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Greenhouse gas concentrations surge to new record

Posted on 1 November 2017 by Guest Author

via the WMO

Globally averaged concentrations of COreached 403.3 parts per million in 2016, up from 400.00 ppm in 2015 because of a combination of human activities and a strong El Niño event. Concentrations of CO2 are now 145% of pre-industrial (before 1750) levels, according to the Greenhouse Gas Bulletin.

 Rapidly increasing atmospheric levels of CO2 and other greenhouse gases have the potential to initiate unprecedented changes in climate systems, leading to “severe ecological and economic disruptions,” said the report.

The annual bulletin is based on observations from the WMO Global Atmosphere Watch Programme. These observations help to track the changing levels of greenhouse gases and serve as an early warning system for changes in these key atmospheric drivers of climate change.

Population growth, intensified agricultural practices, increases in land use and deforestation, industrialization and associated energy use from fossil fuel sources have all contributed to increases in concentrations of greenhouse gases in the atmosphere since the industrial era, beginning in 1750.

Since 1990, there has been a 40% increase in total radiative forcing – the warming effect on our climate - by all long-lived greenhouse gases, and a 2.5% increase from 2015 to 2016 alone, according to figures from the US National Oceanic and Atmospheric Administration quoted in the bulletin.

“Without rapid cuts in COand other greenhouse gas emissions, we will be heading for dangerous temperature increases by the end of this century, well above the target set by the Paris climate change agreement,” said WMO Secretary-General Petteri Taalas. “Future generations will inherit a much more inhospitable planet, “ he said.

“COremains in the atmosphere for hundreds of years and in the oceans for even longer. The laws of physics mean that we face a much hotter, more extreme climate in the future. There is currently no magic wand to remove this CO2 from the atmosphere,”said Mr Taalas.

The last time the Earth experienced a comparable concentration of CO2  was 3-5 million years ago, the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now.

The WMO Greenhouse Gas Bulletin reports on atmospheric concentrations  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, cryosphere and the oceans. About a quarter of the total emissions is taken up by the oceans and another quarter by the biosphere, reducing in this way the amount of CO2 in the atmosphere.

A separate Emissions Gap Report by UN Environment, to be released on 31 October, tracks the policy commitments made by countries to reduce greenhouse gas emissions and analyses how these policies will translate into emissions reductions through 2030, clearly outlining the emissions gap and what it would take to bridge it. 

"The numbers don't lie. We are still emitting far too much and this needs to be reversed. The last few years have seen enormous uptake of renewable energy, but we must now redouble our efforts to ensure these new low-carbon technologies are able to thrive. We have many of the solutions already to address this challenge. What we need now is global political will and a new sense of urgency," said Erik Solheim, head of UN Environment.

Together, the Greenhouse Gas Bulletin and Emissions Gap Report provide a  scientific base for decision-making at the UN climate change negotiations, which will be held from 7-17 November in Bonn, Germany.

WMO, UN Environment and other partners are working towards an Integrated Global Greenhouse Gas Information System to provide information that can help nations to track the progress toward implementation of their national emission pledges, improve national emission reporting and inform additional mitigation actions. This system builds on the long-term experience of WMO in greenhouse gas instrumental measurements and atmospheric modelling.

WMO is also striving to improve weather and climate services for the renewable energy sector and to support the Green Economy and sustainable development. To optimize the use of solar, wind and hydropower production, new types of weather, climate and hydrological services are needed.

Key findings of the Greenhouse Gas Bulletin

Carbon dioxide

CO is by far the most important anthropogenic long-lived greenhouse gas. Globally averaged concentrations for CO2 reached 403.3 parts per million in 2016, up from 400.00 ppm in 2015. This record annual increase of 3.3 ppm was partly due to the strong 2015/2016 El Niño, which triggered droughts in tropical regions and reduced the capacity of “sinks” like forests, vegetation and the oceans to absorb CO2.   Concentrations of CO2 are now 145% of pre-industrial (before 1750) levels.

