Humans will go extinct if plant life not secured: Study

The continued destruction of the plant life on Earth has put humans in jeopardy, a study says.

According to researchers from University of Georgia, unless humans slow the destruction of Earth's declining supply of plant life, the civilisation may become completely unsustainable.

"The Sun's energy is stored in plants and fossil fuels but humans are draining energy much faster than it can be replenished," said study's lead author and associate professor John Schramski in a paper appeared in the journal Proceedings of the National Academy of Sciences.

Scientists estimate that the Earth contained approximately 1,000 billion tonnes of carbon in living biomass 2,000 years ago. Since that time, humans have reduced that amount by almost half.

It is estimated that just over 10 percent of that biomass was destroyed in just the last century.

"If we do not reverse this trend, we will eventually reach a point where the biomass battery discharges to a level at which Earth can no longer sustain us," Schramski said.

The vast majority of losses come from deforestation, hastened by the advent of large-scale mechanised farming and the need to feed a rapidly growing population.

As more biomass is destroyed, the planet has less stored energy, which it needs to maintain Earth's complex food webs and biogeochemical balances.

"As the planet becomes less hospitable and more people depend on fewer available energy options, their standard of living and very survival will become increasingly vulnerable to fluctuations, such as droughts, disease epidemics and social unrest," Schramski said.

If human beings do not become extinct, and biomass drops below sustainable thresholds, the population will decline drastically. People will be forced to return to life as hunter-gatherers or simple horticulturalists, according to the paper.

Scientists hope that recognition of the importance of biomass, elimination of its destruction and increased reliance on renewable energy will slow the steady march toward an uncertain future.