Given that we are so close to the start of a new year, over the next couple of weeks on the blog I wanted to stop and have a look at how our global, regional, and local environments are tracking along. This post is the first in a two-part State of the Environment feature.
Today and next week, I’m lucky to be joined by Professor William Laurance. He is a distinguished research professor and Australian Laureate at James Cook University in Cairns, Australia. A tropical conservation biologist, he has written eight books and over 450 scientific and popular articles. He is a fellow of the Australian Academy of Sciences and has received many professional honors, including the Heineken Environment Prize. He is director of the Centre for Tropical Environmental and Sustainability Science at James Cook University, and founded and directs ALERT—the Alliance of Leading Environmental Researchers & Thinkers—a global conservation-advocacy group that reaches over 250,000 readers each week. He is also a four-time winner of Australia’s Best Science Writing Prize.
The topic of today’s chat is Biodiversity. Many articles and media over the last few years have reported that the Earth is facing a Mass Extinction event on a scale similar to that which wiped out the dinosaurs. It’s been termed the Sixth Mass Extinction event and is really quite scary for life as we know it on Earth.
This is a really meaty article but I’m excited and proud of that. I don’t like to shy away from the big issues which is why I’ve invited Bill to share his deep insights and knowledge on the topic of biodiversity.
Podcast: Play in new window
Do you agree that we’re currently facing the Sixth Mass Extinction event?
We have this natural rate of extinctions but now it’s happening much faster. We sometimes talk about the background rate of extinctions because species do go extinct naturally over time. The average lifespan of a species is typically 1, 2 or 3 million years although some live a lot longer.
We can look back at what’s happened since humans have come onto the scene. We know, going back tens of thousands of years, everywhere that humans arrived, had giant species. For example, here in Australia we had a giant wombat-like plant-eating animal, the size of a hippopotamus.
Everywhere humans went, they wiped out these gigantic species. That’s only the initial human arrivals. Since then, we know for instance when the Polynesians moved out across the Pacific Ocean they wiped out about 1800 species of birds as they colonised the islands. Most of these were birds were indigenous or as they say ‘endemic’ i.e. lived only on a specific island.
In the last couple of centuries, we’ve seen increasing acceleration of these extinctions and it’s happening for a whole variety of reasons.
The biggest reason is probably habitat destruction, we’re destroying forests and ecosystems and fragmenting them. If you look around, you won’t see large expanses of forest, you’ll see patches often surrounded by agricultural or urban areas. There’s a lot of pollution happening. We’re introducing a lot of exotic species; invasive animals, plants, and diseases, which are having some very serious effects. There’s climate change which is going to affect certain types of species. In fact, it’s already affecting a lot of biodiversity. Then you have a lot of other things; changes in fire regimes, poaching and hunting, and illegal mining. Everywhere you look there is incredible environmental change and it’s accelerating.
What we are seeing right now is 1) we have lost a lot of species already, and 2) we know a lot of species have dramatically shrinking populations. Everything we know about biology and conservation biology is telling us that we are increasingly moving into this very dangerous territory. We need to start getting smarter and doing something about the escalating human population, rapidly growing consumption, disparity of economic opportunities and wealth. There’s a whole set of issues that we can talk about but the bottom line is, we are heading very fast towards a sixth mass extinction and if we don’t start rapidly changing course, we’re going to have a very serious problem happening very soon.
If you look at the actual mass extinctions, they were truly horrendous events. The asteroid that hit planet Earth was the equivalent of 5000 Hiroshima nuclear weapons going off at once. The impact and the magnitude of the extinctions was incredible. Basically, you have much of life on Earth being wiped out in probably a year or two; a heartbeat. The extinctions that we are talking about happening now have been playing out now for many centuries, but it is accelerating.
A lot of this stuff will be playing out in the next century or two or three, but this century will be critical in terms of seeing whether we’re going to start to steer away from this sixth mass extinction or whether we will continue our current course.
What is biodiversity and why is it important?
When biologists talk about biodiversity we actually mean something much more than just species. We talk about species often in a shorthand way of talking about biodiversity. Obviously if we lose a species, it’s not replaced by another species, you’re losing biodiversity.
