5 ms·

Is climate change falsifiable?

HPMOR 3y ago
Yes because you could simulate a small-scale atmosphere, and notice how changing the composition of the "atmosphere" affects average temperature or other features. John Von Neumann actually predicted climate change from first principles and described it as potentially more debilitating than nuclear weapons. --Great essay. https://geosci.uchicago.edu/~kite/doc/von_Neumann_1955.pdf https://geosci.uchicago.edu/~kite/doc/von_Neumann_1955.pdf
- aeternum 3y ago
  Well that's more evidence for it, not an attempt to falsify. If we want to falsify, we should ask questions like: Was there a time in the past when the atmosphere contained even more CO2 than it did now? What was the temp and did life survive? What evidence or experiment would convince you the theory is false? Or is that impossible?
  - mr_mitm 3y ago
    Climate change is not a fundamental theory. It is derived from thermodynamics, the Navier Stokes equation, quantum mechanics and probably quite a few assumptions on what is negligible. Falsify any of those and you falsify climate change.
  - glenstein 3y ago
    >If we want to falsify, we should ask questions like: Was there a time in the past when the atmosphere contained even more CO2 than it did now? What was the temp and did life survive? Do you believe that question isn't already asked and answered? Just going off the top of my head, I understand historical considerations to be a routine observation as part of your typical course or even presentation on the history of climate change. If you believe this counts, then your answer to your own question about the falsifiability of climate change is yes. I also don't think that's the only kind of example - I think the routine things talked about on a day to day basis, including year by year and decade by decade temperature predictions would qualify, and these data are quite frequently discussed and quite visible. I also also don't think the distinction between "evidence in favor" and "attempts to falsify" makes a whole lot of sense. These are two different sides of the same coin, and evidence in favor of something is the same as surviving a test of falsifiability.
    - aeternum 3y ago
      I think most people do believe we are at a historically unprecedented level of CO2. Especially due to graphs like this: https://climate.nasa.gov/internal_resources/2679/CO2_graph.jpeg https://climate.nasa.gov/internal_resources/2679/CO2_graph.j... It's pretty disingenuous to cut the graph at the beginning of the ice age cycles. This tricks people into believing that the current level of CO2 has never been seen before. In contrast, this is a much more contextually accurate graph: https://today.tamu.edu/wp-content/uploads/2021/06/66millionYears-CO2_1200w.png https://today.tamu.edu/wp-content/uploads/2021/06/66millionY... ref: https://today.tamu.edu/2021/06/14/ancient-deepsea-shells-reveal-66-million-years-of-carbon-dioxide-levels/ https://today.tamu.edu/2021/06/14/ancient-deepsea-shells-rev... So I'd ask what parts of climate change are falsifiable? - Is the climate changing? Of course, but it has also been changing for all of earth's history. - Are humans and other organisms contributing? Yes but organisms have contributed to climate change for all of earth's history. Blue-green algae put oxygen into the atmosphere, plants sequestered huge amounts of carbon. - Are we at a historically unprecedented level of carbon? No, the earth was previous at something like 200x the atmospheric CO2. - Will 2x the atmospheric CO2 cause mass death? Probably not, we know life thrived in the past on a much warmer and more CO2 rich globe. Many more humans die of cold rather than heat.
mikem170 3y ago
Predictions have been made, and we can check if they were correct, but maybe not at the moment. Some past short-term predictions, like predictions for 2020 made in 1990, may or may not be correct. We can look those up. Many other predictions are for what will happen in the coming decades, and we won't be able to assess with certainty whether they were correct until those future dates.
roughly 3y ago
Depends on how valid you consider statistics and climate modelling. We're seeing increasing numbers of events that are incredibly statistically unlikely in a climate unaffected by anthropogenic climate change, so - can we say with absolute certainty that X was caused by climate change? That's hard. But we say that X was incredibly, unbelievably unlikely without climate change, and that's usually been a sufficient standard for accepting a hypothesis.
anon84873628 3y ago
Certainly. E.g., set up a model greenhouse system and show that increasing CO2 doesn't increase the temperature. Or demonstrate that convective phenomena aren't affected by changing temperature. "Climate change" comprises a causal chain of well studied and testable hypothesis. Including disproving alternate hypothesis like "solar radiation is increasing".
- aeternum 3y ago
  https://www.researchgate.net/publication/320123470_The_Relationship_between_Atmospheric_Carbon_Dioxide_Concentration_and_Global_Temperature_for_the_Last_425_Million_Years https://www.researchgate.net/publication/320123470_The_Relat... The problem is climate change has become a motte and bailey (https://en.wikipedia.org/wiki/Motte-and-bailey_fallacy https://en.wikipedia.org/wiki/Motte-and-bailey_fallacy). If we do come up with evidence that rising temps aren't all that correlated to CO2, then we just change the target to 'yeah but it causes ocean acidification' or 'natural disasters are increasing' or 'yeah but it kills coral reefs'. At this point, I'm not sure there is any possible experiment or evidence that would actually change most people's mind on climate change. It has become a cause to support rather than a theory.
  - duckmysick 3y ago
    If I understand this paper correctly, it compares the temperature and CO2 levels on geologic time scales: > Atmospheric CO2 concentration is correlated weakly but negatively with linearly-detrended T proxies over the last 425 million years. > To estimate the integrity of temperature-proxy data, δ^18O values were averaged into bins of 2.5 million years (My) It makes sense. Over long time scales, other factors are more important. Does the same apply to shorter time scales, like thousands, hundreds, or tens of years? > At this point, I'm not sure there is any possible experiment or evidence that would actually change most people's mind on climate change. One possible way would be to continue releasing the CO2 at the current or larger rates. If then temperatures and the climate reverse to the state from 200 or 300 years ago then it means it's part of a natural cycle and humans had nothing to do with it.
  - roflyear 3y ago
ianai 3y ago
Yes. The base test for how increased co2 impacts the environment stems from an experiment in the 1800s. https://www.climate.gov/news-features/features/happy-200th-birthday-eunice-foote-hidden-climate-science-pioneer https://www.climate.gov/news-features/features/happy-200th-b... And much science passed that.
croes 3y ago
Pretty easily. Do nothing and wait. But it could have severe consequences.
godelski 3y ago
Yes. Make predictions. Wait. Observe. Measure difference between predicted outcome and actual outcome. We've had scientists making predictions since the 80's, so we have some long term observations. I'll save you the read, historical models are fairly accurate and have become more accurate over time. I'm not sure why anyone considers this a debate. It's not a debate. It's willingness to look at data or not. https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected-global-warming/ https://www.carbonbrief.org/analysis-how-well-have-climate-m... https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL085378 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...

