{"id":29113,"date":"2023-06-07T07:51:09","date_gmt":"2023-06-07T05:51:09","guid":{"rendered":"https:\/\/www.discoverwildlife.com\/?p=77492"},"modified":"2023-06-07T08:35:44","modified_gmt":"2023-06-07T06:35:44","slug":"the-sixth-extinction-what-it-is-what-is-causing-it-and-how-many-species-we-are-losing","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcwildlife\/rss_feed\/the-sixth-extinction-what-it-is-what-is-causing-it-and-how-many-species-we-are-losing\/","title":{"rendered":"The Sixth Extinction: what it is, what is causing it \u2013 and how many species we are losing"},"content":{"rendered":"

‘We are in the middle of a sixth mass extinction,’ says Mark Carwardine, ‘but what makes this one different is that we are to blame’. Here he explains more <\/p>

By Mark Carwardine\n \t\t<\/p>

Published: Wednesday, 07 June 2023 at 12:00 am<\/p>

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What is the Sixth Extinction?<\/b><\/h2>\n

Over the last half a billion years, life on Earth has been nearly wiped out five times. These mass extinctions were caused by climate change, volcanic eruptions and, 65m years ago, a giant asteroid smashing into the planet. Many experts believe that the annihilation of wildlife we are witnessing today means that we are in the middle of a sixth mass extinction. What makes this one different is that we are to blame.<\/p>\n

Does everyone agree?<\/b><\/h3>\n

No. Some scientists argue that we are not yet in the throes of a sixth mass extinction, though even most doubters agree that we are on the brink. What is beyond dispute is that we are living in a time of very elevated extinction rates. The great fear is that mass extinctions are believed to unfold gradually, and then suddenly. So we\u2019ll bump along where everything seems moderately okay and then, suddenly, we\u2019ll be past the tipping point.<\/p>\n

Isn\u2019t extinction natural?<\/b><\/h3>\n

Yes. Some 99.9 per cent of all species that have ever lived are now extinct. First, there is \u2018background extinction\u2019 \u2013 the tick, tick, tick of species gradually disappearing through natural selection because they succumb to competition, as Darwin predicted in his theory of evolution<\/a><\/strong>. Second, there are mass extinctions \u2013 periods in the Earth\u2019s history when a significant proportion of species are wiped out \u2013 when luck, not competitive inferiority or superiority, plays a fundamental role in determining which species survive and which don\u2019t.<\/p>\n

So what\u2019s causing the sixth mass extinction?<\/b><\/h2>\n

Quite simply, human overpopulation and over-consumption. There were 2.5 billion people on the planet in 1950, there are 8 billion today, and there are expected to reach 9.8 billion by 2050<\/a><\/strong>. The more people, the greater the pressure from habitat destruction, direct exploitation, pollution, the spread of alien species<\/a><\/strong> and global warming.<\/p>\n

How many species are we losing?<\/b><\/h2>\n

Estimates vary widely. The Millennium Ecosystem Assessment<\/a><\/strong>, which involved 1,360 experts worldwide, estimated an extinction rate of 24 species a day. Scientists at the UN Convention on Biological Diversity<\/a> concluded that the figure should be 150 per day reported the <\/a><\/strong>Yale School of the Environment in 2015.<\/strong><\/a><\/p>\n

Other estimates are much higher \u2013 between 1,000 and 10,000 times the \u2018natural\u2019 extinction rate<\/a> <\/strong>(which is believed to be roughly two out of every million species disappearing per year \u2013 so slow that speciation and extinction more or less equal out). However, there is general agreement that extinction rates have reached levels unparalleled since the dinosaurs died out 65 million years ago \u2013 with no sign of a slowing down.<\/p>\n

Why does it matter?<\/b><\/h3>\n

A study published in July 2017 in Proceedings of the National Academy of Sciences<\/i> estimates that \u2013 shockingly \u2013 we have lost more than half of all individual animals since 1970. The scientists found that more than a billion populations of mammals, birds, reptiles and amphibians have been lost all over the planet. It\u2019s not just about losing endangered species \u2013 we are swinging a wrecking ball through the Earth\u2019s biosphere.<\/p>\n

Will humans be among the survivors?<\/b><\/h2>\n

When a mass extinction occurs, it takes millions or tens of millions of years for life to recover and, when it does, it generally has a new cast of characters. Humans are very adaptable, but no one knows if we might be among them. Even if we can survive, what sort of world would we be living in? And \u2013 this is the big question \u2013 do we really want to keep going down the same trajectory to find out?<\/span><\/p>\n

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