9 ms·

Flawed climate data

40 points by BearOfNH 17y ago

diego_moita 17y ago
This thing is really blown out of porportion now: http://www.time.com/time/specials/packages/article/0,28804,1929071_1929070,00.html http://www.time.com/time/specials/packages/article/0,28804,1... This "Climategate/Warmergate" thing is just another case of FUD, an invented scandal.
- presidentender 17y ago
  It's literally FUD (UD?), in that the skeptics are spreading uncertainty and doubt about the legitimacy of the models and the underlying data that the world leadership has accepted as gospel truth for the past decade. But it might be good FUD, because it might reopen intelligent discussion on a topic where debate has consisted of name-calling for just as long.
  - gloob 17y ago
    But it might be good FUD, because it might reopen intelligent discussion on a topic where debate has consisted of name-calling for just as long. My suspicion is that it will renew name-calling in a discussion that has consisted of name-calling for just as long, but then, I'm a cynic. Fingers crossed, though.
earle 17y ago
If Mars is heating up a the same rate as earth, they [martians] must have quite a complex underground freeway system to produce all that CO2 on Mars, which is obviously causing Marsian Warming...
- rjurney 17y ago
  They're called canals, sir. http://en.wikipedia.org/wiki/Martian_canal http://en.wikipedia.org/wiki/Martian_canal
- lukifer 17y ago
  How is it erroneous logic to infer human causation in global temperature rise, but not erroneous to infer a solar causation from a temperature correlation between Earth and Mars? In my mind, the question is not whether human activity affects climate, but how much. It seems absurdly naive to me to think that tens of billions of tons of CO2 combined with widespread deforestation will not have repercussions of any kind.
- thaumaturgy 17y ago
  The primary evidence for Martian warming is a comparison of two photographs, one taken in 1977 and one taken in 1999, in which the planet appears brighter in 1977 than in 1999. However, the cause of the albedo change was attributed to dust storms, not to a change in climate per se. Further, if there had been climactic change, there were only two datapoints to go on and a line drawn between them -- not exactly the kind of data that anyone on HN should choose to draw conclusions from. More recent photographs suggest that there may be climactic cycles in effect, however the data gathered so far is utterly insufficient to even begin to guess at the systems and behaviors involved in that other planet. One thing we do know is that Martian atmosphere is dramatically different from Earth's, and it doesn't make any more sense to draw conclusions about the one based on the other than it does to, say, conclude that Windows is subject to the same security vulnerabilities that Macs are.
rjurney 17y ago
How reliant are we overall on tree data to track temperature trends?
- thaumaturgy 17y ago
  Climate scientists rely on (at least, but not limited to) oceanic temperature measurements, satellite measurements, and worldwide ground temperature measurements for current data modeling. Historical data sources include ice cores, tree ring data, geological data (e.g. evidence of past glacial activity), and coral analysis. To some extent, human sources can also be used for historical data -- journals and old weather station logs -- however, I think those are generally considered to be examples of local weather events rather than climate data.
  - rjurney 17y ago
    And what do the other data sources say about temperature in comparison to the tree data?
    - thaumaturgy 17y ago
      I'm glad you asked! The first thing we have to acknowledge is that paleoclimatology yields century-term trends; it's not able to tell us the precise local temperatures of a given day 500 years ago, for example. So what climate scientists do is establish "ranges of uncertainty"; their graphs and data show that, given the raw data, the reconstructed temperature was somewhere between Y1 and Y2 for a particular hundred-year period. After comparing the reconstructions, going as far back as a.d. 1000, scientists are finding that every source of paleoclimatic data that they can come up with is showing that current temperatures are well above historical temperatures, even after taking the uncertainty into account. That is, this century is the warmest global century since a.d. 1000, even if all of the paleoclimatic data were interpreted as warmly as possible. They don't agree precisely in the shape of the graph -- glacial studies show a slightly different-shaped graph than borehole studies do, for example -- but the aggregate graphs do all agree on a warming trend over the last century. However, in geological terms, a warming trend over a thousand-year period is not that big of an indicator. So what happens if we go back further? There is a paper [1] which uses data from several other studies to reconstruct temperature deviations at 20 different global locations over a 2000-year period. It argues that the statistical methods used in other paleoclimate models are flawed, and uses a different statistical method which concludes that, in the absence of tree ring data, the Medieval Warm Period (approx. 