Climate Science Glossary

Term Lookup

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


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


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...

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

Latest Posts


Greenhouse Gas Concentrations Continue Climbing

Posted on 28 November 2011 by John Hartz

The following is a reprint of a news release isssued by the World Meteorological Organization (WMO) on Nov 21, 2011

The amount of greenhouse gases in the atmosphere reached a new high in 2010 since pre-industrial time and the rate of increase has accelerated, according to the World Meteorological Organization’s Greenhouse Gas Bulletin. It focussed special attention on rising nitrous oxide concentrations.

Between 1990 and 2010, according to the report, there was a 29% increase in radiative forcing - the warming effect on our climate system - from greenhouse gases. Carbon dioxide accounted for 80% of this increase.

“The atmospheric burden of greenhouse gases due to human activities has yet again reached record levels since pre-industrial time,” said WMO Secretary-General Michel Jarraud. “Even if we managed to halt our greenhouse gas emissions today – and this is far from the case – they would continue to linger in the atmosphere for decades to come and so continue to affect the delicate balance of our living planet and our climate.”

“Now more than ever before, we need to understand the complex, and sometimes unexpected, interactions between greenhouse gases in the atmosphere, Earth’s biosphere and oceans. WMO will continue to collect data to further our scientific knowledge through its Global Atmosphere Watch network spanning more than 50 countries, including stations high in the Andes and Himalayas, in the remote expanses of Alaska and in the far South Pacific,” he said.

Greenhouse gases trap radiation within the Earth’s atmosphere causing it to warm. Human activities, such as fossil fuel burning and agriculture, are major emitters of greenhouse gases which are drivers of climate change. After water vapour, the three most prevalent long-lived greenhouse gases are carbon dioxide, methane and nitrous oxide.

Carbon dioxide (CO2) is the single most important man-made greenhouse gas in the atmosphere and contributes about 64% to total increase in climate forcing by greenhouse gases. Since the start of the industrial era in 1750, its atmospheric abundance has increased by 39% to 389 parts per million (number of molecules of the gas per million molecules of dry air). This is primarily because of emissions from combustion of fossil fuels, deforestation and changes in land-use.

Between 2009 and 2010, its atmospheric abundance increased by 2.3 parts per million – higher than the average for both the 1990s (1.5 parts per million) and the past decade (2.0 parts per million).

For about 10,000 years before the start of the industrial era in the mid-18th century, atmospheric carbon dioxide remained almost constant at around 280 parts per million.

Methane (CH4) contributes about 18% to the overall global increase in radiative forcing since 1750 and is the second most important greenhouse gas after carbon dioxide.

Before the start of the industrial era, atmospheric methane was about 700 parts per billion (number of molecules of the gas per billion molecules of dry air) Since 1750, it has increased 158%, mostly because of activities such as cattle-rearing, rice planting, fossil fuel exploitation and landfills. Human activities now account for 60% of methane emissions, with the remaining 40% being from natural sources such as wetlands.

After a period of temporary relative stabilization from 1999 to 2006, atmospheric methane has again risen. Scientists are conducting research into the reasons for this, including the potential role of the thawing of the methane-rich Northern permafrost and increased emissions from tropical wetlands.

Nitrous oxide (N2O) contributes about 6% to the overall global increase in radiative forcing since 1750. It is emitted into the atmosphere from natural and man-made sources, including the oceans, biomass burning, fertilizer use and various industrial processes. It is now the third most important greenhouse gas.

The atmospheric burden of nitrous oxide in 2010 was 323.2 parts per billion - 20% higher than in the pre-industrial era. It has grown at an average of about 0.75 parts per billion over the past ten years, mainly as a result of the use of nitrogen containing fertilizers, including manure, which has profoundly affected the global nitrogen cycle.

Its impact on climate, over a 100 year period, is 298 times greater than equal emissions of carbon dioxide. It also plays an important role in the destruction of the stratospheric ozone layer which protects us from the harmful ultraviolet rays of the sun.

