4 ms·

Why did they decided to cut the graphic at 400,000 years before today? Maybe that's because a couple of million years ago the concentration of CO2 was well abov

by kia 16y ago

Why did they decided to cut the graphic at 400,000 years before today? Maybe that's because a couple of million years ago the concentration of CO2 was well above today's level? By the way here is another picture: http://en.wikipedia.org/wiki/File:Atmospheric_CO2_with_glaciers_cycles.gif http://en.wikipedia.org/wiki/File:Atmospheric_CO2_with_glaci...

mkempe 16y ago
Yes, climate and atmosphere do change. There is nothing sacred about current measurements and composition. Here are estimated CO2 levels through geologic time -- "currently" rather low! -- at UCSD site: http://earthguide.ucsd.edu/virtualmuseum/climatechange2/07_1.shtml http://earthguide.ucsd.edu/virtualmuseum/climatechange2/07_1... CO2 is essentially airborne fertilizer. Our planet wouldn't be so green without lots of it. (I'd rather be alive during an interglacial, abundantly green geological period.)
- ceejayoz 16y ago
  > CO2 is essentially airborne fertilizer. Sure, but as with fertilizer on fields, there are consequences for using way too much. > I'd rather be alive during an interglacial, abundantly green geological period. As long as there aren't a billion or so refugees from the low-lying areas rampaging through.
  - mkempe 16y ago
    > using way too much Hence my link to CO2 levels over Geologic Time. Do you think there was "way too much" CO2 in the past?
    - ceejayoz 16y ago
      For Earth? No. For human society as we currently know it? Seems that way. We'll survive climate change, but flooding places like Bangladesh is going to cause tremendous upheaval. Humanity survived the ice age, but that didn't make it a fun period in our history.
      - mkempe 16y ago
        You seem to suggest a pessimistic and static view of human society. The planet is not static, climate isn't either; why would society and civilization be? is there a single, optimum equilibrium for humanity? what's the evidence?
        ceejayoz 16y ago
        There's no single, optimum equilibrium, but a disaster that makes double-digit percentages of the planet refugees seems to fit squarely in the "sucky" end of the spectrum.
        seabee 16y ago
        There is no single optimum, however there is value beyond merely surviving. Our quality of life is better than it was in the past, so why would anyone be happy at the prospect of that going down due to climate change?
        mkempe 16y ago
        True, it shouldn't be survival for its own sake. But do we really believe that our quality of life will be going down because of (some, warmer or glacial) climate change? how soon does that happen, and is humanity powerless to adapt? I have a very optimistic view of human potential, I think in essence and the long term all problems can be solved. Does the fact that CO2 levels have varied hugely in Geologic Time affirm that we are under imminent threat of terrible climate changes? is it irrelevant? or contradictory? or a puzzle? is it impolitick to ask such questions?
        mkempe 16y ago
        How interesting that my honest questions are being down-voted. Edit: I want to be scientific, include all relevant evidence, and some people here dislike it? (I'm not interested in the politics -- I've never even voted in a national election. And yes, I see these down-votes as a form of political activism. Disagree and argue if you have reason and facts.)
mmphosis 16y ago
Look closely at the right edge of the picture. The text below the picture is revealing... Human deforestation and burning of fossil fuel has raised atmospheric CO2 to over 380 ppm in the last century, well above pre-industrialized levels, and "off the scale" of this graph top.
- electromagnetic 16y ago
  "Off the scale" is a complete fucking BS term. The carboniferous period had a mean CO2 concentration of around 800ppm and was marked by glaciation and low sea levels - our current correlation between CO2 and "global warming" is off the bullshit scale. The mean global temperature in the carboniferous period, with CO2 concentrations over double of present day was an astounding, just wait for it... 14C, which is the incredible, * unbelievable* 0C above the mean present day global temperature. As CO2 levels spiked in the carboniferous period, it is marked by the drop of sea levels by 120m to the present day level, and as the CO2 level subsided, the sea levels rose 80m. Sorry, but "off the scale" only counts when you actively pick and choose what scale you want to use, which in terms of geological temperature, CO2 and O2 concentrations quite literally means disregarding millions of years of geological time.
  - deleted 16y ago
    [deleted]
  - jselzer 16y ago
    I have not taken the time to verify your claims here, but don't you think it's fair to use "off the scale" when comparing this to any other time period during the modern human era? As other people have said, life on earth will go on in one form or another. But "off the scale" is a necessary term in this context to drive home the incredible turmoil and human suffering that will result as we are forced to adjust the local pressures of water shortages, mass human migration, and agricultural failures that will be caused by this...
  - pvxc 16y ago
    Both CO2 concentrations and the global temperature varied significantly over that period of Earth's history (~400-250 millions of years ago). Around 300 Mya, CO2 was comparable to what it is today and temperatures were likewise comparable. Around 400 Mya, CO2 was in the 4000ppm's and the temperature was likewise higher (by ~ 8 C). No contradiction. Also, when discussing matters scientific, please cite your scientific sources --- otherwise the discussion is of little value. Like so: http://www.nature.com/nature/journal/v449/n7159/abs/nature06085.html http://www.nature.com/nature/journal/v449/n7159/abs/nature06... http://dx.doi.org/10.1130/1052-5173(2004)014<4:CAAPDO>2.0.CO;2 http://dx.doi.org/10.1130/1052-5173(2004)014<4:CAAPDO&#6...
M1573RMU74710N 16y ago
The fact that C02 levels have been higher is not necessarily in contradiction to the article, nor an important omission. This issue as other's have pointed out is the CAUSE of the current levels and the implications thereof. In the past the high levels of C02 were at least partially due to ice ages, which prevented the normal processes for the mitigation of C02, once the levels built up enough the greenhouse effect melted the ice and restored the levels. Look around, there's no ice age. So not only is there no discernible cause for the increase except out actions, we don't have a huge C02-eating army trapped in the ice waiting to be released. Some natural mechanism will probably step in, but who knows what effects it will have. We are monkeying with a system we know to have far reaching and potentially devastating effects.
- alanh 16y ago
  You repeatedly type cee-zero-two. It's the letter O, as CO₂ stands for (mono-)carbon dioxide, a gaseous molecule with one carbon and two oxygen molecules. I'm sure you know that, but hey, if you didn't, there you go.

