2023-05-31 17:49:53
Not only global warming threatens life on earth as it is known so far, but also other developments influenced by humans. These include, for example, the dwindling freshwater reserves, environmental pollution and the reduction in biodiversity. The Earth Commission, an international association of scientists, has now identified safe and equitable boundaries of the Earth system and put them in numbers. in their study The group writes in the journal “Nature”. around Johan Rockström from the Potsdam Institute for Climate Impact Research (PIK) that seven out of eight safe and just borders have already been exceeded.
From the point of view of the more than 40 scientists, people with their current way of life are endangering the stability and resilience of the entire planet. In the case of biodiversity, for example, the authors of the study believe that two safe and fair limits have already been exceeded: 50 to 60 percent of the land area would have to be left in its natural state or managed sustainably so that the natural services provided by ecosystems, such as pollination, fresh water and fresh air, are preserved. Currently, however, this only applies to 45 to 50 percent of the land area. And the requirement that 20 to 25 percent of each square kilometer should be covered by largely natural vegetation is only met on a third of the land area influenced by humans.
The concept of justice also comes into play when it comes to climate change: while scientists still classify warming by 1.5 degrees as “certain” compared to the pre-industrial age, they only see warming by a maximum of one degree as “fair”. Because even as things stand today, tens of millions of people are massively affected by climate change, the study authors write. This number will increase dramatically with every tenth of a degree of warming.
Regional differentiation necessary
“With the previous focus on global mean values, for example the global mean temperature, all regions are treated the same, which is not the case,” explained Christian Franzke from the Pusan National University in South Korea, who was not involved in the analysis himself. “This study now places the focus on ensuring that all regions remain habitable, which is only fair given that the areas most affected by global climate change have contributed the least to global warming.”
“This is an excellent concept for developing options for action in the various regions, nations and sectors that follow this method and a clear call to action,” Daniela Jacob, Director of the Climate Service Center Germany (GERICS), said German Science Media Center (SMC). “The limits that have been crossed clearly show that there is a need for urgency.”
Only one limit has not yet been crossed
The human-caused aerosols in the air are the only criterion for which the safe and just limit of the Earth system has not yet been exceeded, according to the research team. Locally, the fair value has already been exceeded, but due to a lack of data, the researchers do not state the current status of global aerosol pollution.
However, Johannes Emmerling from the Milan European Institute on Economics and the Environment emphasized to the SMC that of all eight, this limit is also the one that is most difficult to reduce to a one-dimensional variable: “Different aerosols and other emissions could possibly also be based on a very be interesting on a fine geographical scale.” Irrespective of this, however, the study is “a wake-up call for politicians”. It shows how many areas we risk losing control of fundamental Earth subsystems.
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