So what about the current threatened extinction? How is it progressing?
How many species were lost in the Cretaceous-Paleogene Extinction?
>>Some 76 percent of all species on the planet, including all nonavian dinosaurs, went extinct.<<
How long did it take? About 32,000 years.
I have not found an actual number of species lost.
>>Scientists have estimated that there are around 8.7 million species of plants and animals in existence.<<
I haven't found a similar number for the Cretaceous, so let's name a conservative estimate: 1 million species.
76% of 1 million is 760,000. 760,000 species extinct.
How many have gone extinct recently?
>>In the last 500 years, human activity is known to have forced 869 species to extinction (or extinction in the wild). <<
So we are 869 / 760,000 of the way through the current mass extinction.
What if the process speeds up? What if over the next 500 years the process becomes 100 times faster?
86,900 / 760,000 = 11%
In another 500 years we will be 11% through the current mass extinction. Only a short time compared to 32,000 years.
>>But let’s flip the argument to say that our moral exceptionalism is the ticket out of an evolutionary trap. It is the one thing that could avert a sixth mass extinction, one that may well include us. <<
The Earth's population will begin to fall in this century. Given current projections for fertility rates, in 500 years the Earth's population will be between zero and 1 billion. This will undoubtedly terminate the current human-caused extinctions well before it can be considered a mass extinction.
Why are fertility rates plummeting? Because of selfishness and modern contraceptives. It's a lot easier to live these days if you have one or two kids rather than six.
So a moral revolution is not the only prospect for saving nature. We can just be selfish.
That doesn't make as nice a story though, does it?
Great review and it does provide clarity about us humans being the current main cause of the on-going mass extinction. It's the I = PAT thing in action. As a biologist, it's so obvious that we are dooming and doing in lots of our fellow living creatures. I am personally doing what I can to reduce the carnage, but the downward spiral advances. I cringe at people who buy "collapse" and act as if the loss of species is totally out of their control and not their problem, seeming like pathetic fatalistic religious types. I suppose you can just be Zen about it, but then again there are so many things we can all do to stop the extinctions. Don't have kids is probably the biggest although not so easy. You can buy habitat, support land trusts, etc! You can do all kinds of things on your own property to improve conditions for lots of species simply by not being so manic about lawn care - let it grow, leave the leaves, plant lots of native butterfly and bird-supportive plants. You can give to organizations helping wildlife and species. You can support protected areas, national parks, wilderness areas, even by going to visit them to incentivize local communities to keep protecting them. Getting the word out is important to, so thanks for doing that with your creative and thought-provoking essays.
Excellent summary of the mass extinctions!
So what about the current threatened extinction? How is it progressing?
How many species were lost in the Cretaceous-Paleogene Extinction?
>>Some 76 percent of all species on the planet, including all nonavian dinosaurs, went extinct.<<
How long did it take? About 32,000 years.
I have not found an actual number of species lost.
>>Scientists have estimated that there are around 8.7 million species of plants and animals in existence.<<
I haven't found a similar number for the Cretaceous, so let's name a conservative estimate: 1 million species.
76% of 1 million is 760,000. 760,000 species extinct.
How many have gone extinct recently?
>>In the last 500 years, human activity is known to have forced 869 species to extinction (or extinction in the wild). <<
So we are 869 / 760,000 of the way through the current mass extinction.
What if the process speeds up? What if over the next 500 years the process becomes 100 times faster?
86,900 / 760,000 = 11%
In another 500 years we will be 11% through the current mass extinction. Only a short time compared to 32,000 years.
>>But let’s flip the argument to say that our moral exceptionalism is the ticket out of an evolutionary trap. It is the one thing that could avert a sixth mass extinction, one that may well include us. <<
The Earth's population will begin to fall in this century. Given current projections for fertility rates, in 500 years the Earth's population will be between zero and 1 billion. This will undoubtedly terminate the current human-caused extinctions well before it can be considered a mass extinction.
Why are fertility rates plummeting? Because of selfishness and modern contraceptives. It's a lot easier to live these days if you have one or two kids rather than six.
So a moral revolution is not the only prospect for saving nature. We can just be selfish.
That doesn't make as nice a story though, does it?
Rodes.pub/OneBillion
Great review and it does provide clarity about us humans being the current main cause of the on-going mass extinction. It's the I = PAT thing in action. As a biologist, it's so obvious that we are dooming and doing in lots of our fellow living creatures. I am personally doing what I can to reduce the carnage, but the downward spiral advances. I cringe at people who buy "collapse" and act as if the loss of species is totally out of their control and not their problem, seeming like pathetic fatalistic religious types. I suppose you can just be Zen about it, but then again there are so many things we can all do to stop the extinctions. Don't have kids is probably the biggest although not so easy. You can buy habitat, support land trusts, etc! You can do all kinds of things on your own property to improve conditions for lots of species simply by not being so manic about lawn care - let it grow, leave the leaves, plant lots of native butterfly and bird-supportive plants. You can give to organizations helping wildlife and species. You can support protected areas, national parks, wilderness areas, even by going to visit them to incentivize local communities to keep protecting them. Getting the word out is important to, so thanks for doing that with your creative and thought-provoking essays.