Humanity is killing itself, but the solution may be found on Mars

Pick up a book titled “The Decline and Fall of the Human Empire — Why Our Species is on the Edge of Extinction” (St.Martin’s Press), and it’s safe to assume its pages won’t be full of sunshine, lollipops and rainbows.But while the author, British paleontologist Henry Gee, delivers an occasionally apocalyptic vision of the future, he also offers some hope for just how humanity can get itself out of a pickle of its own making.

“The fact remains that as a species, humans are remarkably pox-ridden, worm-eaten and lousy,” says Gee.“But it is reasonable to ask if humans might evade extinction’s great scythe, and persist indefinitely.”In “The Decline and Fall of the Human Empire,” Gee examines the many reasons why the human race finds itself in multiple instances of peril. From over-reliance on agriculture to huge lifestyle changes to domestication of animals and our inability to cope with disease, Gee’s book reveals that the most successful species to ever exist has played a strong hand in its own potential downfall. The overriding issue affecting our future is population growth — or lack of it. According to United Nations data, the rate of global population growth peaked at 2.24% a year in 1964 but today it stands at just 0.88% and that represents an existential problem.

“The growth rate is projected to become negative — that is, the population will start to shrink — in 2086, when the world population will top out at 10.431 billion,” writes Gee, who also wrote the award-winning “A (Very) Short History of Life On Earth.”For context, the population of the United States was 324.84 million in 2017 and will peak at 363.75 million in 2062 before falling back to 335.8 million in 2100.A cursory look at life expectancy reveals the extent of the crisis that we might face.Today, there are 1.7 billion people over the age of 65 in the world, a figure that will increase to 2.37 billion by 2100.“The figure for octogenarians is even more...