The Sixth Extinction
66 million years ago dinosaurs became extinct – an inconceivably long time span. However, they roamed the planet for even longer: astounding 165 million years. Our species has only been around for ~300.000 years now. When the dinosaurs died, three-quarters of all plant and animal species vanished with them, also known as the Cretaceous-Paleogene extinction event. The cause was, to our best knowledge, the impact of an asteroid with devastating effects. The precise number of such large extinction events is under debate, but by many the Cretaceous-Paleogene extinction is regarded as the fifth and latest one.
So, what does the title of this post refer to? It refers to right now: this millennium, this month, this day. Today, a lot of species are dying. Forever. They will be lost for all of the remaining time this planet exists. Estimates vary from 24 up to 150 species every day. It’s neither possible to precisely guess the actual number, nor it’s easy to evaluate how drastic the estimated numbers really are. The question at heart ist: How much larger is this decline of species than the background noise of species extinction that happens naturally? Some people argue it’s 100-1000 as much as it would be without human interference. Others say these numbers are inflated and global mass extinction is, for now, not as drastic as proposed (because the common assumption that decline in habitat area is highly correlated with decline in diversity might not hold true). One of the major hurdles in assessing the severity of the current biodiversity situation is not only that estimates of dying species vary widely, but also that the total number of species that are currently living is still largely unknown.
In 2010, the UN agreed upon 20 major goals for the upcoming decade regarding biodiversity, including specific plans for the conservation of nature and variety of species. The last decade was even termed the ‘United Nations Decade on Biodiversity’. So, how are we doing so far?
Pretty bad! And irregardless of how accurate the estimates on global diversity decline might be, some other numbers are well proven and unambiguous: There is a large decline in animal populations across most domains of life. Since 1970, populations show an average decline of 60%. In south America, due to deforestation of rain forests, the decline in biodiversity is already estimated at 94%. The number of insects in Germany has gone down 70-80% in the last 30 years alone. 25% of all plant, fungi, and animal species are endangered. To quote a rather optimistic assessment: If we presume a total of 8 million species, we will loose at least 1 million by the end of the century. And these effects can mostly be traced back to modern agriculture alone. As soon as climate change really hits (very soon), these numbers are expected to increase significantly again. And even if these changes do not necessarily mean a decline in global biodiversity, the effects of declining local biodiversity are the ones we will pay for.
So the UN agreement from 2010 didn’t turn out well – and by now, I doubt that the Kunming declaration from this year will cause any large-scale systemic change. For me, reading about these events evokes two opposing feelings. First, sadness and helplessness. That we, as a society, are responsible for this undesirable change. That I, as an individual, am responsible for this horrible change. And second, relief. At least five times life has recovered from the most harsh conditions imaginable. And it probably will continue to do so until the heat death of the universe. It’s unclear though whether the species Homo sapiens will survive this next great extinction; by several scientists, this threat is estimated to be even more dangerous than climate change.
Yesterday, the winners of the European Wildlife Photographer of the Year 2021 were announced. Check them out here. Stunning pictures all around! The winning picture of this year also entails a grave background story about our influence on precious nature.