Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings


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

Home Arguments Software Resources Comments The Consensus Project Translations About Donate

Twitter Facebook YouTube Pinterest

RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
Keep me logged in
New? Register here
Forgot your password?

Latest Posts

Archives

How do human CO2 emissions compare to natural CO2 emissions?

What the science says...

Select a level... Basic Intermediate

The natural cycle adds and removes CO2 to keep a balance; humans add extra CO2 without removing any.

Climate Myth...

Human CO2 is a tiny % of CO2 emissions
“The oceans contain 37,400 billion tons (GT) of suspended carbon, land biomass has 2000-3000 GT. The atpmosphere contains 720 billion tons of CO2 and humans contribute only 6 GT additional load on this balance. The oceans, land and atpmosphere exchange CO2 continuously so the additional load by humans is incredibly small. A small shift in the balance between oceans and air would cause a CO2 much more severe rise than anything we could produce.” (Jeff Id)

Before the industrial revolution, the CO2 content in the air remained quite steady for thousands of years. Natural CO2 is not static, however. It is generated by natural processes, and absorbed by others.

As you can see in Figure 1, natural land and ocean carbon remains roughly in balance and have done so for a long time – and we know this because we can measure historic levels of CO2 in the atmosphere both directly (in ice cores) and indirectly (through proxies).

Figure 1: Global carbon cycle. Numbers represent flux of carbon dioxide in gigatons (Source: Figure 7.3, IPCC AR4).

But consider what happens when more CO2 is released from outside of the natural carbon cycle – by burning fossil fuels. Although our output of 29 gigatons of CO2 is tiny compared to the 750 gigatons moving through the carbon cycle each year, it adds up because the land and ocean cannot absorb all of the extra CO2. About 40% of this additional CO2 is absorbed. The rest remains in the atmosphere, and as a consequence, atmospheric CO2 is at its highest level in 15 to 20 million years (Tripati 2009). (A natural change of 100ppm normally takes 5,000 to 20,000 years. The recent increase of 100ppm has taken just 120 years).

Human CO2 emissions upset the natural balance of the carbon cycle. Man-made CO2 in the atmosphere has increased by a third since the pre-industrial era, creating an artificial forcing of global temperatures which is warming the planet. While fossil-fuel derived CO2 is a very small component of the global carbon cycle, the extra CO2 is cumulative because the natural carbon exchange cannot absorb all the additional CO2.

The level of atmospheric CO2 is building up, the additional CO2 is being produced by burning fossil fuels, and that build up is accelerating.

Basic rebuttal written by GPWayne

Last updated on 1 August 2013 by gpwayne. View Archives

Printable Version  |  Offline PDF Version  |  Link to this page

Further reading

Both graphs from this page are taken from Chapter 2 of the IPCC AR4 report.

Real Climate goes in-depth into the science and history of C13/C12 measurements.

It's not particularly relevant to this argument but World Resources Institute have posted such a great resource, I had to put it somewhere. It's the World GHG Emissions Flow Chart, a visual summary of what's contributing to manmade CO2 (eg - electricity, cars, planes, deforestation, etc):


UPDATE: Human CO2 emissions in 2008, from fossil fuel burning and cement production, was around 32 gigatoones of CO2 (UEA).

Comments

Prev  1  2  3  4  5  Next

Comments 101 to 150 out of 237:

  1. A correction...the sentence about upwelling should read...

    If it comes to the surface and warms (and phytoplankton don't take up the CO2), large amounts of CO2 can evade(as in the Equatorial Pacific).
  2. The ionic equilibria are independent of any organic phenomena. The carbonate, bicarbonate, CO2, and water will equibrate regardless of what else is going on. The numbers relating the equilibrium concentrations of these specis are essetntally independentof dissoled or suspended or living organic matter (the only way the ionic equilibria could be altered by organic matter is through activity coefficients. and I cannot imagine these being altered in any substantial way by the presence of organic matter at the concentrations in the ocean) Your statement that organic matter can pose problems for analytical solutions is correct only if the organic matter is affecting the concentration of disolved CO2 faster than the ionic eqilibrations can respond which is vary hard for me to believe. The upshot is that regardless of the organic processes, which do, I agree. have a large effect on the amount of CO2 ultimately taken up in the oceans. The ionic equilibria give the equilibrium relations between the concentrations of the species, which is all that I am relying on. What you say about the southern latitudes having "to see that higher partial pressures occur" is wrong. All that is needed is for the atmosphere to circulate, which as I am sure you know it does, carrying the CO2-rich air to the CO2-poor region. Actually that statement is not exactly correct for if their were no circulation there would still be a chemical potential gradient and the CO2 would diffuse. This would occur even if there were do air, i.e., if the atmosphere were CO2 only. Of course diffusion would be a lot slower thn the circulation but this idea about "seeing" has no physical basis. I cannot imagine how you envision the CO2 in the carbon cycle being transported if not by circulation of the air. And, for the reasons given immediately aobve, it will not dissolve when it gets there unless the partial pressure exceeds that given by Henry's law for the temperature and concentration at the lower temperature.
  3. #98: "a forcing level of 1,4 K per century is a scientific reality."

    Indeed! However, we see average rates of change that are higher: 0.16 deg C/decade is a commonly quoted linear trend for the global temperature record. When one looks 'only' at the last 50 years, rates of twice that are not uncommon - and may in fact be the new norm.

