I would like to add 2 additional points.

Point 1:I think that it is easy to see humans can do great damage via pollution, even if you don’t think global warming is happening (and I feel odds are that it is these days) there is still the toxic pollution that has been added to rivers, lakes, and some pieces of land that has a detrimental effect of plant and animal life in that area. So we do cause pollution and it does cause harm.Does that last point mean that life/from Earth would be better without us? I argue no. Not only are we part of life on/from Earth but if we are able to limit the damage we do to various ecosystems around the world so they do not collapse then we provide means by which life on Earth will become life from Earth and those have the potential to survive past the point (in about 5 billion years from now-so keep paying your mortgage) when the sun expands and most things remaining on Earth get cooked. While humanity should learn how not to damage other forms of life on Earth and should actively work to avoid harm now, we are the only species likely to currently enable space travel and thus create the ability to evacuate the planet when such an evacuation becomes necessary to sustaining most of the life on/from Earth (not just us).Thus calling for human extinction actually removes a potential boon to the survival of Earth’s various life-forms.

Point 2:

I would argue the harm via pollution that humans cause is mainly not due to the number of humans but to the manner we go about economic development. Global Warming is caused by greenhouse gasses. This are released by the burning of fossil fuels. If not for the latter the former would not be a problem. Also look at China, it has a great deal of problems relating to both air and water quality because of the many emissions (some of which are quite toxic) put into each. China's emissions problem (touching on fossil fuels again) has grown worse after it started its population control program. This can happen because of the fact that there is no stable ratio between the amount of humans and amount of emissions, factories, cars, coal powers plants, and so on. China jumped ahead of the USA in CO2 emissions not by a population boost but through rapid and reckless economic development in which consideration of the environment was not an issue. Thus focusing on economic systems systems to be the logical way to prevent pollution and environmental damage.

Note: Population control does not involve counting and limiting the amount of emissions-only the number of humans. This is why it actually fails to serve as effective protection for the environment.

Expand full comment

J Thomas, my wish for chimps, or starfish, or intelligent aliens, to prosper has (so far as I can tell) very little to do with the genes they share with me. Which is hardly surprising; nothing in our evolutionary past has selected us for preferring the interests of creatures sharing 90% of our DNA over those of creatures sharing 0% of it, since we've never had any of the latter to interact with. But, regardless, why *should* the fact that (say) starfish share some genes with us make any difference to how much we value their survival?

(I can't tell whether my preference for native Australians over chimps has anything to do with the genes they share with me. Causally, it probably has. But I like to try to minimize the excess of rationalizing over reasoning in my value judgements, and it doesn't seem to me as if those shared genes are much of a *reason* for preferring them. But there are other reasons that seem better.)

Expand full comment

When I think about it, it seems quite reasonable to want other species to survive us if we die out.

I care about my sister's children even though they aren't my children. After all, they share 1/4 of my genes.

I care about my cousins even if all my immediate family dies.

I care about people who seem unrelated -- go back 40 generations and pretty much everybody's related to everybody else.

If we're all gone but chimpanzees remain, they share 99+% of our genes. Why not wish them well? But then, mice share 99% of our genes. Wish them well too. (Depending on how you count the chimpanzees may be only 98% or 95% similar. Is that difference important?)

Same sort of thing. If humanity died out except for the native australians who've done less mixing than the rest of us, wouldn't you wish them well?

And if the closest survivor to us was a starfish species, still isn't that better than only bacteria surviving?

Expand full comment

Chris, I agree than an attempt to achieve option 2 could lead in fact to option 1. Nevertheless, considered as achieved outcomes, these are relevant options to compare to clarify whether you do or do not consider human extinction to be the "optimistic" outcome, if the alternative is mass extinction of other species. Instead of forcing my own interpretation of your words in Nature, I am trying to get you to clarify your interpretation; why won't you choose?

