The current mass extinction
The planet and its physical systems are not in danger. The earth will continue to turn, volcanoes to erupt, tides to ebb and flow and rain to fall. Nothing we can do can alter that. But the planet’s biological system is a different matter. The earth’s ecology is a thin and delicate sheen that can be damaged very easily. Because historically, that damage has been local, nature can return and rebuild. But if the damage is global, there’s nowhere for nature to return from. Now, the most important thing for humans to consider is that we need that ecological sheen to survive. So damage it and we damage ourselves. Damage it too much and we might not survive. Our position is that that is too much of a risk to be relegated in importance below national interests and share prices.
We’re currently in a mass extinction event.
The growth in extinctions is exponential. Edward O. Wilson, the world’s most respected biologist, tells us that we’re on track to lose half of all species of plants and animals by the end of this century. Ecology is a web of connections, and so if we do lose 50% of all species, it won’t stop there – it will snowball (ecologists call this the ‘cascade effect’). For humans, it will mean deterioration of health and quality of life, and eventual extinction if it doesn’t stop. An ecological crash will be much more dangerous than any economic crash.
Extinction means the end of the line for a species. There’s a natural extinction rate, and it’s about the same rate as the development of new species – around 1 every 4 years. Species hang around for roughly 5 million years on average before becoming extinct, and new species evolve to fill the niches that are left. 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.
Who says so?
Is this view alarmist? Some would say that it is. Who do we believe? How do we make an informed decision? Ultimately, it comes down to figuring out who you can trust. There is simply too much information in the world – too much specialist knowledge in too many disciplines for us to test everything ourselves. So the key is knowing which sources of information you can rely on and which you can’t. When it comes to ecology, surely the most reliable source of information is peer-reviewed academic ecologists? Here’s what they’re saying:
- E O Wilson: the current extinction rate is 1000-10,000 times the natural rate
- American Museum of Natural History: 70% of biologists think that this could be the biggest mass extinction ever
- Convention on Biological Diversity: species are going extinct at rates 1,000 times the background rate
- Peter Raven (ex-President of the International Botanical Congress): we will lose 30-60% of all species of plants and animals during the second half of this century, if current trends continue
- International Union for Conservation of Nature: extinctions are currently around 1000-10,000 times the pre-human rate
- Pitman and Jorgensen in ‘Science’: current extinction rates are about 30,000 per year, which means we’ll lose about half of all species by the end of this century
- World Resources Institute (WRI), in the Millennium Ecosystem Assessment – 1000-10,000 times, and it’s accelerating
- WWF: Living Planet Report, a study of hundreds of species populations from 1970 to 2000, found a 40% drop in populations
- Zoological Society of London: globally, we’re losing around 1% of species per year
- see our links page for more evidence
You don’t have to be a mathematical genius to know that this can’t continue for long. But some people will contest the figures; they will underplay the dangers of continued ecological damage on this kind of scale; they will claim to have better evidence than professional scientists who have worked in the field all their lives; or, for political reasons, they will work hard to oppose the kinds of things we will have to do to stop the extinctions.
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 – 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 can be so low that it doesn’t really contribute to biodiversity (a diverse and healthy ecology) any more. 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?
What’s causing it?
It’s not an asteroid or volcanic activity this time – 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 main causes of extinctions, in order of importance:
- destruction and fragmentation of habitats
- toxification of environment
- overexploitation – direct removal of species / biomass
- introduction of non-native species that outcompete or kill native species
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, some 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, and it falls over.
Ecology delivers the things that we need to survive – clean, oxygen-rich air, fertile soil, 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 we do?
Plus policy changes:
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