thus the science of AGW and ETS are joined at the hip.

    Hence my comment “If i have anything to thank Skip for it would be the knowledge he has shared of narratives.”

    You need to remember what we were discussing Mandas, the two quotes were not intended to prove a contradiction between two people but to highlight the narratives

    (yes i know Skip its a bit thin i was planning on writing an indepth version and sending it to you for red penning if interested)

    of self serving politicians. Due to this i did not care which study they came from and did not check because there was no point, it was idiot Browns response that i wanted to show to prove my point.

    However Mandas has asked that i apologies to all and just to keep the peace i will, i apologies for not making it clear in my post there was a distinction between the two quotes.

  22. #22 mandas
    January 21, 2010

    crakar
    I see what you are saying, even if I think you have shifted position slightly. But you also have to remember that the CSIRO is not saying there is no evidence of climate change (because they have said that for the Murray Darling), just that they cannot say for sure is causing the drought in Tasmania (ie ‘the jury is out’).

    I do not disgree with your assertion about self serving politicians, which is why I don’t use them as sources for anything. You also may remember that I work in a Commonwealth Government department, so I am used to dealing with them every day. I put no credence in what Bob Brown is alleged to have said. If he really said that, it is disengenuous and would certainly have pissed off the scientists.

    But I also do not see anything wrong with the government using the Murray Darling study as justification for action. It clearly is appropriate under the circumstance. I offer no opinion on whether an ETS is the best way of dealing with it though. That being said, I don’t like the one being offered by the Government, but am pragmatic enough to understand the political processes involved and what may or may not be practically achieved.

    Have a good weekend. Golf for me!

  23. #23 skip
    January 22, 2010

    Interesting exchange, but I would add this, Crakar.

    In general avoid the guilt-by-association argument: “Idiot X is on your side; therefore you’re position is idiotic.”

    I don’t know anything about OZ politics (is there a sheep-shagging lobby or a Fosters political action committee?) but I hate when my American denier antagonists flip me shit about Al Gore AS IF I GIVE A DAMN. Its about the scientific consensus, not how some self-serving politico attaches himself to it.

  24. #24 Nils Hafrolic
    March 10, 2010

    Now that’s a very interesting comment by dhogaza

    > “No one claims that AGW will “destroy the world”. The claim is that over the next century, at least, if we do nothing there will be a significant *human* cost.
    If all we care about is the earth itself after humanity disappears, sure, AGW is no problem.”

    First I’d like to point out that no matter what, there will probably be significant human costs in the times to come, be it due to AGW, water shortage, wealth distribution, wars, famines, political systems etc. AGW is just one of the many problems (IF it is anything of a problem).

    Second I’m very glad to hear somebody at last acknowledge that if we’re doing this, we’re doing this for ourselves. Seems pretty straightforward I know, but ask your average green earth lobbyist, he won’t be telling you that.
    (they ARE the people you hear the most, most of the time)

    Regards,

    Nils

  25. #25 Nils Hafrolic
    March 10, 2010

    Sorry I had missed that :

    > “No one claims that AGW will “destroy the world”. ”

    I beg to differ ! If you listen to some, it’ll be almost the case (hurricanes, droughts, 7m ocean level rise, refugees, wars, animals getting extinct etc.)
    Maybe these people are the ones causing the worse damage to the AGW theory (yes I’ll continue saying ‘theory’ if you will). Not as much the sceptics.

    Regards,

    Nils

  26. #26 Joseph
    March 10, 2010

    I beg to differ ! If you listen to some, it’ll be almost the case (hurricanes, droughts, 7m ocean level rise, refugees, wars, animals getting extinct etc.)

    That’s not the same as “it will destroy the world,” is it? BTW, several meters of sea level rise are a done deal, in my view, but it takes several centuries for that, if not thousands of years.

  27. #27 Nils Hafrolic
    March 10, 2010

    Well … as I said, according to some, it’ll be almost the case. I.e., the end of the world, as we know it. (wink REM) (or as they see it).

