OK, I do want to say a few things that weaken what I've said so far. There are papers out there from reputable scientists that suggest things won't be so bad. Either that the ocean's uptake of CO2 will increase, or cloud feedbacks will be more negative, etc. There are a lot of things where we've had to make guesses, er, I mean parameterizations.
But it's not the whole story, and it never has been. The reason we run ensemble models is that we know things are guesses, so we build a range of likely results -- which are, in general, reflected in the IPCC report. There are some things which are not knowable, like future CO2/CH4/NH3/O3/chlorofluorocarbon emissions and pollution beyond the next couple of years.
I'm also going to say that anthropogenic global warming may not be bad for the human race. The heating that happened as the Pleistocene transitioned to the Holocene seemed to work out pretty well for humans, allowing them to expand out of Africa and into the mid-latitudes. This might allow us to do the same for higher latitudes, like Canada. But the key problem here is that it's too fast. Anything approaching the speed with which we are changing the world corresponds to mass extinction events in the fossil record. We have issues getting that below 500 years or so, so we don't know if a century of high temps with a return to "normal" wouldn't be so "bad". But it's not good.
And the main problem with geoengineering experiments like this on Earth is that right now we only got one of 'em. There's no backup plan. The science on greenhouse gasses themselves is well known. Anything volatile with 3+ atoms can be a greenhouse gas, due to the additional rotational quantum states you can get. Water is the #1 greenhouse gas, but
the atmosphere is already fully opaque in light bands that water
blocks. So it's the trace gasses that matter. There's a good amount of CO2 already out there, so it's one of the weakest GGs -- what you're doing is mainly growing the spectral bands out a little bit, trapping just a bit more infrared light in the atmosphere. Methane is much stronger, because it blocks on nearly empty bands. CFCs block a lot and are very important to stop, but thankfully we already did that for the unrelated ozone hole problem. HCFCs aren't quite as bad, and they have a much shorter residence time in the atmosphere.
And the other, deeper problem is that you're waiting for people's actual experiences, but humans aren't good at experiencing things that happen over 20+ years. The first problem is change blindness, where you don't notice things that changing because they're so subtle, but build up over a long time. It's like how you don't really notice your child growing up, but one day they're moving out and your baby is leaving you forever. The harder part is for even longer changes, that happen on scales outside of human lifetimes. None of us here remember what weather was like before the industrial revolution. We don't have actual experiences of it, so how can we say it's changed? So we rely on the data and the proxies. The giant sequoias? They remember what it was like. But asking trees for their experience doesn't work, so we use tree rings, ocean sediments, and other proxy data.
It's a major part of Buddhism that one life typically isn't enough to experience all of the things you need to reach enlightenment. And experience of life can show us illusion as much as truth. Now, Christians have a cheat code here, in that God is merciful and graceful, and extends truth and peace to those despite their life, their sin, their karma. (OMG HAX!) All I'm really saying here is that a major point of religion is to get us to imagine greater perspectives than any human life can cover.
-- ∇×V
But it's not the whole story, and it never has been. The reason we run ensemble models is that we know things are guesses, so we build a range of likely results -- which are, in general, reflected in the IPCC report. There are some things which are not knowable, like future CO2/CH4/NH3/O3/chlorofluorocarbon emissions and pollution beyond the next couple of years.
I'm also going to say that anthropogenic global warming may not be bad for the human race. The heating that happened as the Pleistocene transitioned to the Holocene seemed to work out pretty well for humans, allowing them to expand out of Africa and into the mid-latitudes. This might allow us to do the same for higher latitudes, like Canada. But the key problem here is that it's too fast. Anything approaching the speed with which we are changing the world corresponds to mass extinction events in the fossil record. We have issues getting that below 500 years or so, so we don't know if a century of high temps with a return to "normal" wouldn't be so "bad". But it's not good.
And the main problem with geoengineering experiments like this on Earth is that right now we only got one of 'em. There's no backup plan. The science on greenhouse gasses themselves is well known. Anything volatile with 3+ atoms can be a greenhouse gas, due to the additional rotational quantum states you can get. Water is the #1 greenhouse gas, but
the atmosphere is already fully opaque in light bands that water
blocks. So it's the trace gasses that matter. There's a good amount of CO2 already out there, so it's one of the weakest GGs -- what you're doing is mainly growing the spectral bands out a little bit, trapping just a bit more infrared light in the atmosphere. Methane is much stronger, because it blocks on nearly empty bands. CFCs block a lot and are very important to stop, but thankfully we already did that for the unrelated ozone hole problem. HCFCs aren't quite as bad, and they have a much shorter residence time in the atmosphere.
Quote:I tend to put more belief in peoples actual experiences over scientific theory.So yeah, we're telling you that quantum chemistry is causing global change. I mean, that's hard to accept as fact, unless you've done the experiments, or read the papers, or generally trust scientists. But it's the same process that led to the great discoveries of the last century.
And the other, deeper problem is that you're waiting for people's actual experiences, but humans aren't good at experiencing things that happen over 20+ years. The first problem is change blindness, where you don't notice things that changing because they're so subtle, but build up over a long time. It's like how you don't really notice your child growing up, but one day they're moving out and your baby is leaving you forever. The harder part is for even longer changes, that happen on scales outside of human lifetimes. None of us here remember what weather was like before the industrial revolution. We don't have actual experiences of it, so how can we say it's changed? So we rely on the data and the proxies. The giant sequoias? They remember what it was like. But asking trees for their experience doesn't work, so we use tree rings, ocean sediments, and other proxy data.
It's a major part of Buddhism that one life typically isn't enough to experience all of the things you need to reach enlightenment. And experience of life can show us illusion as much as truth. Now, Christians have a cheat code here, in that God is merciful and graceful, and extends truth and peace to those despite their life, their sin, their karma. (OMG HAX!) All I'm really saying here is that a major point of religion is to get us to imagine greater perspectives than any human life can cover.
-- ∇×V