Other greenhouse gases: The combined radiative forcing by halocarbons is 12%. Some halocarbons such as chlorofluorocarbons (CFCs), previously used as refrigerants, as propellants in spray cans and as solvents, are decreasing slowly as a result of international action to preserve the Earth’s protective ozone layer.

However, concentrations of other gases such as HCFCs and HFCs, which are used to substitute CFCs because they are less damaging to the ozone layer, are increasing rapidly. These two classes of compounds are very potent greenhouse gases and last much longer in the atmosphere than carbon dioxide.

Global Atmosphere Watch Programme

WMO, through its Global Atmosphere Watch Programme, coordinates the observations of greenhouse gases in the atmosphere through a network of stations located in more than 50 countries. The measurement data are quality controlled, archived and distributed by WMO’s World Data Centre for Greenhouse Gases, hosted by the Japan Meteorological Agency (JMA).

The new Greenhouse Gas Bulletin is the seventh in the series, which began in 2004. This bulletin reports the atmospheric burdens and rates of change of the most important long-lived greenhouse gases – carbon dioxide, methane, nitrous oxide, CFC-12 and CFC-11 – and provides a summary of the contributions of the lesser gases.

Greenhouse gas figures


Notes to Editors

The Intergovernmental Panel on Climate Change defines radiative forcing as a measure of the influence a factor has in altering the balance of incoming and outgoing energy in the Earth-atmosphere system and is an index of the importance of the factor as a potential climate change mechanism. Radiative forcing values are often expressed in watts per square meter.

The Greenhouse Gas Bulletin reports on atmospheric concentrations – and not emissions - of greenhouse gases. Emissions represent what goes into the atmosphere. Concentrations represent what remains in the atmosphere after the complex system of interactions between the atmosphere, biosphere and the oceans.

The Greenhouse Gas Bulletin, translated in all UN languages, as well as earlier issues, are available through the WMO Global Atmosphere Watch Programme Web page at the following URL:

0 0

Bookmark and Share Printable Version  |  Link to this page | Repost this Article Repost This


Comments 1 to 39:

  1. With the exception of SF6 (c. 0.6% of GHG forcing), the 'lesser' GHGs do appear to have reached stable levels, including HCFC-22, if this NOAA graph can be relied on. Or are there some further gases missing from this account? HFCs? That's new acronym for me.
    0 0
    Moderator Response: [John Hartz] HFC = hydrofluorocarbons, heat-trapping industrial gases used in air conditioners and refrigerators. HFCs are replacements for hydrochlorofluorocarbons, or HCFCs, gases that gained favor in the early 1990s as an alternative to chlorofluorocarbons, or CFCs, linked by scientists to the depletion of the ozone layer.
  2. Hydro-fluoro-carbons
    0 0
  3. Related article...

    Emissions of hydrofluorocarbons, heat-trapping industrial gases used in air conditioners and refrigerators, must be curbed to help combat climate change, according to the United Nations.

    The UN report today comes as governments adhering to the ozone-protection rules of the Montreal Protocol consider phasing out hydrofluorocarbon-23 production, whose warming potential per molecule of HFC is 11,700 times more powerful than carbon dioxide. The European Union this year banned as of 2013 its use in the emissions-trading program of credits linked to the industrial gas generated under the UN carbon market.

    “Keeping a global, 21st century temperature rise under 2 degrees Celsius (3.6 degrees Fahrenheit) will require urgent action” to reduce hydrofluorocarbons, the UN Environment Program said today in a statement. “By 2050, HFCs could be responsible for emissions equivalent to 3.5 gigatons to 8.8 gigatons of carbon dioxide, comparable to total current annual emissions from transport estimated at 6-7 gigatons annually.”

    Source: “Air-Conditioning Gases Must Be Curbed to Protect Climate, UN Says” Bloomberg, Nov 21, 2011

    To access the entire in-depth article, click here.
    0 0
  4. I think that:

    These two classes of compounds [HCFCs and HFCs] are very potent greenhouse gases and last much longer in the atmosphere than carbon dioxide.

    is wrong.