Below the level of species, you have a lot of variations. Within an individual species, you’ll have a lot of genetic and behavioural variation, and variation in the body size, shape, form, and colouration. We call this morphological variation. You’ll have variation in their calls and their physiology. All this variation tends to be oftentimes local adaptations to particular environmental conditions that we see in different parts of geographic range. So, species in a drier area, might be physiologically adapted for drier conditions.
All that variation is critical to the species and so when we see the collapse of populations and the loss of this genetic variation and their numbers, even though the species may be surviving, it may have lost an enormous amount of that critical variation which is the raw fuel of evolution. That’s what allows a species to adapt to new environmental challenges.
A classic example would be if a new disease comes along, we know that when we treat ourselves with antibiotics we kill off most of the bacteria but there’s a few individuals that survive. This is because they have genetic variation and they then become more common. We also know that when we spray pesticides in the environment, we kill off 99.8% of the mosquitoes but there’s a small percentage that survive because of their genetic variation and they then become more common. We can see this happening around us all the time; that genetic variation that allows species to do that.
Above the level of species, there is also an incredibly rich array of ecological and environmental interactions. We know that in rainforests most of the tree species rely on specialised animals to pollinate them. Without those specialised animals, the trees cannot reproduce. They rely on different species of animals to disperse their seeds around which is how they move.
Trees have specialised relationships with fungi which is associated with their roots. Many trees in ecosystems are protected by various kinds of chemical poisons and toxins that they use to defend themselves, and the things that feed on them have physiological specialisations to digest those particular proteins. But this means that they’re very specialised and can only feed on that plant and not other types of plants.
There is an incredibly complicated web of life that is interconnected and is the product of many eons of evolution and co-evolution. Biodiversity is everything from genes at the lowest level all the way up to ecosystems at the highest level and everything in between. We talk about species because they’re the thing in the middle that we all know about, so it’s the shorthand way of talking about biodiversity.
In the modern world today, we’re losing tremendous amounts of genetic variation in many of our species. For instance, the cheetah is a well-studied species and you can take a skin graft from one cheetah and graft that onto another and it will not be rejected. You can’t do that with a human being or most other species, but cheetahs are so uniformed genetically that they’re almost clones of each other. What that means is that if some new pathogen comes along, there’s going to be almost no genetic variation left for cheetahs to survive that. Tens of thousands of years ago they evidently went through some population collapse and they lost much of their genetic variation. A lot of the species that are alive today, are moving into that kind of precarious territory.
We know that these ecosystems are also becoming greatly simplified. We know that there lots of species of plants that produce great big seeds but there’s nothing around today that eats or disperses them.
That’s the modern world that we’re living in that the ecosystems are caricatures of their original richness in biodiversity. It’s not that we’re not going to have biodiversity, we’ll always have something around but it will be a much poorer world. Not just poor because it’s not very interesting, but poor because a lot of things that we rely on are the natural products and services that biodiversity provides. We will be feeling the impacts of this just as the rest of nature will.
What are the current rates of biodiversity loss?
Using the best available information, we know that just since the year 1900, species who are well studied are disappearing right now at between 50 and 100 times the background rate.
A lot of the ecosystems that we live in today have already lost some of their most dramatic and iconic species. The most vulnerable have already disappeared and what we’re seeing is a second wave of extinctions; those that need intact forest habitat, or they’re vulnerable to exotic predators or diseases.
They say if you want to be a good boxer, throw punches in bunches. Well that’s what we’re doing to nature right now. Nature’s not just getting hit with one punch, it’s getting this whole flurry of punches from habitat destruction to fragmentation of the habitat to invasive species to invasive pathogens to climate change to poaching and over-hunting, and all other environmental changes happening all at once. The net impact on the species is not just one of these things but the combination of them all.
If we look at populations of species all around the world we see that they’re not technically extinct but in fact they’re ecologically extinct for all purposes. For instance, if you look at many large-bodied animals such as certain species of elephants, rhinos, and tigers, they have become vanishingly rare. They’re surviving today in only tiny areas of their original geographic range and in maybe only 5% of their original numbers. A lot of these animals were important in dispersing seeds of trees and plants in their ecosystem. Some were important as pollinators. Many of them were important in moving nutrients around ecosystems as part of natural disturbance regimes, and they had other animal species which relied on them in various ways.