    The pdf on your website takes CO2 up to 688ppm (100 years from now) from a starting point of 386ppm (now); not quite a doubling. So your 1.4 degrees per century implies a low sensitivity (approx 1.6 degrees per doubling of CO2). Unfortunately, this seemingly low rate would warm even a denier's stone-cold heart.

    I suggest that you contact John Cook directly using the 'Contact us' link at the bottom of every SkS page regarding the newer version.
  4. I feel the need to put my comments above in perspective. There is for carbon dioxide (or any other chamical species) a given chemical potential at a given T,P and chemical composition. In every cirumstance if there are two phases at a given temperature and applied pressure (ocean and air at some point on the surface, for example) the species will tend to go from phase 1 to phase 2 if and only if the chamical potential is greater in phase 1 than it is in phase 2. In terms of the oceans and the atmosphere the chemical potentials of carbon dioxide in the two phases are, to a very good approximation, given by (not equal to, but functions of at the given T an P) the partial pressure of CO2 in the air and the molality of CO2 in the water. When at equilibrium the chemical potantials are equal The chamical potential of the CO2 in the ocean could be influenced by the present of other dissolved substances. I am asserting, and my experience leads me to believe that it is a correct assertion, that the chemical potential of the CO2 is not significantly influenced by the presence of dissolved organic species at the level at which they occur in the ocean and is certinly not influenced by living organisms. what do I mean by significantly? A plus or minus 50% error would lead to the same conclusions that I reach, and I would be very surprised if the calculated molalities are off by even 1% because of organic solute species. I believe this assertion to be true for carbonate and bicarbonate as well. For this reason I claim that the equilibria of these inorganic species are independent of life processes and the resultant organic matter in the oceans. Because they carry a charge their The chemical potentials of ionic species,because they carry a charge, are influnced by dissolved salts, and in my calculations I include this influence using the Debye-Hueckel Law. This calculation is actually going to extremes to try to get the best result possible - the argument here is basically about the tendency (spontaneous direction) for chemical reactions and does not depend upon the actual molalities but rather upon the change in reaction direction with increasing and decreasing temperature and basic thermodyanamics. That is, it is a rquirement of thermodynamics that in order for CO2 to pass from the ocean to the atmosphere it is necessary that the chemical potential of CO2 in the aqueous phase be greater than that in the solution phase. The deniers, by the wauy, miss this point entirely. Be that as it may, as the temperature of the system is seasonally increased the chemical potentials, which are equal at equilibrium, are unbalanced in the direction so that CO2 passes from the ocean into the atmosphere (the chemical potential of aqueous CO2 increases more rapidly with temperature than does that of the gaseous CO2). That higher chemical potental CO2 will move with the air mass, and when it comes to a place where the chemical potenial in the ocean is lower than it is in the atmosphere (i.e., at a point at which the temperature is lower than at the starting point) it will dissolve. Thus do we get transport in one direction. When the temperatures seasonally revert to their original values the processes reverse. Therefore a cycle. This is Physical Chemistry. I know nothing about the life processes in the ocean and their role and I am anxious to learn. But this I do know: what I have stated immediately above is thermodyamics plain and simple and unless something completely unknown is occrrring the organic natter and living organism are a red herring in the discussion of the ionic equilibria. So my question about charge balance is a highly relevant one - the ionic equilbria, which I agree do not tell the whole story because of biological processes but do none-the-less tell an independent story that cannot be denied without denying thermodynamics, can shift only in a manner consistent with electrical neutraliy. This in turn means that the way in which the deniers claim that CO2 comes out of the ocean in copious amounts is nonsense and the notion that 300 GT of carbon dioxide pass from one to another portion of the ocean in a year is highly suspect.
    Response: [Daniel Bailey] Please break long comments into paragraphs. The average human mind has difficulty in following statements beyond a certain length (3-4 sentences per paragraph is about the limit). You'll find more engagement as a result.
  5. muoncounter: thabk you for looking at my website! I take what you say to mean thst the forcing is lower than you would like. I don't see any way around that - the data used fit observed laboratory spectra and the calculation does not allow any wiggle room. It is juat plain hard science. But I think anyone who's heart is warmed by a 1.4 degree per hundred year forcing is not vary smart! After all we are dealing with a century of ca, 1 deg forcing right now - is anyone happy with the curreht rates of change in our environment.

    At any rate I did this because there are those whose denial takes the form, "it's not happening" and to my way of thinking it is useful to be able to confront them with what I consider hard facts and rigorous logic as opposed to conjecture and statistics. By demonstrating that the warming we are experiencing right now is almost exactly predictable using undergraduate chenistry and physics I think I strengthen the hand of the climatologists who can then go on, hopefully, to convince deniers that in the future feedbacks are likely and potentially catastrophic.
  6. #105: "don't see any way around that - the data used fit observed laboratory spectra"

    And the higher temperature gradients are derived from observed temperatures.

    Here is a graphic from the Temperature record reliability thread.

    The vertical scale is degC/decade.

    However, since your model is determined (if I read it correctly) by ocean-CO2 interaction, perhaps it is significant that the rate of change you calculate agrees with the rates shown for oceans only.
  7. hpfranzen

    104 is clearer than 102, and I largely agree with it except that you are still underplaying the role of biology. I'll address some quotes from 102 post keeping your clarifications in 104 in mind.