    While they are potent greenhouse gases, HCFCs and HFCs were developed specifically to have much shorter lifetimes (about 10 years) in the atmosphere than CFCs (about 100 years).

    So their impact and lifetime is comparable to that of methane, and is one or more orders of magnitude shorter than that of CO2.
    0 0

    [DB] Closed subscript tag.

  5. CDIAC shows the lifetime of HFC-134a as 14 years, CFC-11 as 45 years, CFC-12 as 100 years.
    0 0
  6. Of course, you know how the deniers are going to spin this:

    "The fact that greenhouse gas percentages continue to go up but that temperatures have stayed flat [they get extra crackpot points if they say that warming stopped in 1998] just *proves* that AGW is a crock!"
    0 0
  7. Yes, Topquark, but global surface temperatures do not follow a monotonic trend. Some studies have attempted to ascertain why (see Sks posts: Why Wasn't The Hottest Decade Hotter?, The Deep Ocean Warms When Global Surface Temperatures Stall and Ocean Heat Poised To Come Back And Haunt Us?

    Natural variation was never expected to simply disappear because humans have polluted the atmosphere with too much CO2. Indeed, seeing as over 90% of heat is going into the oceans, there has scarcely been a slowdown in global warming at all, even though surface temperatures in some datasets have not changed much. Check out the ocean heat content below:

    This will likely come back to bite us in the backside.
    0 0
  8. topquark at 11:53 AM on 28 November, 2011

      Of course, you know how the deniers are going to spin this:

      "The fact that greenhouse gas percentages continue to go up but that temperatures have stayed flat [they get extra crackpot points if they say that warming stopped in 1998] just *proves* that AGW is a crock!"

    Well sort of, over the last 160 years, temperature has gone up about 0.7°C and CO2 has gone up around 40%. Works out to a climate sensitivity of around 1.5°C per doubling of CO2 - far short of the claims that are made.

    0 0
    Moderator Response: [muoncounter] Or you could say that in the last 40 years, temperature anomaly is up more than 0.6 degrees C. Works out to a much greater sensitivity.
    But this is neither a sensitivity thread nor a how fast is earth warming thread. Either can be found using 'Search.'
  9. Rob Painting at 12:12 PM on 28 November, 2011

    According to the IPCC:

      The oceans are warming. Over the period 1961 to 2003, global ocean temperature has risen by 0.10°C from the surface to a depth of 700 m.
      IPCC AR4 Chapter 5

    Below 700 meters I expect that they aren't warming at all.

    And so regarding Rob Painting's chart, 10 to the 21 joules may be a big number, but 0.1°C isn't going to warm up anything very much.

    0 0

    [DB] "Below 700 meters I expect that they aren't warming at all."

    You expect wrong (and make yet another unsupported assertion).  You must have missed these recent posts on the warming of the deep oceans:

  10. Maybe this link will work
    0 0
  11. Steve, I believe this has been pointed out to you before, but the 2007 IPCC report has been superseded by more recent scientific research. Such as Church (2011) which the figure @7 is based upon. In fact if you continue in the same vein one can only presume you are either trolling, or have a memory like Guy Pearce in Momento

    See also SkS post: Ocean cooling corrected, again. And note the key graphic:

    "And so regarding Rob Painting's chart, 10 to the 21 joules may be a big number, but 0.1°C isn't going to warm up anything very much"

    This is a nonsensical statement. Small global changes in water temperature can mean vast local changes in water temperature over short periods, such as the extreme marine heatwave off Western Australia over 2010-2011, which devastated the local marine life.