Expand full comment

Correction. Mistyped the first line. I meant that point 2 leads to point 1, not the other way around.

Expand full comment


Your dichotomy is spurious since your point one is liable, albeit with unknown probability, to lead to your point two. If you interpret my text as "advocating human extinction" - that is your interpretation, not mine! And certainly not Nature's.

The immediate challenge is to find ways whereby we minimise the extent to which the planet is denuded of other life forms and ecosystem goods and services (i.e., useful things we get from the biosphere, usually without paying for them directly - benefits that are generally speaking not internalised within the prices of the goods we purchase, for example). These goods and services are required to maintain humans in the way that it seems you advocate. At present, we are "mining" our biological resources faster than they can regenerate. This is not sustainable.

As to why anyone cares about anything, human or otherwise, I leave to you to philosophise over.

Expand full comment

Chris, I saw no clues suggesting your book review was a humor piece, nor that your offending paragraph was "a few tongue-in-cheek comments." Many commentors here suggested less offensive interpretations of your words, but none guessed you were "obviously ... expressing the view of a highly sentient squid." I don't see how your description of "humans having `gone' " differs substantially from my "humans and any descendants with a remotely similar population or resource-intensive technology will be extinct." And we both know that Nature would not allow a book review advocating exterminating a particular race or ethnicity, so it is noteworthy that Nature allowed your apparently advocating human extinction. So please clarify, which scenario is to you more "optimistic":<ol><li> Humans and any descendants with a remotely similar population or resource-intensive technology become extinct in a million years, and in thirty million years, the biosphere goes back to normal.<li>Human and/or their descendants continue to maintain no less than today's population and resource-usage over millions of years, with a continued severe extinction event and denuded planet. </ol>

Expand full comment

Well, you have all been busy! Talk about over-interpreting a few tongue-in-cheek comments I made. A few minor points.

1. Nature does not "endorse" what I wrote. The journal is always clear that the views are those of its authors, not official views of the journal (even if they did edit a few grammatical errors into the final version at the last minute!).

2. I was very careful in my wording of humans having "gone" in few million years, and included uncertainty in the sentence. I did not say "extinct", which is how the above contributors have interpreted my comment. Yes, complete human lineage extinction is a possibility. However, species also evolve into other entities, which then become known by other species names, and this could be "our" fate. My guess is that any such species that exists, in say 10 million years, will not be anything like as abundant or industrialised as the current Homo sapiens. Naturally, I could be entirely wrong.

3. The substance of the last paragraph of my review is to emphasise that humans are not capable of wiping out all forms of life on Earth, and if (I suspect when) we become extinct (or far less abundant), new life forms will subsequently emerge. "Optimistic" .... obviously I was expressing the view of a highly sentient squid that hopes that its descendants will inherit the Earth and subsequently colonise the universe!

Expand full comment

Julian, your eloquent description of our place in nature deserves reposting in its entirety:>You say you're being scientific, but you're anthropomorphizing the hell out of "nature". None of those animals, plants, etc matters at all in and of themselves. They are the chance products of a chance process, and the fact of their existence is mere luck. No part of nature makes an ethical distinction between the status quo and the scorched Earth that would result from a nearby gamma-ray burst. It's all just atoms and fields, going about their business.

So, when you overlay an ethical function that assigns desirability to outcomes (that they don't have in themselves), you are implicitly adding a desirer. Action implies actor. Since the only creatures who can think abstractly at the moment are ourselves, you're introducing a human desirer. But oops - the scenario you propose deletes humans. So it deletes desirability. Doing ethical algebra with human-less outcomes is like doing division with zero. It's nonsensical by definition.

What you are doing is projecting your enjoyment of a wilderness (seen from afar, I might add, and not as a participant) onto a situation with total wilderness. You're forgetting to include the observer in the experiment; consequently you are not noticing that a wilderness without an observer is meaningless.<

This clearly expresses the human bias: that we are the only species on Earth that matters. Without us, the entire biosphere has no meaning, and to consider otherwise is to anthorpomorphize it. Makes one wonder how life muddled through without meaning before we came along.

