A recent major report in Science magazine by 23
scientists shows that biodiversity has fallen to dangerously low levels across
two-thirds of the Earth’s surface. By ‘dangerously’ they mean likely to
undermine the natural services, such as food production and waste disposal, on which
we depend. The loss of biodiversity is mainly due to changes in land use.
They authors found that original
species are more than 14% less abundant as before we started changing the land and
are at least 10% less abundant – the accepted warning level – over 90% of the
Earth’s surface.
The authors further show
that this is true for that 58% of the planet on which 71% of people live; so
this is not a small issue for our species.
Should we panic?
Probably not. The loss of
biodiversity does not imply the immediate collapse of world farming (though
there are certainly risks) or the pollution of all ours rivers.
But, it will make the
ecosystems more vulnerable to shocks such as the droughts, floods, storms, etc.
that climate change will make increasingly common and severe. Over and over we’ve
seen how areas of original habitat are reduced to patches in which all the
species seem present. But after shocks, or just lapse of time, key species
disappear. Though we don’t know the tipping points we do knows that they are
there.
The changes in land use have
neither stopped nor slowed. Neither will they stop whilst our numbers and impacts
grow. The extrapolation is obvious: Further loss of habitat and biodiversity.
So though we shouldn’t panic
we should ACT. We need to adopt genuinely
sustainable policies – as the Green Party has always said.
Reference:
·
Title: Has land use pushed terrestrial biodiversity
beyond the planetary boundary? A global assessment
·
Author:
Newbold, Tim, et al.
·
Ref: Science 15 Jul 2016: Vol.
353, Issue 6296, pp. 288-291
·
DOI: 10.1126/science.aaf2201
The paper is behind a paywall but there’s a summary in ZME Science.
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