Yes because you could simulate a small-scale atmosphere, and notice how changing the composition of the "atmosphere" affects average temperature or other features. John Von Neumann actually predicted climate change from first principles and described it as potentially more debilitating than nuclear weapons. --Great essay. https://geosci.uchicago.edu/~kite/doc/von_Neumann_1955.pdf https://geosci.uchicago.edu/~kite/doc/von_Neumann_1955.pdf

aeternum 3y ago
Well that's more evidence for it, not an attempt to falsify. If we want to falsify, we should ask questions like: Was there a time in the past when the atmosphere contained even more CO2 than it did now? What was the temp and did life survive? What evidence or experiment would convince you the theory is false? Or is that impossible?
- mr_mitm 3y ago
  Climate change is not a fundamental theory. It is derived from thermodynamics, the Navier Stokes equation, quantum mechanics and probably quite a few assumptions on what is negligible. Falsify any of those and you falsify climate change.
- glenstein 3y ago
  >If we want to falsify, we should ask questions like: Was there a time in the past when the atmosphere contained even more CO2 than it did now? What was the temp and did life survive? Do you believe that question isn't already asked and answered? Just going off the top of my head, I understand historical considerations to be a routine observation as part of your typical course or even presentation on the history of climate change. If you believe this counts, then your answer to your own question about the falsifiability of climate change is yes. I also don't think that's the only kind of example - I think the routine things talked about on a day to day basis, including year by year and decade by decade temperature predictions would qualify, and these data are quite frequently discussed and quite visible. I also also don't think the distinction between "evidence in favor" and "attempts to falsify" makes a whole lot of sense. These are two different sides of the same coin, and evidence in favor of something is the same as surviving a test of falsifiability.
  - aeternum 3y ago
    I think most people do believe we are at a historically unprecedented level of CO2. Especially due to graphs like this: https://climate.nasa.gov/internal_resources/2679/CO2_graph.jpeg https://climate.nasa.gov/internal_resources/2679/CO2_graph.j... It's pretty disingenuous to cut the graph at the beginning of the ice age cycles. This tricks people into believing that the current level of CO2 has never been seen before. In contrast, this is a much more contextually accurate graph: https://today.tamu.edu/wp-content/uploads/2021/06/66millionYears-CO2_1200w.png https://today.tamu.edu/wp-content/uploads/2021/06/66millionY... ref: https://today.tamu.edu/2021/06/14/ancient-deepsea-shells-reveal-66-million-years-of-carbon-dioxide-levels/ https://today.tamu.edu/2021/06/14/ancient-deepsea-shells-rev... So I'd ask what parts of climate change are falsifiable? - Is the climate changing? Of course, but it has also been changing for all of earth's history. - Are humans and other organisms contributing? Yes but organisms have contributed to climate change for all of earth's history. Blue-green algae put oxygen into the atmosphere, plants sequestered huge amounts of carbon. - Are we at a historically unprecedented level of carbon? No, the earth was previous at something like 200x the atmospheric CO2. - Will 2x the atmospheric CO2 cause mass death? Probably not, we know life thrived in the past on a much warmer and more CO2 rich globe. Many more humans die of cold rather than heat.

