This strikes me as a strange reply. For one thing, the deal we're offering developing nations here doesn't seem to me to be all that great. We offer Bangladesh the polio vaccine and then make their country unlivable, and they're supposed to be grateful?
This strikes me as pure rhetoric. I believe that the correct way to consider the "deal" (recognizing the enormous complication that this wasn't really a "deal", as we never got consent) is the thought experiment I proposed in my post:
Ask yourself this question: Would you rather be born at the median income level in Bangladesh today, or at the median income level in Bangladesh in the alternative world where the entire Northern Hemisphere had never escaped life at the subsistence level? That is, to live in a world of lower carbon emissions, but no Western science, none of the economic development inside Bangladesh that would not have occurred had the West not developed, no hospitals, no foreign aid, and no meaningful chance of ever changing the material conditions of your life?
For me, though not necessarily for everyone, the answer to that is obvious.
He goes on to say:
But the big error in thinking here is that it assumes that economic growth -- in the past and, crucially, in the future, cannot take place without this level of carbon emissions. You can have the polio vaccine and warming or neither, in other words, and those are your only choices. But of course, this is absurd.
Yes, this is absurd - and it is beneath Ryan's sophistication as an economic thinker. It's not binary. Imposing carbon emissions restriction would reduce current consumption to some degree, and would in turn reduce the expected value of potential future losses from climate change damages. What matter here are these quantitative trade-offs. I have presented a detailed argument about these trade-offs (from a global, not merely U.S., perspective). Unless Ryan is prepared to point out the errors in the relevant analysis, he should accept its implications.
He goes on to say:
One might have said that we could have our modern economy and an ozone hole, or acid raid, but not both, but they'd have been completely wrong.
Yes, one might have said such a thing, but I never have. Such an argument is analogous to Ryan's caricature of my position, but not very analogous to my actual position.
He then says:
Had the federal gas tax been indexed to inflation over the past two decades, it is quite likely that our national emissions would now be significantly lower with basically no observable decline in economic growth relative to today.
That's a pretty remarkable statement. I'd like to see some evidence for it.
At a broader level, the moral force of the "we made the mess, so it's our responsibility to clean it up" argument is intuitively compelling. It's often expressed in the homey metaphor of dumping trash in our neighbor's yard. But what's buried in this kind of familiar example is that most people reading this live in a world of legally-defined rights and obligations enforced by courts, police, and ultimately the monopoly on large-scale force held by the government in the form of the army.
But nation-states and societies don't live in anything like this relationship to one another. It seems to me that a better analogy would be that of a large number of clans living in somewhat overlapping and disputed areas of a primitive forest. Over centuries almost all clans have had massive feuds with almost all other clans. There are constant low-level skirmishes, as well as alliances through marriage or simple treaties. Some of these clans tend to be more peaceful and trade a lot with their neighbors, while others tend to be much more war-like. Some clans have enslaved others, and fortunes have risen and fallen through time. At some point, one clan figures out how to use fire to make things. They become much, much wealthier than any clan has ever been. All of these fires create soot pollution that threatens to reduce crop yields for other clans. On the other hand, inevitably, knowledge of how to use fire also becomes available to the other clans through imitation. The people who live in this forest, as a whole, become much wealthier than they would have been had the original clan never figured out how to use fire in this way. Is it obvious to you that the original clan has an absolute ethical obligation to either stop using fire or develop new technology that burns without soot? It's not to me.