    Regards,

  28. #28 Nils Hafrolic
    March 10, 2010

    The more I read this blog, the more I’m thinking you guys are maybe not the ones sceptics are trying to debunk (well honest ones, if by any account you can conceive of any of them being honest).

  29. #29 skip
    March 10, 2010

    I need this last statement clarified.

    Is it that most people who post here don’t promote “alarmist” predictions?

  30. #30 mandas
    March 10, 2010

    Nils

    I would like to discuss this quote of yours, and the issue of alarmism etc re climate change.

    “….I beg to differ ! If you listen to some, it’ll be almost the case (hurricanes, droughts, 7m ocean level rise, refugees, wars, animals getting extinct etc.) Maybe these people are the ones causing the worse damage to the AGW theory (yes I’ll continue saying ‘theory’ if you will). Not as much the sceptics….”

    Firstly, there is nothing wrong with calling AGW a theory, because that is exactly what it is. But then again, we also talk about the ‘theory of evolution’, the ‘theory of gravity’, and the ‘atomic theory of matter’. To use the word ‘theory’ or ‘its only a theory’ in an attempt to minimalise the efficacy of something is to fundamentally misunderstand what the word theory means in a scientific context.

    There is some discussion in the debate as to exactly what the long term consequences of AGW will be. One side of the debate – the extreme denialist side – state that increased CO2 and increased temperatures are good, because they will increase crop yields etc, and anyway, it will not affect humanity except in a positive way (milder winters etc). This is dangerous nonsense.

    I am a wildlife scientist, and I am well aware of both the potential effects and the currently observed effects of changes in the climate. And I can tell you it will be devastating for the ecosystem. We can already observe stresses on metapopulations of some species due to climatolgical change on fractured habitat ecosystems. Further pressure will undoubtedly cause local extinctions. While some people are seemingly unconcerned by this, they most definitely should be seriously concerned. Ecosystem changes have an unfortunate habit of cascading throughout other systems such as agriculture, so even if you don’t care if animals like the Nail-tailed wallaby goes extinct in parts or all of its range, the cascading effects such as reduced competition on invasive species has implications for grazing in the region. Increased temperatures can also allow invasive species such as the cane toad to spread further south (in Australia), with devastating effects on riverine systems, predatory species such as the quoll or black snake, acquaculture and even companion animals.

    I won’t go on about things like economic and climate refugee movements, although I did study that extensively when I worked in the national security arena. But this issue is taken very seriously by military organisations around the world, and there is a lot of planning being conducted in order to be prepared to deal with the effects of climate change.

    People need to have a slightly wider view of these things, rather than looking from a very narrow perspective that only takes in the view from their own backyard. Because like it or not, what goes on in your backyard is influenced by events far and wide.

  31. #31 SkepticalbyNature
    April 15, 2010

    “But in the natural process, for roughly the last 10K years until the industrial revolution, every gigatonne of carbon going into the atmosphere was balanced by one coming out. What we have done is to alter only one side of this cycle. We put approximately 6 gigatonnes of carbon into the air but, unlike nature, we are not taking any out.”
    This is something I’m confused about and maybe one of you can help me, as I’ve tried to find an answer but either haven’t found sufficient detail or the answer is confusing me further.
    Nature ‘emits’ a lot more CO2 than humans do(?)
    But nature takes everything it emits back out again so the overall atmospheric carbon concentration in the absence of anthropogenic sources would remain stable(?)
    Since humans add such a small extra amount of CO2 relative to nature, why can’t nature accommodate this extra amount? Why can it take all its own carbon out but none of ours?
    If there was a major volcanic eruption tomorrow that added a ‘significant’ amount of CO2 to the atmosphere, would this remain in the atmosphere for a long time to add to the greenhouse effect, or would nature ‘take it out’ and quickly restore the previous CO2 concentration stability (in the absence of anthropogenic emissions)? Or are eruptions not part of nature’s balancing act, as mentioned by Coby in his piece above?
    Also, the way we know the increase in atmospheric CO2 concentration is anthropogenic is due to the C12/C13 ratio, which is the human signature, right? How come human emissions can persist in the atmosphere, but not nature’s (for a given global mean temperature—I am aware that as global temperature rises, the CO2 concentration would rise, even without anthropogenic emissions)?
    So the summary of my question is: if nature can remove the 95% of the total atmospheric carbon amount it is responsible for each year, why can’t it accommodate the extra 5% we throw at it and take that out as well?

