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Comments 301 to 350:

  1. wilddouglascounty at 02:25 AM on 29 December 2018
    Greta Thunberg's TEDx talk

    Nick #2,

    While Greta talked about nothing being done and needing to stop emissions immediately, she also brought up the need for rich countries to reduce emissions by 15% per year, adding that if rich countries don't take a leadership role, then we can't expect developing countries to take similar steps.  While this is different from just stopping emissions totally immediately, it does require that much, much more be done than is currently being done; hence her call for action first in order to release the pent up hope that comes with that action but is otherwise just so much greenwash, pie-in-the-sky talk that can actually reduce our inclination to act.

    Thank you, Greta, for the excellent talk. I will add it to a resource page I hand out to all who are seeking more information on this topic.

  2. Greta Thunberg's TEDx talk

    Yes there is a lot happening. Yes it takes a lot of time. But few people feel the sense of urgency, and we are moving too slow. So I. for one, welcome any message from anyone pushing for urgency. And this young lady says it so honestly, so simply, so forcefully that it compels. And that is welcome.

  3. Greta Thunberg's TEDx talk

    I think it's pushing it a bit to say that nobody's talking about things and that nothing is happening. I also think it's disingenuous to imply that we could stop using all fossil fuels tomorrow to solve the climate crisis without acknowldging that a sudden cut off would create a devastating, and almost immediate economic impact. It's the immense difficulties in balancing the rate of transition to a low carbon future without damaging or destroying our current economy which explains a lot of what appears superficially to be little or no action or urgency

  4. Global warming ‘hiatus’ is the climate change myth that refuses to die

    We are talking as though there are deniers and non-deniers. This is not the case. The people following and contributing to SkS are on one end of the spectrum. Deniers are on the other end of the spectrum. In between there are the hoards trying to make up their minds, and they are listening, more than they are speaking. As conditions in the world rachet up with continued global warming, people will become more open to our message. The more we learn from others about how to speak to the people in the middle, the faster we will move them to accept the science.

    I agree about not trying to convert the hard-core deniers. But if you are challenging a hard-core denier in a group of people, there will be many, many people listening to what you have to say. Many people who are more open than the deniers.

  5. Global warming ‘hiatus’ is the climate change myth that refuses to die


    We agree that it is difficult to explain the situation to people who are not really interested.  I find people who are genuinely interested (but uninformed) are easy to talk with.

    On the positive side, I taught High School Science for 15 years until last year.  15 years ago every class had 3 or 4 rabid deniers (out of 25 students) who thought scientists were faking the data.  In the last few years there was essentially no-one who thought the data was faked.  Unfortunately, I did not keep a count of everyone's position.

    It was rare for skeptical students to listen to anything I had to say.  I was able to reach a number of students by assigning them to read the NCDC climate reports (no current link due to shutdown).  They frequently expressed surprise at how much temperature has already changed.

    Sunspot: what your said times 2.  Unfortunately, that is the situation we are in.

  6. Global warming ‘hiatus’ is the climate change myth that refuses to die

    Susnspot@11 I understand the spirit you are conveying about the need to stop catering to fools. However, part of the purpose of this site is to help sharpen people's ability to spot and debunk myths. I find value in discussing the myths with people here because I learn about new data and analysis to help debunk the myths. Because of the discussions with others in this comment section, this week I formulated a new analogy that I will be posting on SkS.

  7. Breathing contributes to CO2 buildup

    bsettlem @122,

    While you highlight the increase in the biomass of mankind with its domesticated flocks, in your comparison with wildlife you manage to ignore the decrease in the biomass of wildlife that is also a by-product of human activity. This rather makes your grand theory (that there are tons-more animals exhaling CO2 into the human-dominated world) less than the drama you hope. Not that it makes a ha'p'orth of difference as it is the source of the carbon that is the important issue here, this being the fuel "they burn" according to you comment @119.

    So where does this carbon comes from so as to fuel all these humans and noisy old bleating goats that we meet? You answer @122 is rather poor. You say it was ejected from an exploding star 5 billion years ago. (There is probably an "over" missing from within that reply.) Then miraculously the carbon reappears in the Earth's Hadean atmosphere (of course a hypothetical composition) whence we lose track of it again before it magically reappears for a second time within the breath of today's biomass. I think it's safe to say, bsettlem, you will never make it as a detective with such threadbare reasoning. You would be laughed out of court!!

