The World Will End Tomorrow

Again.

The original claim, based on the influential 1972 best seller "The Limits to Growth," by the Club of Rome, was that resources would have begun to run out by now. Instead supplies of minerals have increased, thanks to ingenuity, technology and demand.

Later the emphasis shifted to humankind's "ecological footprint," which, it was claimed, was exceeding the planet's carrying capacity. But this, too, took a blow when the most thorough assessment of the world's ecology, by Helmut Haberl of the University of Klagenfurt in Austria, found that people and their domestic animals were eating or damaging just 23.8% of the vegetation growing on land, and that in richer parts of the world they were enhancing the productivity of the remaining vegetation by almost as much through irrigation and fertilizer. 

The Riocrats now have a new tack, which will dominate next week's discussion: planetary boundaries. An influential paper in 2009 written by Johan Rockstrom of Stockholm University and 28 colleagues argued that there are nine thresholds, crossing any of which will trigger collapse of the Earth's life support systems: land-use change, loss of biodiversity, nitrogen and phosphorus levels, water use, ocean acidification, climate change, ozone depletion, aerosol loading and chemical pollution.

The trouble with this approach, according to a new report by Linus Blomqvist, Ted Nordhaus and Michael Shellenberger of the Breakthrough Institute in San Francisco, is that, for six of these measures, "there are no global tipping points beyond which these ecological processes will begin to function in fundamentally different ways. Hence the setting of boundaries for these mechanisms is an arbitrary exercise."