    Regards,

  32. #32 mandas
    April 15, 2010

    SBN

    I really don’t know exactly where to begin to answer your question, because it is such a complicated issue. And I apologise if my answer appears to be overly simple – but I am not sure how much you or others understand here.

    The issue is not so much CO2 being taken up/emitted, but carbon per se, because carbon exists in many forms, and CO2 is just one of them. Methane (CH4) is obviously another important GHG. The total amount of carbon in the Earth’s ecosystem has remained relatively constant for millions (if not billions) of years – there are small changes but these can be effectively discounted. However, the form in which that carbon exists is in constant change. Over time, the carbon that once existed as part of plants and animals has become buried deep underground, and become coal and oil. Consequently, a lot of the carbon in the ecosystem has effectively been taken out of circulation, while the remainder has been in a form of relative balance.

    That balance is occasionally thrown out of wack if some form of change takes place to the ‘natural’ order, such as a volcanic eruption, which can emmit a large amount of carbon, or in the case of insolation changes which can cause the CO2 and CH4 etc which is locked up in the ocean or tundra to be released into the atmosphere. This causes positive climate feedbacks, resulting in relatively small insolation changes causing major climatic shifts (ice ages and interglacial periods). In all these ‘natural’ changes, CO2 et al is the feedback mechanism, not the primary driver of climate change. This phenomenon is well understood by climate scientists – but has become a rallying call for deniers; the whole ‘CO2 lags not leads’ nonsense.

    However, in recent times, humans have caused the system to change significantly by digging up all the buried carbon and burning (oxydising) it, with the result that there is now more carbon in the carbon cycle (and less oxygen, but that is a relatively minor matter). Not only has more carbon been added to the mix, but there are now a lot less photosynthesising plants as a result of human induced land clearance. As a consequence, there is more carbon being emmitted, and less being taken up – causing the dramatic increase in CO2 and CH4 we are observing.

    You have correctly identified the difference between ‘natural’ carbon and ‘human’ carbon (C12/C13), but as far as the take up of carbon is concerned, ‘nature’ doesn’t differentiate between the two. ‘Human’ carbon doesn’t persist in the system any longer than ‘natural’ carbon, but the ratio is changing as more and more ‘human’ carbon is added to the mix. Nature IS capable of absorbing some of this extra carbon, but there is only so much that it can. Right now, our emmissions are continuing to increase at a rate that exceeds the ability of nature to absorb the extra.

    Finally, when you ask if there was a major volcanic eruption tomorrow, you are either being provocative or you don’t read the news, because there WAS a major volcanic eruption yesterday. Volcanoes DO add carbon to the mix, and unfortunately we now have additional carbon to deal with. In the short term, temperatures will drop because of aerosols (ash etc). But in the longer term, the additional carbon from the volcano will just add to the GHG problem (although it is a relatively small amount compared to the cumultive effects of decades of human emmissions).

    I could recommend some reading for you, but there is so much out there. Any biology text book will explain the carbon cycle much better than I can.

  33. #33 SkepticalbyNature
    April 15, 2010

    That’s a very helpful post, Mandas. Thank you. You should think about setting up your own website/blog on the AGW topic. You’re always very understandable and reliable, which can’t be said for many others (Coby excepted, naturally).

    I’m a little clearer now. I have misled myself to the extent that I thought the “nature emits much more carbon, but captures it all back” argument meant that in the case of a volcanic eruption it would make no difference to warming because nature had some magical way of capturing all this CO2 in the short term so it wasn’t available for warming. I did not realise that the carbon inventory was indeed carbon, and not just CO2.

