EARTH POPULATION
We hear a lot about the over-population of the Earth. Let's look at some statistics and math that applies to the consideration. First some relevant numbers:
Acre: 0.0015625 square mile (statute) or 640 acres per square mile
4.3560 x 10^4 square feet
0.40468564 hectare
Hectare: 2.471054 acres
1.07639 x 10^5 square feet
Now we have the stats, and they are all over the map, no pun intended:
Earth land: Encyclopedia Brittanica, article Earth (1963)
58,552,330 square miles
or 37,473,491,200 acres
52,559,999 square miles without Antartica
or 33,663,999,360 acres
or
Wikipedia, article Earth (2016)
57,510,000 square miles
or 36,806,400,000 acres
Agricultural: Encyclopedia Brittanica, article Agriculture (1963)
3,884,000,000 hectare Arable or arable under tree crops
9,597,573,736 acres
5,662,000,000 hectare unused but potentially productive
13,991,107,748 acres
so
23,588,681,484 total acres
but goes on
400,000,000 to 3,500,000,000 hectare estimated productive land
or
Readers Digest Atlas of the World (1987) @ 58,552,330 square miles
11% used or 6,440,756.3 square miles = 4,122,084,032 acres
and
20% more available or 11,710,466 square miles = 7,494,698,240 acres
so
11,616,782,480 total acres
or
Wikipedia, article Earth (2016) @ 57,510,000 square miles
6,326,100 square miles= 4,048,704,000 acres
and
11,502,000 square miles = 7,361,280,000 acres
so
11,409,984,000 total acres
Population: At 7,000,000,000 people
and using the Wikipedia number of acres 36,806,400,000
This gives 5.258057142857143 acres; say 5.25 acres per person
In 1 AD, in Britain, the amount of land to support 1 person for 1 year (I think it should actually be 1 family per year) was a Hide of land, approximately 160 acres. Today, the land necessary to support 1 person for 1 year is 36 square meters, or a plot about 20x20 feet. That's with artificial light; hydroponic farming uses even less area. (The Skeptical Environmentalist, 2001, by Bjorn Lomborg, quoting Julian Simon, The Ultimate Resource 2, 1996)
That's 400 square feet.
From above, an acre is 43,560 square feet, so we need less than 1 percent of the land. Or less than 4% for a family of 4 on 1 acre.
Rush Limbaugh once said we could put the world's population in Texas. Well, Texas is 268,581 square miles, or 172,891,840 acres (Wikipedia, 2016). That would give to each person .025 acre. That's a population density of 40 people per acre. 40% of the acre would be needed to grow a years food for all.
Tokyo, the most densely populated city, has a population of 36,923,000 people (Wikipedia, 2016); 16,121.8 per square mile or 25.19 per acre. So the densest modern city is 5/8th as dense as cramming all into Texas. Still, it is theoretically possible.
And the above figures say each of the 7 billion today can have over 5 acres. Double the population to 14 billion, you still have over 2.5 acres to yourself. Few humans are happy hermits, most want human company within a reasonable distance. Hence, highrise apartments, small suburban lots, and parks. 80% of the population in the US live in urban areas. With 1% of the land needed for food, at 14 billion people, a family of 4 would still have over 10 acres to themselves. Living on 1/10 of the land, that family has an acre, a large suburban lot.
This look at population admittedly ignores practical questions about water, sewage, transportation, jobs, and a million others. But from a simple "too many people" angle, we are a long way from over-population if in a land area twice the size of Texas we can live peacefully at under the density of Tokyo, or if 14 billion people can live on 1/10 of the land in suburban comfort.
We hear a lot about the over-population of the Earth. Let's look at some statistics and math that applies to the consideration. First some relevant numbers:
Acre: 0.0015625 square mile (statute) or 640 acres per square mile
4.3560 x 10^4 square feet
0.40468564 hectare
Hectare: 2.471054 acres
1.07639 x 10^5 square feet
Now we have the stats, and they are all over the map, no pun intended:
Earth land: Encyclopedia Brittanica, article Earth (1963)
58,552,330 square miles
or 37,473,491,200 acres
52,559,999 square miles without Antartica
or 33,663,999,360 acres
or
Wikipedia, article Earth (2016)
57,510,000 square miles
or 36,806,400,000 acres
Agricultural: Encyclopedia Brittanica, article Agriculture (1963)
3,884,000,000 hectare Arable or arable under tree crops
9,597,573,736 acres
5,662,000,000 hectare unused but potentially productive
13,991,107,748 acres
so
23,588,681,484 total acres
but goes on
400,000,000 to 3,500,000,000 hectare estimated productive land
or
Readers Digest Atlas of the World (1987) @ 58,552,330 square miles
11% used or 6,440,756.3 square miles = 4,122,084,032 acres
and
20% more available or 11,710,466 square miles = 7,494,698,240 acres
so
11,616,782,480 total acres
or
Wikipedia, article Earth (2016) @ 57,510,000 square miles
6,326,100 square miles= 4,048,704,000 acres
and
11,502,000 square miles = 7,361,280,000 acres
so
11,409,984,000 total acres
Population: At 7,000,000,000 people
and using the Wikipedia number of acres 36,806,400,000
This gives 5.258057142857143 acres; say 5.25 acres per person
In 1 AD, in Britain, the amount of land to support 1 person for 1 year (I think it should actually be 1 family per year) was a Hide of land, approximately 160 acres. Today, the land necessary to support 1 person for 1 year is 36 square meters, or a plot about 20x20 feet. That's with artificial light; hydroponic farming uses even less area. (The Skeptical Environmentalist, 2001, by Bjorn Lomborg, quoting Julian Simon, The Ultimate Resource 2, 1996)
That's 400 square feet.
From above, an acre is 43,560 square feet, so we need less than 1 percent of the land. Or less than 4% for a family of 4 on 1 acre.
Rush Limbaugh once said we could put the world's population in Texas. Well, Texas is 268,581 square miles, or 172,891,840 acres (Wikipedia, 2016). That would give to each person .025 acre. That's a population density of 40 people per acre. 40% of the acre would be needed to grow a years food for all.
Tokyo, the most densely populated city, has a population of 36,923,000 people (Wikipedia, 2016); 16,121.8 per square mile or 25.19 per acre. So the densest modern city is 5/8th as dense as cramming all into Texas. Still, it is theoretically possible.
And the above figures say each of the 7 billion today can have over 5 acres. Double the population to 14 billion, you still have over 2.5 acres to yourself. Few humans are happy hermits, most want human company within a reasonable distance. Hence, highrise apartments, small suburban lots, and parks. 80% of the population in the US live in urban areas. With 1% of the land needed for food, at 14 billion people, a family of 4 would still have over 10 acres to themselves. Living on 1/10 of the land, that family has an acre, a large suburban lot.
This look at population admittedly ignores practical questions about water, sewage, transportation, jobs, and a million others. But from a simple "too many people" angle, we are a long way from over-population if in a land area twice the size of Texas we can live peacefully at under the density of Tokyo, or if 14 billion people can live on 1/10 of the land in suburban comfort.