A new study by researchers from the University of Georgia warns that unless humans do something to slow down the destruction of the diminishing supply of plant life on the planet, civilization as we know it today may eventually become unsustainable.
Study researcher John Schramski, from UGA's College of engineering, said the Earth can be thought of as a battery that was slowly charged over billions of years. Fossil fuels and plants have become storage houses of solar energy but humans drain this energy faster than this can be replaced.
It is estimated that the living biomass on Earth has about 2,000 billion tons of carbon two millennia ago but this amount has been reduced by nearly half. More than a tenth of that biomass is estimated to have been destroyed last century alone.
Schramski said that if humans do not reverse this trend, there will come a point when the biomass battery discharges to a point where the planet can no longer be able to sustain us.
The researchers showed that the a bulk of the losses can be attributed to deforestation, which was hastened with the demand to feed a fast growing population and the advent of large-scale farming.
When more biomass is destroyed, the Earth is able to store less energy than it needs in order to maintain its crucial processes and balance.
"With the rapid depletion of this chemical energy, the earth is shifting back toward the inhospitable equilibrium of outer space with fundamental ramifications for the biosphere and humanity. Because there is no substitute or replacement energy for living biomass, the remaining distance from equilibrium that will be required to support human life is unknown," the researchers wrote in their study, which was published in PNAS on July 15.
Schramski said that as our world becomes less hospitable, more people would rely on fewer energy options that are available, which could affect their survival and standard of living as disease epidemics, droughts and social unrest could become more prevalent.
The researchers wrote that even if humans do not go extinct, there would be a drastic decline in population when the biomass drops below the sustainable threshold. People will also be forced to live a life as simple horticulturalists or hunter gatherers.
"We have a limited amount of biomass energy available on the planet, and once it's exhausted, there is absolutely nothing to replace it," Schramski said.
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