The Sixth Mass Extinction is Progressing Nicely

The depletion of natural resources, ocean acidification, sea level rise, melting glaciers and climate change are all ahead of schedule. Conflicts over energy choices threaten global economies and security. Nuclear proliferation and unstable regimes have been a diplomatic quagmire and security conundrum.

What else is going terribly wrong that we are ignoring?

Ecosystems are nature’s way of transferring and distributing nutrients and energy through a dynamic living system. A few ecosystems are linear like chains, but the vast majority are like spider webs. Diversity means that there are many strands in the web that keep the system functioning. If we cut one strand, the others take up the slack; but if you cut too many, the system collapses. That is what we see happening to the global ecosystem today.

The resilience of the planet depends upon having a diverse portfolio of animal and plant species to buffer environmental extremes. For example, the American Bison, the prairie dog, prairie grasses and microbes in the soil are significantly responsible for the fertile soils of the Midwestern United States. The ecological nutrient system passed from the microbes in the soil that grew the grass to the Bison and Prairie Dog that ate the grass. The millions of Bison turned the soil with their hooves and dropped fertilizer. Prairie dogs burrowed deep and lined their underground nests with manure and grasses, thoroughly mixing the nutrient material and slowing erosion. That material fed the microbes that refined and further dispersed the nutrients.  The cycle repeated itself until the middle of the U.S. had a dozen feet of the richest soil in the world.

By removing the Bison, over harvesting monoculture crops, killing microbes with pesticides and removing the vast colonies of prairie dogs, we destroy the ecosystem that formed and maintained America’s breadbasket.

The ability of ecosystems to adapt is called resilience. Anthropogenic climate change is altering weather patterns and moisture circulation. It alters ocean currents and the distribution of nutrients. Climate change contributes to ecosystems changing faster than the flora and fauna can adapt.

Dams, roads, cities, fences, agricultural chemicals and agribusiness that seeks monoculture crops also contribute to species extinction. The spread and resource demands of 7.5 billion humans are reducing the resilience of the planet at an exponential rate. Human enterprise and population are threatening the organisms that allow the flow of energy and nutrients that sustain us.

There have been five previous planetary mass extinctions in Earth’s history. A mass extinction means a significant percentage of species on land, in the sea, or a combination of both die; altering the global ecosystem forever. Life has to start over. The worst took place during the Permian extinction event at the end of the Permian and beginning of the Triassic Epoch, about 250 million years ago. Nearly 96 percent of all species were wiped out over a span of several million years. Recovery took tens of millions of years and had little resemblance to life before the extinction.

When ecosystems change, they never return to their previous form. We will never again see thousands of square miles of old growth forest ecosystems. We will never see tall grass prairie stretching across five states. In a few decades, we will no longer see an African savanna filled with wild herds of elephants, lions, rhinoceroses, or giraffe. Those iconic species are already endangered. The ecology that gave us those fertile plains is dying.

We are already well into the sixth massive planetary extinction. It is progressing faster than any of the previous five extinctions in Earth’s history. A May, 2017 report was published in the peer-reviewed Proceedings of the National Academy of Sciences of the United States. The report offered some of the most recent comprehensive research correcting a common public perception of their natural environment. Most people believe that a decline in species diversity and extinctions is happening slowly if at all. The findings of this report strongly indicate the opposite is occurring.

The researchers sampled 27,600 terrestrial vertebrate species with a more detailed analysis of 177 mammal species. More than 40% of species have experienced severe decreases in population with a greater than 80% loss of range. The authors found that the decreases in population and range were primarily due to anthropogenic “erosion of biodiversity… and ecosystem services essential to civilization.” The pace of extinction is off the charts. It is taking place faster than most species can adapt, migrate or alter their behavior.

The longer our leaders procrastinate and promote ideologies contrary to scientific reality, the more threats will appear. The longer we wait, the more severe each crisis will become. The human-caused Sixth Global Mass Extinction is already well underway. It adds a new dimension to the complexity of time-critical crises facing humanity in the 21^st century.

W. Douglas Smith is an environmental scientist, environmental diplomat, explorer, educator and a retired Senior Compliance Investigator for the U.S. Environmental Protection Agency, where he worked for 36 years.