    When I mentioned in my original post about the eruption scenario, I wasn’t trying to be provocative. I had created a draft of that post last night in Word, so I could spell-check, etc, and then copied and pasted it today, without ever thinking about the news about the Icelandic eruption! So perhaps I am guilty only of a little prophesising and a little poor self-editing.

    By the way, there is a lot of poor information on the Net about the nature-swamps-human-emissions argument. Some sites do make it appear as if nature spews out 95% of the total CO2 that goes into the atmosphere each year, hence our piddly 5% contribution couldn’t be doing any harm relatively. It’s good to be able to come here and get some straight answers.

    Regards,

  34. #34 mandas
    April 15, 2010

    SBN

    I apologise if I have mislead you in some way, but it is true that nature does emit a great deal more CO2 than humans; and your 95% figure is quite reasonable. But that doesn’t mean that the extra 5% is not capable of causing problems. Much of that extra IS being absorbed – perhaps around half of it (which can cause other problems – changing the pH of the ocean could lead to VERY serious consequences). But as I indicated, we are adding more and more to the mix, and the natural system can only absorb so much.

  35. #35 SkepticalbyNature
    April 16, 2010

    Mandas,
    You’ve helped me resolve how and why I was confusing myself, so thanks for that. Our emissions, though ‘small’ relative to nature’s are anything but insignificant because what we emit is more than nature’s capacity to absorb, so the excess stays in the atmosphere to cause ongoing warming, and the fraction of anthropogenic emissions that nature can absorb is having a negative effect on the oceans (which are a major CO2 sink) by way of pH decrease. And of course as that fraction of our emissions stays in the atmosphere and promotes additional warming, so that warming heats the oceans and thaws the permafrost, which leads to more natural emissions, not all of which can be taken out by nature (because it’s warmer), hence more warming, further lowering of ocean pH, and thus a vicious circle.
    Hopefully I’ve got that more or less right now.

    P.S. Has Crakar disappeared off the face of the Earth? I’ve not seen any posts from him since before the House of Commons CRU report. Have you guys managed to scare him off for good?!

    Regards,

  36. #36 skip
    April 16, 2010

    ‘Human’ carbon doesn’t persist in the system any longer than ‘natural’ carbon, but the ratio is changing as more and more ‘human’ carbon is added to the mix. Nature IS capable of absorbing some of this extra carbon, but there is only so much that it can.

    exactly.

    Thanks, Mandas.

    And yes, SBN, it appears that Crakar has faded out of the atmosphere like a non-persistent carbon atom. I frankly miss him.

  37. #37 Marco
    April 16, 2010

    @SBN and mandas:
    I’m having a similar discussion with a guy on Bart Verheggen’s blog (ourchangingclimate). There’s a few things to remember when dealing with the carbon cycle in relation to CO2:

    1. Equilibria: while the upper layer of the ocean releases a lot of CO2, it also takes up a lot of CO2, simply due to CO2 exchange. That is, one molecule out, one molecule in. Add more CO2 to the atmosphere, and according to Le Chatelier’s principle more CO2 should dissolve in the oceans. But the ratio between ocean and atmosphere will stay the same. Under these conditions of continuous addition of CO2 to the atmosphere there will be a net flux of CO2 into the oceans. Stop this addition, and the equilibrium will be established again.

    2. Equilibria with a little twist: a similar issue will take place with the biosphere: more CO2 in the atmosphere allows plants to grow faster, and more plants to grow. But ultimately they also die, so the equilibrium will be established again if the extra addition of CO2 ceases.

    3. Now, there are some slow uptake mechanisms that are almost irreversible. Rock weathering, in particular in the deep ocean, is one. Plants fossilising is another. But these are really slow processes even compared to elevated CO2 concentrations due to volcanic activity.

    There will also be other mechanisms that prevent a run-away effect (since reversal of high CO2 levels takes place), but those don’t seem to be taking place right now…

  38. #38 Chris S.
    April 17, 2010
  39. #39 skip
    April 17, 2010

    hehe.

    that never even dawned on me. thanks for the link.

  40. #40 Bob
    February 22, 2012

    “So whatever the total amounts going in and out on their own, humans have clearly upset the pre-existing balance and altered significantly an important part of the climate system.”

