We must all act to stop extinctions

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It is important for everyone ‹ from captains of industry to school children ‹ to understand that documented extinction is happening at a faster rate than our planet has seen in the past 66-million years. If this continues, Earth would have reached the 75% threshold for mass extinction in as little as 240 years: three human lifetimes, or just 10 generations says Prof Robert Blumenschine, Chief Scientist at PAST.

12 Oct 2015 | Robert Blumenschine

Education is key to help society understand the immense challenges we face now and for children just a few human lifetimes away, writes Robert Blumenschine

FOR every CEO, government official or parent, the very real threat of species extinction must matter. Reversing the decimation of nature cannot happen without the challenges resonating in the minds of all society.

The golden thread running through all initiatives should be for everyone to think about the big picture — it is not just our lives and our ecosystems and economies at stake, but those of children just a few human lifetimes away. The time for everyone to starting thinking ecosystemically is now.

We must all conduct our lives, produce products, and provide services in ways that are truly sustainable. The legacy all of us can leave for future generations is to be recognised as having valued nature rather than standing idly by while the slide into the lonely abyss of mass extinction took place.

It is important for everyone — from captains of industry to school children — to understand that documented extinction is happening at a faster rate than our planet has seen in the past 66-million years. If this continues,

Earth would have reached the 75% threshold for mass extinction in as little as 240 years: three human lifetimes, or just 10 generations.

Even though many species have become extinct and many others are critically endangered and teetering on the brink of extinction in the wild, the resounding message is we need to change our practices now to save the planet’s biodiversity and the environments they — and we — depend on.

First and most important, we need to realise we are a part of nature, not apart from nature — a fundamental change in attitude is essential if we are going to change our ways radically and realise that our future prosperity, and perhaps even our very survival, depends on the survival of natural ecosystems and the biodiversity they support.

Palaeontologists have recorded five mass extinctions in the past 540-million years. This is when a large proportion (at least 75%) of living things went extinct in very brief periods of geological time. It is well documented that there is a sixth mass extinction occurring. But, unlike early events, this one is caused largely by human activities, such as the destruction of natural habitats for farming and grazing, building up of urban centres and economic over-exploitation. For example, depletion of fisheries worldwide is threatening many fish species with extinction. We are not concerned only about cuddly pandas — we are talking about the loss of essential ecosystem services. It is about obvious things such as resources we need for our survival — food and water — or insect pollinators.

A significant proportion of crops human populations depend upon are pollinated by insects. Bees are particularly important, but a number of wild bee species are threatened with extinction. If 75% of species become extinct, we are looking at the potential collapse of ecosystems upon which we are dependent for our survival. Any technological innovations to get by thereafter will likely be expensive and benefit only a small proportion of humans.

THE past is still the best place to find the right solutions. Of the five extinctions recorded by fossil records, the most widely known is the demise of non-avian dinosaurs 66-million years ago (with birds the only surviving remnants of the dinosaur lineage).

This mass extinction also wiped out virtually all large and medium-sized terrestrial animals and a large number of plant species. It was primarily related to the fact that photosynthesis had ceased, or receded to very low levels, for a prolonged period of time following a large asteroid impact on Earth.

The World Wildlife Fund’s Living Planet Report paints a disturbing picture of how fast the planet is being catapulted into extinction again. One important point that jumps out is that the living planet index, which measures more than 10,000 representative populations of mammals, birds, reptiles, amphibians and fish, has declined 52% since 1970.

It shows that in less than two human generations, population sizes of vertebrate species have dropped by half. The number of mammals, birds, reptiles, amphibians and fish across the globe is, on average, about half the size it was 40 years ago.

Biodiversity is declining in both temperate and tropical regions, but the decline is greater in the tropics. The tropical living planet index shows a 56% reduction in 3,811 populations of 1,638 species from 1970 to 2010.

The 6,569 populations of 1,606 species in the temperate living planet index declined 36% over the same period. Latin America shows the most dramatic decline — a fall of 83%.

We are increasingly on borrowed time as the rate at which we are using resources and producing wastes shows we surpassed levels of planetary sustainability (ability of natural systems to regenerate resources and recycle the wastes) in the early 1970s.

In fact, it would now take a planet 50% bigger than Earth to generate resources and recycle waste at the rate we are using and producing them.

The International Union for Conservation of Nature estimates of the percentage of species threatened with extinction for each group include cycads 63%; amphibians 41%; chameleons 38%; conifers 34%; reef-forming corals 33%; cacti 31%; sharks and rays 31%; freshwater crabs 31%; freshwater shrimps 28%; mammals 26%; groupers 18% and birds 13%. Very dramatic effects leading to this situation started about 250 years ago with the industrial revolution, which is also when human populations began to grow at exponential rates. We now number 7-billion and are expected to exceed more than 10-billion in the not too distant future.

Humans, one of millions of species on the planet, currently use about 25% of Earth’s net primary production.

Our gluttony will only get worse as human population sizes increase. When one species expands its niche, itis doing so at the expense of other species to the point of decreasing their numbers and affecting their range.

HOMO sapiens, which originated in Africa about 200,000 years ago, was an organism biologically with our capabilities, but technologically less advanced than we are. But this technology was potent as they invented projectile weapons, such as bows and arrows, that allowed them to become the top predators in many ecosystems.

Since then, with the advent of farming 10,000 years ago and recently the industrial revolution, there has been progressively broader niche expansion and much greater production of wastes that are starting to tax Earth to such a degree that we are approaching the sixth mass extinction.

Seminal research by Gerardo Ceballos, Paul Erlich, Anthony Barnosky and colleagues published in June in Science Advances demonstrates that even under conservative assumptions, the average rate of vertebrate species loss over the past century is up to 100 times higher than the background rate.

This is an important finding, because the claim that Earth is entering a sixth “mass extinction” depends on clearly demonstrating that current extinction rates are far above the “normal”, “background” rates prevailing between the five previous mass extinctions.

Society needs to understand the immense challenge and begin to take action today. Education is one way to bring about change.

One organisation doing this is the Palaeontological Scientific Trust, a Johannesburg-based NGO that promotes research, education and outreach in the sciences related to our origins. Its Walking Tall educational theatre project portrays the first forms of life, shows the extinction of dinosaurs 66-million years ago and illustrates the past 7-million years from our first upright-walking ancestors to modern day Homo sapiens. It then tackles the ecological crisis we are in today and the urgent need for effective conservation measures.

The programme is being rolled out to companies and government, too, as it is imperative that the corporate world and policymakers are part of the solution.

Far more needs to be done by everyone in changing patterns of behaviour before a disturbing slide into extinction that will permeate economies and ecosystems alike takes place.

• Prof Blumenschine is chief scientist for the Palaeontological Scientific Trust and is an emeritus professor of

Anthropology at Rutgers University


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