Species extinction and biodiversity loss

Humans haven’t just limited our destruction of the environment to digging up carbon-rich materials and setting fire to them.  We’ve also caused a somewhat separate, but related, planetary effect from the sheer number of people and the intensity with which we exploit the environment.  

Here are some sobering statistics to give you the scale of the problem of loss of habitat and biodiversity from the actions of 7.6 billion people:

  • Human action has significantly altered 75% of land- and 66% of the sea environment.  
  • 1/3 of land on earth is now used for agriculture (70% in the UK)
  • 96% of the biomass of mammals on earth is either a human, or one of our livestock animals.  70% of the biomass of birds is made up of chickens or other poultry we keep for meat and eggs.
  • 290 million hectares of forest (that‘s over 10 times the area of the whole UK) were lost between 1990 and 2015 – clearing land for cattle, growing feed crops for animals, and palm oil are major causes
  • Since 1700 over 85% of wetlands have been lost
  • Since the rise of human civilisation 83% of wild mammals have been lost
  • The rate of species extinction is currently 10-100 times faster than the historical average. That’s not loss of a population in a particular place (eg red-backed shrike in the UK), that’s total irreversible loss of the species across the entire world (eg dodo).  
  • The average abundance of native species in most major land-based habitats has fallen by at least 20%, mostly since 1900. (eg In the UK hedgehogs have declined by 70% in the last 20 years, 30% of bees and pollinating insects are in decline, not great since 75% of crops globally need animal pollinators)
  • 1 million species (around 15% of the total) are threatened with extinction, including 40% of amphibians and 25% of mammals.

What is the cause of all this loss of species and biodiversity?  There are several factors, in decreasing importance . . .

  1. Changes in land and sea use – mainly using land for agriculture
  2. Direct exploitation of organisms – eg unsustainable fishing
  3. Climate change, so this is related to co2 emissions but not a sole consequence
  4. Pollution – eg agrochemicals
  5. Invasive alien species – getting worse with climate change

Clearly a lot of these are global problems but we believe that local action is the root of a lot of the solutions to stopping and restoring our worldwide damage to nature.  The food we eat – 40% of our food is from outside the UK – and the products we buy (eg the 50% of things in supermarkets that contain palm oil) have reverberations around the world. Nobody clears rainforest for fun, it happens because of economic incentives and developed-world markets are a large part of these.  

Even though our own region and country looks a green and pleasant land, we’ve had very substantial loss of habitat and wildlife – more than the global average – and there is plenty we can do to improve our environment.  Only 12% of the UK is covered in forest (9% is urban), the european average is 37% forest.