Comment by tasty_freeze | Hacker News Reader

Comment by tasty_freeze | Hacker News Reader

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Here is a great, low emotion description that covers the "CO2 lags temperature change". Potholer54 cites his claims, and does a lot of work to run down where claims first originated, then reads that paper instead of just citing some random web blogger or popular news article.

https://www.youtube.com/watch?v=zQ3PzYU1N7A

One of the problems cited: the temperature/CO2 graph probably came from an antarctic ice core sample ... and temperature leading/lagging there is different than in non-polar locations.

Second, the climate is a complex feedback system; there isn't one independent variable and everything else is dependent. If something forces any of the variables in the feedback system it can affect the other variables. For instance, say the artificial release of CO2 by humans results in the thawing of the arctic, releasing gigatons of methane, at which point CO2 might no longer be the primary driver. Over geologic time there are different causes for these forcings, but that doesn't mean that the current forcing (human released CO2) isn't the current problem.

He covers all of that and more, much better, in 13 minutes.

[EDIT] I forgot to address "what's even the big issue with changes in global temperatures?"

That is a supremely cavalier attitude. Nobody is saying AGW is going to kill off all life. In the long term life will recover. But in the short term we humans are going to have to deal with the consequences: displacement of millions of people through crop failures and loss of coast, disruption of economic systems, and more civil unrest. The US military is gaming out these scenarios because they believe the science, not because they are pinko tree huggers who hate freedom.

> One of the problems cited: the temperature/CO2 graph probably came from an antarctic ice core sample ... and temperature leading/lagging there is different than in non-polar locations.

Specifically, he points out that CO2 lags temperature by hundreds of years in the southern hemisphere, but that temperature lags CO2 by again hundreds of years in the northern hemisphere.

CO2 is claimed to have accelerated natural warming through a feedback loop - until it didn't, and temperatures began drifting down again.

That's fair enough. That's reasonably nuanced. I'm missing the extent to which this feedback loop actually made an impact though, because clearly it can't be the dominant driver or ultimate control lever. Otherwise, we'd have had a runaway greenhouse already.

> Nobody is saying AGW is going to kill off all life.

One might get that impression from the media narrative though.

> But in the short term we humans are going to have to deal with the consequences: displacement of millions of people through crop failures and loss of coast, disruption of economic systems, and more civil unrest.

I don't think that's such a big deal, all things concerned. Sometimes, people have to move. Sometimes, crops fail. Sometimes, coasts move. Sometimes, there's civil unrest. Telling people in China or Brazil that they'll have to cut down on their emissions is going to cause civil unrest. "Vote for me, I'll make you poorer" is not a winning political provision.

> The US military is gaming out these scenarios because they believe the science, not because they are pinko tree huggers who hate freedom.

They're also gaming out scenarios of mass epidemics, or political secession. What do you expect them to do?

> Sometimes, people have to move. Sometimes, crops fail. etc

If the ebola infections started appearing in all the major cities with airports and seaports, would you want the experts to try their best to stop it, or would you shrug and say, eh, sometimes people live and sometimes they die,

> One might get that impression from the media narrative though. (that AGW is going to kill all life)

I have two responses: one, as potholer likes to point out, we all know that press headlines are sensational. Don't deny the science because you don't like the way the press reports it. Second, I don't personally get the impression that even the press claims AGW will sterilize the planet. It sounds like a strawman to me.

> If the ebola infections started appearing in all the major cities with airports and seaports, would you want the experts to try their best to stop it, or would you shrug and say, eh, sometimes people live and sometimes they die

That highly depends on what "the experts" recommend that we do. In any case, your bad analogy is bad.

> I have two responses: one, as potholer likes to point out, we all know that press headlines are sensational.

...which is what makes me far less worried about climate change.

> Don't deny the science because you don't like the way the press reports it.

All this talk about "95% of scientists agree (that the charts point up)" and "science denial" is an argument from authority.

Given that 50% of science is estimated to be wrong[1], I'm willing to take my chances on this one, especially since there's a strong ideological component to it.

The actual simulations are drastic simplifications with wide margins of error, and even those margins have been crossed by observation even in the close term, where the margins are still narrow. All the interesting stuff happens way further down the line, however.

Perhaps a bit more humility regarding the practical limits to the scientific method is in order, at least in this case - but then how would you make your argument from authority?

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1182327/

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