We are dismantling ecosystems and making them more impoverished. Even though the species are still clinging to survival in a tiny part of the geographical range, for all intents and purposes they’re basically gone. We have an awful lot of species that are in this situation right now.
Where does Australia sit among the rest of the world regarding the issue of biodiversity?
At every level, most nations are hypocritical. Certain nations like Australia, US, Europe and others have enjoyed high standards of living, and I think we should be very careful to look after our own backyards as well as talking to other nations and hoping they don’t repeat the same mistakes we do.
Australia has lost more mammal species than any other continent. We’ve also got many imperilled species here. We still have high rates of bushland clearing in parts of the country. Australia’s one of the largest exporters of coal which is the dirtiest of all the energy-generated fuels on the planet. This is contributing profoundly to global warming. There’s plenty of things that one can point the finger at Australians and say we can and should do a better job.
That having been said, there’s still important support and national efforts going on. I’ve just returned from Java and Sumatra in Indonesia myself and I’ve just seen orangutans and elephants in the wild; it’s been a fantastic experience. There’s a lot of people from the developing world that are assisting and working there from the UK, US, Australia, Germany, and other parts of the world. They are dedicated and working compatibly with Indonesians. Resources from a lot of these non-Governmental groups and conservation organisations are critical in terms of promoting conservation. Many of these countries are limited in the terms of the resources that they have.
I think that we should be conscious of the fact that these are sovereign nations and we should respect that they make their own decisions. Of course, we can share the lessons that we’ve learnt the hard way. We can help them make better and more informed decisions.
It’s wrong to say that developing nations don’t care about their natural resources, in fact they do and often there is a great deal of pride. We should be willing to work with them on their own terms and respect their own traditions and aspirations. There is a fine line that we must play and if one gets too heavy-handed and start accusing nations of doing a bad job, then you get the notion of hypocrisy thrown in your face pretty fast.
You must operate in a sensitive manner, try to build up the positives, and focus on helping where you can. These are politically sensitive issues and you’re dealing with nations that, by our standards of living, still have many people that are not enjoying anywhere near the material comforts that we have. We must respect their aspirations to have more options and luxuries that we have and enjoy.
What needs to happen to halt or slow the current rates of biodiversity loss worldwide?
There’s a few critical things, you can talk about ultimate factors and proximate factors.
Ultimate factors are the big drivers. When my grandfather was young there was about 1 billion people on the planet, today we’ve got 7.4 billion. We’re heading towards around 11 billion. Most of these people are being born in developing countries which are also the tropical and sub-tropical parts of the world. They’re incredibly biologically diverse and environmentally important. We’ve got climate change and all the drivers of climate change. We’ve got habitat destruction. These are the ultimate drivers.
The proximate drivers are what’s really happening on the ground. This is where we focus more. We continue to talk about the need to discuss family planning, and for young women to have opportunities for education and information about reproduction so they can make decisions. The difference between a woman having her first child at 16-years-old vs 23-years-old is enormous. If she has her first child at 23-years-old, she’ll typically have a smaller, better-educated family, lower rates of divorce, more social stability, better opportunities for employment, and for her children to have better education. Her children will be more likely to be employed and less vulnerable to be attracted by extremist groups etc. When you plug all of that into a computer model, you can see that if you slow down the rate of the birth of the first child, a whole bunch of good things happen.
We focus on what’s happening on the ground. Roads, highways, hydroelectric dams, power lines, gas lines, mining projects, fossil fuel projects. Everywhere we look, these things are exploding all over the world. In many cases, these new projects are road building into some of the last wild places in the world.
Because of increasing human population, we’re seeing a lot of pressure on our parks, world heritage sites, and other protected areas of the world. There’s a huge amount of illegal encroachments; people are invading, hunting and poaching using illegal modern technologies like cable snares and high-powered rifles. They’re slaughtering wildlife in many of these areas as well as burning and destroying a lot of areas that are supposed to be protected.
I’m the director of two research centres and we’re working in more than 40 different tropical nations around the world. For my group here at James Cook University, our focus is around this idea of helping nations better plan and manage where their infrastructure is going to go, to try to maximise the benefits for food production, and try to minimise the impacts on the last wild places on earth. We have to have wild places if we are to have nature surviving, it simply comes down to that.