    (It is interesting that your final point is presaged by the words "I comment on one part of your message." It suggests that only in this final point you were not trolling.) As a plant tend to grow in size with passing time, it is thus accumulating carbon. My understanding (which is not great on this particular matter) is that plant respiration is from all parts of the living plant and it obtains its carbon from the glucose produced by photosynthesis. Thus the living plant as a whole will be a net absorber of carbon from the atmosphere during photosynthesis and a net emitter of carbon through respiration during periods without photosynthesis (or diminished photosynthesis). And I think it is very likely there is a wider lesson to be had here about that damned ellusive source of carbon harnessed for human respiration.

  8. Breathing contributes to CO2 buildup

    Bottom of carbon cycle is plants. When a plant dies, the carbon in it is eventually oxidized and returns to the atmosphere. If it is eaten by anything, then that carbon is going back into atmosphere via respiration somewhere down the track. It doesnt change the amount of carbon in atmosphere whatever the relative no. of human to other organisms is.

    Fortunately, we can test the truth of hypothesis. All carbon in the normal cycle contains the C14 isotope. Carbon in fossil fuels has no C14. If the increase in CO2 in atmosphere was due to humans, the atmospheric concentration of C14 wouldnt change. If the increase in CO2 in the atmosphere is due burning CO2, then the C14 would be diluted. Guess what the actual measurements show.

  9. Philippe Chantreau at 14:24 PM on 28 December 2018
    Breathing contributes to CO2 buildup

    I'm still not sure exactly what your point is. All the yelling and grandstanding certainly doesn't help.

    Human respiration can not cause a net addition to the carbon cycle. That would violate thermodynamics. Extracting carbon from the crust and releasing it in the cycle does, so would intense sustained volcanic activity or a carbon-containing space object impact. Once carbon has been injected in the cycle, it will of course be found throughout the cycle. However, if 9 billion humans were to produce all their energy from carbon neutral sources, inluding producing nitrogen and phosphate rich fertilizers through carbon neutral chemical processes, their respiration would not increase the atmospheric content of CO2. Long term storage of carbon can cause subtraction, that's what happened in the carboniferous. Shifts in biomass do not constitute net addition or subtraction.

    As for warming attribution, if you know of some other forcing, it should be verifiable and its effect should be quantifiable. It should also be discussed on the appropriate thread.

  10. Positive feedback means runaway warming

    AFT - if we keep adding CO2, then it keeps getting hotter.  Do you mean how much hotter would it get if we stopped adding CO2? There have been papers on this - see the articles at Realclimate that discuss them.  The CMIP5 model projections are the best guide to what temperatures will be under various emission scenarios. See below for summary but looking at the IPCC AR5 WG1 report would give you a lot more detail. The "RCPxxx" are the different emission scenarios considered. 2.6 is what happens with stringent mitigation of emissions, and 8.5 at the other extreme is a continue to burn all we can scenario.


  11. Positive feedback means runaway warming

    I apologize if this was addressed in the articles and/or comments and I missed it — given the limitations on feedbacks and the current rates of increasing CO2, what is the scientific consensus of where we "max out" on temperature increase from today's levels? As in, how much hotter will it get, by when? Thanks in advance for replies.

  12. Global warming ‘hiatus’ is the climate change myth that refuses to die

    Anticorncob6 - I also like to use the axial tilt theory of seasons as an analogy -  on average each day of Spring will be warmer than the day before but we don't expect a few days or weeks of colder than average weather in Spring to mean there won't ever be Summer any more or that it "proves" the axial tilt theory must be wrong.

    I admit I was surprised at how much traction "the Pause" got; to me it always looked exactly like the variability overlaying a continuing warming trend that closer studies confirm. Too little "expert" effort distinguishing between shorter term variability and underlying warming and expert efforts at learning what processes are involved in that shorter term variability?

    Foster and Rahmstorf's work that estimated and "removed" ENSO, Volcanic Aerosol and Solar Intensity changes confirmed what I thought - that known sources of variability alone were enough to make "the Pause" indistinguishable within a longer term warming trend.

    Averages of many model runs, where each run has ups, downs, pauses, accelerations may make for a smooth, each year warmer than the last type graph; it is not and should never be seen as a year by year prediction. Should perhaps have taken a leaf out of Exxon's book; their projections were of a (smooth) band of tempertures rising, not a single line average. But people making policy or having fiduciary duties of care - or journalists reporting about it - should be expected to know better.

