In discussing climate change, the very broadest view we can take is the unfolding of evolution. Recent findings uncover a strong connection between the composition of gases in the atmosphere and the development of life on Earth. Factors such as earthquakes, volcanoes, the activity of the sun, the warming and cooling of the globe, Earth’s slightly irregular rotation in orbit and the impact of asteroids have affected the amount of methane, oxygen, carbon dioxide and other gases in the atmosphere and water. Some species thrive and others falter when this mix of gases changes, either suddenly or over large expanses of time.
Most relevant to this discussion is the percentage of oxygen in the air. Paleontologist Peter Ward (University of Washington) and geologist Joe Kirschvink (California Institute of Technology) explain in A New History of Life: The Radical New Discoveries about the Origins and Evolution of Life on Earth that in Triassic times, just before the extinction event that ushered in the Jurassic period, the precursors of mammals called the therapsids dominated the earth. Compared to reptiles, these ur-mammals had less efficient lungs (as do mammals), but it didn’t matter since the earth was relatively rich in oxygen.
But something happened during the extinction event that separates the Triassic and the Jurassic periods to reduce the percentage of oxygen in the atmosphere, enabling reptiles, including dinosaurs, to thrive and impeding the development of mammals. The rise of the dinosaurs may result directly from a reduction of oxygen and increase in nitrogen in the atmosphere. While science now confirms that the crash of a large asteroid is implicated in the death of all land dinosaurs and most avian dinosaurs (the surviving flyers becoming birds), evolutionary scientists now believe that the central factor in the rise of mammals, and thus primates and humans, was the increase in the amount of oxygen in the atmosphere from 14-16% to about 21% about 65 million years ago.
Humanity’s current spewing of millions of tons of carbon dioxide into the atmosphere a year is already changing the mix of gases dissolved in our oceans. Once the waters become supersaturated with carbon dioxide, if we are still in the midst of our fossil fuel burning spree, we can be reasonably certain that the overall percentage of CO2 in the atmosphere will increase and, more significantly for the survival of humanity, the percentage of oxygen will decrease.
That’s the long-term threat of failing to limit severely the amount of carbon we release into the environment. But before the composition of atmospheric gases radically could change, humanity would already have suffered—and perhaps gone extinct—from pandemics, famines, extreme weather events and resource wars: The four horses of the apocalypse known as global warming.
I recently did the latest version of the individual footprint test, which estimates the number of earths it would take to have the resources to support every human being in my style. Now I’m a voluntary simplicity warrior: I walk or ride the subway as much as possible, only occasionally taking the bus. I was in a car for less than 200 miles last year and took one airplane trip. We eat primarily locally grown food and I eat energy-intensive red meat but once a week. We compost. We live in a 1,200 square-foot apartment in a 17-story building that recently switched to gas heating. We buy only wind-powered electricity and recycle everything allowed. But despite these best efforts, my footprint computes to 1.5 earths for everyone. What else can I do without government intervention, besides maybe to get my building to go solar? The subway has to start using less energy and the buses have to eventually run on wind- or solar power, probably on rails. My food, clothes, computers—everything will have to be made and delivered more cheaply.
And that’s in energy efficient New York City! What about the rest of the country, where automobile travel dominates, mass transit has been allowed to wither and people live in and therefore heat larger spaces, and do so less efficiently, in free-standing houses? If everyone in the world lived as the average American does, it would take the resources of five earths.
The upside of the downsizing of the American dream that the growing inequality of wealth and income has produced is that it will soon shrink the footprint of many Americans. But we have to change what we do with the vast excess capital produced by squeezing the middle and lower classes. Currently, we give it to a small group of very lucky, if typically well-connected, individuals and families, AKA the super wealthy. Instead, we should use taxes to confiscate this excess capital and fund mass transit, wind and solar power, alternative technology development and adaptation, local sourcing projects throughout the United States.
We should also invest heavily in promoting negative population growth. Imagine, if everyone in the world limited themselves to having one child, the population would naturally shrink to a more manageable size. With fewer people, we could sustain a higher average quality of life.
Make no doubt about it—for humanity to survive, Americans will have to start using less energy and other resources and there will have to be a lot fewer of not only us, but of all the peoples of all the nations.