Are there any habitats that we should prioritise when it comes to conservation?
There’s been quite a lot of work along these lines and there’s something we call biodiversity hot spots. These are areas where you’ve got large number of species and a high proportion of those species are locally endemic. This means that they only occur there and nowhere else in the world.
The second criterion that you need to be a biodiversity hotspot; most of your original habitat must have been destroyed. The original definition was at least 70%. We’ve just done an analysis of the biodiversity hotspots around the world, and we found that half of them have more than 90% of their original habitat destroyed. That’s a real concern.
Today there are 35 recognised biodiversity hotspots. The last and most recent were the forests of Eastern Australia. The other biodiversity hotspots are in the tropics and the heavily impacted forests of West Africa, Brazilian Atlantic Forest and other areas in Central America and the Caribbean. Mediterranean habitats are vulnerable as well, and then we have some island systems which are geographically or climatically unique.
You can google biodiversity hotspots and you’ll get a map come up that will show you these 35 places in the world. If we had to focus on anything, it would be these hotspots. This is because the difference between losing 90% of the habitat and 98% of the habitat is huge. The last surviving bits of forest or habitat in these areas are absolutely jam-packed with unique locally endemic species. If we want to save biodiversity, we need to spend effort focusing on these hotspots.
These hotspots are also where we are finding the newest species. These are species that are completely new to science and have never been discovered. One of the reasons that they haven’t been found before is that they only live in small parts of the world, so they’re not that easy to find.
The bottom line is, if we had to pick one strategy it would be going to the biodiversity hotspot, and doing everything we can to save or restore these last remnants of surviving vegetation, because they’re critical.
You’ve been quoted as saying “the world’s forests will collapse if we don’t learn to say no”. What do we need to say no to?
It’s really these infrastructure projects. Deforestation across the world is spatially contagious, that means when you get an initial deforestation happening, additional deforestation tends to spread away from that initial site. The critical thing is avoiding that first cut; because once that first road goes in, you’re either going to have a lot of deforestation, or you’re up for continual heavy enforcement and monitoring costs that are often only partially successful.
The smartest, best and most cost-effective way is to say no in the first place. It’s the only solution that really works. The good news is that we have the choice; we can say no and we need to say no more often, particularly in these last vanishing wilderness areas because they’re under assault everywhere we look.
We’re seeing enormous proliferation of roads and hydro-electric dams and other kinds of projects, that either produce roads or provide an economic impetus for road-building. We need to focus the infrastructure and the roads on places where land’s already been settled and most of the native vegetation has already been cleared. We need to help the farmers in those areas, try to give them better access to markets, better world investment, and better agricultural productivity in those places. We should not keep continually opening up these last wild places on the Earth and seeing them being trashed, destroyed, and degraded, and then becoming hostile for wildlife and biodiversity. That’s what I meant when I said we have to learn to say no.
What advice do you have for those who are keen to do something about the alarming rates of biodiversity loss?
The first thing I would say is that one engaged, determined person can probably have an impact of ten thousand people. This is not an exaggeration. If you look at individuals who get involved, and get their teeth into an issue, they can have an amazing impact.
If you’re interested in learning more about these issues and getting involved, join one of the conservation organisations. They are good at engaging you by telling you what’s happening, and there is different levels in which you can work. You could join a local group or an international group. There are all different kinds of initiative that they’re looking for; help with writing to politicians, supporting campaigns, or writing to individuals overseas.
There are many opportunities to support at all kinds of levels. It comes down to how much time and effort that you’re willing to put in. There is an opportunity for those individuals who want to become leaders, they can learn about an issue and become spokespeople. In fact, some of the best conservation that we see happening, oftentimes is led by somebody who suddenly became inspired by a particular issue and then ran with it.
Politicians listen to the public; the silent majority have very little impact but the ones that stand up and say ‘this is not right’, and talk to the journalists and get the word out there and engage, those are the people that have the big influence. Believe me, the politicians do hear them and listen to them.
That’s how you affect change in the world; reach out and get engaged. We’re all capable of doing it if we put in a little time and effort, learn to educate ourselves, and get involved. It’s a matter of trying to decide what makes you, as an individual, passionate and what you care about. Those are the things that you’ll do the best and have the most impact on.
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