Geologists divide the history of the Earth into time periods based upon the nature of the rocks formed during that period. The Holocene epoch began about 11,700 years ago after the last Ice Age. Seventeen years ago, the Nobel Prize winning Dutch scientist Paul Crutzen claimed that human beings have changed the Earth’s environment so drastically that we now live in a very different geological period. He called this new period the Anthropocene, which means resulting from human action. Crutzen argued that industrialization, intensive agriculture, population growth and the destruction of biodiversity were the main forces transforming the Earth’s ecology.

Most scientists date the Anthropocene from the atomic era, which began in 1945 and has left radioactive traces in sediments around the globe. The post-World War II period also experienced “The Great Acceleration,” a huge global expansion of economic production, human population and energy consumption. The magnitude of environmental destruction during and before the Anthropocene is truly shocking.

Greenhouse gases, which trap heat in our atmosphere, have increased dramatically since 1750 (the end of the preindustrial era). Carbon dioxide has increased by 43 percent, nitrous oxide by 63 percent and methane by 150 percent. The U.N. Intergovernmental Panel on Climate Change (IPCC) warns that the maximum tolerable temperature increase over preindustrial levels is 2 degrees Celsius. Without radical social changes, the IPCC predicts average temperature will increase between 3.7 degrees C and 4.5 degrees C by 2100, and between 8 degrees C and 12 degrees C by 2300. This would mean the end of organized human life on Earth.

But global warming is only part of the Anthropocene crisis. About 90 million tons of plastic junk have been dumped into our oceans, not to mention mountains of raw sewage and toxic fertilizer runoff. Ocean acidification is 26 percent above the preindustrial level, causing brutally high mortality of sea life. Biologists estimate that overall species extinction now occurs at about 1,000 times the natural rate. At the current pace, 20 percent of animal species will disappear by 2030. Human beings and their domestic animals now constitute 97 percent of all land vertebrate biomass, leaving only 3 percent of biomass for the remaining 30,000 land-dwelling vertebrate species. In light of these realities, paleontologists often speak about a looming “sixth mass extinction” (the fifth was the mass extinction of dinosaurs 65 million years ago).

Energy use has also leaped ahead during the Anthropocene era. Between 1800 and 2000, human energy consumption increased by a factor of 40. Agricultural land and cities covered about 5 percent of the Earth’s land area in 1750. They now occupy almost one-third. It is estimated that 84 percent of the Earth’s ice-free land is presently under direct human influence. A few years ago, a team of Swedish scientists specified nine ecological parameters which must not be crossed if the Earth’s biosphere is to avoid catastrophic decline. Four of these tipping points are already passed: greenhouse gas emissions, extinction of biodiversity, nitrogen cycle and phosphate cycle.

Former Vice President Al Gore says that “the climate crisis is the greatest challenge humanity has ever faced.” Indeed, it is not clear that humanity will survive two more centuries of the Anthropocene epoch. Many rational observers would bet against it. In contrast to Paul Crutzen, some ecologists think the Anthropocene should be re-named the Capitalocene (Bonneuil and Fressoz, The Shock of the Anthropocene (2016)). This seems appropriate because the current environmental crisis is largely caused by a tiny fraction of humanity: owners of capital and their rabid addiction to capital accumulation.

The Rocky Mountain Peace and Justice Center’s “Peace Train” runs every Friday in the Colorado Daily.