PARIS: Human activity and appetites have weakened Earth’s resilience, pushing it far beyond the “safe operating space” that keeps the world liveable for most species, including our own, a landmark study said on Wednesday (Sep 13).
Six of nine planetary boundaries – climate change, deforestation, biodiversity loss, synthetic chemicals including plastics, freshwater depletion, and nitrogen use – are already deep in the red zone, an international team of 29 scientists reported.
Two of the remaining three – ocean acidification along with the concentration of particle pollution and dust in the atmosphere – are borderline, with only ozone depletion comfortably within safe bounds.
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 civilisation developed”, said lead author Katherine Richardson, a professor at the University of Copenhagen’s Globe Institute.
The study is the second major update of the concept, first unveiled in 2009 when only global warming, extinction rates, and nitrogen had transgressed their limits.
“We are still moving in the wrong direction,” said co-author Johan Rockstrom, director of the Potsdam Institute for Climate Impact Research (PIK) and a co-creator of the schema.
“And there’s no indications that any of the boundaries” – except the ozone layer, slowly on the mend since the chemicals destroying it were banned – “have started to bend in the right direction”, he told journalists in a briefing.
“This means we are losing resilience, that we are putting the stability of the Earth system at risk.”
The study quantifies boundaries for all nine interlocking facets of the Earth system.
Source: CNA