    "The ionic equilibria are independent of any organic phenomena."

    I'm not sure but I think you've getting caught up in a minor caveat I made for the sake of completeness. Dissolved organic matter can definitely affect the ionic charge balance because it is abundant, acidic and usually have a negative charge. Equilibria between cations and ions in solution must obey charge balance, that includes carbonate and bicarbonate. In dilute systems this can pose a problem. However, DOM is less of an issue in marine systems because the high salinity of seawater swamps the effect of dissolved organic matter. I think we agree on that so lets leave that aside.

    "Your statement that organic matter can pose problems for analytical solutions is correct only if the organic matter is affecting the concentration of disolved CO2 faster than the ionic eqilibrations can respond which is vary hard for me to believe. "

    I don’t think you are thinking of the same mechanism I am. Biological uptake of CO2 via photosynthesis only needs to be faster than diffusion of CO2 across the surface to affect the carbonate equilibria. When that happens aqueous CO2/carbonic acid decreases and bicarbonate and carbonate must dissociate to reestablish equilibrium between the carbon species. That dissociation consumes protons and raises pH. The increase in pH and alkalinity (and decrease in pCO2 and DIC) resulting from photosythesis is routinely measured and can be used to infer net CO2 uptake by photosynthesis. Because the water is now undersaturated with CO2 relative to the atmosphere, net flux of CO2 is into the water.

    If photosynthesis stops, eventually the carbonate equilibria will restablish its initial equilibrium as CO2 ingresses and the atmosphere and ocean come back into equilibrium. If the all the organic matter produced by photosynthesis is respired to CO2 again, the whole process happens in reverse and no net CO2 exchange happens. If the organic matter sinks to depths that do not exchange with the atmosphere, or if the water sinks to depth due to downwelling, there is a net removal of CO2 from the atmosphere, and DIC from surface waters..

    "What you say about the southern latitudes having "to see that higher partial pressures occur" is wrong. All that is needed is for the atmosphere to circulate, which as I am sure you know it does, carrying the CO2-rich air to the CO2-poor region."

    Based on 104, I think we can agree that for net CO2 flux into the ocean to occur, waters must be undersaturated with CO2 relative to the atmosphere above those waters, right? So, for CO2 released by seasonal warming at high latitudes to be absorbed by warmer less seasonal tropical waters, the seasonal warming of high latitude waters would have to cause the CO2 concentration in the atmosphere above those tropical waters to increase in summer, resulting in a similar increase (though possibly lagged) above tropical waters. Only that way would a gradient in chemical potential exist that could drive CO2 influx.

    Unfortunately, the data I linked to shows little evidence of such a seasonal cycle in the southern hemisphere where the ocean dominates the earths surface area. The northern hemisphere does show a seasonal cycle, but it is timed to accrual of terrestrial biomass during the northern hemisphere spring and yields the opposite seaonal pattern you predict (low pCO2 as northern waters warm in spring).

    The lack of the predicted pattern results from a number of causes, but the main one is that increased biological uptake of CO2 in spring/summer counterbalances the effect of increasing temperature to a large degree by decreasing pCO2 in surface waters. To the degree that release of CO2 does occur due to warming at high latitudes (and it does in places), it is too small to register as a strong enough signal to drive influx in the tropics.

    FWIW...I think you are engaged in a fine but difficult activity. I just want to make sure you're not misled.
    I suggest reading chapter on the carbon cycle in Sarmiento and Grubers Ocean Biogeochemical Dynamics. Your probably easily advanced enough to understand it and we can only go so far here.
  8. Somebody...tell me that makes sense. I'm not sure I can do better!
  9. I don't think we are so very far apart. Since I am not familiar with the influence of biological activity I can only learn from what you present. Since I am considering the situation when the CO2 in the air and water phases are very close to equilibrium it is clear that I cannot deal with the situation in which photosynthesis is faster than diffusion. I don't understand what you mean by carbonate dissociating. I think that must be a "slip of the tongue".

    A point that I have been trying to make is that if the hydroxide ion concentration, the bicarbonate ion concentration, and twice the carbonate ion concentration re summed and then the hydrogen ion concentration is subtracted the result is far from zero - it is in fact, quite close to the bicarbonate ion concentration, a fact that is immediately apparent when one recognizes that bicarbonate is the most important species in the solution. It is by a large factor more importamt than hyrogen at the nominal pH of sea water of 8.1 plus or minus. The exact value is not important to the argument, just the fact that the concentration is much lower than the bicarbonate concentration.

    The significance of this apparent charge imbalance is that the majority of the carbon dioxide present in the three solute species cannot have arrived in the oceans from the atmosphere for if it had these charges would balance, but it has to have come in from another source such as from the worlds rivers as dissolved strong electrolyte (I would say dissolved calcium bicarbonate and carbonate, but of course there is no way to associate the ions anions and cations in a strong electrolyte solution.

    The important fact is that of the myriad of cations in the ocean some came in with the bicarbonate (and, to a lesser extent the carbonate). These must be in the sea and they do not, of course, exchange with the gas phase. Here is my main point: any attempt to consider the inorganic chemistry of the carbon bearing species must be made recognizing the existence of the cationic charge that balanced the bicarbonate and carbonate when they entered the sea.

