Tuesday 29 January 2019

2019 – The Earth’s Sixth Mass Extinction

Climate change is only the second most important issue we face.  Even more important than this is the extinction crisis!

Put to one side the point that climate change and the extinction crisis are linked by the human drivers that cause these problems (consumption, economic growth, politics, population etc), but even an awareness of the crisis seems to feature somewhere below the football results in much of the media.

It is difficult to talk about the seriousness of our situation without sounding extreme.  Perhaps a good illustration is by looking back into prehistory.  Some 250 million years ago the earth went through one of its 5 mass extinctions.  That was probably caused by climate change - about 95% of the species on earth went extinct.  It was the great dying.  However, climate change today is progressing even faster and extinction rates are about the same as they were then! 

Of course, species go extinct all the time.  But it has been estimated that we are losing species about 1000 times faster than would be expected for the normal background rate.That’s about 150 to 200 species a day.

But it now looks like even this might be too optimistic with some scientists estimating that extinction might be 10 times higher. So we could be losing species about 10,000 times faster than we should be.  We are indeed in the middle of the 6th mass extinction!

Extinction is the loss of species.  But alongside this is the huge reduction populations of plants and animals.  We are losing bioabundance as well as biodiversity.  Perhaps we’ve focussed too much on extinction – it is the huge drop-off of bioabundance that is most obvious, and most destructive.

WWF Living Planet report looked at about 6,000 populations of vertebrates (animals with backbones) around the world.  The shock discovery was that the average reduction of numbers in all these populations was about 60% since the 1970s. 

Elsewhere scientists have seen a 75% reduction in insect numbers in Germany in just 27 years and this was in protected areas like nature reserves!  Even more shocking was a resurvey of a rainforest in Puerto Rico.  In a time-span of just 35 years the forest had lost 98% of its insect species.  With this had gone much of the bird and mammal life that relied on the insects. 

Furthermore, this is not just something happening a long way away.  Over a similar time-span in Sussex we know that species like turtle dove, eels and water vole have all gone down about 90%.   Once common birds like house sparrow, starling and song thrush are much reduced and the familiar sound of the cuckoo is becoming much less familiar.

Talk about losses like this and we are often asked “is it important”.  A fair question (although you never get the same level of scrutiny when talking about economic growth, beauty products or the cricket scores!) so is this anything other than the loss of unimportant stuff from a past world. 

David Attenborough answers this far better than I can but we are talking about our own life support systems.  Their destruction is already having untold impacts on our economy (but we avoid worrying about that through the simple expedient of not measuring it) to say nothing of the growing human tragedies around the world.  Every mouthful of water you take every piece of food, every breath you make all comes from the natural world.  Even the condition of the climate and our protection from solar radiation relies on a healthy functioning environment.  Is that important enough for you?!  And, by the way, the majesty of nature make life worth living.  Extinction of experience is as big a trajecy as extinction of species.

Instead of just a regrettable loss of a few special species, we are now seeing the crash of bioabundance and the gathering loss of species as the symptoms of the destruction of whole life support systems.  Again Greta Thunberg sums it up neatly – “I don’t want your hope… I want you to panic….I want you to act as though your house is on fire, because it is.”

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