How to think about extinction

At the end of May, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), a UN body, released a policyholder summary of its staggeringly ambitious global assessment report on the state of the world vis a vis the environment. I expected to read, and did read, about humanity’s progress down the road described by Elizabeth Kolbert in her stunning 2014 book The Sixth Extinction. Put simply, our collective responsibility for mass species extinctions accelerates. As IPBES reports, around 25% of animals and plants are “threatened,” meaning that a million species may within decades face extinction. Apparently extinction’s harvest is being reaped hundreds of times faster than in “normal” times. No surprise also that climate change is winding the whole process up.

Oh, how frail I felt when reading the summary! Too expansive, too much to handle. So I decided that one ongoing task would involve narrowing my lens down to the fifteen Crane species I’ve begun to research. What are their prospects?

IPBES says 14% of bird species are under threat of extinction. This is way better than mammals (25%) and amphibians (40%), but we expect flight-powered birds to be able to flee humans better, and in any case 14% is one in seven! On examination it turns out IPBES obtains its extinction-risk data from the “Red List” of another international body, the International Union for Conservation of Nature. The Red List has been going for half a century and it has nine categories of extinction risk. Although coverage of some species of living things is spotty, that of birds seems complete. At the frightening tail end, some 5% of bird species are close to the edge, classified as endangered or critically endangered.

Four of the fifteen crane species are “close to the edge” on the Red List. Eleven are under threat but not so much so. Only four of the fifteen can be seen as healthy in terms of 21st Century survival.

All of which, once more, left me drained. I also felt more lost than ever. I realize classifying extinction risk is subjective. It’s also political: developers downplay any risk, environmental activists seek funding. Right now, I’m no closer to understanding how my cranes will fare over my lifetime, let alone that of my grandchildren. I sighed: more work needed!