For the sake of discussion, I'll go along with your contention that, "there isn't much point in arguing whether or not life is valuable in and of itself, there is no way to settle the point." So, if life forms have no intrinsic value, perhaps it doesn't matter that we are eliminating them. However, if life forms do have intrinsic value, we should not. The possibility that life only has value when we value it seems to me a weak justification for eliminating it.

Humans may be the only species with a sense of ethics, but then we're the only ones who need it. After we're gone, the natural processes of evolution will continue without regard to right and wrong. Until then, our unique position as the cause of the sixth great extinction, coupled with our ability to make ethical judgements, obligates us to behave as if we are not the only life form that has value.

"As to your worries about microorganisms, I can see zero evidence beyond what amounts to science fictional speculation on your part. . ."

Of course you can't see it, that's why they're called microorganisms. And speaking of science fictional speculation: "WE won't go extinct, and we can rebuild biodiversity according to our preferences."

Expand full comment

Up until the invention of agriculture, yes, we were basically twiddling our thumbs. This comment reveals a depth of callous ignorance that I don't really know how to respond to.

Unimportant. WE won't go extinct, and we can rebuild biodiversity according to our preferences. Can? No - you believe that, in the future, we will gain the ability to do so. That may or may not turn out to be the case. You're counting your chickens before their eggs are laid, much less hatched.

Expand full comment

That was based on your own remark: "We have a significant chance of getting knocked back a century or two by war or disease". I agree (but I'd add climate change and resultant ecological and food chain collapses as a possible additional drivers). I think my point was simply that since we are currently utterly dependent on the larger biosphere, it behooves us to take care of it as best we can until such time as we can upload ourselves into gleaming, eternal, entropy-proof silicon substrates. For now, we are 100% dependent on biological processes that we don't understand very well, let alone are capable of controlling in arbitrary ways.

Expand full comment

Neandertals were a dead end because we modern homo sapiens ate them. Mammals were limited to the role of small rodent in the time of the dinosaurs. After their mass extinction a great many niches were opened up to that family, which were (relatively) quickly filled. In the absence of humanity it is likely that given enough time it would happen again. Baboons are a candidate to replace us, as are rats.

Expand full comment

"we are [...] going to be knocked back to a preindustrial level of civilization"

Oh really? Do tell.

Expand full comment

A poster child for alienation writes "The biosphere is meaningful because (in priority order): we breathe it, we eat it, it's storing genetic potential, and we find it enjoyable." Well, there isn't much point in arguing whether or not life is valuable in and of itself, there is no way to settle the point. However, until we succeed in porting ourselves to silicon crystals, there is much to be said for having a bit of respect for the infrastructure that supports our wondrous brains.

he says: "we can rebuild biodiversity according to our preferences." Right, we are simultaneously going to be knocked back to a preindustrial level of civilization and develop the ability to tailor and resurrect extinct species at will.

There seems to be a big gap between those of us who live on a planet and those who live in a science fiction novel.

Expand full comment

@mtraven"it's as if the entire biosphere is just some sort of minor annoying middle tier standing in between physics and the glory that is the human mind."

Exactly that. The biosphere is meaningful because (in priority order): we breathe it, we eat it, it's storing genetic potential, and we find it enjoyable.

Expand full comment

A "trillion trillion" years? I thought this blog was supposed to have some respect for quantitative argumentation. People here seem to be having trouble keeping track of the difference between 10^3, 10^6, 10^9, and now 10^24 years, which is a seriously impressive example of innumeracy.

"The two primary forces on Earth right now are humanity and entropy. One or the other is eventually going to gain complete control of the planet."

Weird, it's as if the entire biosphere is just some sort of minor annoying middle tier standing in between physics and the glory that is the human mind.

Expand full comment