There is little need for metaphors here, the situation is easy to visualize directly. Some ecosystems will adjust, some will not and will be replaced by other ecosystems. Unless you are very attached to the particulars of the status quo why is this horrible?
Some ecosystems will be replaced by other ecosystems, but total biological and ecosystem diversity is likely not to rebound for millions of years (judging by comparable past climactic changes and mass extinction events.)
Some ecosystems are liable to collapse and be replaced by dramatically impoverished systems, not just in terms of diversity, but in terms of total biological productivity. Reef ecosystems, for instance, are extremely biologically productive, but this productivity relies on highly sophisticated recycling of limited resources between species. If certain species die out, not only does that particular ecosystem die out, it takes millions of years for the level of species mutualism necessary to sustain such a productive ecosystem to evolve again. The same is true of a number of other ecosystems (although reef systems are particularly close to the edge right now.)
When mass extinction events occur, it doesn’t just result in other species immediately stepping in and adequately filling the niches that are now vacated. There’s a time lag in which niches are left unfilled, or are filled by species which perform the roles in a substantially inferior way until they can adequately adapt to their niches.
total biological and ecosystem diversity is likely not to rebound for millions of years
Why are you assuming that the “total biological and ecosystem diversity” will diminish and what metric are you using for it?
Some ecosystems are liable to collapse and be replaced by dramatically impoverished systems, not just in terms of diversity, but in terms of total biological productivity.
Wouldn’t the reverse also happen—some “impoverished” systems will get replaced by highly productive ones?
Besides, is having a low-biological-productivity ecosystem bad in itself?
When mass extinction events occur
Are you claiming that the climate change (as envisaged, say, by the latest IPCC projections) is going to be a mass extinction event?
Why are you assuming that the “total biological and ecosystem diversity” will diminish and what metric are you using for it?
My metrics for “total biological and ecosystem diversity” are the total numbers of ecosystems and species, and the degrees to which they’re represented. As for why I’m “assuming” they will diminish, this the conclusion, not the presumption, of most of the research in that area.
In broad terms, we should expect this kind of thing to happen because so many species are adapted very strongly to very specific niches. When circumstances change rapidly, those species are unable to cope, and die out, but there are no species which are strongly adapted to the new circumstances to adequately replace them. Because ecology is much more complex than a simple intersection of weather conditions, the result is that rather than ecosystems and species being shuffled around, a lot just ends up being lost entirely. But of course, there’s a whole lot of research indicating specific ways in which this is already happening and is likely to happen in the future, outside the general principles that predict it.
Wouldn’t the reverse also happen—some “impoverished” systems will get replaced by highly productive ones?
Yes, and over timescales of millions of years, with temperature increases, these effects would likely dominate. But over timescales humans are more practically concerned with, the dominance will tend to be in the other direction.
As for whether a low biological productivity ecosystem being bad in itself, I’ll simply say this. Some such impacts are likely to have significant direct influence on our economy. Some are not, and there are those who care deeply about them regardless, who are willing to go to great expense to prevent them, and those who are not, and regard such expense as worthless. But in my experience, I have not known anyone to regard those impacts which are unlikely to directly influence human economy as positive and worth paying for.
Are you claiming that the climate change (as envisaged, say, by the latest IPCC projections) is going to be a mass extinction event?
Yes. By itself, anthropogenic climate change is unlikely to result in a mass extinction on the level of one of the Big Five, but it would still almost certainly be visible in the fossil record as a mass extinction event (I emphasize again that the degree of impact here is due to the rapidity, not the degree, of climate change.) Along with other forms of human influence though, a mass extinction event on the level of the Big Five is distinctly within the realm of possibility. Our current estimated rate of species extinction is around ten thousand times the usual background rate-and accelerating.
As for why I’m “assuming” they will diminish, this the conclusion, not the presumption, of most of the research in that area.
What you call “conclusion” is probably a forecast, since we’re talking about the future, right?
In broad terms, we should expect this kind of thing to happen because so many species are adapted very strongly to very specific niches. When circumstances change rapidly, those species are unable to cope, and die out, but there are no species which are strongly adapted to the new circumstances to adequately replace them.
Recent ice ages have advanced and retreated very quickly on the evolutionary time scale. Earth’s various ecologies survived, for example, the last ice age just fine and the glaciation looks to me to have been MUCH more disruptive for temperate zones than a couple of degrees of warming are likely to be.
Yes. By itself, anthropogenic climate change is unlikely to result in a mass extinction on the level of one of the Big Five, but it would still almost certainly be visible in the fossil record as a mass extinction event
I agree that we’re in the middle of an anthropogenic mass extinction, the only thing is that it has nothing to do with climate change. It’s just man taking over the planet. This mass extinction started thousands of years ago, goes on now, and will likely continue in the future.
I think that whatever extinctions global warming may cause, they will be insignificant and indistinguishable from noise given the ongoing (non-climate) human impact.
What you call “conclusion” is probably a forecast, since we’re talking about the future, right?
In some cases, yes, in other cases, it’s already observable as an ongoing process (I brought up reef ecosystems before because they’re a particularly visible example of this.)
