what are they?Extinction means the end of the line for a species. There’s a natural rate of extinction, and it’s about the same rate as the development of new species – around 1 every 4 years. Species hang around on average for around 5 million years before becoming extinct. New species evolve to fill niches as others become extinct. Biologists estimate that we only know about 5% of all the species that exist. But from the extinctions of species we know, scientists can extrapolate to estimate total numbers of extinctions. If habitats disappear, then so will all the animals and plants in it, whether we have discovered them or not. What if the extinction rate was double the natural rate? Or 100 times? what if we told you that the world's top ecologists, biologists and botanists calculate the current extinction rate to be up to 10,000 times the natural rate? Would you wonder why that wasn't on the front page of every newspaper, or what the implications of that sort of rate might be? Here's what they're saying:
You don't have to be a mathematical genius to know that that can't go on for very long. But some people will contest the figures. They will claim to have better evidence than professional scientists who have worked in the field all their lives. Or they will oppose the kinds of things we will have to do to stop the extinctions on political grounds. They will work hard to rubbish their figures, or underplay the dangers of continued ecological damage on this kind of scale. There have been 5 mass extinction events in history, including the one that did for the dinosaurs 65 million years ago (giant asteroid impact), and the biggest of all, at the end of the Permian, 250 million years ago (volcanic activity), which led to the extinction of about 95% of all species on earth – life on earth was almost completely destroyed. We're in the 6th mass extinction event now. A species may not actually be extinct, but it's numbers are so low that it doesn't really contribute to biodiversity (a diverse and healthy ecology). Species like pandas fall into this category. Less genetic diversity can damage ecology as much as extinctions. According to the World Resources Institute, British butterfly populations have declined by 70% in the last 20 years, and eel populations in Europe have declined by about 99% in 30 years. 99%! that's not extinction, but what has damaged nature so much that only 1% of eels can survive in our waters nowadays? It's not an asteroid, or volcanic activity - it's our activity. Extinctions have always followed humans around the globe, but there are 7 times more of us, and our economy is 30 times bigger than in 1800. Now we are rapidly removing rainforest, overfishing, putting billions of tonnes of synthetic chemicals into the air, soil and oceans, and urban areas are expanding, along with the transport infrastructure that joins them, as well as agricultural land, golf courses, resorts and out-of-town supermarkets. And it's not slowing down, it's accelerating. How can there be any room left for nature? In his book, the Sixth Extinction, Richard Leakey described one particular forested ridge in Ecuador. Ecologists carried out a survey in the 70s and found 90 species not found anywhere else on earth. when they returned 10 years later, the ridge had been completely converted to agriculture, due to a rising human population, and the 90 unique species had gone forever. The only special thing about this ridge is that it was studied before it was destroyed. This is happening unrecorded all over the world. These are the big contributors, in order of importance:
what are the consequences?Clearly, current extinction rates cannot continue forever - there would be no species left at all in a relatively short time. But well before then, there will come a point where the ecology of the planet just doesn't work any more, because all species are interlinked in a complex ecological web (if David Attenborough taught us anything at all, surely that's it). For example, certain plants need certain insects to pollinate them, and their seeds need to pass through other species to germinate; some species can only eat one kind of plant or animal, some are parasitic on others, or have symbiotic existences, etc. So take enough species out of global ecology and, like a game of Jenga, it looks fine until one too many is taken out, then it falls over. Ecology delivers things that we need to survive – clean, oxygen-rich air, soil fertility, fisheries, pollination, pest control, etc. If these 'services' start to break down in a world where the human population is expanding, international relations could easily degenerate into resource wars between countries possessing nuclear weapons. A radioactive world with air quality, soil fertility, fisheries, pollinators and pest predators plummeting, and with high levels of disease and toxicity could indeed be fatal for us – especially if infrastructure and health systems begin to break down too. In that scenario, yes, we could well become extinct. what can I do?Are you sick of politicians and businesses claiming that we can make our current way of life sustainable by not leaving electrical equipment on standby, but encouraging us to buy more electrical equipment? We can't. We have to change the way we live. And the changes required will make your life better. It's not about sacrifices or hair-shirt living. It's about making better lives and a better world. You can join a conservation organisation that campaigns to protect habitats and species - but that's not enough if your lifestyle is contributing to extinctions. You can check your eco-footprint, downshift, and start to incorporate more sustainable ways of living into your life. And you can network with like-minded people, and influence other people by example. And don't be fooled. Those who call for constant growth or 'development' (in the West at least) do not understand ecology and must be ignored if we are to survive, let alone prosper as a species. Economics must stop trumping ecology. We can survive an economic crash, but we may not survive an ecological crash. Individual change is only part of what's needed of course, but without it, social, political and economic change can't happen anyway. We need to limit our activities, in terms of the sheer numbers of us, and what we're asking from the earth's ecology. You can debate the points made in this factsheet on our forum. If you have additional information, or think we've got things wrong, we'd be glad to hear from you.resources
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Siberian tigers used to roam from Turkey (where they were known as Caspian tigers) to the Bering Strait – an enormous area. There are now only 400 tigers left in the wild; so although not extinct, like many creatures, they no longer play any meaningful role in the ecology of their natural range
Edward O Wilson is probably the world's most respected biologist; he thinks we should be extremely worried by the current rate of extinctions
dinosaurs such as this fossilised T-rex became extinct around 65 million years ago, due to an enormous asteroid impact. Human impact is less spectacular, but it's not a one-off, and so the effects are continuing and getting worse; if we don't change, the current extinction event will be the biggest ever
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