    These marine heatwaves will become more prevalent as more heat is added to the ocean. Sadly global warming hasn't stopped, and no amount of wishful thinking will avert the negative impacts we are all going to experience.
    0 0
  12. Steve, you might like to look up what IS meant by climate sensitivity so you know what "claim is being made". What you are seeing so far is simply the fast feedbacks - but check out the proper SkS thread on this for more on this.
    0 0
  13. "Below 700 meters I expect that they aren't warming at all. "

    Instead of "expecting", then why not look up what 0-2000m is doing? See the Von Schuckmann paper in Rob Painting's post that he linked to above.
    0 0
  14. IPCC claims for climate sensitivity vary but they are in the range of 2° to about 4°C
    0 0

    [DB] Let the reader note that a number of Steve's recent comments did not survive moderation due to trolling and complaints about moderation.

    Steve:  Please note that posting comments here at SkS is a privilege, not a right.  This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Moderating this site is a tiresome chore, particularly when commentators repeatedly submit argumentative, trolling and complaints about moderation posts. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
    Finally, please understand that moderation policies are not open for discussion.  If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.

    Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

  15. "I go back to what I know about thermoclines, and it doesn't warm below the thermocline. I don't much care what Schuckmann says."

    Sorry, you are saying you dont care what the data says, you will prefer your (mis)understanding of thermoclines?

    IPCC sensitivity are not transient sensitivities. If you want to evaluate a prediction you have to compare the observation to actual prediction. Since it takes a while to reach equilibrium temperature, then you are better to compare observation to predicted temperature from models since the model effectively include the lag.
    0 0
  16. 14, Steve Case,

    You have multiple gross misunderstandings of the system in question.

    It is strong advised that rather than steadfastly applying what little you know to arrive at the answer you prefer, that you put your time into using this site and others to learn more about the science, so that you can make a reasoned and accurate evaluation of what is going on.
    0 0
  17. Thank you for this post. It will be interesting (and perhaps very discouraging) to see what is causing the recent increase in methane levels and whether the increase persists, or perhaps worsens. While I understand that methane currently accounts for a relatively small fraction of the total radiative forcing, there is a tremendous amount of methane that could eventually be emitted from thawing permafrost. Just out of curiosity: To what extent is this positive feedback factored into the climate sensitivity estimates reported in IPCC? Or is this phenomenon too uncertain at present to quantify?
    0 0
  18. Enginerd - as far as I know, carbon cycle feedbacks were factored into very few AR4 models and werent part of the CMIP.

    For this kind of feedback, I think you have to have new generation of Earth System Model (put into google) which will be part of the AR5 model reporting.
    0 0
  19. @mods - something's happened to the formatting around the start of comment 5 - the font size is smaller from then on. Also affects the 'recent comments 'page'. And a brief correction to the first sentence that introduces the post - it's World Meteorological Organization, not Association. Will have to let the Americanised spelling slide as the WMO go for that!
    0 0
    Moderator Response: [DB] Sky, the fonts look OK on my screen (both locations). Will fix the other bit, thanks.
  20. Getting the font issue here as well, on Firefox.

    Looks to me like the subscript at the end of comment 4 wasn't closed (i.e. the subscripted 2 in CO2).
    0 0
    Moderator Response: [DB] That was it; congrats (no prize tho).  Still looks the same on my screen (Firefox 8.0).
  21. Yep, subscript fix worked... (a few versions behind on Firefox here at work, hence the discrepancy).
    0 0
  22. "Between 1990 and 2010, according to the report, there was a 29% increase in radiative forcing - the warming effect on our climate system - from greenhouse gases."

    Could someone contextualise this - a naive interpretation could be that there should have been a 29% increase in temperature due to greenhouse gases, or about 9C of warming.

    (I'm also getting reduced font size.)
    0 0
    Moderator Response: [DB] CO2 increases do not cause linear increases in temperatures.  The accepted sensitivity of the climate is about 3 degrees C per doubling of CO2 concentrations.  And there is about a 40-year delay in temperature response of the climate due to the thermal inertia of the oceans. 

    Thus, the temperature rise we see today is largely attributable to the CO2 emissions from the 1970s.