by kia 16y ago

mkempe 16y ago

Yes, climate and atmosphere do change. There is nothing sacred about current measurements and composition. Here are estimated CO2 levels through geologic time -- "currently" rather low! -- at UCSD site: http://earthguide.ucsd.edu/virtualmuseum/climatechange2/07_1.shtml http://earthguide.ucsd.edu/virtualmuseum/climatechange2/07_1... CO2 is essentially airborne fertilizer. Our planet wouldn't be so green without lots of it. (I'd rather be alive during an interglacial, abundantly green geological period.)

ceejayoz 16y ago
> CO2 is essentially airborne fertilizer. Sure, but as with fertilizer on fields, there are consequences for using way too much. > I'd rather be alive during an interglacial, abundantly green geological period. As long as there aren't a billion or so refugees from the low-lying areas rampaging through.
- mkempe 16y ago
  > using way too much Hence my link to CO2 levels over Geologic Time. Do you think there was "way too much" CO2 in the past?
  - ceejayoz 16y ago
    For Earth? No. For human society as we currently know it? Seems that way. We'll survive climate change, but flooding places like Bangladesh is going to cause tremendous upheaval. Humanity survived the ice age, but that didn't make it a fun period in our history.
    - mkempe 16y ago
      You seem to suggest a pessimistic and static view of human society. The planet is not static, climate isn't either; why would society and civilization be? is there a single, optimum equilibrium for humanity? what's the evidence?
      - ceejayoz 16y ago
        There's no single, optimum equilibrium, but a disaster that makes double-digit percentages of the planet refugees seems to fit squarely in the "sucky" end of the spectrum.
      - seabee 16y ago
        There is no single optimum, however there is value beyond merely surviving. Our quality of life is better than it was in the past, so why would anyone be happy at the prospect of that going down due to climate change?
        mkempe 16y ago
        True, it shouldn't be survival for its own sake. But do we really believe that our quality of life will be going down because of (some, warmer or glacial) climate change? how soon does that happen, and is humanity powerless to adapt? I have a very optimistic view of human potential, I think in essence and the long term all problems can be solved. Does the fact that CO2 levels have varied hugely in Geologic Time affirm that we are under imminent threat of terrible climate changes? is it irrelevant? or contradictory? or a puzzle? is it impolitick to ask such questions?
      - mkempe 16y ago
        How interesting that my honest questions are being down-voted. Edit: I want to be scientific, include all relevant evidence, and some people here dislike it? (I'm not interested in the politics -- I've never even voted in a national election. And yes, I see these down-votes as a form of political activism. Disagree and argue if you have reason and facts.)