    For this reason there is a restraint on the concentrations of the ions - they are subject to the restraint that the sum that I listed above plus the balancing cationic charge that entered the oceans with them is zero and unchanging. This restraint is an equation on a par with the equlibrium constants - i.e. there are 4 equilibrium constants and the charge balance equation fixing the concentrations of hydrogen ion, hydroxide ion, bicrbonate ion, carbonate ion, dissolved CO2 and the partial pressure of CO2(g) when one of these is fixed.

    Where you say, "and carbonate (sic) and bicarbonate must dissociate to reestablish equilibrium" I would say, "and bicarboante must dissociate to reestablish equilibrium subject the the restraint of the charge balance equation".

    I cannot agree with your statements in the paragraph that starts, "Based on 104". All that is required for transport is: 1.as the result of a temperature increase at point A the CO2 partial pressure is increased with loss of dissolved CO2 from the ocean owing to the endothermicity of the reaction forming CO2(g) from CO2(aq) 2. the partial pressure in this parcel of air is then at this time greater than the average value, 3. thus when the parcel arrives at point B, if its temperature was not increased by the same amount the chemical potential of CO2 in the gas phase will be greater than that in the water solution and some CO2 will dissolve. Thus some CO2 is transported from A to B. When the temperatures seasonally revert to their original values the process will be reversed, hence a cycle results.

    My problem with the 300 GT cycle is, if what I suggest is a correct interpretaton of the transport, as follows:
    I can calculate the increase in pressure at point A if T increases by ten degrees - it is 0.000091 bar. I can then calculate, using the ideal gas law, the volume that 300 GT of the released gas would occupy at the median temperature- the result is eight time 10 to to the 19 cubic meters. I can now calculate, again using the ideal gas law, the number of moles of air in this volume at 1 bar and 300K - the answer is 3 times ten to the 21 moles. But there are only 1.88 times ten to the 20 moles of air in the whole atmosphere. Of course there is nothing to say that the same air doesn,t circle back many times, but the amount of air required is absurd. The point here is that 300 GT of CO2 is an enourmous amount of CO2 and it would take an unbelievable amount of air to move it.
  10. i have posted a power point on charge balancing and buffering in aqueous solutions on my website, hfranzen.org. This web post, "CB with Buffering", provides a rather complete, explicit treatment of the reactions involved in the dissolution of carbon dioxide in the absence of buffers and a general treatment providing the fundamental equation for determining the pH of a solution containing any number of weak acids and weak acid anions and in equilibrium with gaseous carbon dioxide.
  11. Just a couple thoughts:
    1) I read a statement about as the atmosphere warms that will release more carbon dioxide from the oceans making the atmosphere even warmer. This can not be the case otherwise if the atmosphere ever got a little warm, it would be doomed to continue to heat up. Since we have had ice ages and hot "ages", the plant would not have made it to now.

    2) The discussion seems to be centered around human activity releasing around 29GT of CO2 annually. However per epa.gov human breathing generates 2.3lbs per average person per day. (2.3lb) x (6,000,000,000 people on the planet) / (2000 lb/ton) x (365 days per year) = 2.5GT CO2 annually.
    Also, from wiki.answers.com (less reliable source), domesticated animals produce 6GT, and insects produce 48GT.
    I have no idea how much more is released by other mamals, fish, birds, etc.
    On the whole 29GT does not sound like much compared to the overall living population of the animal kingdom.

    3) For such a small fractional increase (3.8%) compared to the overall amount of CO2 in circulation, a measly 4% increase in plant/algae life would more than make up for the difference.

    4) Ice cores tell you nothing about reaction. I keep reading that ice cores show in increase in temperature after an increase in CO2 (this is debatable, but I'll skip that). This tid bit is then being used to say that since CO2 has risen x amount in 30 years, that now we are going to have a temperature rise in the next decade. Ice cores have a resolution in the 1000s (or tens of thousands) of years, not 10. The problem is that the ice core is giving you an average over that 1000 years. Within a given 10 years the CO2 could have been three times higher than it is now, but you can't know because you only have an average over 1000 years. The variations we seen now could have been going on for all of history, and you will NOT see it in ice cores. Remember that you have no source to see a snapshot in time from history until we started keeping regular interval written data, and even that data is questionable as the sampling location evironment is usually not stable over long durations. You only have long duration averages which tell you nothing about how the planet would react from a 2 decade departure from an average developed over the last 12 decades of real data.

    5) I read about how the ice caps are melting. Well if you look at the data of the ice cap extents over the last 60 years the north pole all but completly melts EVERY YEAR. I don't care if ice sheets are breaking off the north pole, it happens every year. The south pole, it a little different, the western sheet does seem to be shrinking some, but the easter sheet (4 x larger) is reported to be getting colder and is freezing more ice: "Australia Antarctic Division glaciology program head Ian Allison said sea ice losses in west Antarctica over the past 30 years had been more than offset by increases in the Ross Sea region, just one sector of east Antarctica." (per This article and This Report)
    Response: Anyone who replies to this, please, please do so by pointing to the appropriate thread.
  12. Briago1,
    Welcome to Skeptical Science. There is a search function in the upper left corner. Please post each of your points in the appropriate thread. I suggest you read the start here button before you proceed.