The rate of increase of atmospheric CO2 over the past 70 years is nearly 100 times larger than that at the end of the last ice age. As far as direct and proxy observations can tell, such abrupt changes in the atmospheric levels of CO2 have never before been seen.

Over the last 800 000 years, pre-industrial atmospheric CO2 content remained below 280 ppm, but it has now risen to the 2016 global average of 403.3 ppm.

From the most-recent high-resolution reconstructions from ice cores, it is possible to observe that changes in CO2 have never been as fast as in the past 150 years. The natural ice-age changes in CO2 have always preceded corresponding temperature changes. Geological records show that the current levels of CO2correspond to an “equilibrium” climate last observed in the mid-Pliocene (3–5 million years ago), a climate that was 2–3 °C warmer, where the Greenland and West Antarctic ice sheets melted and even some of the East Antarctic ice was lost, leading to sea levels that were 10–20 m higher than those today.


Methane (CH4) is the second most important long-lived greenhouse gas and contributes about 17% of radiative forcing. Approximately 40% of methane is emitted into the atmosphere by natural sources (e.g., wetlands and termites), and about 60% comes from human activities like cattle breeding, rice agriculture, fossil fuel exploitation, landfills and biomass burning.

Atmospheric methane reached a new high of about 1 853 parts per billion (ppb) in 2016 and is now 257% of the pre-industrial level.

Nitrous Oxide

Nitrous oxide (N2O) is emitted into the atmosphere from both natural (about 60%) and anthropogenic sources (approximately 40%), including oceans, soil, biomass burning, fertilizer use, and various industrial processes.

Its atmospheric concentration in 2016 was 328.9 parts per billion. This is 122% of pre-industrial levels. 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. It accounts for about 6% of radiative forcing by long-lived greenhouse gases.

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Comments 1 to 19:

  1. Minor but important correction of the opening statement:

    "Concentrations of carbon dioxide in the atmosphere surged at a record-breaking speed in 2016 continuing the industrial age increases that, in the early 1900s, pushed it above the 300 ppm highest level in the previous 800 000 years, ..."

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  2. The correction to (1) does not change the basic message, that the present CO2 concentration is the highest in 800 000 years, it just makes the message less clear.

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  3. eschwartzbach@2,

    The statement uncorrected implies that 2015 CO2 levels were lower than 2014 levels but the surge in 2016 set a record level of CO2. It also implies many previous values had been records as the CO2 level bounces around.

    The correction uses more words because more words need to be used. Perhaps a different set of words would be better, but more words needed to be more correct.

    A way to say it more correctly with fewer words is:

    "Concentrations of carbon dioxide in the atmosphere surged at a record-breaking speed in 2016, according to ...", with reference to a chart showing the 800 000 year CO2 history.

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  4. Another minor correction:

    "Over the last 800 000 years, pre-industrial atmospheric CO2 content remained below 300 ppm."

    The highest level through the past 800 000 years was 300 ppm occurring a little more than 300 000 years ago (as I mentioned in the correction @1 which is based on a multitude of sources that provide CO2 level history through the past 800 000 years, one of which is provided by NOAA)

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  5. A clarification of my correct #4 requiring more words to be more correct:

    The pre-industrial level is indeed 280 ppm, but that term is not referring to the maximum level through the past 800 000 years. That term is the starting point for discussing things like how much impact the industrial age has had. The industrial age pushed CO2 up from 280 (278 in the NOAA presentation) to a level of 300 ppm by the early 1900s (as indicated in my suggested correction/clarification @1).

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  6. @4:  After looking at the NOAA link it looks like the highest point at 300,000 years is just below the 300 ppm line to me, not on it.  Also, if you follow the first link in the post to the WMO Bulletin they state:

    "As illustrated in the inside story of this bulletin, over the last ~800 000 years, pre-industrial atmospheric CO2 content remained below 280 ppm (1) across glacial and interglacial cycles, but it has risen to the 2016 global average of 403.3 ppm."

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    Moderator Response:

    [DB] Truncated and hyperlinked URL that was breaking page formatting.

