A Jim Holt review that considers future lives

Oh!  I haven't read anything by Jim Holt for ages - he was a favourite writer on science matters for a long time.

But on a whim I checked New York Review today, and he has an interesting review entitled The Power of Catastrophic Thinking.    Actually it's a review of a cheery sounding book The Precipice: Existential Risk and the Future of Humanity by one Toby Ord.

The basic question the book and review addresses is the extent to which we should value future lives, and at what cost to our current lives if some sacrifice is needed.  All very relevant to the question of climate change, which does get a mention, with this somewhat surprising statement:

Could global warming cause unrecoverable collapse or even human extinction? Here too, Ord’s prognosis, though dire, is not so dire as you might expect. On our present course, climate change will wreak global havoc for generations and drive many nonhuman species to extinction. But it is unlikely to wipe out humanity entirely. Even in the extreme case where global temperatures rise by as much as 20 degrees centigrade, there will still be enough habitable land mass, fresh water, and agricultural output to sustain at least a miserable remnant of us. 

Gee.  I would not have thought global average of 20 degrees would barely be survivable unless you were living in a airconditioned dome anywhere on the planet - but I really don't know what the daily temperature at the poles in summer or winter would be like under those conditions.    

He does point out the runaway global warming idea next:

There is, however, at least one scenario in which climate change might indeed spell the end of human life and civilization. Called the “runaway greenhouse effect,” this could arise—in theory—from an amplifying feedback loop in which heat generates water vapor (a potent greenhouse gas) and water vapor in turn traps heat. Such a feedback loop might raise the earth’s temperature by hundreds of degrees, boiling off all the oceans. (“Something like this probably happened on Venus,” Ord tells us.) The runaway greenhouse effect would be fatal to most life on earth, including humans. But is it likely? Evidence from past geological eras, when the carbon content of the atmosphere was much higher than it is today, suggests not. In Ord’s summation, “It is probably physically impossible for our actions to produce the catastrophe—but we aren’t sure.”

Anyway, the rest of the review goes into the more philosophical and analytical issues with thinking about the value of future lives, and Holt points out some of the flaws in certain ways of thinking about it.

It's a bit too complicated to do it justice here, but here is a key section:

Ord cites both kinds of reasons for valuing humanity’s future. He acknowledges that there are difficulties with the utilitarian account, particularly when considerations of the quantity of future people are balanced against the quality of their lives. But he seems more comfortable when he doffs his utilitarian hat and puts on a Platonic one instead. What really moves him is humanity’s promise for achievement—for exploring the entire cosmos and suffusing it with value. If we and our potential descendants are the only rational beings in the universe—a distinct possibility, so far as we know—then, he writes, “responsibility for the history of the universe is entirely on us.” Once we have reduced our existential risks enough to back off from the acute danger we’re currently in—the Precipice—he encourages us to undertake what he calls “the Long Reflection” on what is the best kind of future for humanity: a reflection that, he hopes, will “deliver a verdict that stands the test of eternity.”

I guess I have always felt a similar way:  and if you are keen on an Omega Point idea, it makes it particularly important that humanity doesn't stupidly kill itself, just in case it's the only way it can be reached.

But if this is the sort of thing that interests you - just go read the whole review article (set up an account to be able to read it for free).