Follow Slashdot stories on Twitter


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×
Earth Stats Science

Observed Atmospheric CO2 Hits 400 Parts Per Million 367

symbolset writes "Over the past month a number of individual observations of CO2 at the Mauna Loa Observatory have exceeded 400 parts per million. The daily average observation has crept above 399 ppm, and as annually the peak is typically in mid-May it seems likely the daily observation will break the 400 ppm milestone within a few days. This measure of potent greenhouse gas in the atmosphere should spark renewed discussion about the use of fossil fuels. For the past few decades the annual peak becomes the annual average two or three years later, and the annual minimum after two or three years more."
This discussion has been archived. No new comments can be posted.

Observed Atmospheric CO2 Hits 400 Parts Per Million

Comments Filter:
  • Yawn (Score:4, Insightful)

    by DoofusOfDeath ( 636671 ) on Sunday May 05, 2013 @08:33AM (#43634139)

    This measure of potent greenhouse gas in the atmosphere should spark renewed discussion about the use of fossil fuels.

    No it won't. It's not like politicians and the public have been just sitting on the sidelines, waiting util a value about 400 PPM was observed. I don't believe the public really doubts that atmospheric CO2 is increasing, and so a wonky measure of it is pretty irrelevant to public sentiment.

    • This year I've heard 3 people I know say in passing "so much for global warming" because of the abnormally cold weather we're getting this season. Can someone offer a short and simple explanation for why abnormally cold weather doesn't mean "global warming is a myth"?
      • Re: (Score:3, Informative)

        by Bengie ( 1121981 )
        Just remind them of the thousands of record highs set in the past few years all around the world. For every small increase in average temps caused by global warming, larger extreme temperatures are seen throughout the year. Higher highs and lower lows but an overall average of warmer.
      • One cold year says nothing about the trend in the Earth's climate.
      • One season of locally cold weather is a simple fluctuation. You need to consider all the data. []

      • THats partly because of idiots who last year said "See? Global warming" when we had abnormally warm weather.

        You make your bed, you lie in it.

      • Yes.

        Warmer global temperatures have caused a massive loss in arctic ice. Warm water extends farther north this year than it ever has before. The high pressure stationary air masses that form over this water extend into the North Pacific and North Atlantic. In years past, the jet stream (the west to east moving flow of cold air around the poles) would have encountered colder, low pressure air over ice and moved on through. Instead it encounters the high pressure warm air in the north pacific, gets squeezed u

        • It's funny, because I would get annoyed in years past when people would say, "it's hot! Must be global warming!" Or "it's cold! So much for global warming!" Or blame GW for specific storms like Katrina or Sandy, when those are just weather events, and not climate. But, this cold spring is the first time I think you can really say, "this is a changed climate due to global warming."

          So, do you get annoyed when you do the same thing as those people saying "it's hot! Must be global warming!" or "it's cold! So mu

          • That's the point. Warming changed the flow of the jet stream, and it will happen again next year and again and again. The cold spring this year (and the cold spring we'll get next year) was due to a changed climate and is not just a weather event.

      • Because they are so used to hearing how abnormally warm weather is proof that gloabl warming exists.
      • Because "weather" is not "climate."

        Weather is what it is out right now. Feel free to dig through graphs of past temperature records, and you can satisfy yourself that no day of the year will have the same temperature, humidity, rainfall, or anything graph on two successive years. Climate is the time-averaged expectation value and ignores anything on shorter than several year scales at the very least.

        It's not even that simple, as there are many characteristic timescales involved in the climate, not jus
      • Tell them that Global warming causes prostitution. []
      • by dodobh ( 65811 )

        This needs paper and pencil, but it's an easy explanation (even if imperfect).

        If you draw a graph of temperature vs time, you will see a wave pattern emerge over a few years. Global warming implies that there is more energy in the atmosphere, so the amplitude of the wave will increase. This means summers get hotter and winters get colder.

        The scientific debate is about how much of an amplitude change will result, and what the consequences of that will be (we don't know this yet).

    • And yet here we are: discussing it.
    • by hey! ( 33014 )

      I don't believe the public really doubts that atmospheric CO2 is increasing, and so a wonky measure of it is pretty irrelevant to public sentiment.

      I have my doubts about both these assertions.

      The persuasion game works like state lottery commissions claim their games work: you can't win if you don't play. In the Internet age it's impossible to drive a stake through the heart of a crackpot theory; people assemble into self-reinforcing communities which preserve and spread fringe ideas until they're no longer so fringe. Take scientific racism; it was a museum-piece article of crankery when I went to school in the 80s, but all those sloppy, half-baked pa

    • by flyneye ( 84093 )

      Wait a minute, is there something I've been missing out on here? Should you take atmospheric tests for CO2 from just one spot, a volcanic spot? Or should it be taken and averaged over several points on the planet?
      I admit to not knowing much about this, but isn't it akin to taking readings from the exhaust of a semi-truck, rather than a good random sample of traffic? Or even taking a Semi-truck reading in New Jersey to apply to Montana?

      • Wait a minute, is there something I've been missing out on here? Should you take atmospheric tests for CO2 from just one spot, a volcanic spot?

