Humanity deep in the danger zone of planetary boundaries: Study

According to a seminal research released on Wednesday, Earth's resilience has been undermined by human activities and appetites, pushing it well beyond the "safe operating space" that maintains conditions suitable for most species, including our own.

An multinational team of 29 scientists found that six of the nine planetary boundaries—climate change, deforestation, biodiversity loss, synthetic chemicals including plastics, freshwater depletion, and nitrogen use—are already far into the red zone.

Only ozone depletion is securely within acceptable limitations, whereas the other three—ocean acidification, dust accumulation in the sky, and particle pollution—are borderline.

Lead author Katherine Richardson, a professor at the Globe Institute at the University of Copenhagen, explained that the planetary boundaries identify "the important processes that keep the Earth within the kind of the living conditions that prevailed over the last 10,000 years, the period when humanity and modern civilization developed."

Since the notion was initially introduced in 2009, when only global warming, extinction rates, and nitrogen had exceeded their limitations, the study represents the second significant update to the idea.

Director of the Potsdam Institute for Climate Impact Research (PIK) and co-creator of the schema Johan Rockstrom stated, "We are still moving in the wrong direction," in reference to the shared writing.

"And there's no indications that any of the boundaries"—aside from the ozone layer, which is gradually recovering since the chemicals that destroy it were outlawed—"have started to bend in the right direction".

"This implies that we are becoming less resilient and endangering the stability of the Earth system."

Boundaries for each of the nine interconnected components of the Earth system are quantified in this study.

headed towards catastrophe

In terms of biodiversity, for instance, it is considered acceptable if the rate of extinction of a species is less than ten times the average rate of extinction during the previous 10 million years.

In actuality, however, extinctions are happening ten times faster than the planetary boundary limit and at least 100 times faster than this so-called background rate.

The atmospheric CO2 content, which stayed very close to 280 parts per million (ppm) for at least 10,000 years until the industrial revolution, is crucial in determining the threshold for climatic change.

Currently, that quantity is 417 ppm, much above the 350 ppm safe limit.

"When it comes to climate, we're still on a path that will unquestionably lead to disaster," stated Rockstrom. "We're going to a temperature that hasn't been reached in the last four million years—2.5C, 2.6C, or 2.7C."

He said, "There is absolutely no evidence that humans can survive in that environment."

In the latest study, thousands upon thousands of chemical compounds made by humans were identified for the first time and found to exceed acceptable limits. These chemicals ranged from micro-plastics and pesticides to nuclear waste and pharmaceuticals that have leached into the environment.

The same is true for the depletion of freshwater found in rivers and lakes, as well as in soil and plants, which collectively constitute "green" and "blue" water.

establishing boundaries

The latest version makes the significant discovery that various boundaries reinforce and magnify one another.

The study predicts rises in temperature when any or both of these factors grow. It specifically looks at the relationship between rising CO2 concentration and harm to the biosphere, particularly the loss of forests.

It demonstrates that even if mankind quickly reduces greenhouse gas emissions, rising global temperatures might push the globe into a trajectory of further warming that would be difficult to reverse unless the loss of carbon-absorbing forests is stopped at the same time.

Head of Earth System Analysis at PIK and co-author Wolfgang Lucht stated, "The integrity of the biosphere is the second pillar for our planet, after climate change."

"By removing too much biomass, destroying too much habitat, and deforesting too much land, we are currently destabilizing this pillar."

The investigation found that all borders could be restored to the safe operating area.

"It simply comes down to establishing boundaries for the quantity of waste we release into the open ecosystem and the quantity of living and non-living raw materials we remove," Richardson stated.

The planetary limits concept, which was first hotly contested, soon emerged as a keystone of Earth system research and continues to have an impact on industry and politics today.