  23. (Not any more!)
    0 0
  24. Moderator Response: [DB] CO2 increases do not cause linear increases in temperatures.

    Yes, but my naive understanding was that *radiative forcing* does cause linear increases in temperature (e.g. from AR4
    "Radiative forcing can be related through a linear relationship to the global mean equilibrium temperature change at the surface"

    I thought the nonlinearity part was between CO2 increase and resulting radiative forcing.
    0 0
  25. OPatrick
    I don't know where your 9 °C comes from. A 29% increase in forcing from 1990 to 2010 means that the equilibrium temperature anomaly would be 29% higher. If we take, for example, the equilibrium anomaly relative to 1990 forcing as 1 °C, the one relative to 2010 forcing would be 1.29 °C.
    0 0
  26. Riccardo, the 9C comes from 29% of the 33C of temperature ususally assigned to greenhouse gases.

    I know that we wouldn't be expecting 9c of warming, but at a superficial reading I that is what is implied by "there was a 29% increase in radiative forcing - the warming effect on our climate system - from greenhouse gases".

    I think I understand your explanation, though I'm not sure, but I definitely don't think it's clear from the WMO report.
    0 0
  27. OPatrick
    it's 29% from pre-industrial not from an atmosphere witout greenhouse effect.
    0 0
  28. Ah yes, I see the IPCC definition of radiative forcing is relative to pre-industrial levels: "Radiative forcing is a measure of the influence a factor has in altering the balance of incoming and outgoing energy in the Earth-atmosphere system and is an index of the importance of the factor as a potential climate change mechanism. In this report radiative forcing values are for changes relative to preindustrial conditions defined at 1750 and are expressed in watts per square meter (W/m2)."

    Is that the generally accepted usage?
    0 0
  29. OPatrick @28.
    Indeed. Measurement is usually taken from pre-industrial times ie 1750. Forcing from the LLGHGs by that measure stood at 2.8 W/m^2 in 2010 which is a rise of 29% over the previous 20 years. The WMO bulletin linked in the first paragraph of this story is not long (4 pages inc pictures & info boxes) and quite readable.
    0 0
  30. It took me a while to get my head around as a non-climatologist, but the NOAA page linked to in the release helped me to understand what's going on.

    Yes, the answer is down to using pre-industrial levels as a reference. 350 to 390 ppm (about 10%) at first seemed too small to give a 39% increase (for CO2 alone), but it's from a pre-industrial 280 ppm, so it's more like a 57% increase. This is also sufficient to show that it is the radiative forcing that primarily contributes to the non-linearity as you were saying, OPatrick.

    Plug the numbers into the equations on the page and everything makes sense.
    0 0
  31. Continue Climbing

    It is worth set a background for discussion - change the size of natural sources of C in the period when it was being precise measurements of CO2 and other GHGs in the atmosphere - run without interruption in time - since 1958.

    In the figure above we can see significant fluctuations in the amount of added CO2 to the atmosphere - from circa 0.5 ppmv CO2 - to 3 ppmv of CO2 - for a year.

    Erbrecht & Lucht (2006):
    “The amount of carbon dioxide in the atmosphere steadily increases as a consequence of anthropogenic emissions but with large interannual variability caused by the terrestrial biosphere.”
    “The response of soil respiration to changes in temperature and precipitation explains most of the modelled anomalous CO 2 flux.”
    “We therefore conclude that during the last 25 years the two largest disturbances of the global carbon cycle were strongly controlled by soil processes rather then the response of vegetation to these large-scale climatic events.”

    Of course there are other natural sources "quick response" - the ocean: degassing of C - mainly CO2 (ENSO) in the equatorial zone, upwelling, and Coastal Ocean.
    However: “... were strongly controlled by soil processes.” Soil organic matter - humus and the "remainder" of NH „... and increased emissions from tropical wetlands.”.

