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.
· 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.