Weekend Facebook post, amended:
The Sixth Extinction: Curious this topic is in the news suddenly, all over the past couple days, since the idea has been recognized for years and the latest Pulitzer Prize winning nonfiction book, by Elizabeth Kolbert, was on precisely this subject. Coincidentally, I read that book a couple weeks ago and will post a summary and comments about it on my blog shortly. The current trigger that all the news is about a new report from an American Association for the Advancement of Science site, http://advances.sciencemag.org/content/1/5/e1400253, which summarizes:
The oft-repeated claim that Earth’s biota is entering a sixth “mass extinction” depends on clearly demonstrating that current extinction rates are far above the “background” rates prevailing in the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction.
As the Time article indicates, “this paper hardly breaks ground in its premise…. What differs, here, are the criteria; the scientists estimated very conservatively when it came to how many species have recently gone extinct, and still found that conservative estimate showing the likelihood of an environmental cataclysm.”
Here’s another post about this at Slate: The Earth’s Sixth Mass Extinction is Here—and Humans are to Blame
There’s a tie here with the recent Pope environmental encyclical and criticism of it on the grounds that it dismisses a primary cause: the exploding [in the contest of Earth’s history] population of the human race.
Some realists/rationalists/scientists welcome the Pope’s stance on accepting climate change, while being troubled by his sidestepping of one of the principal causes: the every-expanding population of humanity. (Of course, the Catholic Church’s stance on abortion to birth control has the underlying motivation of *increasing the human tribe*. Be fruitful and multiply! If only the Church would acknowledge that we humans are smart enough to perceive that this advice cannot continue forever, or we will fill up the planet, destroy all other life on the planet, and doom our species.)
Here’s Lawrence M. Krauss at Scientific American:
One can argue until one is blue in the face that God has a preordained plan for every zygote, but the simple fact is that if one is seriously worried about the environment on a global scale population is a problem. A population of 10 billion by 2050 will likely be unsustainable at a level in which all humans have adequate food, water, medicine and security.