5 ms·

In climate 130 years is not a long time. I wish these articles showed graphs with historical data that go back thousands of years so that I could see how, in a

by nixy 11y ago

In climate 130 years is not a long time. I wish these articles showed graphs with historical data that go back thousands of years so that I could see how, in a historical context, greenhouse emissions are affecting the world. I've only ever seen data from the 1900's, and it looks pretty hockey stick, but would be interesting to see fluctuations with the ice age(s) and local highs included. Edit: historical data is of course not available, but approximations must exist?

flavor8 11y ago
http://www.epa.gov/climatechange/science/indicators/ghg/ghg-concentrations.html http://www.epa.gov/climatechange/science/indicators/ghg/ghg-... http://www.geocraft.com/WVFossils/last_400k_yrs.html http://www.geocraft.com/WVFossils/last_400k_yrs.html http://www.sciencemag.org/content/339/6124/1198.abstract http://www.sciencemag.org/content/339/6124/1198.abstract
- deleted 11y ago
  [deleted]
  - merpnderp 11y ago
    That's the human contribution to atmospheric CO2 compared to geological time scales.
    - fexl 11y ago
      Sorry I deleted my comment out from under your feet. He was responding to my exclamation about the large spike upward in CO2 levels on that first graph on the EPA site. After posting it, I deleted it because I answered my own question.
- fexl 11y ago
  Are there any data on water vapor concentrations? I ask that because I have read that the contribution of water vapor to the greenhouse effect is perhaps two to four times greater than CO2.
  - dnautics 11y ago
    Not only that, all greenhouse models require a 'water feedback loop'. Of course there are plenty of anthropogenic water emissions to go about. When you irrigate, you are effectively throwing water into the air - by increasing the surface area of water evaporation through plant transpiration networks. I have never seen anyone talk about this alternative hypothesis. A disclaimer - I am all for reducing CO2 emissions strictly on principle (this is not dependent on the effects of CO2) and have put my money behind my beliefs - I have driven hybrid vehicles to support technology towards that end since 2003. But in my judgement as a scientist in general (and to some degree as a chemist who has done advanced spectroscopy including IR spectroscopy) I am losing confidence in climatology.
    - hackuser 11y ago
      I'm pretty sure your concerns have been addressed. Is it reasonable to 'lose confidence' because you haven't read the research?
      - dnautics 11y ago
        pray tell, enumerate my concerns and show me how they've been addressed. Is it reasonable to assume they've been addressed just 'because scientists'?
        deleted 11y ago
        [deleted]
    - chris_va 11y ago
      It's a reasonable question. While I am not a climatologist... Anthropogenic evaporation is probably minuscule next to deviations in natural evaporation due to small changes in temperature. A single hurricane, for example, dumps more power (as heat) than all human power generation. Also, unlike CO2, I would also guess that atmospheric water probably reaches equilibrium much faster (half life ~1 year instead of ~30 years).
fexl 11y ago
http://www.ncdc.noaa.gov/paleo/globalwarming/temperature-change.html http://www.ncdc.noaa.gov/paleo/globalwarming/temperature-cha... There you can see a strong correlation between CO2 levels and temperature going back nearly half a million years. Teasing out cause and effect is the interesting task.
- dnautics 11y ago
  yeah, that correlation is totally the wrong way; the blue curve leads the red curve. Now, Look at the key: Temperature change (blue) and carbon dioxide change (red)
  - fexl 11y ago
    Yes I understand that effect, and it makes sense that higher temperatures might cause more CO2 to come out of solution, as in a bottle of soda going flat more quickly at room temperature than in the refrigerator. That said, I am not certain that the recent dramatic spike to 400 ppm of CO2 (from what I've read) could be entirely caused by the fairly moderate temperature rises measured in recent years.
_petronius 11y ago
I think in the context of convincing people that we urgently need to address the current climate problem (for economic, ecological, and security reasons), that might be distracting. Assuming there are probably other interglacial periods in Earth's long history that were a lot warmer than the current one[0], or maybe had lots more greenhouse gasses from some non-human source (if such a thing is geologically possible), that doesn't make the implications of global temperature rise on current human society any less disastrous, or absolve the fact that the current warming period is from gasses released by burning fossil fuels. The fact is, that the Earth has had worse ecological disasters than the human species (although not many, and most of them were caused by big asteroid impacts[1]). So I'm less afraid of how this stacks up against the entire climatalogical history of the planet than I am of armed conflicts breaking out over water rights, or the loss of huge swaths of agricultural land. [0]: And it looks like there are: https://en.wikipedia.org/wiki/Interglacial https://en.wikipedia.org/wiki/Interglacial [1]: https://en.wikipedia.org/wiki/Extinction_event#Major_extinction_events https://en.wikipedia.org/wiki/Extinction_event#Major_extinct...
- andyjohnson0 11y ago
  "...the Earth has had worse ecological disasters than the human species..." True, but they were a long time ago and the human species wasn't around to experience them. The rate of change of present warming, and its likely effects, are going to cause very severe difficulties for our (and many other) species.
  - fexl 11y ago
    Likely yes, but please be careful that the remedies do not cause more severe difficulties than the problem itself.
    - primroot 11y ago
      Implicit in this remark is the idea that all humans share roughly the same interests and concerns. As difficult conditions exacerbate conflicts the weight of interests is measured first in capital and then in violent prowess. http://www.ft.com/cms/s/0/bc2016e2-d320-11e4-9b0a-00144feab7de.html#axzz3dzguJ9wf http://www.ft.com/cms/s/0/bc2016e2-d320-11e4-9b0a-00144feab7...

