An annual full-body check-up for the planet

Multimorbide, so nennt man Menschen, die an mehreren Krankheiten gleichzeitig leiden. Und mehrfach schwer erkrankt ist nach dem Dafürhalten vieler Wissenschaftler auch unser Planet. Patient Erde wird schlechter. Das ist an sich nicht neu, die Katastrophenbilanzen der Klimaforscher waren zuletzt immer öfter flankiert von ökologischen Mängelberichten aller Art. Aber nun ist das Siechtum des Patienten Erde zum ersten Mal auch aktenkundig: Im „Planetary Health Check“ sind die Resultate des ersten Ganzkörper-Gesundheits-Check-Ups unseres Heimatplaneten seit diesem Mittwoch in einem 97-seitigen englischsprachigen Bericht nachzulesen.

Es ist der erste von voraussehbar vielen weiteren Check-ups. Denn der planetare Arztbrief soll von nun an jährlich aktualisiert und veröffentlicht werden. Zuständig dafür ist eine internationale Gruppe von Wissenschaftlern mit dem schwedischen Erdsystemforscher Johan Rockström an der Spitze. Der diesjährige Preisträger des Tyler-Preises – des “Umweltnobelpreises“ – ist seit einiger Zeit Direktor des Potsdam-Instituts für Klimafolgenforschung (PIK) und war vor anderthalb Jahrzehnten entscheidend an der ersten Aufarbeitung der für den Check-up entscheidenden „planetaren Belastungsgrenzen“ beteiligt. Sie sind namensgebend für die Autorengruppe des Planeten-Check-ups, die quasi eine neue Wissenschaftsdisziplin repräsentieren: „Planetary Boundaries Science“. Ausgangspunkt ihrer Arbeit sind die im Holozän für viele Jahrtausende stabilen Umweltbedingungen auf der Erde. Sie sind, wenn man so will, der medizinische Maßstab für einen gesunden Planeten. Und sie legen fest, wann die störungsfreien Limits überschritten, die Leitplanken des ökologisch dauerhaft Tragbaren gesprengt werden.

What is now to be determined annually is, so to speak, the complete blood count – plus whole-body scans. Nine different measurements indicate how far the planet is from safe ecological operation (from the “safe operating space”). And the first edition of the check-up is indeed somewhat worrying, which is not surprising after the sometimes disastrous findings collected in recent years: Six out of nine stress limits have been exceeded. The earth is operating outside the safe green area “and is rapidly approaching the red alert state,” it is said.

The global extinction of organisms, for example, has progressed beyond the long-term tolerable limit, as has “functional” and “genetic” biodiversity. Nitrogen and phosphorus pollution of the environment is also already well advanced, as is man-made climate change, in which the radiation effect of additional greenhouse gases and the increase in carbon dioxide in the atmosphere are particularly relevant. The overuse of land, seas and freshwater is also already beyond the scientifically defined limits. As for ocean acidification, which has been increasing for decades with the input of carbon dioxide into the oceans and primarily affects skeletal marine animals – and thus entire ecosystems – the report states: The value is on the brink, and the ecologically tolerable limit may be about to be exceeded.

There are only two environmental values ​​that are still within the normal range globally: the thinning of the stratospheric ozone layer – including the “ozone hole” discovered forty years ago – and the aerosol – i.e. particle and fine dust – pollution of the atmosphere. Recently, air pollution has improved overall around the globe, which is mainly thanks to technical advances in air pollution control, the energy transition and, not least, stricter air pollution standards in many countries. Significantly, air pollution is the only one of all nine pollution values ​​that is declining – and this certainly has its price. Because the decrease in pollution and aerosol density in the air is heating up the atmosphere and the oceans even more. In a sense, the “climate disease” is worsening even faster than it already was.

When presenting the report, Colombian Nobel Peace Prize winner and former President Juan Manuel Santos made it clear how urgent countermeasures are to ensure that the condition of patient Earth gradually improves again, using the example of the particularly explosive climate crisis: “We only have five years left to turn things around.” What he meant was the remaining budget of carbon dioxide emissions. If the global community does not reduce emissions quickly in time and achieve climate neutrality by the middle of the century as internationally agreed, said Johan Rockström, even the last intact climate buffers on Earth would be overwhelmed and critical tipping points with global consequences would be the result.

In addition to Santos and the Irish ex-president and High Commissioner for Human Rights, Mary Robinson, the planetary health check-up has also received support from indigenous groups. Their important role in dealing with environmental damage and protecting ecologically intact habitats has become increasingly clear in recent years. Levke Caesar, one of the main authors of the “Planetary Health Check”, said: “The message is clear: the environment is often damaged locally, but this puts the planet as a whole under pressure and can ultimately affect everyone, everywhere.” If the planet suffers, people suffer: the planet's organs are becoming weaker, warned Caesar, and its resilience is increasingly decreasing.