Earth is exceeding its 鈥渟afe operating space for humanity鈥 in six of nine key measurements of its health, and two of the remaining three are headed in the wrong direction, a new study said.
贰补谤迟丑鈥檚 , biodiversity, land, freshwater, nutrient pollution and 鈥渘ovel鈥 chemicals (human-made compounds like microplastics and nuclear waste) are all out of whack, a group of international scientists said in . Only the acidity of the oceans, the health of the air and are within the boundaries considered safe, and both ocean and air pollution are heading in the wrong direction, the study said.
鈥淲e are in very bad shape,鈥 said study co-author Johan Rockstrom, director of the Potsdam Institute for Climate Impact Research in Germany. 鈥淲e show in this analysis that the planet is losing resilience and the patient is sick.鈥
In 2009, Rockstrom and other researchers and used scientific measurements to judge 贰补谤迟丑鈥檚 health as a whole. Wednesday鈥檚 paper was an update and it added a sixth factor to the unsafe category. Water went from barely safe to the out-of-bounds category because of worsening river run-off and better measurements and understanding of the problem, Rockstrom said.
These boundaries 鈥渄etermine the fate of the planet,鈥 said Rockstrom, a climate scientist. The nine factors have been 鈥渟cientifically well established鈥 by numerous outside studies, he said.
If Earth can manage these nine factors, Earth could be relatively safe. But it鈥檚 not, he said.
In most of the cases, the team uses other peer-reviewed science to create measurable thresholds for a safety boundary. For example, they use 350 parts per million of carbon dioxide in the air, instead of the Paris (2.7 degrees Fahrenheit) of warming since pre-industrial times. This year carbon in the air
The nine factors are intermingled. When the team used computer simulations, they found that making one factor worse, like the climate or biodiversity, made other Earth environmental issues degrade, while fixing one helped others. Rockstrom said this was like a simulated stress test for the planet.
The simulations showed 鈥渢hat one of the most powerful means that humanity has at its disposal to combat climate change鈥 is cleaning up its land and saving forests, the study said. Returning forests to late 20th century levels would provide substantial natural sinks to store carbon dioxide instead of the air, where it traps heat, the study said.
Biodiversity 鈥 the amount and different types of species of life 鈥 is in some of the most troubling shape and it doesn鈥檛 get as much attention as other issues, like climate change, Rockstrom said.
鈥淏iodiversity is fundamental to keeping the carbon cycle and the water cycle intact,鈥 Rockstrom said. 鈥淭he biggest headache we have today is the climate crisis and biodiversity crisis.鈥
University of Michigan environmental studies dean Jonathan Overpeck, who wasn鈥檛 part of the study, called the study 鈥渄eeply troubling in its implications for the planet and people should be worried.鈥
鈥淭he analysis is balanced in that it clearly sounds a flashing red alarm, but it is not overly alarmist,鈥 Overpeck said. 鈥淚mportantly, there is hope.鈥
The fact that ozone layer is the sole improving factor shows that when the world and its leaders decide to recognize and act on a problem, it can be fixed and 鈥渇or the most part there are things that we know how to do鈥 to improve the remaining problems, said Carnegie Mellon chemistry and environment professor Neil Donahue.
Some biodiversity scientists, such as Duke鈥檚 Stuart Pimm, have long disputed Rockstrom鈥檚 methods and measurements, saying it makes the results not worth much.
But Carnegie Mellon environmental engineering professor Granger Morgan, who wasn鈥檛 part of the study, said, 鈥淓xperts don鈥檛 agree on exactly where the limits are, or how much the planet鈥檚 different systems may interact, but we are getting dangerously close.鈥
鈥淚鈥檝e often said if we don鈥檛 quickly cut back on how we are stressing the Earth, we鈥檙e toast,鈥 Morgan said in an email. 鈥淭his paper says it鈥檚 more likely that we鈥檙e burnt toast.鈥
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