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I hear this a lot and feel like it is a muddled response to a muddled understanding of climate change. For what it is worth: * Science is clear that CO2 c

by gwright 10y ago

I hear this a lot and feel like it is a muddled response to a muddled understanding of climate change. For what it is worth: * Science is clear that CO2 causes warming (pure physics), but so do many other gases (methane, water vapor, etc). * Science is clear that global temperatures are rising (even if you quibble about the 'pause') * Science isn't clear regarding what part of global temperature rise is due to human activity. * Science isn't clear on how much and how fast temperatures might rise. * Science isn't clear on how to model the climate. Climate models have incorporated a net positive sensitivity to CO2 warming and make predictions that have exceeded actual temperature gains. So the models are not accurately predicting the climate. * Science isn't going to provide a definitive policy response to increased temperatures. There are many options. In particular, the warming due to CO2 physics is NOT the catastrophic warming that we see reported in the news. That warming is based on climate models incorporating a large positive sensitivity to the CO2 warming (as well as many other factors). The models are not "settled science". The actual sensitivity is not something that can be measured with today's scientific understanding of complex climate systems. Even if the climate models were making correct predictions. It doesn't automatically follow that the policy solution is to reduce CO2 emissions to 0. The costs of clean energy have to be borne by someone and cutting off energy supplies (because energy is more expensive) to developing economies, for example, also has consequences. The negative affects of warming can be mitigated also via relocating people, communities, and changing our land-use patterns, etc. The correct policy mix is going to depend on many factors, most of which are going to vary from place to place. A single global policy proscription isn't likely to be feasible for lots of reasons. Finally, criticism of policy proscriptions shouldn't automatically be interpreted and characterized as rejecting the climate change hypothesis. In many cases there are argument for or against policy proscriptions that aren't even related to climate change, such as improving air quality, increasing the efficiency of our energy systems, using market based approaches to avoid crony capitalism and favored industries, and so on.