  13. Global warming ‘hiatus’ is the climate change myth that refuses to die

    Whether or not there was a "pause" in the rise of surface temps is actually irrelevant, and the fact that so much time is being wasted debating the issue is just another example of how we have let the deniers hijack the conversation. It's like debating the ridiculous notion that climate researchers are getting rich by forming a worldwide conspiracy to lie about the scientific data to justify their "enormous" research grants, which they spend sipping wine on the Riviera instead of freezing their butts off on the Greenland ice sheet. We are wasting time with these fools. We need to find a way to stop this.

  14. Breathing contributes to CO2 buildup

    Thanks for the Chart.
    Humans account for about 36 percent of the biomass of all mammals. Domesticated livestock, mostly cows and pigs, account for 60 percent,
    It wasn’t always this way. Humans are responsible for this.
    A similar situation exists for birds. Poultry biomass is about three times that of wild birds.
    It wasn’t always this way. Humans are responsible for this too.
    Where did all this carbon come from you ask. Best guess, from a cloud of hot gases and other mass that resulted from the explosion of a very large star about five billion years ago.
    It is speculated that this early ball of mass was surrounded with an atmosphere mainly composed of nitrogen, CO2 and water vapor.
    I comment on one part of your message, Plants breathe day and night. During the day they do their photosynthesis thing, and produce oxygen. During the night it’s air in and air out. A very few plants are especially talented and do produce oxygen during the night.


  15. Greta Thunberg's TEDx talk

    This is possibly the single best video I have seen on this website. A scarily intelligent young woman. Even if the words are not all her own, she clearly understands them. 

    However unfortunately its well known that humans are built in a way where we respond best and most urgently  to short term threats, and not things that unfold more slowly in the future, even if they are huge. We have to recognise this, and find a way of overcoming it.

  16. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    MAR @19,

    Can you clarify something briefly. I gather you have looked at the last 20 years of atmospheric emissions trends (which are accelerating)  and found a slowing in the acceleration of these over about the last 5 years by pulling out el nino and la nina years? Looks  convincing approach to me, my maths is too rusty for the details. But they are rather short time frames arent they?. Give it a couple more years of data you should publicise your views more widely. You may be onto something novel because I havent seen anyone else articulate this.

    You also said that you found no compelling evidence for an increase recently in non anthropogenic emissions. But haven't we seen some evidence of more release of methane from the tundra and tropics?

  17. Global warming ‘hiatus’ is the climate change myth that refuses to die

    M Sweet @8 ah I see what you mean. Deny was a bad use of words on my part. I should have said scientists have found there was 'no pause'. Apologies if it was confusing.

    However I stand by the rest of what I said. Lots of people see any slight flattening in temperatures as global warming stopping, unfortuntately we have to tediously explain otherwise. Unfortunately people don't see the obvious that you assume.

  18. Philippe Chantreau at 04:18 AM on 28 December 2018
    Climate's changed before

    Let me guess James, you spent haf a day on Google too?

  19. Philippe Chantreau at 04:16 AM on 28 December 2018
    Breathing contributes to CO2 buildup

    Bsettlem, you're not making any more sense than previously, sorry. It seems you may even somewhat contradict yourself. In any case, I don't have that kind of time. It's not that difficult to be clear and concise. Try.

  20. Climate's changed before

    Very nice site.  However, as I've also been reading from various Noble prize winning scientists who insist on exactly the things this site purports to 'debunk' I think I consider you debunked instead.... unless you have a Noble prize in scientific fields germane to the subjects. 

    Moderator Response:

    [TD] Fittingly, you misspelled "Nobel." The only Nobel prize winning scientist that I'm aware of denying human-caused climate change is Ivar Giaever. He has no training, background, or scientific publications on that topic. He readily admitted:

    "I am not really terribly interested in global warming.  Like most physicists I don't think much about it.  But in 2008 I was in a panel here about global warming and I had to learn something about it.  And I spent a day or so - half a day maybe on Google, and I was horrified by what I learned.  And I'm going to try to explain to you why that was the case."

    A fuller explanation of breadth and depth of his incorrect opinions is in an article here on Skeptical Science.

