Se vogliamo che tutto rimanga come è, bisogna che tutto cambi!
“There are very strong indications that the current rate of species extinctions far exceeds anything in the fossil record.”
This is from Magurran and Dornelas, writing in Phil Trans Royal Society, the PNAS of the old world.
Joe Romm has more. You can accuse Joe of overstating his case sometimes, but “far exceeds anything in the fossil record” is something that is really, really, really hard to exaggerate.
The scary assertion is referenced back to The Future of Biological Diversity in a Crowded World by Robert May (2002).
recent extinction rates in well-documented groups have
run one hundred to one thousand times faster than the
average background rates
Such figures correspond to likely extinction rates of a
factor of ten thousand, give or take at most an order of
magnitude, above background, over the next century or
so. This represents a sixth great wave of extinction, fully
comparable with the Big Five mass extinctions of the
May makes three cases for conservation:
A narrowly utilitarian argument
One argument for the preservation of biological diversity
is narrowly utilitarian. It correctly emphasizes the benefits
already derived from natural products, as foods,
medicines, and so on. Currently, 25% of the drugs on the
shelves in the pharmacy derive from a mere 120 species
of plants. But, throughout the world, the traditional
medicines of native peoples make use of around 25,000
species of plants (about 10% of the total number of plant
species); we have much to learn. More generally, as our
understanding of the natural world advances, both at the
level of new species and at the level of the molecular
machinery from which all organisms are self-assembled,
the planet’s genetic diversity is increasingly the raw stuff
from which our future can be constructed. It seems a pity
to be burning the books before we can read them, and
before we can create wealth from the recipes on their
A broadly utilitarian argument
Another class of arguments is more diffusely utilitarian.
The interactions between biological and physical processes
created and maintain the earth’s biosphere as a
place where life can flourish. With impending changes in
climate caused by the increasing scale of human activity,
we should be worried about reductions in biological
diversity, at least until we understand its role in maintaining
the planet’s life-support systems. The first rule of
intelligent tinkering is to keep all the pieces.
An ethical argument
For me, however, a third class of argument is the most
compelling. It is clearly set out by the UK Government in
This Common Inheritance22. It is ‘the ethical imperative
of stewardship . . . we have a moral duty to look after our
planet and hand it on in good order to future generations’.
Yet he admits that these arguments may not be seen as compelling. Personally, I find the highlighted text dispositive. Anyone who has read Lovelock’s Gaia books will understand that at least conceivably we may breaking things which we may never have the capacity to fix.