RobFisher

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New study on choice blindness in moral positions

I didn't notice at first, but only because I did notice that you were quoting the comment above which I had just read and skipped over the quote.

Be Happier

See also the section on anticipation: "...the pleasure derived from window shopping for a dress may exceed the pleasure from actually acquiring the dress." I get happiness from the process of comparison shopping. It is part of the anticipation. Perhaps this advice needs further qualification.

Climate change: existential risk?

I'm surprised to find statements here such as "the existence of anthropogenic global warming is a fact". I'm new here, haven't read all the sequences, and this may seem obnoxious. But I'm testing my beliefs and willing to change my mind.

Let's start with the article linked to by the OP. It says that 4 degrees of warming is likely and bad. I'll concentrate on likely.

The argument for athropogenic global warming goes something like this:

  • 1) carbon dioxide levels have increased since pre-industrial times
  • 2) increased carbon dioxide levels in the atmosphere will cause a small amount of warming
  • 3) we have measured a large amount of warming (since, say, 1880)
  • 4) there may be feedback effects that mean that the small amount of warming caused by CO2 could lead to a large amount of warming
  • 5) if we build a computer model of the atmosphere including supposed feedbacks, and tweak it until it predicts past events correctly, then it predicts a large amount of warming in the future

1 and 2 are uncontroversial.

3 is difficult to measure. For example land based thermometers are only accurate to, say, 1C, and we are extracting a signal that varies by tenths of a degree. Or we are using proxies like tree rings that are difficult or impossible to calibrate. The signal we do extract is not linear, to say the least. For example warming stops at times even as CO2 increases, so we know there are large variations not accounted for by CO2 which makes it hard to determine the influence of CO2 alone. The signal looks very different depending on what timescale one looks at, hence arguments about natural variation, decadal oscillations, the medieval warm period and so on.

The feedback effects in (4) are not well understood, which means that the models in (5) do not necessarily reflect how the real climate system works.

And if a model does not include important parts of the system, even if it correctly predicts past events that does not mean it can predict future events. I could build psuedo-random-number generators until I find one that happens to match closely the observed past temperature signal, but it will not predict future temperatures.

All this does not add up to a high level of certainty that additional CO2 will lead to any particular amount of warming. The sensitivity of climate to doubling of CO2 is not known with any degree of certainty. In short, climate is not as well understood as evolution and atoms.

The OP speaks of "meaningful climate reform and legislation" which means redirecting lots of resources to change the amount of CO2 emitted. Resources that could generate more utility elsewhere.

So what is going wrong? Possibilities:

  • a) I am wrong about 1-5 -- I haven't linked to any sources for them partly because I have built this picture by reading around a lot and filtering everything through whatever untamed cognitive biases I have. I think I will explore this more.
  • b) I am not being rational
  • c) I or other commenters are making poor certainty estimates outside their area of expertise
  • d) other commenters are assuming that the majority is right
  • e) other commenters have discounted climate skepticism after having seen poor climate skeptic arguments without having seen the good ones; or I have made the opposite error
  • f) something else…