  21. Global warming ‘hiatus’ is the climate change myth that refuses to die

    This is an excellent, clearly written article, but I do have two minor quibbles. First, the title is misleading, because this is not the climate change myth that refused to die, it's a climate change myth that refused to die. There are many others--for example, the myth that our current warming is caused by the sun.

    Second, the singular of "phenomena" is "phenomenon."

    I congratulate the authors on my finding only two things to quibble about. I'm hypercritical--in most essays I find many more problems.

    Moderator Response:

    [TD] On the left side of every page of this site is a list of the most used climate myths. At the bottom of that list is a link to let you view all the myths ("arguments"). Alternatively, hover over the "Arguments" (myths) link in the menu bar at the top of the page. Each myth (argument) is listed with a factual rebuttal.

  22. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    MA Rodger@21 I understand these curves, and my point remains the same. Even if carbon intensity falls, if total CO2 continues to rise as the Keeling curve shows that it is, none of these other metrics will ever matter. The only value of these other metrics is that they give hope that we might solve the problem. In the meantime, atmospheric CO2 concentrations continue to accelerate upwards. If we focus on the graph that you show, we give people hope that we are getting on top of this problem and that we can relax. In other words, I see talk after talk that show graphs bending downwards, giving hope that we are winning, when all the while the Keeping curve is accelerating upwards. In the end analysis, it is the atmospheric CO2 concentration that will matter.

    Can you explain why CO2 concentrations are increasing at such a rapid rate when carbon intensity is decreasing? If we were to continue to burn fossil fuels at the same rate we are now, but simply get the growing energy we need from renewables, we could continue to grow GDP without increasing carbon emissions. But even though carbon intensity would drop (i.e., GDP going up due to use of renewables and carbon emissions held constant), if renewables don't displace fossil fuels but merely add on top of them, then although carbon intensity will drop, CO2 will continue to rise. Or am I missing something?

  23. Global warming ‘hiatus’ is the climate change myth that refuses to die


    You said " I think the problem is some scientists have denied there was a pause" which is completely false.  It cannot be twisted into a correct statement.  there was never a pause in the increase of global surface temperature.

    I think it is better to explain the escalator (available in the sidebar):


    In person describe the escalator.  I thnk most people over the age of five recognize that there is variation in temperature from day to day.  From today until August 15 in the USA everyone expects it to get hotter (in New Zealand it will get colder).  There will be periods of cold during the warming.  This week happens to be warm at my house.  The warm period does not prove winter has ended.  

    There was never a period of "slowdown, haitus or pause" in atmospheric warming.  Your verbal gymnastics confuse the situation.  Deniers deliberately lie about the existance of the "pause".  Scientists should be vigorous in confronting those lies.

  24. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    Evan @20,

    Perhaps then some further food on the subject.

    I don't think "cool summers" (or warm winters) will have much impact on the Keeling Curve. They are quite local phenomena and the proportion of our emissions resulting from space heating (& cooling) is small - some 16% in UK.

    Population as a factor in AGW is a poor measure. A better factor is the size of the world economy but this has a varrying 'carbon intensity', the graphic below from here. The steepness of the downward trajectory is a useful measure of how well we are doing, although with a growing world economy 'carbon intensity' must drop quicker than economic growth rises. So the big big question is whether we have truly decoupled carbon emissions from economic growth, and in how many sectors and how many countries, and are doing it in time to prevent too much damage from AGW.

    Carbon Intensity PWC 2018

  25. Breathing contributes to CO2 buildup

    bsettlem @119,

    The prospect is "horrible" indeed. Golly!! Lucky you spotted that!!!

    So then, from where do humans get their 270g carbon fuel to allow continued breathing out of a kg of CO2 per day? As a human yourself, you should have some idea. Do you chew on a lump of coal for breakfast? Or perhaps you have a bedtime pint of crude oil?

    Biomass of planet

    Of course the problem is not just humans. We are a minor part of the animal kingdom. And bacteria & fungi - they breathe. And even plants breathe when the sun doesn't shine. With all that breathing out of CO2 (the graphic shows biomass, Fig 1 from here), where does all this carbon come from?

  26. Global warming ‘hiatus’ is the climate change myth that refuses to die

    I like to use the analogy of seasonal climates. From February to July in the northern hemisphere, the temperature gradually warms. But that doesn't mean every day will be hotter than the last. That should help people understand why "no warming since 2016" is not a valid argument.

    From the think tank:

    “we just had […] the biggest drop in global temperatures that we have had since the 1980s, the biggest in the last 100 years.”

