It's the aggregate market demand that counts.
Let's look at the aggregate market demand. The annual passenger total is about 3 billion people.
Doesn't look "barely economically viable" to me. At all.
And yet airlines lost money for most of the past decade. So these 3 billion passengers aren't paying them that much. (And I don't think it just doesn't occur to airlines to raise prices; presumably they wouldn't get as many passengers if they did.) Even more recently, it looks like the average net profit per passenger (average, not marginal) is of the order of $5.
Note: Please see this post of mine for more on the project, my sources, and potential sources for bias.
I have written a couple of blog posts on my understanding of climate forecasting, climate change, and the Anthropogenic Global Warming (AGW) hypothesis (here and here). I also laid down the sources I was using to inform myself here.
I think one question that a number of readers may have had is: given my lack of knowledge (and unwillingness to undertake extensive study) of the subject, why am I investigating it at all, rather than relying on the expert consensus, as documented by the IPCC that, even if we're not sure is correct, is still the best bet humanity has for getting things right? I intend to elaborate on the reasons for taking a closer look at the matter, while still refraining from making the study of atmospheric science a full-time goal, in a future post.
Right now, I'm curious to hear how you formed your views on climate change. In particular, I'm interested in answers to questions such as these (not necessarily answers to all of them, or even to only these questions).