    This is very weak. “Clearly upset” is a subjective and non-scientific judgement.

  41. #41 mandas
    February 22, 2012

    Ok Bob, let me fix that for you.

    “So whatever the total amounts going in and out on their own, humans have exceeded the pre-existing balance and altered significantly an important part of the climate system.”

    Happy?

  42. #42 Dominik
    July 9, 2012

    Hey all. I started my personal “quest of truth” on this topic not long ago. It is difficult to avoid polemic or colored arguing throughout the internet.

    On this “nature dwarfs us” thing, I am currently researching on earth’s climate history. The ordivician ice age and in general the Eocene age are two very interesting examples I would like to mention. I would be happy to find any resources which try to put those times into the context on how influential or “benefical” GHG really can be.
    I am pussled by two things: The OIA happened even though there was about 2000-4000ppm CO2 in the atmosphere. Can this really be so easily explained by a weaker solar power at those times?
    The Eocene apparently was one of the most globally warm periods and during that times, large amounts of Fauna and Flora came into existence, even on the poles. This seems to contradict our worries about biodiversity and extinctions? Also, this: http://www.nature.com/ngeo/journal/v2/n8/full/ngeo582.html

    Sorry if I am posting here slighty out of context; but it is difficult to find any specific leads on how GHG is historically proven oder disproven to have decisive effects.

    In general it seems not clear what drove earth in to cold or warmth, even though GHG play a part in it, each ice age or warmth period seems to have different circumstances.

    What I described here I largely got from some german webpages. http://g-o.de/index.php?cmd=suchen

  43. #43 Dominik
    July 9, 2012

    Edit! Sorry, I just discovered now the link to your page “What’s Wrong With Warm Weather” and “no past no present”. Nevertheless, I believe the information or discussions there are not really answering my questions. But maybe, dear moderator, you could relocate my questions to “no past no present”?

  44. #44 Richard Simons
    July 10, 2012

    Dominik: It is not particularly the fact that Earth is becoming warmer that is the concern. Rather, it is that it is all taking place so quickly that organisms will not have the time to evolve sufficiently or to change their range enough to avoid extinction. Remember, too, that for many of the larger species their ranges have become fragmented and the potential for movement is severely constrained.

    As far as humans are concerned, most crop plants are adapted to moderate conditions. High temperatures already limit the range of wheat, barley and other crops and crops such as corn (maize) and rice are more frequently being affected by heat stress.

  45. #45 Dominik
    July 10, 2012

    Richard, my question was still on the linkage to AGW. On your point, I recognize that. It is amazing having to recall this to most sceptics. But this is also a second vulnerable point. What will really happen to humanity and the ecosystems we depend on? I saw the projections of the IPCC report. But the Eocene’s PETM seems to tell a different story. Also, the link to bad weather events seems to be very weak. Even IPCC says “There is insufficient evidence to determine whether trends exist in the meridional overturning circulation (MOC) of the global ocean or in small-scale phenomena such as tornadoes, hail, lightning and dust-storms.” (http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-direct-observations.html)
    The footnotes for the table on that website are telling: “More likely than not” -> “f) Magnitude of anthropogenic contributions not assessed. Attribution for these phenomena based on expert judgement rather than formal attribution studies.”

    Here, http://scienceblogs.com/illconsidered/2006/04/historically-co2-never-causes/#comment-16944
    …my current impressions from that ,frankly, give me some small hope that human life will not suffer too much if we botch it this time.

  46. #46 wow
    July 11, 2012

    Dominic, there are far more things in weather than those few things you list.

    Hope is not a risk management strategy. Ask Japan.

  47. #47 Vince Whirlwind
    July 24, 2012

    With over 6 billion humans on the planet, it’s high time for a big cull, anyway.

  48. #48 Wow
    July 24, 2012

    You first.

  49. #49 Vince Whirlwind
    July 26, 2012

    Nah, I think it will be the non-self-sufficient unproductive over-populating societies that will suffer the most.

  50. #50 Wow
    July 26, 2012

    So, you, then.