    Where to follow the fastest and largest changes in this source?
    “... potential role of the thawing of the methane-rich Northern permafrost.”
    Zimov (2006):
    “Frozen yedoma deposits across Siberia and Alaska typically have average carbon contents from 2% to 5%—roughly 10 to 30 times the amount of carbon generally found in deep, nonpermafrost mineral soils.”
    “The 13C/12C isotope ratio of the permafrost reservoir is similar to that of soil, vegetation, and marine biota. Unlike these reservoirs, however, permafrost carbon is depleted in radiocarbon (14C).”

    In terms of of isotopes - so it is the same as the source of "our" - fossil fuels.

    “Permafrost is a globally significant carbon reservoir that responds to climate change in a unique and very simple way: With warming, its spatial extent declines, causing rapid carbon loss; with cooling, the permafrost reservoir refills slowly ...” - frozen "remainder "(without the humification process) after the thawing, shall be rapid mineralization.
    “About 4 m of yedoma-like soils accumulated across 3 million km2 in the steppe-tundra ecosystems of Europe and south of West Siberia toward the end of the glacial age and thawed ...” “... it would have released about 500 Gt of permafrost carbon at the beginning of the Holocene. “
    Of course at that time also we had strong degassing of CO2 from the deep ocean area polar. Up to now “... the total terrestrial carbon reservoir did not decrease in glacial times but instead may have even absorbed several hundred gigatons of carbon from the atmosphere and ocean.” - We have now, and mostly we had - during the Holocene - the excess of net terrestrial carbon sinks over sources.

    Therefore, terrestrial - as a whole - having advantage of carbon sinks to sources - are currently participating in the removal of part of our GHGs emissions.

    It is worth noting how much permafrost has thawing in the twentieth century before the year 1958 and beyond. Between c. 1910 and 195? - circa "3 million km2", between c. 1960 and 200? - about the 2 million km2. Total c. 4.5 million km2. (in the 50s we had growth area of Permafrost). At the beginning of the Holocene the source (identical - C isotopes - of ours) has grown by melting the "3 million km2" about 500 Gt C (Pg C) ... Our CO2 added is the atmosphere during the 150 years from the combustion of fossil fuel + cement - is circa 350 Pg C. With the change in land use 500 Pg C.

    In the 50s we had in many regions - high latitudes of NH - rapid cooling, then-Keeling began his precise study of CO2 concentration in the atmosphere and ... a constant trend increase temperature. Similarly, in areas of permafrost. From 195? years we note the much larger increase in temperature on the permafrost (4-4.5 degree C) than the global average. High Latitudes NH - generally: I propose this paper: Esper (2010) ... and for zone 64N-90N: “... the recent warming in this zone is over 5 °C per century!”
    Rising temperatures in the period: between c. the 1910 and 195? probably influenced the fact that: Khatiwala (2009): “... terrestrial biosphere was a source of CO2 until the 1940s, subsequently turning into a sink.”

    As we can see two important (the largest source of natural and anthropogenic) analyzed - identical in isotopic composition - the source of Carbon increased. Without a natural source increase biosphere would certainly has removed the more (all?) of our C.
    0 0
  32. What quantities of carbon were - and are currently - in the soil especially permafrost?
    Zimov (2006): “... a total carbon content of ~720 Gt.”
    Schuur (2008): “We show that accounting for C stored deep in the permafrost more than doubles previous high-latitude inventory estimates, with this new estimate equivalent to twice the atmospheric C pool.”
    The 1000 PgC estimate for the permafrost storage change of Zimov (2009),
    Tarnocai (2009):
    ”Our estimate for the first meter [32.2–69.6 kg m −2] of soil alone is about double that reported for this region [northern circumpolar permafrost] in previous analyses.
    Kuhry (2010):
    “ A new estimate of 1672 Pg C of belowground organic carbon in the northern circumpolar permafrost region more than doubles the previous value and highlights the potential role of permafrost carbon in the Earth System.”
    Zech (2011) :
    “Recent findings show that the amount of organic carbon stored in high-latitude permafrost regions has been greatly underestimated.”
    - comment on the paper Koven (2011) : “At stake is an estimated 2,167 petagrams of carbon in all layers of high-latitude soil.”

