What is the carrying capacity of planet Earth?

Feb 2011
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14,356
The formerly great golden state
How many humans can the Earth sustain? That would seem to me an important question, given the likely results of the human race exceeding that number.

One estimate is about 9 to 10 billion, which is't too far off from what we have today:

Many scientists think Earth has a maximum carrying capacity of 9 billion to 10 billion people. [How Do You Count 7 Billion People?]
One such scientist, the eminent Harvard University sociobiologist Edward O. Wilson, bases his estimate on calculations of the Earth's available resources. As Wilson pointed out in his book "The Future of Life" (Knopf, 2002), "The constraints of the biosphere are fixed."
Globally, the fertility rate is falling to the "replacement level" — 2.1 children per woman, the rate at which children replace their parents (and make up for those who die young). If the global fertility rate does indeed reach replacement level by the end of the century, then the human population will stabilize between 9 billion and 10 billion. As far as Earth's capacity is concerned, we'll have gone about as far as we can go, but no farther.
source

There are a lot of variables, of courses. The Earth can no doubt sustain more bicycle riding vegetarians than car driving carnivores, for example, and then there is the unknown of improved technology.
 
Nov 2013
12,040
12,289
NY
How many humans can the Earth sustain? That would seem to me an important question, given the likely results of the human race exceeding that number.

One estimate is about 9 to 10 billion, which is't too far off from what we have today:




source

There are a lot of variables, of courses. The Earth can no doubt sustain more bicycle riding vegetarians than car driving carnivores, for example, and then there is the unknown of improved technology.
Whatever the number is, should there ever be an unsustainable limit reached, this planet has a self-cleaning defense mechanism.

If i’m sure of one thing, it is that the human parasite will not bring this planet down... we’re merely an episode in earth’s’ story... and most likely a rather short one.
 
Jan 2016
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Colorado
Whatever the number is, should there ever be an unsustainable limit reached, this planet has a self-cleaning defense mechanism.

If i’m sure of one thing, it is that the human parasite will not bring this planet down... we’re merely an episode in earth’s’ story... and most likely a rather short one.
The planet better have a pretty damn strong 'self-cleaning defense mechanism', if it is going to be able to recover from a thermonuclear holocaust. All the stresses and pressures thrown up by rapid population growth and climate change just might trigger World War III.
 
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Feb 2011
19,337
14,356
The formerly great golden state
The planet better have a pretty damn strong 'self-cleaning defense mechanism', if it is going to be able to recover from a thermonuclear holocaust. All the stresses and pressures thrown up by rapid population growth and climate change just might trigger World War III.
Planets live a long time. Earth would be around long enough for radioactive materials to decay and new species to evolve. We humans aren't as important as we'd like to think.
 
Nov 2013
12,040
12,289
NY
The planet better have a pretty damn strong 'self-cleaning defense mechanism', if it is going to be able to recover from a thermonuclear holocaust. All the stresses and pressures thrown up by rapid population growth and climate change just might trigger World War III.
Earth survived the comet hit that create the moon (from that meteorite‘s ‚debris‘)...
A few hundred thousand years of nuclear apocalypse is an issue for mankind, but not for a solid rock circling the sun since 4billion years plus...
 
Jan 2007
39,695
9,366
How many humans can the Earth sustain? That would seem to me an important question, given the likely results of the human race exceeding that number.

One estimate is about 9 to 10 billion, which is't too far off from what we have today:




source

There are a lot of variables, of courses. The Earth can no doubt sustain more bicycle riding vegetarians than car driving carnivores, for example, and then there is the unknown of improved technology.
What quality of life? That also needs to be asked of the USA. Why more bodies ? This next census will be interesting. IN 1960 we had 180 million. In 2000 we had 282 million. In 19 years another 50 million. This is insanity IMMIGRATION.
 
Jan 2007
39,695
9,366
The planet better have a pretty damn strong 'self-cleaning defense mechanism', if it is going to be able to recover from a thermonuclear holocaust. All the stresses and pressures thrown up by rapid population growth and climate change just might trigger World War III.
Add up all the countries unfit to live in.
 
Jan 2016
57,388
54,210
Colorado
Earth survived the comet hit that create the moon (from that meteorite‘s ‚debris‘)...
A few hundred thousand years of nuclear apocalypse is an issue for mankind, but not for a solid rock circling the sun since 4billion years plus...
Comet?!? That was another PLANET that smashed into the Earth back then, and it even has a name: Theia:

Theia (planet) - Wikipedia

Theia (/ˈθiːə/) is a hypothesized ancient planet in the early Solar System that, according to the 'giant impact hypothesis', collided with Gaia (the early Earth) around 4.5 billion years ago.[1][2] According to the hypothesis, Theia was an Earth trojan about the size of Mars, with a diameter of about 6,102 km (3,792 miles). Geologist Edward Young of the University of California, Los Angeles, drawing on an analysis of rocks collected by Apollo missions 12, 15, and 17, proposes that Theia collided head-on with Earth,[3] in contrast to the previous theory that suggested a glancing impact. Models of the impact indicate that Theia's debris gathered around Earth to form the early Moon.
 
Jan 2016
57,388
54,210
Colorado
Planets live a long time. Earth would be around long enough for radioactive materials to decay and new species to evolve. We humans aren't as important as we'd like to think.
Well, I was talking about the survival of the biosphere, not the entire planet. It takes millions of years to recover from a mass extinction. It can take TENS of millions of years to recover from a MAJOR mass extinction, and that is what is unfolding, right now, even WITHOUT a nuclear holocaust.

Add a holocaust on top of that, and the Earth's biosphere might not recover for a hundred million years.