jwatte 10y ago
* Science isn't clear regarding what part of global temperature rise is due to human activity. * Science isn't clear on how much and how fast temperatures might rise. I believe science does have confidence intervals on the ranges, and even the lower ends are pretty bad. As in, it's not a question on "whether" the global food supply pipeline will collapse, but "when" -- 2035 to 2070, depending on the side of the confidence interval you pick. * It doesn't automatically follow that the policy solution is to reduce CO2 emissions to 0. Nobody is arguing for reducing CO2 emissions to 0. Most of the majority arguments are actually quite tame -- leading to a reduction of profits in coal and oil industries, not a wholesale dissolution. Yet, even that, is seen as an unacceptable cost of increasing the chances of civilization survival by the right-wing party of the United States.
- gwright 10y ago
  It isn't clear to me what a confidence interval is for a prediction from a complex climate model. What are the sources of error for a software model? How can they be quantified? In any case, my understanding is that global warming increases that are at the low end of predictions is not catastrophic and that is actually where measured changes fall. Here is a report from the NOAA that says: > The “pause” in global warming observed since 2000 followed a period of rapid acceleration in the late 20th century. Starting in the mid-1970s, global temperatures rose 0.5 °C over a period of 25 years. Since the turn of the century, however, the change in Earth’s global mean surface temperature has been close to zero. https://www.climate.gov/news-features/climate-qa/why-did-earth’s-surface-temperature-stop-rising-past-decade https://www.climate.gov/news-features/climate-qa/why-did-ear... That report is interesting because it argues against the pause indicating a true slowdown in global warming because the period of time is too short, that climate change works on much longer intervals. Perhaps that is true, and the 15 year pause is temporary. Time will tell.
splawn 10y ago
While this response seems 100% reasonable, I don't see how this it is any more effective in the face of "Climate change is a Chinese hoax" level absurdity. At this point with deniers it is religion so reason is out the door regardless.
- btdiehr 10y ago
  You are misrepresenting the opposing argument being made. The opposing argument is that people are making is as follows: 'climate-alarmists' misuse climate-science as a means of making political change. It is not a denial of all climate-change science. I don't care to argue this topic because I'm not expert nor do I care to pretend to be one on the topic of climate change, but this misrepresentation of the opposing views is part of the liberal-bubble so many people live in - all while smugly assuring themselves how much smarter they are than everyone else.
  - burkaman 10y ago
    Are you unaware of the hundreds of times Trump has literally claimed all climate change science is a hoax, or are you saying his view is unimportant?
    - gwright 10y ago
      Trump and many other people don't seem to clearly understand the difference between the 'settled science' part of climate change and the 'unclear science' part. As such Trump and many others have very muddled and confused responses to those advocating various public policy changes due to climate change. Some clarity about what is and isn't 'settled' would certainly improve the public debate on policy but I'm not holding my breath.
      - burkaman 10y ago
        I disagree, what has Trump been unclear about? He doesn't think humans cause climate change, but he also doesn't think the planet is getting warmer. He doesn't even seem to think that CFCs are a real problem. He wants to cut the EPA. He thinks asbestos regulations are pointless. Trump has been clear and consistent for decades on this stuff, which I'm not sure you can say about any other belief of his. A new clarifying statement from the IPCC would not suddenly clear everything up for him.
thefastlane 10y ago
i would love to dive into this further (both the science itself, and how we cross the bridge from science to policy), can you recommend any resources or papers (DOI if possible)?
alecst 10y ago
Can you elaborate on this part? * Science isn't clear regarding what part of global temperature rise is due to human activity. I just want to contrast the above with this statement by the IPCC [1]: "Human influence has been detected and attributed in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, and in global mean sea level rise; and has been extremely likely been the dominant cause of the observed warming since the mid century. In recent decades, changes in climate have caused impacts on natural and human systems on all continents and across the oceans." [1] https://www.ipcc.ch/pdf/assessment-report/ar5/syr/drafts/SYR_FOD_Final.pdf https://www.ipcc.ch/pdf/assessment-report/ar5/syr/drafts/SYR...
- nonbel 10y ago
  >"[human activity] has been extremely likely been the dominant cause of the observed warming since the mid century." This is worded strangely so that it doesn't mean anything. Of course human activity has been the dominant cause of humans observing something. Why don't they say CO2 emitted by human-made machines or something more specific?
  - alecst 10y ago
    That reply doesn't address my original comment, but the IPCC do say just that -- although not in that paragraph. You will find statements all over the IPCC about how climate change is nearly certain to be caused by people, and in particular, by people burning fossil fuels. If you go to the link I posted and search for "fossil" you will that in those notes. You can also read the official IPCC reports yourself to get a clearer idea. Maybe I'm misunderstanding you, but there's no anthropic principle at work. It would be perfectly fine to say (although it would not be true) that "plasma fluctuations on the surface of the sun are extremely likely to be the dominant cause of observed warming since the mid century."
    - nonbel 10y ago
      I was just commenting on the strange word choice used for that statement. Almost like whoever was editing that section wanted a way to weasel out of the implications later, if need be.

by gwright 10y ago

jwatte 10y ago

* Science isn't clear regarding what part of global temperature rise is due to human activity. * Science isn't clear on how much and how fast temperatures might rise. I believe science does have confidence intervals on the ranges, and even the lower ends are pretty bad. As in, it's not a question on "whether" the global food supply pipeline will collapse, but "when" -- 2035 to 2070, depending on the side of the confidence interval you pick. * It doesn't automatically follow that the policy solution is to reduce CO2 emissions to 0. Nobody is arguing for reducing CO2 emissions to 0. Most of the majority arguments are actually quite tame -- leading to a reduction of profits in coal and oil industries, not a wholesale dissolution. Yet, even that, is seen as an unacceptable cost of increasing the chances of civilization survival by the right-wing party of the United States.