    There is thus a possibility that this natural source of increase throughout the twentieth century (and today) is much larger than the simple use (by me) estimates Zimov team in 2006. It is possible that the increase was not similar to the volume of the source of our emissions (at the same time) but probably (several times?) larger.
    0 0
  33. Arkadiusz Semczyszak - Your previous two posts amount to a claim that "It's not anthropogenic emissions, it's melting permafrost - without which our emissions would have no consequences."

    This is a curious assertion, as we know what our emission levels are, and we know what the rate of rise in CO2 is. Given that the increase in atmospheric levels is less than our emissions, a simple mass balance analysis shows that we are indeed responsible for the rise in atmospheric concentrations. And your hypothesis is a fascinating call to abdicate responsibility for our actions.

    I'll also note that you have not provided any references supporting your theory, nor have you shown any estimates for CO2 contributions from melting permafrost. Even more importantly, I cannot think of a historic record indicating anything natural close to the rate of CO2 increase occurring now, including the PETM, which was at least an order of magnitude slower in onset.

    I strongly suggest that you read (and comment upon) either the How do human CO2 emissions compare to natural CO2 emissions, or the Murry Salby finds CO2 rise is natural threads. I don't think there's a thread specific to your permafrost claims - perhaps because I don't recall anyone ever proposing it before... which should tell you something.
    0 0
  34. Arkadiusz Semczyszak - My apologies, an error in my previous post. You did present some references regarding amounts of permafrost.

    I will, however, point out that permafrost doesn't melt without cause - it instead responds to temperature changes, as a feedback. From Zimov 2006, one of your references:

    "Factors inducing high-latitude climate warming should be mitigated to minimize the risk of a potentially large carbon release that would further increase climate warming."

    Not a forcing, but a feedback; you seem to be claiming otherwise. And, I'll note again, current rates of change in CO2 (and temperature) are not found in the paleo record - indicating that natural causes are insufficient to drive the current changes.
    0 0
  35. 32, Arkadiusz Semczyszak,

    Can you point to a single scientist or published study that endorses your rather bizarre theory that somehow, magically, against all odds, anthropogenic CO2 is having no effect on CO2 levels while melting permafrost (and when did this start melting, by the way, and why) is responsible for all of it?

    By the way, the following assertion of yours is utterly unsupported by anything except presumption:
    Without a natural source increase biosphere would certainly has removed the more (all?) of our C.
    Your hypothesis fails on several points:

    1) Where is the anthropogenic CO2 going?
    2) Why does this sink affect the anthro-CO2 but not the permafrost CO2 that you propose?
    3) How has the permafrost CO2 suddenly been released into the atmosphere?
    4) Your accounting of CO2 now must include everything released anthropologically, everything supposedly released from permafrost, everything remaining in the atmosphere, and everything absorbed by the ocean... and those numbers do not balance.
    5) What are your hard numbers... where is your numerical evidence (an accounting) that any of this is happening, or even that another source of carbon can and should exist?

    Why are you solving a problem that does not exist? Is it that important for you, now that you have apparently accepted that CO2 causes dangerous global warming, that you instead prove that the source of CO2 is not our own human activity but instead some other, magical source, which is beyond our control?
    0 0
  36. The real issue is that our CO2 emissions are raising the temperature of the Earth towards tipping points, so called because once they are underway they are irreversible. Is the next retreat of the deniers to blame global warming on these tipping points once they are underway and thus label them as 'natural'? My current fears for the future habitability of our Space Ship Earth were already dire. With embarrassingly stupid thinking and shouting by deniers in general the very real warnings are falling on the now deaf ears of the uninterested public.
    As a lowly Physicist I think that when all of this equilibrates the conditions on Space Ship Earth will not be recognisable by some of our current generations alive today. It will be the youngest that will see the worst changes.
    The science has given us a measure of the situation we are all in. Only real action will avert us damaging our planet beyond repair. The time for squabbling is long past. We all need to take remedial action before it is too late. Bert
    0 0
  37. @ Sphaerica

    You forget the fallback mantra underlying the "anything-but-fossil-fuel-derived-CO2" agenda:
    "It's turtles, all the way down..."
    And turtles produce...