950 a.d. to 1250 a.d.) was warmer than the current century. I don't have the necessary background in statistics to be able to analyze the two different methods. However, even if we take that paper at face value, 2000-year data is still not geologically significant. So, we turn to Antarctic ice cores. Specifically, data from the Vostok ice core sample shows a clear 150,000 year warming and cooling cycle, going back about 400,000 years ago (with increasing uncertainty). At first glance, someone might think that this is damning evidence in the case for AGW. However, the recent thousand year period is a mere blip on a graph stretching back 400,000 years, so it's difficult to see the part that has climate scientists really concerned: The amount of CO2 currently in the atmosphere, and reconstructed over the last thousand years, is dramatically greater than at any other point in the last 400,000 years. Specifically, CO2 concentrations have peaked at around 300 ppmv during the 150,000 year cycle, but are currently at around 383 ppmv. To put this in perspective, the difference between the amount of CO2 in the atmosphere now, versus the amount in the peaks of the last 400,000 years, is close to the same as the difference between the peaks and the troughs. So while the Earth clearly does have its own warming and cooling cycle, we have induced a dramatic change in the cycle, which should lead to some interesting results. (Further reading: "Surface Temperature Reconstructions for the Last 2,000 Years", free download at http://www.nap.edu/catalog.php?record_id=11676 http://www.nap.edu/catalog.php?record_id=11676) [1]: http://www.ncasi.org/publications/Detail.aspx?id=3025 http://www.ncasi.org/publications/Detail.aspx?id=3025
ghosttrails 17y ago
Surely the flabbergasting thing is not whether this proves or disproves GW but that scientists are allowed to flat-out refuse to release the raw data they used to generate results.
- rjurney 17y ago
  Public funding should require full disclosure of all data as well as the paper generated by the research.
  - mechanical_fish 17y ago
    I believe in the free availability of all publicly-funded research papers. And I'd be prepared to argue for the free availability of raw data as well, if we lived in a world where it wouldn't be cherry-picked by axe-grinders and used for character assassination. I don't think we live in that world. Maybe someday.
    - deleted 17y ago
      [deleted]
    - thaumaturgy 17y ago
      I'm with you. I really really wanted to read (for example) "An observationally based energy balance for the Earth since 1950". However, all of the references to it that I can find are stuck behind paywalls, despite the paper having been authored primarily by NOAA scientists. I fully support spending tax dollars on scientific research. That said, I think that the results of this particular bit of research have already been paid for. I'm considering paying the nine bucks and putting it up for download. Any takers?
      - grandalf 17y ago
        I'd download it. I think the idea of a "napster of academic research" is a great idea, fwiw :)
patrickgzill 17y ago
There is one part that sticks in my craw, that is, the part about the correction applied for post-1960 tree ring data. It smacks of corporate / bureaucratic mindset that there was (apparently) so little effort to find out why the tree ring data diverged after 1960. Wouldn't a scientist be fascinated by the question of why this divergence was occurring-instead of just accepting it happened? Example: Feynman wondered if he could describe in mathematical terms the way that a spinning plate would wobble. He took it as a challenge to himself as a physicist to determine this, despite it not appearing to have any practical application. These calculations later led to his work on electron spin. THAT is the level of curiosity I would expect from people at a top flight research institution. Or am I wrong, and there was a lot of research to determine the tree ring divergence?
- TeHCrAzY 17y ago
  I beleive that, even as the idealistic "curious scientist", one would have priorities. Perhaps it wasn't interesting enough compared to the myriad of other things one could be working on.
guelo 17y ago
This McKitrick guy is like a cockroach that keeps poping back up. Not only are there TONS of datasources besides the tree ring proxies that he is so obsessed with (http://www.realclimate.org/index.php/data-sources/ http://www.realclimate.org/index.php/data-sources/), his specific claims have been rejected many times including by peer reviewed sources such as Nature. http://www.realclimate.org/index.php/archives/2004/12/myths-vs-fact-regarding-the-hockey-stick/ http://www.realclimate.org/index.php/archives/2004/12/myths-... http://www.realclimate.org/index.php/archives/2004/12/false-claims-by-mcintyre-and-mckitrick-regarding-the-mann-et-al-1998reconstruction/ http://www.realclimate.org/index.php/archives/2004/12/false-... http://www.google.com/url?sa=t&source=web&ct=res&cd=3&ved=0CA4QFjAC&url=http%3A%2F%2Fwww.realclimate.org%2Findex.php%3Fp%3D98lp_lang_view%3Dfr&ei=QTYXS_myJpGIsgOulPGcDg&usg=AFQjCNHWtWJ8gNZzvxIPmHlKmccI0qThsw&sig2=k27aZwbMFh_k7xHuBz9dxw http://www.google.com/url?sa=t&source=web&ct=res&#38...
- anamax 17y ago
  The released e-mail reveal that the peer-review process was hacked. And, since that e-mail also shows that realclimate is one of the participants in the supression of contrary views from the beginning, citing it as evidence now is ....
  - guelo 17y ago
    Ok this is preposterous. If the entire peer-review process was "hacked" we can't trust any climate science? I guess all that science must be thrown away with the coal companies' refuse water.
    - anamax 17y ago
      > If the entire peer-review process was "hacked" we can't trust any climate science? Pretty much. We don't know how the data was adjusted and the original data seems to be unavailable. Given that, what's to trust? Maybe they're right, maybe they're wrong, but without data.... There is other data, from folks that disagree with the CRU folks....
codahale 17y ago
Ah yes, The Financial Post. The newspaper I turn to for all of my climatological analysis. It's like International Journal of Climatology, but with better op-eds and stock listings.