mmphosis 16y ago

Look closely at the right edge of the picture. The text below the picture is revealing... Human deforestation and burning of fossil fuel has raised atmospheric CO2 to over 380 ppm in the last century, well above pre-industrialized levels, and "off the scale" of this graph top.

electromagnetic 16y ago
"Off the scale" is a complete fucking BS term. The carboniferous period had a mean CO2 concentration of around 800ppm and was marked by glaciation and low sea levels - our current correlation between CO2 and "global warming" is off the bullshit scale. The mean global temperature in the carboniferous period, with CO2 concentrations over double of present day was an astounding, just wait for it... 14C, which is the incredible, * unbelievable* 0C above the mean present day global temperature. As CO2 levels spiked in the carboniferous period, it is marked by the drop of sea levels by 120m to the present day level, and as the CO2 level subsided, the sea levels rose 80m. Sorry, but "off the scale" only counts when you actively pick and choose what scale you want to use, which in terms of geological temperature, CO2 and O2 concentrations quite literally means disregarding millions of years of geological time.
- deleted 16y ago
  [deleted]
- jselzer 16y ago
  I have not taken the time to verify your claims here, but don't you think it's fair to use "off the scale" when comparing this to any other time period during the modern human era? As other people have said, life on earth will go on in one form or another. But "off the scale" is a necessary term in this context to drive home the incredible turmoil and human suffering that will result as we are forced to adjust the local pressures of water shortages, mass human migration, and agricultural failures that will be caused by this...
- pvxc 16y ago
  Both CO2 concentrations and the global temperature varied significantly over that period of Earth's history (~400-250 millions of years ago). Around 300 Mya, CO2 was comparable to what it is today and temperatures were likewise comparable. Around 400 Mya, CO2 was in the 4000ppm's and the temperature was likewise higher (by ~ 8 C). No contradiction. Also, when discussing matters scientific, please cite your scientific sources --- otherwise the discussion is of little value. Like so: http://www.nature.com/nature/journal/v449/n7159/abs/nature06085.html http://www.nature.com/nature/journal/v449/n7159/abs/nature06... http://dx.doi.org/10.1130/1052-5173(2004)014<4:CAAPDO>2.0.CO;2 http://dx.doi.org/10.1130/1052-5173(2004)014<4:CAAPDO&#6...

M1573RMU74710N 16y ago

The fact that C02 levels have been higher is not necessarily in contradiction to the article, nor an important omission. This issue as other's have pointed out is the CAUSE of the current levels and the implications thereof. In the past the high levels of C02 were at least partially due to ice ages, which prevented the normal processes for the mitigation of C02, once the levels built up enough the greenhouse effect melted the ice and restored the levels. Look around, there's no ice age. So not only is there no discernible cause for the increase except out actions, we don't have a huge C02-eating army trapped in the ice waiting to be released. Some natural mechanism will probably step in, but who knows what effects it will have. We are monkeying with a system we know to have far reaching and potentially devastating effects.

alanh 16y ago
You repeatedly type cee-zero-two. It's the letter O, as CO₂ stands for (mono-)carbon dioxide, a gaseous molecule with one carbon and two oxygen molecules. I'm sure you know that, but hey, if you didn't, there you go.