Well, actually, it seemed to me that you were being pretty dismissive of the “dire consequences” aspect, too. In any case, the difference between dire consequences that have some impact on the species and dire consequences that might take it to the verge of extinction or beyond is only a matter of degree. Paleontologists and paleoecologists like Anthony Barnosky have suggested that the rate of species loss may indicate that a sixth mass extinction is already under way, and a study recently published in the Proceedings of the National Academy of Sciences projects that even aggressive measures to limit population may not be enough to curtail ongoing environmental damage and, as suggested by other studies, the acceleration of species extinction.
I know that the Titanic analogy is old and well-worn, but it seems to me to carry some enduring truths. A bit of digressionary trivia: contrary to common belief, the lack of sufficient lifeboat capacity for everyone on board was not due to the White Star Line putting profit before safety, nor did they actually claim that the ship was unsinkable. Indeed it carried more lifeboats than were required by the then current regulations. Instead, it was believed that the design of the ship coupled with the modern miracle of radio telegraphy guaranteed that rescue ships would arrive before the Titanic could possibly sink in even the worst imaginable contingency, so that the function of the lifeboats was nothing more than to expedite shuttling passengers to the other ships – the supposedly “modern” view of an era where man dominates nature. We seem to have a way of underestimating risk and overestimating our technological capabilities, and that misplaced optimism wasn’t limited to the hubris of the early 20th century.
All species have some degree of interdependency with others, and the whole concept of a mass extinction event is that it implies major risk to the entire ecosystem. If you think we’re immune you might ponder the probabilities of human survival faced with major species extinction and long-term massive global crop failures.
I’m all for optimism and for informed speculation, optimistic or not. But I don’t countenance baseless optimism, especially when so often it’s just something that’s been concocted to support a myopic ideology of infinite economic expansion and boundless consumerism. I note that the segment of the population that tends to express the most optimism about our future well-being – the Captains of Industry, the Republican Job Creators, and so on – are generally the same segment currently trashing the environment all over the world.
Also, here in the West, a lot of people have grown up in a world where “they” will fix things before they get too bad. I grew up in a world always on the brink of nuclear armageddon, but it never happened. After awhile I just got burned out on always being on the brink, and figured “they” wouldn’t let anything really, really bad happen. I’ve spoken with a fair number of people who don’t care that much if climate change is real or not, because “they” will fix it at the last second, so no worries.
This is the best sort of neighbourhood there is, in this universe anyway. Only ten percent of all galaxies are as habitable as ours is, and only part of our galaxy is as safe as our neighbourhood.
Even if we find other planets with life and an Earth-like environment, the life itself in those worlds is likely to be indigestible, toxic or otherwise pathogenic. I would guess that shirtsleeve environments where you can eat the local lifeforms are vanishingly rare. But as Mjinn suggested, we will always have the opportunity to manufacture our own environments.
All of that is probably true. Within the relatively narrow constraints of what we consider to be habitable conditions, there is in fact an incredibly wide range of conditions under which life can evolve that are all dramatically different than the ones in which we evolved. But in terms of our survival, neither that nor our ability to somehow assemble our own environment – out of the asteroid belt, as someone suggested, or terraforming Mars, or whatever else – is particularly relevant in the context of our relatively short-term survival.
Our prospects for survival in the immediate future have to be measured against the time required to create new habitats off-world versus the time we have before this one starts to become uninhabitable at the current rate of environmental destruction. And it seems to me that there may be a disconnect of an order of magnitude or more between the two. If we are 100 years away from serious existential threats becoming manifest and a thousand years away from planetary colonization, we’re in deep trouble. There is a vast, vast difference between merely getting to Mars, for instance, and having large human populations living there as on Earth. The place has almost no atmosphere, what little there is of it has almost no oxygen, and there is so much carbon in it that it has twice as much lethal carbon monoxide as the earth’s air has CO2. This is not a happy place. And what else is there, in any foreseeable future?