40 points by BearOfNH 17y ago

This thing is really blown out of porportion now: http://www.time.com/time/specials/packages/article/0,28804,1929071_1929070,00.html http://www.time.com/time/specials/packages/article/0,28804,1... This "Climategate/Warmergate" thing is just another case of FUD, an invented scandal.

presidentender 17y ago
It's literally FUD (UD?), in that the skeptics are spreading uncertainty and doubt about the legitimacy of the models and the underlying data that the world leadership has accepted as gospel truth for the past decade. But it might be good FUD, because it might reopen intelligent discussion on a topic where debate has consisted of name-calling for just as long.
- gloob 17y ago
  But it might be good FUD, because it might reopen intelligent discussion on a topic where debate has consisted of name-calling for just as long. My suspicion is that it will renew name-calling in a discussion that has consisted of name-calling for just as long, but then, I'm a cynic. Fingers crossed, though.

earle 17y ago

If Mars is heating up a the same rate as earth, they [martians] must have quite a complex underground freeway system to produce all that CO2 on Mars, which is obviously causing Marsian Warming...

rjurney 17y ago
They're called canals, sir. http://en.wikipedia.org/wiki/Martian_canal http://en.wikipedia.org/wiki/Martian_canal
lukifer 17y ago
How is it erroneous logic to infer human causation in global temperature rise, but not erroneous to infer a solar causation from a temperature correlation between Earth and Mars? In my mind, the question is not whether human activity affects climate, but how much. It seems absurdly naive to me to think that tens of billions of tons of CO2 combined with widespread deforestation will not have repercussions of any kind.
thaumaturgy 17y ago
The primary evidence for Martian warming is a comparison of two photographs, one taken in 1977 and one taken in 1999, in which the planet appears brighter in 1977 than in 1999. However, the cause of the albedo change was attributed to dust storms, not to a change in climate per se. Further, if there had been climactic change, there were only two datapoints to go on and a line drawn between them -- not exactly the kind of data that anyone on HN should choose to draw conclusions from. More recent photographs suggest that there may be climactic cycles in effect, however the data gathered so far is utterly insufficient to even begin to guess at the systems and behaviors involved in that other planet. One thing we do know is that Martian atmosphere is dramatically different from Earth's, and it doesn't make any more sense to draw conclusions about the one based on the other than it does to, say, conclude that Windows is subject to the same security vulnerabilities that Macs are.