  7. I would suggest putting the two emissions graphs in the article right under the opening statement. This would answer the valid comments of both OPOF and eschwarzbach.

    My own criticism is the first graph of 22000 years is confusing as it omits the CO2 hockey stick since 1900. You have to mentally join the two graphs. In fact I think you would get the essential message across fine with just one composite graph, even if it has slightly less detail on it.

    But its a nit pick and very good article overall.

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  8. We are now receiving two messages 1) human CO2 output is stable or possibly dropping, 2) CO2 in the atmosphere continues to climb and break all previous records.  Many of us are worried about permafrost CO2 production.  This is already estimated to produce as much CO2 this century as the United States will (at current production levels).  We all appreciate the work that is being done to quantify these two parameters, but its important, going forward, to be able to distinguish human CO2 production from CO2 coming from positive feedbacks in the natural environment.  Those of us concerned about the AGW trajectory are actually watching these feedbacks most closely.  We want to know the bad news as it happens, and more importantly the good news as soon as is possible.  Western capitalism may have gone off the Fox News deep end, regarding physical reality, but many of us are just not able to go there with it.

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  9. The image on page 4 of the WMO article that is referred to should be included. It shows the CO2 history from several million years ago to the recent spike. And it shows the maximum of nearly 300 ppm that occured a little more than 300 000 years ago.

    So the WMO article statement about 280 ppm being the maximum level through the past 800 000 years is not correct.

    Also, the CO2 levels in the more recent 1000 years include values up to 285 ppm. 280 ppm is the level from the mid 1600s up to the industrial age push (except a brief dip to about 275 ppm in the late 1700s).

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  10. Back to comment No.3 of One plantet..

    Semantic analysis of the uncorrected text does not imply that "2015 CO2 levels were lower than 2014". There is just one minor uncorrectness in the original text: "...surged at a record-breaking speed in 2016". The increase rate (speed) was 2015 slightly higher than in 2016 (both globally and Mauna Loa). Human language is seldom absolutely correct and exhaustive. But saying "...surged at a record-breaking speed in 2015 and 2016 to the highest level in 800 000 years" should be perfectly valid, without too much words.

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  11. Landfills give off a lot of methane. Why not cover the lanfill sites with transparent greenhouse plastic sheeting a metre or two above the ground and collect the gas under the plastic sheet and feed it into a tower where it can be flared? A large updraft will be formed and the flared gases will disperse high up. See The gases will be heated by flaring and the greenhouse effect if transparent greenhouse plastic is used above the landfill. The system will simulate a solar updraft tower.

    To reduce CO2, increase rainfall in desert areas near the sea and grow trees there. The wind speed is low just over the ocean (as it is just above the ground). There is therefore a fairly stagnant layer with very high relative humidity just above the sea. If one used thousands of floating devices as shown below one could increase moisture in the air so that air blowing to land would produce more rain. Water has a very high emissivity (about 0.95), so the greenhouse plastic will keep in a lot of radiation from the sea surface. For high sea surface temperatures of 30 deg C or so, the greenhouse will keep in about 450 W per square metre of infrared radiation from the sea surface.
    The light portion of the solar energy passing through the greenhouse plastic will be absorbed by the black sheet instead of it penetrating deep into the ocean. The infrared portion of solar energy entering the greenhouse will be absorbed within the uppermost few centimetres of the sea surface. Any infrared radiation from the sea that is reflected back to the sea by the greenhouse plastic will also be absorbed in the upper few centimetres of the sea. The result will almost certainly be a heating of the sea surface under the greenhouse plastic, enhancing evaporation and high humidity. About 53% of solar energy is light energy, so the black sheet will prevent a lot of energy from escaping down to deeper levels and will concentrate it near the surface - see diagram at

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  12. eschwarzbach@10,

    The wording of the opening statement of the OP is wide-open to interpretation. In my reading of the rest of the document the only specific years mentioned are 2015 and 2016.

    With the corrrections I suggested (either one), the result is less open to the interpretation that 2015 levels of CO2 were lower than 2014 or a previour record year, and it is 'less open from the beginning'.