    The 1980s wasn't 100 years ago; I don't get why he used two numbers there.

    fireofenergy @5

    That photo helps visualize exactly how many fossil fuels we burn, and is a great resource to deal with the "humans are too insignificant to change the planet" argument, but it shouldn't be used as an argument in of itself that burning fossil fuels does indeed warm the planet by unsafe amounts.

  27. Global warming ‘hiatus’ is the climate change myth that refuses to die

    Michael Sweet @4 yes point understood, and I clearly said there is no pause in underlying warming,  but you have to see this from the publics perspective: They see a pause as just a flat period of temperatures on a graph, understandably, and the scientific explanation is a bit arcane for them. I've seen this confusion.

    Perhaps the answer is simply to say temperatures were flat for a few years and explain why it happened and is of no consequence in the scheme of things etc, and there was no pause in underlying build up of energy.

  28. Global warming ‘hiatus’ is the climate change myth that refuses to die

    Just wanted to say thanks for the good work!

    What I'm concerned about is not the little bit of cherry picked data that could be construed to say "the physics of GHGs have now changed to suit skeptic claims". No, what I'm concerned about is how we will come up with enough (clean) energy and willpower to remove the excess CO2. Realize that the growing world will need at least 25 TW of clean energy generation to meet the demands of almost 10 billion at high enough standards, to build very large space programs and to remove the excess CO2 by means of more infrastructure.

    This is how I like to deal with skeptics. I show them the picture and say "we've burnt upwards of a hundred of these cubic miles of oil. Do you really think there will be no consequences?". We now burn the equalivalent of about 3 of them in all forms of FFs every year.

    Will we ever come up with enough renewables/molten salt nuclear to match our fossil fuels use?

    Cubic Mile of Oil

    Moderator Response:

    [DB] Reduced image width.

  29. Global warming ‘hiatus’ is the climate change myth that refuses to die

    Nigelj and Evan,

    As the OP clearly states, rigourous statistical analysis has shown without any doubt that there was no "slowdown", "hiatus" or "pause" at any time in global warming between 1990 and the present.  Chopping into smaller lengths only increases the uncertainty.  Your 2002-2007 time period is so short that no useful analysis can be done on it. 

    Noisy data always has periods where the data increases faster and periods when it increases slower.   That is caused by chance.  All periods that appear by eye to have a slower slope are due to this random variations.  They cannot be ascribed to any pause or slowdown.  They are just expected , random variation around the upward trend.

    Most of the claims of "haitus" use the technique of broken trends which is unphysical.  Unphysical claims by defination cannot be considered as real under any reasonable standard.

    Experienced scientists know that eyeballing the data often yields incorrect results.  Re-read the OP if you have questions.  It has been definatively shown that there was no "pause".

  30. Australia - Moving to Renewable Energy


    This essay was written in November, 2018. I have now updated it by replacing Fig 2 and the first two paragraphs under the heading ‘New Investment’ so that they show Pipeline status at the end of December, 2018.

  31. Australia - Moving to Renewable Energy

    Michael Sweet

    In 20-25 years time photovoltaic technology is likely to have advanced to the point where to-days massive panel arrays are replaced be cheaper, transparent and more efficient film applied to built and other structures. Such development would probably make to-days panels, salvage value only, probably involving a lot of waste

  32. Breathing contributes to CO2 buildup

    MA Rodger
    Good numbers math but horrible science
    Humans are similar to engines, fuel them and they burn the fuel. Are you assuming that humans can continue to function without eating until they burn up all their carbon content?

    Moderator Response:

    [DB] Please limit the usage of bold font.

  33. Breathing contributes to CO2 buildup

    Philippe Chantreau, Thank you for your response.
    I humbly respond to your reply. I have sectioned your message and responded in italics

    Bsettlem, your post makes no sense at all. You're acknowledgeing that total contribution from human respiration with a population of 9 billions would be only 0.5% of just gasoline burning emissions, therefore an even smaller fraction of all fossil fuel CO2.
    Yes, I essentially said the above. But the fact that my post makes no sense at all to you IMO tells me you need to read it more closely and reason it without self inflicting more information than I have written
    And somehow that makes it a bigger problem than fossil fuel?
    I never said this!