    For your question #2 you say "I have no idea how much more is released by other mamals, fish, birds, etc.
    On the whole 29GT does not sound like much compared to the overall living population of the animal kingdom."

    If you read the post at the top of this page that data is graphed for you to read. All the information needed to be informed about that subject is included. It appears that you have made no effort to inform yourself, including not reading the post you are responding to. Why did you make such a flaming post? If you want to learn read some of the material. If you seek to disrupt, please go elsewhere.

    Does anyone know why are there so many trolls this week?
  13. #111: Reply to briago1's point #5 (Arctic ice melt) on Arctic icemelt is natural.
  14. I am a lay environmentalist and I have to admit that I'm confused about the issue of Climate Change and specifically Global Warming. It seems to me that the comments on these pages are testament to the fact that the experts (or at least those who are knowledgeable about the science) do not agree on very much.

    Amongst the IPCC experts, we are told that there is a general concensus that it is definitely happening, yet there seems to be poor science in many of the arguments. Perhaps both sides of the debate are guilty of misinformating to some degree or other.

    I am inclined to think that in order to tackle most global issues, including Climate Change and polution, the ultimate solution is to significantly reduce the human population. Yet we never hear governments banging on about this, do we? All we hear are rather trivial suggestions about reducing use of plastic bags and putting flourescent bulbs in.

    Some arguments for and against are included in past issues of Nature Matters
    Response: [Daniel Bailey] Welcome to Skeptical Science! In addition to the sage advice given by both les and JMurphy below, there is an immense amount of reference material discussed here and it can be a bit difficult at first to find an answer to your questions. That's why we recommend that Newcomers, Start Here and then learn The Big Picture. I also recommend watching this video on why CO2 is the biggest climate control knob in Earth's history. Further general questions can usually be be answered by first using the Search function in the upper left of every Skeptical Science page to see if there is already a post on it (given the plethora of posts [I get paid extra for using big words and alliteration :-) ] odds are, there is). Or you can search by Taxonomy. If you still have questions, use the Search function located in the upper left of every page here at Skeptical Science and post your question on the most pertinent thread. Remember to frame your question in compliance with the Comments Policy and lastly, to use the Preview function below the comment box to ensure that any html tags you're using work properly. I'm afraid parts of your comment are simply incorrect. The warming of the globe is an accepted fact. That humans are causing a good part of it is accepted at over a 90% scientific certainty level. Only the anthropogenic contribution (which did not exist in the paleo record) completes the picture, explaining the warming we can empirically see and measure in the absence of other forcings. Else we would be measuring a decades-long cooling trend, which we aren't.
  15. 114 mikea01.
    1/ "experts (or at least those who are knowledgeable about the science) do not agree on very much." you might conclude that if you like, but I'd suggest it's possible to draw another conclusion - there is a high level of consensus in the broad trends, but science always has room for improvement and clearing up details.
    2/ " poor science in many of the arguments" - yes, but most the poor science and, indeed, argumentation, is confined to people motivated not to accept what's going on for one reason or another.

    - on a personal note, your posts contains a chain of assertions and non-sequitors, that I feel it may come under the umbrella of poor-argumentation it's self.

    3/ you might be inclined to go for an "ultimate solution" of population reduction... but most governments would feel that that sounds to much like a "final solution".
    However, on that topic, the best means of getting population growth under control known to man is increasing the standard of living. The only exception to that seems to be the US to a small degree and in extreme cases. Improving wealth, by not using developing countries to dump our pollution in and evening out consumption between the rich and poor is a grand and very difficult strategy, however.
  16. mikea01, the "IPCC experts" you mention don't actually exist as a body : the IPCC is an aggregation of thousands of scientists and their work. The IPCC Reports are the agreed output of much scientific input, agreed to by not only those who worked on the Reports but also by the vast majority of science and scientists from all branches.
    What is it that confuses you, and which bits (and why) do you consider to be "poor science" ?
  17. mikea01 - it is also inaccurate to consider the discussion in these posts as some kind of convocation of "experts" and thus judge that there is little agreement among them. In fact, my perception is that this site tends to be flooded with ramblings from inexpert ideologically motivated denialists whose purpose is to create the exact impression of non-agreement that you are reporting. In fact, it is established beyond doubt that more than 95% of real
    "experts" (i.e., folks who know what they are talking about) do agree that climate change resulting from the massive combustion of fossilized hydrocarbons is becoming a serious threat to our fragile modern civilization. Please take the time to read one of the excellent books on the subject written by actual experts such as Dr. James Hansen.
  18. This item at Tamino's gives a very nice analogy for the "it's not very much" line of thinking.

    At least I like it.
  19. What's the difference between gross CO2 emissions and net CO2 emissions?
    Response: [DB] Traditionally, gross emissions are thought of as the total worldwide emissions of the natural carbon cycle plus the injection of the extra CO2 emissions mankind additionally adds into it, while net emissions are total CO2 emissions (natural+manmade) minus the CO2 taken back up by natural sinks. Currently, natural sinks manage to take up about half of the extra manmade CO2 emissions; the result is the net increase reflected in the Keeling Curve database maintained by the Mauna Loa research station. We are currently about 40% higher CO2 concentration levels than at any point in the past 800,000 years (the last time CO2 levels were this high the world was a much warmer place with sea levels about 20-25 meters higher).
  20. I'm not sure if my question is on-topic or not, but shouldn't we be examining what the consequences of temperature increases rather than if it's natural and within error parameters? I'd think that would be more important. How much global warming is going to affect our human existence, what its effect will be on our food chain, weather patterns, water supply...and what we can do to prevent these consequences. So even if global warming is due to natural cycles, shouldn't we do something to prevent it anyways?