by nixy 11y ago

flavor8 11y ago

http://www.epa.gov/climatechange/science/indicators/ghg/ghg-concentrations.html http://www.epa.gov/climatechange/science/indicators/ghg/ghg-... http://www.geocraft.com/WVFossils/last_400k_yrs.html http://www.geocraft.com/WVFossils/last_400k_yrs.html http://www.sciencemag.org/content/339/6124/1198.abstract http://www.sciencemag.org/content/339/6124/1198.abstract

deleted 11y ago
[deleted]
- merpnderp 11y ago
  That's the human contribution to atmospheric CO2 compared to geological time scales.
  - fexl 11y ago
    Sorry I deleted my comment out from under your feet. He was responding to my exclamation about the large spike upward in CO2 levels on that first graph on the EPA site. After posting it, I deleted it because I answered my own question.
fexl 11y ago
Are there any data on water vapor concentrations? I ask that because I have read that the contribution of water vapor to the greenhouse effect is perhaps two to four times greater than CO2.
- dnautics 11y ago
  Not only that, all greenhouse models require a 'water feedback loop'. Of course there are plenty of anthropogenic water emissions to go about. When you irrigate, you are effectively throwing water into the air - by increasing the surface area of water evaporation through plant transpiration networks. I have never seen anyone talk about this alternative hypothesis. A disclaimer - I am all for reducing CO2 emissions strictly on principle (this is not dependent on the effects of CO2) and have put my money behind my beliefs - I have driven hybrid vehicles to support technology towards that end since 2003. But in my judgement as a scientist in general (and to some degree as a chemist who has done advanced spectroscopy including IR spectroscopy) I am losing confidence in climatology.
  - hackuser 11y ago
    I'm pretty sure your concerns have been addressed. Is it reasonable to 'lose confidence' because you haven't read the research?
    - dnautics 11y ago
      pray tell, enumerate my concerns and show me how they've been addressed. Is it reasonable to assume they've been addressed just 'because scientists'?
      - deleted 11y ago
        [deleted]
  - chris_va 11y ago
    It's a reasonable question. While I am not a climatologist... Anthropogenic evaporation is probably minuscule next to deviations in natural evaporation due to small changes in temperature. A single hurricane, for example, dumps more power (as heat) than all human power generation. Also, unlike CO2, I would also guess that atmospheric water probably reaches equilibrium much faster (half life ~1 year instead of ~30 years).

fexl 11y ago

http://www.ncdc.noaa.gov/paleo/globalwarming/temperature-change.html http://www.ncdc.noaa.gov/paleo/globalwarming/temperature-cha... There you can see a strong correlation between CO2 levels and temperature going back nearly half a million years. Teasing out cause and effect is the interesting task.

dnautics 11y ago
yeah, that correlation is totally the wrong way; the blue curve leads the red curve. Now, Look at the key: Temperature change (blue) and carbon dioxide change (red)
- fexl 11y ago
  Yes I understand that effect, and it makes sense that higher temperatures might cause more CO2 to come out of solution, as in a bottle of soda going flat more quickly at room temperature than in the refrigerator. That said, I am not certain that the recent dramatic spike to 400 ppm of CO2 (from what I've read) could be entirely caused by the fairly moderate temperature rises measured in recent years.

_petronius 11y ago

I think in the context of convincing people that we urgently need to address the current climate problem (for economic, ecological, and security reasons), that might be distracting. Assuming there are probably other interglacial periods in Earth's long history that were a lot warmer than the current one[0], or maybe had lots more greenhouse gasses from some non-human source (if such a thing is geologically possible), that doesn't make the implications of global temperature rise on current human society any less disastrous, or absolve the fact that the current warming period is from gasses released by burning fossil fuels. The fact is, that the Earth has had worse ecological disasters than the human species (although not many, and most of them were caused by big asteroid impacts[1]). So I'm less afraid of how this stacks up against the entire climatalogical history of the planet than I am of armed conflicts breaking out over water rights, or the loss of huge swaths of agricultural land. [0]: And it looks like there are: https://en.wikipedia.org/wiki/Interglacial https://en.wikipedia.org/wiki/Interglacial [1]: https://en.wikipedia.org/wiki/Extinction_event#Major_extinction_events https://en.wikipedia.org/wiki/Extinction_event#Major_extinct...

andyjohnson0 11y ago
"...the Earth has had worse ecological disasters than the human species..." True, but they were a long time ago and the human species wasn't around to experience them. The rate of change of present warming, and its likely effects, are going to cause very severe difficulties for our (and many other) species.
- fexl 11y ago
  Likely yes, but please be careful that the remedies do not cause more severe difficulties than the problem itself.
  - primroot 11y ago
    Implicit in this remark is the idea that all humans share roughly the same interests and concerns. As difficult conditions exacerbate conflicts the weight of interests is measured first in capital and then in violent prowess. http://www.ft.com/cms/s/0/bc2016e2-d320-11e4-9b0a-00144feab7de.html#axzz3dzguJ9wf http://www.ft.com/cms/s/0/bc2016e2-d320-11e4-9b0a-00144feab7...