If there were a checklist that could be used to check the health of planet Earth, it would be full of alarming ticks. For the first time, researchers have quantified all nine planetary limits, which together define a safe operating space for humanity. Six of these nine exposure limits have been exceeded, according to a new study from the Potsdam Institute for Climate Impact Research (PIK). The scientists were able to provide a detailed overview of the Earth’s dwindling resilience.
The six planetary boundaries exceeded concern, among other things:
Even after they have been exceeded, the pressure of global processes on these boundaries continues to grow, according to the study, which was published in the journal “Science Advances”.
“This general update of planetary boundaries clearly shows that Earth is a patient that is not doing well,” said PIK director Johan Rockström, one of the study’s authors. It is unclear how long crucial limits could be exceeded in this way before the effects lead to irreversible changes and damage.
According to the information, crossing a border does not mean drastic changes that become immediately visible. However, it marks a critical threshold for significantly increasing risks.
“We can think of the Earth as a human body and the planetary boundaries as a form of blood pressure,” explained lead author Katherine Richardson of the University of Copenhagen. “A blood pressure of over 120 over 80 does not mean that there is an immediate risk of a heart attack, but it does increase the risk.” That’s why we’re working on lowering blood pressure.
For the first time, the limit for so-called novel entities – the introduction of new substances – was quantified for the study. The assessment shows that it has been exceeded. Novel entities therefore include the entry into the environment of all new, human-made chemical compounds such as microplastics, pesticides or nuclear waste.
Furthermore, scientific evidence for the quantification of the limit for aerosol pollution in the atmosphere was evaluated for the first time. This limit has not yet been exceeded, but it may be exceeded regionally.
