Are we in the Sixth Great Extinction?
By Robert and Sonia Vogl
President and Vice President,
Illinois Renewable Energy Association
Some studies indicate that we are in the midst of what is referred to as the “Sixth Great Extinction” as the rate of species loss is similar to that occurring in the previous five events. While species gains and losses are ongoing, a mass extinction is recognized when three fourths of all species vanish quickly. A dramatic episode was the extinction of the dinosaurs when dust from the Yucatan meteor hit cooled the global climate ending the lush growth needed for their survival.
The sixth extinction differs from the others in that it can be attributed to human activity changing the global environment to suit our needs and desires. While we think of the changes as progress we downplay or ignore their adverse consequences. In her book, “The Sixth Extinction”, Elizabeth Kolbert points out the impacts of our activities. We are changing the global atmosphere and the water cycle, increasing the amount of heat in the ocean, degrading the health of coral reefs, destroying forests and changing evolution through invasive species.
While we are able to document many of these impacts, others of them are unknown as are their potential consequences. What we do know is that current trends in biodiversity losses are accelerating, which suggests a more stressful future for human well-being. While not a complete species loss, the cod fishery off the Atlantic Coast is an example of a collapse of sufficient size that it no longer supports commercial fishing. Warmer temperatures in the Rocky Mountains have enabled mountain pine beetles to have two reproductive cycles per year, dramatically increasing their population and contributing to massive die off of lodgepole and Ponderosa Pines. The dry timbers then feed some massive fires.
In this area we are familiar with the adverse impacts of invasive species such as buckthorn, garlic mustard and Asian carp. The broad expanse of the typical lawn reduces biodiversity while increasing the consumption of water, chemicals and fuel to keep it mowed. The monarch butterflies once seen in migrating clouds of orange are dwindling as are frogs succumbing to pesticides and habitat loss.
Some species whose numbers dropped precipitously are occasionally seen in the area. The black bear that wandered through northern Illinois last year caused a frenzy among some while delighting others. An occasional cougar or wolf has been spotted in the area producing similar reactions.
There are numerous efforts in the area to delay species loss through turning lands covered with alien plants back to natives. Prairie restoration has become an accepted and popular effort over the last 50 years. Nachusa Grasslands is an example of a large scale project restoring native ecosystems. Originally focused on prairie, its holdings also include oak savannas, forests and wetlands. A small herd of bison has been introduced to provide a more complete ecosystem.
There are also small scale efforts to save native species as exemplified by plantings of milkweed to support monarch butterflies. While small steps, they can add up. They may even lead to a groundswell of behavior sufficient to limit the Sixth Great Extinction.