    So the semantic problem is the statement that 2016 set a New Record without closing the opennings to interpretation about when the Previous Record was set.

    The type of opening available in the uncorrected opening statement is exactly the type of opening abused by a misleading information provider. They will claim you don't have to read more than the first sentence to know that the item is an incorrect presentation attempting to make things appear different from what they actually are, accurately adding justification for that claim by stating that CO2 levels have been higher than 280 ppm through the past 800 000 years and that they were even higher than 280 ppm in the past few hundred years.

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  14. As far as I can tell, the majority of the GHG in the atmosphere above natural baseline is due to agriculture and topsoil is the largest potential ag sink and therefore the largest potential source. The IPCC counts farming practices, but has totally ignored loss of topsoil and the carbon contained therein. Some like to claim that the carbon is just deposited in colluvium and stored, but half of erosion is from wind and it takes some pretty powerful voodoo to store organic carbon in an oxidizing environment. Much of the water erosion carbon turns into biogenic methane. I posit further that loss of topsoil adds a temperature independent water vapor component to the atmospheric GHG concentration and this has been going on for over 10,000 years with rapid soil loss since ≈1900.

    CSIRO estimates that just adding 0.5% organic carbon to 2% of the Oz ag land would offset all industrial emissions. Doubling either term would result in a net-carbon negative process like amount. This would restore atmospheric CO2 to pre-industrial levels if adopted on a much larger scale in countries that can afford it. Reducing atmospheric GHG concentration quickly to acceptable levels is something that cannot happen even if the world was 100% renewable as of today. So why all the focus on carbon neutral when we can be carbon negative for likely a lot less investment?

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  15. Kanknapper, you need much more substantiation to your assertions than "as far as I can tell." The largest sink is the ocean. You don;t demonstrate otherwise. Does loss of topsoil square with the isotopic characteristics of atmospheric carbon? Still, the burning of hundreds of billions of tons of fossil fuel isn't going away, where is that carbon going?

    Temparature independent water vapor component? How exactly are physics going to accomodate keeping water vapor in the air below the dew point? The atmosphere has a way to discriminate between regular water vapor and the one coming from your preferred source? Please elaborate.

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  16. I wasn't clear. The largest source/sink that humans have disrupted that is easily accessible and amenable to recovery. For reference, see Climatic Change 61: 261–293, 2003. “The Anthropogenic Greenhouse Era
    Began Thousands of Years Ago”. Since soil respiration is 9x larger than all industrial emissions, it takes a much smaller change in this large carbon sink to store all industrial emissions. As far as “respiration” is just part of the “natural” carbon cycle, that is hogwashy. Organic decomposition results in CO2 emission, organics stored in topsoil is sequestration (takes effort, but still sequestration). One would think after 10,000+ years of practice, humans would know how to keep the topsoil.

    For your second comment, let’s reframe your point and focus on atmospheric coupling via vegetation, specifically desertification (Sahara, Australia, greater Gobi). At the dawn of agriculture, these were areas of “natural” topsoil containing huge amounts of both carbon and water. Topsoil destroyed, vegetation gone, link destroyed……..where did the water go? From the paper above, we know where the carbon went because it forms a non-condensible gas. Hard to measure a condensible gas, but estimations can be made based upon a ratio with the measured CO2 which is above my pay grade. Where did all this water vapor go?

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  17. KanKnapper@16,

    Interesting hypothesis, but what about all the new carbon introduced into the recycling environment by digging up and burning fossil fuels?

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  18. KanNapper @14

    Soils could indeed potentially store all industrial emissions, or a large component of them. This is a useful thing to do with better farming of the permaculture variety.

    The problem you have is it would require radical changes to all farming on global scale, and rates of achieving this would likely be very slow, and rates of absorption of emissions into plants and thus soil carbon are very slow over millenia time scales. Therefore reducing emissions at source is the priority.

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  19. KanNapper, you asked "Where did all the water vapor go?" Eventually it condensed out of the atmosphere, becoming liquid and solid water in the oceans, lakes, streams, absorbed by plants, sunk into the soil,...

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