SUNDAY, AUGUST 16, 2015
Eric Lee, A-SOCIATED PRESS
TOPICS: POPULATION, FROM THE WIRES, THE CURVE
TUCSON (A-P) — Graphs can inform the numerate and yet fail to convey enormity. The following looks back in time and summarizes the history and prehistory of our species. The X axis only goes back 200,000 years even though Homo sapiens go back over 300,000 years, a blip in geological time. The Y axis indicates human population change over time, each tick marking 100,000,000 humans added. One hundred million added human lives, one tick, is an enormous number human minds cannot expect to grasp. If the graph were printed out, it would be 56 feet (17 meters) long. If that seems excessive, well, consider the subject. If each tick marked the number of humans one human can reasonably 'know', maybe 100, then the printout would be over 10,000 miles long, so the scale chosen cannot but fail to convey enormity.
So since setting foot on the moon, human population has doubled and since today's centurians were born it has quadurpled. The elders of today have seen an increase of five billion humans in their lifetime. It took 200,000 to 300,000 years (2,400,000 to 3,600,000 months) to add the first 100,000,000 people. Now, with the slowing of the population growth rate, it takes, thanks to continued "progress," less than 14 months to add another 100,000,000 people. But in the early 1960's it only took 7.5 months, so we're slacking off. It's starting to not look like progress anymore, so we need to redouble our efforts to keep on growing. Maybe ban birth control, abortion, criminalize homosexuality and masturbation everywhere, not just in the more progressive areas of the world.
A reasonable evidence-based best guess as to Earth's carrying capacity for humans, when not feeding off the immense trough of fossil fuels (for a time), would be less than 1 billion. Global population, at the start of the Industrial Revolution, was about 650,000,000. Nature's carrying capacity, sans fossil fuel inputs, has been substantially decreased since. The attempt to prolong the fossil fueled pulse will further degrade Earth's carrying capacity for humans and the life-support system for all life, so 1 billion may be a starry-eyed overestimate.
The way down to <1 billion will resemble the way up. In 100 years the way down will not move the red line above to the right by one pixel and so will not be noticeable. The question is where will the population be in 1000 years as it barely moves the red line to the right and how far up will the red line have reached? No prize will be given if we reach 8 billion, 9 billion, 10 billion, or 11 billion, as the higher the red line goes, the greater the loss of carrying capacity, and the lower the red line will emerge assuming it doesn't terminate at zero.
Of course, there will be cold fusion, zero-point energy, some rabbit will be pulled from the technological hat. Carrying capacity will be irrelevant. No one will ask, "And then what?" The lithosphere will be hollowed out, the land developed in kilometers deep highrises from former sea to non-shining sea as the oceans will be covered with floating cities. Life on Earth, thanks to the entertainment value of some, will be happily living in natural looking preserves formerly known as zoos.
The story doesn't begin 200,000 years ago, of course. See "Human Origins in Deep Time" for the prior 5 billion years.