    Indeed CO2's radiative properties are independent of its origins, and of anyone's opinion as well.
    Yes, I essentially said this but not in these words. CO2 does have an effect on the radiative relationship between the sun and Earth.
    As you stated yourself, human respiration generated CO2 is a tiny fraction of that coming from other sources,
    Yes I said this!
    so these other sources, over which we have control, are what matters.
    This is not something I said in my writing. What I conclude is that all CO2 counts even that discharged by humans exhalations, and I add now, that this quantity is approximately 4X that produced by humans when I was born. But there are other somewhat small sourceses which we do not have control over.
    You being absolutely sure of anything does not make it real.
    There is some evidence that Antarctica was once a paradise of life and during this time the Earths average atmospheric temperature was much warmer than it is now. And during the “ice ages” the atmospheric temperatures were much lower. It is absolutely real that the sun warms the earth and it is absolutely real that some atmospheric conditions create an imbalance to the amount of the suns energy that the earth accepts and rejects. The state of balance is the radiative equilibrium. And I am absolutely sure that human behavior is negatively affecting the probability that humans will survive until the earth will no longer be able to sustain life
    Some people are absolutely sure that the Earth is flat.
    And I am sure that your opinions interfered with what you thought I was writing.

    Can you tell me what is wrong with this statement?  By breathing out, we are simply returning to the air the same CO2 that was there to begin with.

    Moderator Response:

    [DB] Note that in this venue, an overusage of bold font is considered shouting.  Please keep its usage to a minimum.

    Also note that the usual custom when quoting someone is to put their text between quote marks and in italic text.  For additional clarity, you can indent the passage.  Like this:

    "I have sectioned your message and responded"

  34. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    MA Rodger@19 Please see the curve and analysis in Evan@18.

    I like to think of a thick branch that has a bend in it. How easy is it to bend the branch opposite its natural bend? The reverse bend occurs slowly. If there are temporary reductions due to a cool summer that reduces the air conditioning load in a country and leads to a reduction of CO2 emissions from coal plants, such temporary cool summers are bound to not be often repeated.

    I have not done the detailed analysis that you are doing, but rather have chosen to base my analysis on the 60-year data trend indicated by the Keeling curve, combined with the fact that with global population is continuing to rise, and no international agreements are yet enacted for serious reductions in emissions. I see any temporary blip in the data as inconsequential to the overall trend. In other words, in the same way that we correct climate deniers for focusing on "pauses" and not looking at the long-term data, I also tend to focus on the long-term Keeling curve and not get excited by short-terrm blips.

    But I appreciate all the points you make and you've given me a lot more food for thought. Thanks.

  35. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    Evan @15,

    Indeed you are correct in putting the MLO measurements of atmospheric CO2 levels as the prime data and to say that it shows there has undoubtedly been an acceleration in the CO2 rise since 1960. Back then, the rise was averaging some 0,7ppm/yr and it is now averaging some 2.4ppm/yr, suggesting an acceleration of roughly 2% per year over the period. And over that same period, the CO2 emissions from all anthropogenic sources have also risen at a rate of roughly 2% per year. This does suggest that the Keeling Curve is driven by anthropogenic emissions, and nothing else.

    So if in recent years (since 2014), if anthropogenic sources have shown no rise, would this suggest that the acceleration may have been halted (at least for the years 2014-17 as we still await the 2018 figure for total emissions)?

    Now, the MLO data does show a lot of wobble, much of it based on the ENSO cycle. If the ENSO cycle is accounted using MEI (shifted by 8 months which gives he best fit to the CO2 wobble) and correlated against the CO2 Airborne Fraction (as per the Global Carbon Project numbers), the MLO data does appear to show an end to the acceleration (abet still noisy), or at least no reason to suggest that there is any significant non-anthropogenic source of CO2 emissions impacting the atmospheric levels.

    With no increase in anthropogenic emissions, I would suggest that any notion of continued acceleration through recent years requires a non-anthropogenic source. (This of course does not mean a return to accelerating anthrpogenic emissions can be guaranteed.) I have not ever found evidence to support the existence of any significant non-anthropogenic emissions as the source of acceleration. (This of course does not mean there has not been such accelerating emissions, either now or future.)

    So is there some reason to consider such analysis invalid?

  36. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    nigelj @16&17, great question. Here is a look at the Keeling curve that uses the following data fits.