rjurney 17y ago

How reliant are we overall on tree data to track temperature trends?

thaumaturgy 17y ago
Climate scientists rely on (at least, but not limited to) oceanic temperature measurements, satellite measurements, and worldwide ground temperature measurements for current data modeling. Historical data sources include ice cores, tree ring data, geological data (e.g. evidence of past glacial activity), and coral analysis. To some extent, human sources can also be used for historical data -- journals and old weather station logs -- however, I think those are generally considered to be examples of local weather events rather than climate data.
- rjurney 17y ago
  And what do the other data sources say about temperature in comparison to the tree data?
  - thaumaturgy 17y ago
    I'm glad you asked! The first thing we have to acknowledge is that paleoclimatology yields century-term trends; it's not able to tell us the precise local temperatures of a given day 500 years ago, for example. So what climate scientists do is establish "ranges of uncertainty"; their graphs and data show that, given the raw data, the reconstructed temperature was somewhere between Y1 and Y2 for a particular hundred-year period. After comparing the reconstructions, going as far back as a.d. 1000, scientists are finding that every source of paleoclimatic data that they can come up with is showing that current temperatures are well above historical temperatures, even after taking the uncertainty into account. That is, this century is the warmest global century since a.d. 1000, even if all of the paleoclimatic data were interpreted as warmly as possible. They don't agree precisely in the shape of the graph -- glacial studies show a slightly different-shaped graph than borehole studies do, for example -- but the aggregate graphs do all agree on a warming trend over the last century. However, in geological terms, a warming trend over a thousand-year period is not that big of an indicator. So what happens if we go back further? There is a paper [1] which uses data from several other studies to reconstruct temperature deviations at 20 different global locations over a 2000-year period. It argues that the statistical methods used in other paleoclimate models are flawed, and uses a different statistical method which concludes that, in the absence of tree ring data, the Medieval Warm Period (approx. 950 a.d. to 1250 a.d.) was warmer than the current century. I don't have the necessary background in statistics to be able to analyze the two different methods. However, even if we take that paper at face value, 2000-year data is still not geologically significant. So, we turn to Antarctic ice cores. Specifically, data from the Vostok ice core sample shows a clear 150,000 year warming and cooling cycle, going back about 400,000 years ago (with increasing uncertainty). At first glance, someone might think that this is damning evidence in the case for AGW. However, the recent thousand year period is a mere blip on a graph stretching back 400,000 years, so it's difficult to see the part that has climate scientists really concerned: The amount of CO2 currently in the atmosphere, and reconstructed over the last thousand years, is dramatically greater than at any other point in the last 400,000 years. Specifically, CO2 concentrations have peaked at around 300 ppmv during the 150,000 year cycle, but are currently at around 383 ppmv. To put this in perspective, the difference between the amount of CO2 in the atmosphere now, versus the amount in the peaks of the last 400,000 years, is close to the same as the difference between the peaks and the troughs. So while the Earth clearly does have its own warming and cooling cycle, we have induced a dramatic change in the cycle, which should lead to some interesting results. (Further reading: "Surface Temperature Reconstructions for the Last 2,000 Years", free download at http://www.nap.edu/catalog.php?record_id=11676 http://www.nap.edu/catalog.php?record_id=11676) [1]: http://www.ncasi.org/publications/Detail.aspx?id=3025 http://www.ncasi.org/publications/Detail.aspx?id=3025

ghosttrails 17y ago

Surely the flabbergasting thing is not whether this proves or disproves GW but that scientists are allowed to flat-out refuse to release the raw data they used to generate results.