    Can someone post some facts about earth habitability during various global temperature extremes? And what the prospects are for our habitability during these extremes. I think that would be pretty useful.
  21. See the moderators remarks @119.

    Sea levels 20-25 metres higher sounds like a major impact on habitability of every coastal city I've ever heard of.
  22. Aye, Tri1cky--but the thing is that we're not going to be able to do anything about it until we've convinced the people who run the democracies that we are the problem. We are the problem. We're dumping massive CO2 into the atmosphere. Want to solve the problem? Stop dumping massive CO2 into the atmosphere. Or find a way that allows the CO2 to be taken out of the atmosphere at the rate it's being dumped (or slightly greater).

    There are threads for habitability here, here, and here.
  23. Why doesn't the GHG chart include Water Vapor, which is, I believe, the largest GHG? When Water Vapor is included as a GHG, it represents 95% of the GHGs. I thought it was well established that Water Vapor plays the largest role in keeping the Earth at a temperature that will support life. We do not seem to be considering all the variables here.
  24. Ken at 123: "Why doesn't the GHG chart include Water Vapor..."

    Because it is an emissions chart. Our emissions have no direct effect on global water vapor levels; those levels are a direct function of global temps, and essentially nothing else. Water vapor is the only GHG that will precipitate out of the atmosphere at temps we experience. The other GHG's stay aloft a lot longer, in particular CO2. Water vapor really only acts as a feedback, not as a forcing. Our emissions of other GHG's are forcings.
  25. Ken, please see the thread Water vapour is the most important greenhouse gas.
  26. No mention of green house gas emissions from volcanic sources. Why is this?
  27. #126: "No mention of green house gas emissions from volcanic sources. Why is this?"
    Because volcanic GHG emissions are tiny compared to other sources - about 130 to 150 times less per year than what we release burning fossil fuels, for instance.
    Response: Indeed. For details see "Volcanoes emit more CO2 than humans."
  28. Well, the story sounds inconvincing for me.

    1. It is assumed, the "natural" sources/sinks of CO2 are still in a perfect equilibrium. Who has proven that?

    2. The humans emit just 5% of the total CO2 influx. This is nothing and could increase the CO2 percentage in the air by the same 5%, no more.

    The CO2 concentration not far from equilibrium behaves as

    d(CO2)/dt = Source - (CO2)/tau

    where tau is the relaxation time.
    We know that tau is somewhere between 5 and 10 Years.

    The equilibrium concentration

    CO2 = Source*tau.

    If you add extra (antropogenic) source Sa, the equilibrium concentration changes to

    CO2_new = (Source + Sa)*tau

    Because Sa = Source*0.05, we have new equilibrium

    CO2_new = 1.05*CO2 (natural).

    That is a negligible change. Result: antropogenic emissions cannot possibly account for observed CO2 rise. No way.

    However, if there is a significant change in the relaxation time "tau", the CO2 concentration can change dramatically.

    The relaxation time is defined by the CO2 absorption by the ocean surface and its consumption in there by the phytoplankton.

    The biological consumption is very fast, comparable with the abiotic purely ionic exchange with the atmosphere!

    It is known that due to pollution with fertilizers and pesticides large regions of ocean lose phytoplankton. According to some "studies", we have already lost up to 40% of phytoplankton since mid-1900. If true, this has certainly a big influence on the relaxation time "tau" and can easily explain the CO2 rise.

    Another certain reason for CO2 rise is the observed warming of the last century, because the water temperature explicitely influences the relaxation time tau.

    These are the two main reasons for CO2 rise, not the tiny emission by the fuel combustion.

    When you bathtube is overflowing, you should either check whether you opened the tap too far, or you check the sink. And very often it is the case that you must call a plumber to clean the sink.
  29. Bugai,

    Look up Suess effect, in reference to the work of Hans Suess, for independent, empirical confirmation that the CO2 is from fossil fuel combustion.

    I apologize for not providing a direct link, as this is being tapped out on the phone.
  30. bugai wrote: "1. It is assumed, the "natural" sources/sinks of CO2 are still in a perfect equilibrium. Who has proven that?

    No, the natural sources and sinks were in approximate equilibrium prior to the industrial revolution. Anthropogenic emissions have disturbed this equilibrium and hence the natural carbon cycle is in a state of imbalance in an attepmt to restore the equilibrium. This is demonstrated by the fact that atmospheric CO2 is rising at a rate of about half anthropogenic emissions, which implies that the natural environment is a net sink, taking in more CO2 than it emits.

    2. The humans emit just 5% of the total CO2 influx. This is nothing and could increase the CO2 percentage in the air by the same 5%, no more.

    The flaw in this argument is that while humans emit only 5% of the total CO2 influx, the natural environment is responsible for 100% of the outflux, which we know to be in excess of natural emissions. The annual growth in atmospheric CO2 depends on the difference between total emissions and total uptake. Anthropogenic emissions are large comparted to the natural net flux, and hence are what currently governs the increase or decrease of atmospheric concentrations.

    where tau is the relaxation time.
    We know that tau is somewhere between 5 and 10 Years."