    What is interesting is that fitting the data for 1988-2017 and 1998-2017 give almost the same trends. But, during the 90's three things happened. The USSR was collapsing and reducing their energy usage, Britain was converting from coal to gas, and France was finishing their conversion to nuclear. After the 90's things started to increase.

    There are two scary things in the following plot. Using all of the data from 1958-2017 shows that CO2 concentration is accelerating upwards, But looking at how the curves get steeper and steeper as you use only the most recent data suggests that the acceleration is accelerating.

    However, I am not ready to publish that in a blog article, because whereas 60 years of data gives a long-term solid trend, something like 10-20 years of data may not stand statistical rigor. But still, the point is that CO2 concentrations are accelerating upwards.

    If you divide the increases by the population in each year, you can attribute have of the increase to increasing population and half the increase to the rise of affluence.

    Keeling Curve fit over varying time intervals

  37. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    So there is actually a recent acceleration in the acceleration. so much for my eyeballing.

  38. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    I'm trying to figue out what you guys mean. I look at a graph of the Mauna loa data here, and I see by eye a gentle curve over the period 1960 - 2018 so a mild acceleration over the full period. Is that what you mean Evan?

    But eye balling the last ten years I dont see an obvious acceleration in this acceleration.

    I think the decrease in emissions over the last few years is real, but the exact numbers would be approximate. But would a couple of years slowdown in actual emissions even show up in the mauna loa trend? I think you would need something more substantial wouldn't you?

  39. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    MA Rodger@14, please see figure 2 in Evan@3. This is the Keeling Curve (gray dots) with a quadratic function fitted. The quadratic function fits with R2 = 0.99 for the period 1960 to present. If you use just the last 20 years the curve is steeper! The fact that the second derivative of the Keeling curve is positive means that CO2 concentrations are accelerating upwards.

    For whatever it's worth, Ralph Keeling (son of Charles David Keeling) says the same thing (that CO2 concentrations are accelerating upwards) in the Nova program "Decoding the Weather Machine."

    I would love for somebody to shoot a hole in my argument, but the CO2 measurements represent one of the most solid data sets we have, and include the balance of all sources and sinks, but natural and human.

  40. 2018 was the hottest La Niña year ever recorded

    nigelj@7 people who live in earthquake zones know that when there is a pause in earthquake activity that the big one might be coming. The energy keeps building up year after year, whether or not it is periodically released.

  41. Global warming ‘hiatus’ is the climate change myth that refuses to die

    nigelj@2 yes, we agree on the need to acknowledge a slowdown in atmospheric warming. When we acknowledge a pause in atmospheric warming, we need to remind people that during that period the oceans are still warming. In other words, we don't want to let people think that by natural variation we mean the warming has stopped for a few years and may stop for a couple of decades. Natural variation means that the way that oceans move energy around has natural variations, but that as long as there is an energy inbalance, the energy is always increasing. If you live in an earthquake zone, you become more concerned during a lull in earthquakes, not less, because you know that the energy is still building, and that the next one might be the big one.

  42. Global warming ‘hiatus’ is the climate change myth that refuses to die

    Excellent, and well explained, however I think the problem is some scientists have denied there was a pause which is technically correct in energy accumulation terms etc, but the public see a clear slowdown or "pause" in surface temperatures from about 2002 - 2007 in the smoothing line in the nasa giss graphs, so the public get confused. You have to ackowledge there was a pause in surface temperatures, or it looks deceitful.

    I remind people that the intermittent slow periods of warming of a few years are just the influence of natural variation, and that the early IPCC reports predicted there would be slow warming periods of up to 10 years, due to the impact of natural variation. We have seen a couple so its exactly what was predicted! So the so called pause never bothered me.

  43. 2018 was the hottest La Niña year ever recorded

    Excellent, and well explained, however I think the problem is some scientists have denied there was a pause which is technically correct in energy accumulation terms etc, but the public see a clear slowdown or "pause" in surface temperatures from about 2002 - 2007 in the smoothing line in the nasa giss graphs, so the public get confused. You have to ackowledge there was a pause in surface temperatures, or it looks deceitful.

    I remind people that the intermmitent slow periods of warming of a few years are just the influence of natural variation, and that the early IPCC reports predicted there would be slow warming periods of up to 10 years, due to the impact of natural variation. We have seen a couple so its exactly what was predicted! So the so called pause never bothered me.

  44. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    Evan @13,

    It is good that we have clarified your meaning. And to be entirely accurate, with this talk of "acceleration," you are evidently not talking "emissions" but man-made "emissions."