        Weather patterns [] combined with the jet stream [] keep the atmosphere well-mixed and fairly homogeneous, especially at high altitude. That's why the recording station is on Mauna Loa []:

        Mauna Loa was originally chosen as a monitoring site because, located far from any continent, the air sampled is a good average for the central Pacific. Being high, it is above the inversio

  • There are groups (misguided in my opinion, but that's not relevant to the question) such as that want to restrict CO2 levels to 350ppm, feeling that that level is the "trigger" for global warming.

    It's not clear to me exactly how much time they propose it will take to get there though. On their web site are some generic words about installing solar panels and stopping fossil fuel subsidies, which I think anybody is generally for. But I don't see anything about how much time they expect this to
    • by Hentes ( 2461350 ) on Sunday May 05, 2013 @09:16AM (#43634295)

      You can't make predictions when a human factor is involved. If we were all controlled by a hivemind and made CO2 decrease our highest priority, stopping CO2 production could be done in 20 years (there's enough nuclear power to sustain our needs, and we have electric vehicles - technologically it's already possible). After that, the oceans would absorb the excess CO2 and bring it below 300ppm in about 300 years (according to a study I sadly can't find now). So absent some miracle like fusion reactors even in a best case scenario it would take at least 150 years to get below 350.

      But the most important thing is the human factor which depends on our decisions, and can make that time much much longer.

      • I'm not sure, but might some of the geoengineering approaches to removing carbon from the atmosphere considerably accelerate your estimate? Like for example, iron-fertilizing the oceans to create massive plankton blooms that, hopefully, remove carbon faster?

        Not that I'm sure that the proposed geogengineering approaches are GOOD IDEAS, I'm just wondering if reducing CO2 could be done quicker.


        • by Hentes ( 2461350 )

          To be honest I doubt we can engineer a carbon sink that could rival the capacity of the oceans. Most of the plankton from the blooms, for example, gets devoured by marine wildlife fairly quickly, so it only removes carbon temporarily. To be able to sequestrate a reasonable amount of CO2 we would have to use up energy in the order of magnitude of the energy gained from fossil fuels. Stuff like reforestration could help, but that's also a slow process.

    • by Bengie ( 1121981 )
      CO2 levels will come down naturally. As levels rise and temps rise, more and more CO2 will get trapped by dissolving rock through acidification, which will eventually scrub our atmosphere of much CO2 and kill off the plants.
    • Those groups generally are getting their numbers from this paper [] by Hansen et al.
  • Seems Odd To Me (Score:2, Insightful)

    by Anonymous Coward

    Why would you take this measurement in such close proximity to one of the most active volcanoes on the planet?

    • You bring up a good point [].

      The MLO [] is located 34KM WNW from and well above the summit of Kilauea. The primary volcanic emissions plume from Kilauea is driven by trade winds which blow mostly from the NE, and because of the topography of the Big Island most of that plume will bypass the observatory. However, there has to be some effect from it; the question is how much?

      FWIW, I live on the Kona [] side of the Big Island and get to enjoy the effects of Kilauea's vog [] (volcanic smog) more than would like.

    • Re:Seems Odd To Me (Score:5, Informative)

      by Misagon ( 1135 ) on Sunday May 05, 2013 @09:14AM (#43634289)

      The Muana Loa observatory measures only at night, when air is descending from far up high. That air has come from across the Pacific Ocean, far from any specific CO2 sources.
      At night, the volcanic gasses are trapped in a thin layer near the ground by a temperature inversion. The observatory measures the air at several towers at different altitudes and also closer to the volcano so as to get a comparative reading.

      You can read more in this report [].

  • Linear Growth? (Score:3, Insightful)

    by Anonymous Coward on Sunday May 05, 2013 @10:09AM (#43634583)

    Why does rate of increase seem constant. I mean, if it's influenced by human activity (of which I have no doubt), then shouldn't it track closely to the fluctuations in the global economy. Specifically, shouldn't there be a dip or flat corresponding to the Great Recession periods of '08/'09?

  • That seems a fair, though perhaps somewhat generous, estimate for the ratio of signal to noise here. "News for nerds" has become just another giant Red vs. Blue flamefest. Might as well just turn my attention to my wife's cat pictures on FB.

  • Bringing the numbers closer to human-scale, a 300 parts per million is the same as 3 parts per 10,000. Similarly 400 is 4 parts per 10,000. So basically, we've gone from 3 molecules per 10,000 to 4 molecules of CO2 per 10,000 molecules of air.

    In the same period, plankton levels have declined over 1% per year since the late 1970's []. John Martin at MBARI [] postulated that the decline was due to a decline of dissolved iron in the oceans. He's quoted as saying "Give me a tanker full of iron and I'll give yo

  • by Vainglorious Coward ( 267452 ) on Monday May 06, 2013 @01:02AM (#43639317) Journal

    Observed Atmospheric CO2 Hits 400 Parts Per Million

    That's not true, the observations are wrong. And anyway it's not important. And even if was, we're not responsible. Peddling these myths is exactly what I'd expect from leftist, reality-based terrorists

Nothing ever becomes real until it is experienced. - John Keats