    This is incorrect, the residence time is about 5 years, but for CO2 the residence time and relaxation time (known as "adjustment time" in climatology) are not the same. For the initial response (governed by uptake into the thermocline) the adjustment time is of the order of 74 years, the full response takes much longer. See the articles on residence time for discussion (an advanced version is in preparation).
  31. Antwort an Bibliovermis.

    The Suess effect does not show that the CO2 increase is due to emissions. It only shows that we do emit CO2. This we perfectly know without Suess.

    Antwort an Dikran Marsupial.

    Your claim is that the mankind influences the natural CO2-sinks via CO2 emission. This is very shaky as the antropogenic source is negligibly small. Why should it so drastically change the natural sink? Especially around 1850 when the antropogenic source was even some 10 times smaller.

    It is much more reasonable to assume the change in the CO2 sink is due to a different, more powerful influence, like pollution with fertilizers. For this, there is no more balance between NATURAL CO2-sources and CO2-sinks.

    And - the 5 years IS the relaxation time for extra CO2 (experimentally proven).
    Concerning the 74 years or 1000 years for thermocline - this is only if you neglect photosynthesis by phytoplankton.
  32. 111, Briago1,

    No one seems to have replied to you (because you packed too many off topic arguments into a single post), but your misconceptions are pretty easy to address, so I took the time to help point you in the right directions.

    Response to your first point is on the runaway warming thread.

    In response to your second and third points (which are relevant on this thread):
    2) On the whole 29GT does not sound like much
    The carbon cycle involves a constant flow in and out (refer to this diagram here). What matters is not how much flows in and out, but the net difference. In this context, the system has been pretty much in near perfect balance for thousands of years. We are now shifting it out of balance by 29GT per year, which slowly but surely increases the concentrations both in the atmosphere and the ocean.

    3) ...a measly 4% increase in plant/algae life would more than make up for the difference
    But it doesn't. Scientists have actually measured where the carbon is going, and how much is going into increased vegetation, the ocean and the atmosphere. We don't need to argue about what should or might happen here, because we've pretty much measured it and we actually know exactly how much is going where.

    Response to your fourth point is on the CO2 lags Temperature thread.

    Response to your fifth point is on the Has Arctic Sea Ice Recovered thread.
  33. Bugai wrote: "Your claim is that the mankind influences the natural CO2-sinks via CO2 emission. This is very shaky as the antropogenic source is negligibly small."

    The error in this line of reasoning has already been pointed out, anthropogenic emissions are not negligibly small. Whether CO2 rises or falls depends on the difference between total emissions and total uptake, the volume of the flux is irrelevant. Anthropogenic emissions are large compared to the difference between natural emissions and natural uptake, which are quite closely balanced compared to the magnitude of the fluxes involved.

    Around 1850 the difference between natural emissions and natural uptake was also much smaller than it is now. If you look at the annual increase in atmospheric CO2 you will find it has been roughly 45% of anthropogenic emissions, going back as far as 1850. So as anthropogenic emissions have increased, the difference between natural emissions and natural uptake has increased with it and the natural carbon sink has been strengthening.

    "For this, there is no more balance between NATURAL CO2-sources and CO2-sinks."

    I have already pointed out that there is no balance between natural sources and sinks. You would make more progress if you paid better attention to the replies to your posts.

    Regarding residence time and adjustment time, I suggest you read the glossary of the IPCC report, which explains the distinction very clearly. Carbon cycle models do not neglect photosynthesis by phytoplankton, however they also do not neglect respiration by oceanic biota.

    Here is a challenge for you, if you think that anthropogenic emissions are not the cause of the observed rise then explain (i) how the annual rise in atmospheric CO2 can be less than anthropogenic emissions unless the natural environment is a net sink or (ii) how the natural environment can be the cause of the observed rise if it is a net sink. Nobody has risen to the challenge so far.
  34. 131, bugai,

    Your position is untenable because the accounting has been done and is very straight forward.

    We know how much carbon we burn. This is carbon that has been sequestered under the ground for hundreds of millions of years. It can't get back there on it's own. We take it out, we burn it, it must go somewhere.

    There are three places that it can go; into the air, into the oceans, or into vegetation.

    We have been measuring the level in the atmosphere. We know it is increasing.

    We have been measuring the level in the ocean. We know that it is increasing.

    We know that the balance (amount burned - added to the atmosphere and ocean) is going into vegetation.

    This has all been studied, measured, worked out, and is incontrovertible.

    Hence your conclusion:
    antropogenic emissions cannot possibly account for observed CO2 rise. No way.
    is untenable.

    Beyond this, you have two problems to solve:

    First, if anthropogenic CO2 is not going into the oceans and atmosphere, then where is it going?

    Second, what is the source of the CO2 that is causing the increase in the atmosphere?

    It's not the oceans, because CO2 is increasing there.

    Where is this added CO2 coming from?
  35. bugai#131: "the antropogenic source is negligibly small"

    If that is true, you will need to explain why the rate of increase in global atmospheric CO2 has dropped noticeably in years immediately following global recessions - when emissions decrease. In addition, explain how locally measured atmospheric CO2 concentrations mirror diurnal cycles (increase during higher traffic hours) as well as weekly cycles (drop on weekends).
  36. Answer to Sphaerica: sorry, I am not a "believer". I want to understand. Your "argumentation" does not do it in any way."