    Sadly it does beg the question as to what is causing this "acceleration" in atmospheric CO2 given you say "atmospheric CO2 concentrations continue to accelerate upwards." Or indeed whether there is any evidence of "atmospheric CO2 concentrations continu(ing) to accelerate upwards." Myself, I do not see it. And it is not as though I have not looked. (I am happy to share what this 'looking' has shown me.)

  45. Global warming ‘hiatus’ is the climate change myth that refuses to die

    I have a favorite plot I like to use to show the lack of a pause, and I just updated it with the GISS Global Land-Ocean Temperature Index. I find it interesting that a linear fit of the temperature record since 1970 parallels a linear fit of the decadal maximum temperatures. The point being that if the cherry-pickers were honest, they would see that their cherries are increasing at the same rate as the rest of the data. I don't expect to convince them, but hope others might find this interesting.

    GISS Global Land-Ocean Temperature Index

  46. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    MA Rodger@12 When I say upward acceleration, I am not referring to emissions. I am referring to CO2 accumulating in the atmosphere. I'm sure you agree that it really does not matter if we stabilize emissions if atmospheric CO2 concentrations continue to accelerate upwards, and they are. Atmospheric CO2 concentrations are what we should be focusing on to evaluate how well we're doing, because that gives us the net effect of everything, including changing re-absorption rates by the biosphere and positive feedbacks. Isn't it concerning if emission rates have stabilized but atmospheric CO2 concentrations continue to accelerate upwards? Or am I missing something? I realize the only thing we can write policies for are emissions, but unfortunately the climate only cares about atmospheric CO2 concentrations. I am not trying to be argumentative, just trying to understand the relationship between emissions and accumulating CO2, and where we should be placing our focus. Thanks for your detailed responses.

  47. 2018 was the hottest La Niña year ever recorded

    nigelj@5 I think the point that climate scientists like James Hansen have been making is that the energy continues to be pumped into the climate year after year, but because of the complex ocean circulation and El Nino/La Nino cycles, we just don't see it in the atmospheric temperature record as a smooth increase. I know you know that, but we have to keep reminding ourselves of this when focusing down on short-term trends.

  48. 2018 SkS Weekly Climate Change & Global Warming Digest #51

    Evan @8,

    You say:-

    "However, the idea that the world will respond in a manner to cause CO2 to naturally start decreasing I see as wishful thinking (no offense meant)."

    I do note you continue by describing "reversing an upward acceleration, ... move to a constant increase, ... Then we must decrease from there," so in some manner we do speak at cross-purposes.

    Just to be clear, my talk of this natural process reducing CO2 levels: this year draws to a close and we will have emitted some 11.4Gt(C) of CO2 into the atmosphere over the year. Yet the atmospheric CO2 levels do not increase by 11.4/2.13=5.4ppm over the year. The levels of annual rise in CO2 are wobbly but there is on average 55% of our emissions disappeared, into the oceans & biosphere. This 11.4*0.55=6.27Gt(C) of drawdown is a response not only to this year's emissions but to previous years. The drawdown continues when "you stop emissions" eventually resulting in 80% of our emissions being disappeared over a millenia. (See Archer et al (2009) 'Atmospheric Lifetime of Fossil Fuel Carbon Dioxide') This is the process I describe @5, "once you stop emissions, the falling CO2 forcing would balance with the warming from the remaining un-balanced forcing leaving a roughly constant global temperature, even a cooling."

    I could continue by pointing out that the global CO2 emissions calculated for recent years show little or zero increase, perhaps a sign that "upward acceleration" has ended, but some find this difficult to accept so I won't press the point.

  49. 2018 was the hottest La Niña year ever recorded

    Evan @2, yeah you are right. Looking at NASA GISS and the smoothed line, any slowdown was about 5 years at most around 2002 - 2007 and not dissimilar from previous slowdowns since 1970. Its obviously not significant. The long term  smoothed line does form a step like pattern though, but nothing really radically different recently. 

  50. 2018 was the hottest La Niña year ever recorded

    The fact that the La Niña of 2018 was warmer than the El Niño of 2010 and all El Niños from before is really telling.

    2014 surprassed 2010 as the hottest year on record and it was a neutral year, and it looks like we probably won't get another year cooler than 2014 in our lifetimes, unless we get a really strong La Niña pretty soon.

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