rjurney 17y ago
Public funding should require full disclosure of all data as well as the paper generated by the research.
- mechanical_fish 17y ago
  I believe in the free availability of all publicly-funded research papers. And I'd be prepared to argue for the free availability of raw data as well, if we lived in a world where it wouldn't be cherry-picked by axe-grinders and used for character assassination. I don't think we live in that world. Maybe someday.
  - deleted 17y ago
    [deleted]
  - thaumaturgy 17y ago
    I'm with you. I really really wanted to read (for example) "An observationally based energy balance for the Earth since 1950". However, all of the references to it that I can find are stuck behind paywalls, despite the paper having been authored primarily by NOAA scientists. I fully support spending tax dollars on scientific research. That said, I think that the results of this particular bit of research have already been paid for. I'm considering paying the nine bucks and putting it up for download. Any takers?
    - grandalf 17y ago
      I'd download it. I think the idea of a "napster of academic research" is a great idea, fwiw :)

patrickgzill 17y ago

There is one part that sticks in my craw, that is, the part about the correction applied for post-1960 tree ring data. It smacks of corporate / bureaucratic mindset that there was (apparently) so little effort to find out why the tree ring data diverged after 1960. Wouldn't a scientist be fascinated by the question of why this divergence was occurring-instead of just accepting it happened? Example: Feynman wondered if he could describe in mathematical terms the way that a spinning plate would wobble. He took it as a challenge to himself as a physicist to determine this, despite it not appearing to have any practical application. These calculations later led to his work on electron spin. THAT is the level of curiosity I would expect from people at a top flight research institution. Or am I wrong, and there was a lot of research to determine the tree ring divergence?

TeHCrAzY 17y ago
I beleive that, even as the idealistic "curious scientist", one would have priorities. Perhaps it wasn't interesting enough compared to the myriad of other things one could be working on.

guelo 17y ago

This McKitrick guy is like a cockroach that keeps poping back up. Not only are there TONS of datasources besides the tree ring proxies that he is so obsessed with (http://www.realclimate.org/index.php/data-sources/ http://www.realclimate.org/index.php/data-sources/), his specific claims have been rejected many times including by peer reviewed sources such as Nature. http://www.realclimate.org/index.php/archives/2004/12/myths-vs-fact-regarding-the-hockey-stick/ http://www.realclimate.org/index.php/archives/2004/12/myths-... http://www.realclimate.org/index.php/archives/2004/12/false-claims-by-mcintyre-and-mckitrick-regarding-the-mann-et-al-1998reconstruction/ http://www.realclimate.org/index.php/archives/2004/12/false-... http://www.google.com/url?sa=t&source=web&ct=res&cd=3&ved=0CA4QFjAC&url=http%3A%2F%2Fwww.realclimate.org%2Findex.php%3Fp%3D98lp_lang_view%3Dfr&ei=QTYXS_myJpGIsgOulPGcDg&usg=AFQjCNHWtWJ8gNZzvxIPmHlKmccI0qThsw&sig2=k27aZwbMFh_k7xHuBz9dxw http://www.google.com/url?sa=t&source=web&ct=res&#38...

anamax 17y ago
The released e-mail reveal that the peer-review process was hacked. And, since that e-mail also shows that realclimate is one of the participants in the supression of contrary views from the beginning, citing it as evidence now is ....
- guelo 17y ago
  Ok this is preposterous. If the entire peer-review process was "hacked" we can't trust any climate science? I guess all that science must be thrown away with the coal companies' refuse water.
  - anamax 17y ago
    > If the entire peer-review process was "hacked" we can't trust any climate science? Pretty much. We don't know how the data was adjusted and the original data seems to be unavailable. Given that, what's to trust? Maybe they're right, maybe they're wrong, but without data.... There is other data, from folks that disagree with the CRU folks....

codahale 17y ago

Ah yes, The Financial Post. The newspaper I turn to for all of my climatological analysis. It's like International Journal of Climatology, but with better op-eds and stock listings.