    Answer to Dikran. Or, better, a question. You say: "natural emissions and natural uptake .. are quite closely balanced compared to the magnitude of the fluxes involved. "

    Who balanced that? Why you think they are still balanced? How to describe the balancing process?

    My equations (see first posting) do that. The small extra antropogenic source cannot possibly change the balance. We do change the system by different means: pollution.
  37. bugai Sorry, refusing to answer a question and asking another one in its place is transparent evasion and not something I am going to encourage by indulging such behaviour.

    If you really want to get to the truth, I suggest we go through the arguemnt step by step and you can point out where the error lies when we get to it.

    Step #1: Do you agree that conservation of mass applies to the carbon cycle, in other words the annual increase in atmospheric CO2 is equal to total emissions minus total uptake?
  38. To muon calculon:

    1. "the rate of increase in global atmospheric CO2 has dropped noticeably in years immediately following global recessions": please, provide a reference for this statement.

    2. "CO2 concentrations mirror diurnal cycles (increase during higher traffic hours) as well as weekly cycles (drop on weekends)." Is off-topic, as diurnal changes are (i) local and (ii) too fast to equilibrate with anything.
  39. To Dikran:

    Step #1: Do you agree that conservation of mass applies to the carbon cycle, in other words the annual increase in atmospheric CO2 is equal to total emissions minus total uptake?

    Answer: trivially true.
  40. Bugai,

    "It is known that due to pollution with fertilizers and pesticides large regions of ocean lose phytoplankton. According to some "studies", we have already lost up to 40% of phytoplankton since mid-1900. If true, this has certainly a big influence on the relaxation time "tau" and can easily explain the CO2 rise."

    I would be interested to see these studies. Could you provide a reference please?
  41. To Hyperactive Hydrologist:

    I am not an expert, but here is what Wiki writes:

    http://en.wikipedia.org/wiki/Dead_zone_(ecology)

    "Use of chemical fertilizers is considered the major human-related cause of dead zones around the world."
  42. bugai good, so step #2, do you agree that we can write this more formally as

    dC = E_a + E_n - U_n

    where:

    dC is the annual increase in atmospheric CO2 in GtC/year
    E_a is annual emissions from anthropogenic sources in GtC/year
    E_n is annual emissions from natural sources in GtC/year
    U_n is annual uptake by natural sinks in GtC/year

    Technically there ought to be U_a, which is annual uptake by anthropogenic sinks, but this is effectively zero as we are not yet achieving any significant carbon sequestration.

    Again, this should be fairly obviously true as it is just a restatement of step 1 with total emissions divided into anthropogenic and natural. Do you agree with this?
  43. To Dirkan: I prefer the full differential equation:

    dC/dt = E_a + E_n - U_n

    Do you agree with that?

    It is better to have a true differential equation, because we have then something to solve.
  44. bugai You may prefer a differential equation, however as I will shortly be introducing annual observations into the discussion it makes far more sense to look at annual changes rather than instantaneous rates. So, do you agree with step 2 or not?

    I have solved the differential equations as well, so I am happy to discuss those later once we have agreed on the basics.
  45. To Dirkan: I'd like to stick to the ODE. You may think of dt=1 year, if you wish. 1 year is "instantaneous".
  46. bugai @ 141,

    I had a quick search of the literature and found this paper.

    They do in fact show a -6.3% change in ocean primary productivity between the 79-86 and 97-02 periods. I'm not sure this is sufficient to account for the increase in atmospheric CO2 concentrations over that period.
  47. bugai Sorry, you are just obfuscating. How about this, I will carry on with the dC and you can read it as dC/dt with t=one year if you really want to (although that would be an abuse of notation it would be your error not mine). Do you agree with step #2?
  48. To Hyperactive Hydrologist: Well, to account for the observed CO2 raise from 280 ppm around 1750 to 380 ppm now, we need 100*(1 - 280/(380-280)) = 26% in productivity change. The observed 6.5% over 20 years can be easily extrapolated to 26% over the laser 250 years.
  49. To Dikran: will go any step further? I get tired with you.
  50. bugai wrote : "To Dikran: will go any step further? I get tired with you."

    I have noticed over the years that the difference between those who are genuinely interested in the science and those who are deniers or trolls is that those who are interested in the science will follow a step by step explanation, and those that are not either obfuscate or abandon the discussion when it becomes apparent that they have backed themselves into a corner where they will soon be forced to admit that they were wrong. They normally get further than step #1 though.

    The ball is in your court, if you want to show that you are interested in the science, then either agree with step #2 or show why it is incorrect.

Prev  1  2  3  4  5  Next

Post a Comment

Political, off-topic or ad hominem comments will be deleted. Comments Policy...

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

Link to this page



The Consensus Project Website

TEXTBOOK

THE ESCALATOR

(free to republish)

THE DEBUNKING HANDBOOK

BOOK NOW AVAILABLE

The Scientific Guide to
Global Warming Skepticism

Smartphone Apps

iPhone
Android
Nokia

© Copyright 2014 John Cook
Home | Links | Translations | About Us | Contact Us