gwright 10y ago
It isn't clear to me what a confidence interval is for a prediction from a complex climate model. What are the sources of error for a software model? How can they be quantified? In any case, my understanding is that global warming increases that are at the low end of predictions is not catastrophic and that is actually where measured changes fall. Here is a report from the NOAA that says: > The “pause” in global warming observed since 2000 followed a period of rapid acceleration in the late 20th century. Starting in the mid-1970s, global temperatures rose 0.5 °C over a period of 25 years. Since the turn of the century, however, the change in Earth’s global mean surface temperature has been close to zero. https://www.climate.gov/news-features/climate-qa/why-did-earth’s-surface-temperature-stop-rising-past-decade https://www.climate.gov/news-features/climate-qa/why-did-ear... That report is interesting because it argues against the pause indicating a true slowdown in global warming because the period of time is too short, that climate change works on much longer intervals. Perhaps that is true, and the 15 year pause is temporary. Time will tell.

splawn 10y ago

While this response seems 100% reasonable, I don't see how this it is any more effective in the face of "Climate change is a Chinese hoax" level absurdity. At this point with deniers it is religion so reason is out the door regardless.

btdiehr 10y ago
You are misrepresenting the opposing argument being made. The opposing argument is that people are making is as follows: 'climate-alarmists' misuse climate-science as a means of making political change. It is not a denial of all climate-change science. I don't care to argue this topic because I'm not expert nor do I care to pretend to be one on the topic of climate change, but this misrepresentation of the opposing views is part of the liberal-bubble so many people live in - all while smugly assuring themselves how much smarter they are than everyone else.
- burkaman 10y ago
  Are you unaware of the hundreds of times Trump has literally claimed all climate change science is a hoax, or are you saying his view is unimportant?
  - gwright 10y ago
    Trump and many other people don't seem to clearly understand the difference between the 'settled science' part of climate change and the 'unclear science' part. As such Trump and many others have very muddled and confused responses to those advocating various public policy changes due to climate change. Some clarity about what is and isn't 'settled' would certainly improve the public debate on policy but I'm not holding my breath.
    - burkaman 10y ago
      I disagree, what has Trump been unclear about? He doesn't think humans cause climate change, but he also doesn't think the planet is getting warmer. He doesn't even seem to think that CFCs are a real problem. He wants to cut the EPA. He thinks asbestos regulations are pointless. Trump has been clear and consistent for decades on this stuff, which I'm not sure you can say about any other belief of his. A new clarifying statement from the IPCC would not suddenly clear everything up for him.

thefastlane 10y ago

i would love to dive into this further (both the science itself, and how we cross the bridge from science to policy), can you recommend any resources or papers (DOI if possible)?

alecst 10y ago

Can you elaborate on this part? * Science isn't clear regarding what part of global temperature rise is due to human activity. I just want to contrast the above with this statement by the IPCC [1]: "Human influence has been detected and attributed in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, and in global mean sea level rise; and has been extremely likely been the dominant cause of the observed warming since the mid century. In recent decades, changes in climate have caused impacts on natural and human systems on all continents and across the oceans." [1] https://www.ipcc.ch/pdf/assessment-report/ar5/syr/drafts/SYR_FOD_Final.pdf https://www.ipcc.ch/pdf/assessment-report/ar5/syr/drafts/SYR...

nonbel 10y ago
>"[human activity] has been extremely likely been the dominant cause of the observed warming since the mid century." This is worded strangely so that it doesn't mean anything. Of course human activity has been the dominant cause of humans observing something. Why don't they say CO2 emitted by human-made machines or something more specific?
- alecst 10y ago
  That reply doesn't address my original comment, but the IPCC do say just that -- although not in that paragraph. You will find statements all over the IPCC about how climate change is nearly certain to be caused by people, and in particular, by people burning fossil fuels. If you go to the link I posted and search for "fossil" you will that in those notes. You can also read the official IPCC reports yourself to get a clearer idea. Maybe I'm misunderstanding you, but there's no anthropic principle at work. It would be perfectly fine to say (although it would not be true) that "plasma fluctuations on the surface of the sun are extremely likely to be the dominant cause of observed warming since the mid century."
  - nonbel 10y ago
    I was just commenting on the strange word choice used for that statement. Almost like whoever was editing that section wanted a way to weasel out of the implications later, if need be.