Recent ice ages have advanced and retreated very quickly on the evolutionary time scale. Earth’s various ecologies survived, for example, the last ice age just fine and the glaciation looks to me to have been MUCH more disruptive for temperate zones than a couple of degrees of warming are likely to be.
The original onset of the first ice ages was indeed quite ecologically destructive and qualified as a substantial mass extinction event (although it was still much slower than anthropogenic climate change.) But virtually all species alive today are ones that have persisted through multiple glaciation periods. The flora and fauna of today’s world are denizens of the ice ages.
I should note that all of the points that you’re raising have plenty of representation in the existing literature on climate change. It’s definitely not the case that scientists don’t think of these things. But these points are followed up with more research to determine what kind of expectations are warranted, and in some cases they’re ones that merit concern.
Some ecosystems will be replaced by other ecosystems, but total biological and ecosystem diversity is likely not to rebound for millions of years (judging by comparable past climactic changes and mass extinction events.)
Some ecosystems are liable to collapse and be replaced by dramatically impoverished systems, not just in terms of diversity, but in terms of total biological productivity. Reef ecosystems, for instance, are extremely biologically productive, but this productivity relies on highly sophisticated recycling of limited resources between species. If certain species die out, not only does that particular ecosystem die out, it takes millions of years for the level of species mutualism necessary to sustain such a productive ecosystem to evolve again. The same is true of a number of other ecosystems (although reef systems are particularly close to the edge right now.)
When mass extinction events occur, it doesn’t just result in other species immediately stepping in and adequately filling the niches that are now vacated. There’s a time lag in which niches are left unfilled, or are filled by species which perform the roles in a substantially inferior way until they can adequately adapt to their niches.
Why are you assuming that the “total biological and ecosystem diversity” will diminish and what metric are you using for it?
Wouldn’t the reverse also happen—some “impoverished” systems will get replaced by highly productive ones?
Besides, is having a low-biological-productivity ecosystem bad in itself?
Are you claiming that the climate change (as envisaged, say, by the latest IPCC projections) is going to be a mass extinction event?
My metrics for “total biological and ecosystem diversity” are the total numbers of ecosystems and species, and the degrees to which they’re represented. As for why I’m “assuming” they will diminish, this the conclusion, not the presumption, of most of the research in that area.
In broad terms, we should expect this kind of thing to happen because so many species are adapted very strongly to very specific niches. When circumstances change rapidly, those species are unable to cope, and die out, but there are no species which are strongly adapted to the new circumstances to adequately replace them. Because ecology is much more complex than a simple intersection of weather conditions, the result is that rather than ecosystems and species being shuffled around, a lot just ends up being lost entirely. But of course, there’s a whole lot of research indicating specific ways in which this is already happening and is likely to happen in the future, outside the general principles that predict it.
Yes, and over timescales of millions of years, with temperature increases, these effects would likely dominate. But over timescales humans are more practically concerned with, the dominance will tend to be in the other direction.
As for whether a low biological productivity ecosystem being bad in itself, I’ll simply say this. Some such impacts are likely to have significant direct influence on our economy. Some are not, and there are those who care deeply about them regardless, who are willing to go to great expense to prevent them, and those who are not, and regard such expense as worthless. But in my experience, I have not known anyone to regard those impacts which are unlikely to directly influence human economy as positive and worth paying for.
Yes. By itself, anthropogenic climate change is unlikely to result in a mass extinction on the level of one of the Big Five, but it would still almost certainly be visible in the fossil record as a mass extinction event (I emphasize again that the degree of impact here is due to the rapidity, not the degree, of climate change.) Along with other forms of human influence though, a mass extinction event on the level of the Big Five is distinctly within the realm of possibility. Our current estimated rate of species extinction is around ten thousand times the usual background rate-and accelerating.
What you call “conclusion” is probably a forecast, since we’re talking about the future, right?
Recent ice ages have advanced and retreated very quickly on the evolutionary time scale. Earth’s various ecologies survived, for example, the last ice age just fine and the glaciation looks to me to have been MUCH more disruptive for temperate zones than a couple of degrees of warming are likely to be.
I agree that we’re in the middle of an anthropogenic mass extinction, the only thing is that it has nothing to do with climate change. It’s just man taking over the planet. This mass extinction started thousands of years ago, goes on now, and will likely continue in the future.
I think that whatever extinctions global warming may cause, they will be insignificant and indistinguishable from noise given the ongoing (non-climate) human impact.
In some cases, yes, in other cases, it’s already observable as an ongoing process (I brought up reef ecosystems before because they’re a particularly visible example of this.)
The original onset of the first ice ages was indeed quite ecologically destructive and qualified as a substantial mass extinction event (although it was still much slower than anthropogenic climate change.) But virtually all species alive today are ones that have persisted through multiple glaciation periods. The flora and fauna of today’s world are denizens of the ice ages.
I should note that all of the points that you’re raising have plenty of representation in the existing literature on climate change. It’s definitely not the case that scientists don’t think of these things. But these points are followed up with more research to determine what kind of expectations are warranted, and in some cases they’re ones that merit concern.