mikem170 3y ago

Predictions have been made, and we can check if they were correct, but maybe not at the moment. Some past short-term predictions, like predictions for 2020 made in 1990, may or may not be correct. We can look those up. Many other predictions are for what will happen in the coming decades, and we won't be able to assess with certainty whether they were correct until those future dates.

roughly 3y ago

Depends on how valid you consider statistics and climate modelling. We're seeing increasing numbers of events that are incredibly statistically unlikely in a climate unaffected by anthropogenic climate change, so - can we say with absolute certainty that X was caused by climate change? That's hard. But we say that X was incredibly, unbelievably unlikely without climate change, and that's usually been a sufficient standard for accepting a hypothesis.

anon84873628 3y ago

Certainly. E.g., set up a model greenhouse system and show that increasing CO2 doesn't increase the temperature. Or demonstrate that convective phenomena aren't affected by changing temperature. "Climate change" comprises a causal chain of well studied and testable hypothesis. Including disproving alternate hypothesis like "solar radiation is increasing".

aeternum 3y ago
https://www.researchgate.net/publication/320123470_The_Relationship_between_Atmospheric_Carbon_Dioxide_Concentration_and_Global_Temperature_for_the_Last_425_Million_Years https://www.researchgate.net/publication/320123470_The_Relat... The problem is climate change has become a motte and bailey (https://en.wikipedia.org/wiki/Motte-and-bailey_fallacy https://en.wikipedia.org/wiki/Motte-and-bailey_fallacy). If we do come up with evidence that rising temps aren't all that correlated to CO2, then we just change the target to 'yeah but it causes ocean acidification' or 'natural disasters are increasing' or 'yeah but it kills coral reefs'. At this point, I'm not sure there is any possible experiment or evidence that would actually change most people's mind on climate change. It has become a cause to support rather than a theory.
- duckmysick 3y ago
  If I understand this paper correctly, it compares the temperature and CO2 levels on geologic time scales: > Atmospheric CO2 concentration is correlated weakly but negatively with linearly-detrended T proxies over the last 425 million years. > To estimate the integrity of temperature-proxy data, δ^18O values were averaged into bins of 2.5 million years (My) It makes sense. Over long time scales, other factors are more important. Does the same apply to shorter time scales, like thousands, hundreds, or tens of years? > At this point, I'm not sure there is any possible experiment or evidence that would actually change most people's mind on climate change. One possible way would be to continue releasing the CO2 at the current or larger rates. If then temperatures and the climate reverse to the state from 200 or 300 years ago then it means it's part of a natural cycle and humans had nothing to do with it.
- roflyear 3y ago

ianai 3y ago

Yes. The base test for how increased co2 impacts the environment stems from an experiment in the 1800s. https://www.climate.gov/news-features/features/happy-200th-birthday-eunice-foote-hidden-climate-science-pioneer https://www.climate.gov/news-features/features/happy-200th-b... And much science passed that.

croes 3y ago

Pretty easily. Do nothing and wait. But it could have severe consequences.

godelski 3y ago

Yes. Make predictions. Wait. Observe. Measure difference between predicted outcome and actual outcome. We've had scientists making predictions since the 80's, so we have some long term observations. I'll save you the read, historical models are fairly accurate and have become more accurate over time. I'm not sure why anyone considers this a debate. It's not a debate. It's willingness to look at data or not. https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected-global-warming/ https://www.carbonbrief.org/analysis-how-well-have-climate-m... https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL085378 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...