    0 0
  38. Sorry to reply so late - too much work.


    1. Had Keeling began his research 10-20 years ago, probably would not be any doubt ...

    2. Many conclusion given by you - as mine (for example, that currently only natural sources are responsible for the increase in concentration of Carbon in the atmosphere) are not mine. I only draw your attention to natural sources C - as it evolved in the twentieth century and now. I leave - The readers - conclusions. I think that we can not exclude the participation of natural resources - particularly permafrost - in the current increases in atmospheric CO2 concentrations - now - not only in the future.
    Abrupt Permafrost Thaw ...: "Abbott said [of carbon which is still "trapped" in the permafrost]: "There's more organic carbon in northern soils than there is in all living things combined; it's kind of mind boggling."
    “... around four times more than all the carbon ever emitted by modern human activity and twice as much as is now in the atmosphere, according to the latest estimate.”
    "... we don't yet know how to incorporate them into climate models," Abbott said."

    3. “... a simple mass balance analysis ...” - may get too simple. Of course, accepting paleo - record can be concluded that up to 19? natural sources, the increase, was almost 100% balanced by sinks. According to paleo - record an increase of 1 degree C is maximum 6-7 ppmv of CO2 excess. With at least 500 Gt C of natural emissions - permafrost (years 1910-1950) natural sinks usuwałyby 49? Gt C - 9?%. But the atmosphere is a surplus equal to the size of 50% of our emissions - which shows that the abrupt increase in the size of the source, sinks always respond - but "grow" much slower than the source. In nature, the cases 100% of the balance - in response to the rapid growth of sources (eg, permafrost from 1910 to 1950) there are no ( Khatiwala (2009): “... terrestrial biosphere was a source of CO2 until the 1940s”). Usually it happens this way: this

    Of course You can say that now sinks remove: all growing sources of natural, and yet - additionally - 50% of our sources. The possibility absorbers of sinks, are therefore greater than the increase in natural sources.

    But what will be, but if we assume that the sinks remove only a percentage (determined by a mathematical function) increase in all sources - regardless - irrespective of the size of the sources increase?

    4. Lower (than at present) the temperature - is a accumulation organic C in permafrost, in the form of practically undegraded. Thawing is rapid release of C. Later: the slow formation of permafrost biomes: wetlands and forests - the re-accumulation of C. That these "slowly" by Zimov (2006). The complicated reactions permafrost have best described here : Wisser ( 2011). We may “not like” NIPCC, but similar conclusion (“slowly” re-accumulation of C) follows from this very large study NIPCC - page 228-230(32-34).

    5. Of course, the consequence of my position is to assume that the paleo-data have “drawbacks”: low accuracy in time, smoothing the results, the possibility of underestimation of the size of the former amount of C in the atmosphere. Last possibility is weakly proved (as yet) - I now, moreover discussion on this topic greatly exceed the “framework” of this post.

    6. Salby and Spencer - They really confuse: variability with the trend; and draw attention only to the potentially large oceanic source C - completely incompatible to the current: C isotopic changes in the atmosphere and changes in oxygen content. Two months ago I sent - Salby, “few dozen pages” of my remarks ...

    P.S. I think I replied to most of the comments - by the way - also Sphaerica.
    0 0
  39. ... sorry:
    “... natural sinks removed 49? Gt C - 9?% ...” - of course ...
    0 0

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

The Consensus Project Website



(free to republish)



The Scientific Guide to
Global Warming Skepticism

Smartphone Apps


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