Steven Hawkins estimated if the population continues every 40 years to double by 2600 there will be only standing room here. Just in the United States births increased in 2014 (1 percent) for first time since 2007. In the next few decades we are expected to reach 9 billion.
Since 2000, humans have cut down more than 2.3 million km2 of primary forest. Also we have converted one-third of the ice-free and desert-free land surface of the planet to pasture and cropland. In southeast Asia, almost half of the natural habitat has been converted.
In 2008 Jared Diamond noted that people consume resources like oil and metals, and produce wastes like plastics and greenhouse gases, are about 32 times higher in North America, Western Europe, Japan and Australia than they are in the developing world.
Now we are at 7 billion people on this planet, and that number may grow to around 3 billion within several decades. Presently 5.5 billion people of the developing world are growing in numbers while we in the industrialized countries consume 32 times more than the rest of the world.
How many more people can the world sustain? Our developing countries make an increase in living standards a primary political goal to become industrialized. How can we in the rich countries lessen our material consumption since the poor wish to enjoy the American Dream of a high-consumption lifestyle? As millions of people in the developing world wish enjoy the first-world lifestyle how much carrying capacity can this planet take unless we humans use less? There is not enough pie to go around now to if humans are going to survive here.
Just look at China as the leading developing country. Now it has a two-child policy increasing its per capita consumption rates at home. China is one of the world’s fastest growing economy with 1.3 billion Chinese, or four times the United States population. Yes, our world is already running out of resources rapidly since China is quickly reaching American level consumption rates.
India as well as China were to reach our US rate, world consumption would triple. Finally, if the whole developing world were suddenly to catch up to the US rate it would be as if the world population ballooned to 72 billion people or world rates would increase elevenfold.
Without some human population or birth controls we as a species may implode. Over 10,000 years ago there were just two of us.
There is no greater environmental, economic, social, or other need then to insure we do not mass over reproduce.