TRANSCRIPT
Charli: Down here, right under the ocean's surface, is a forest.
Mick: The kelp forests, the giant kelp forests we talk about, that's the plants that grow to 10, 20, more, metres deep. Not small stuff.
Mick: It's these iconic plants, they are to be specific about it, they are a plant called Macrocystis pyrophorus. It's the fastest growing marine plant in the world. Ideal conditions - it could grow over 30 centimeters, more, in a day.
Charli: Tall, slender kelp stems stretch tens of meters up from their tangled holdfasts on the ocean floor.
Their fronds, long, silky and green, wave and dance with the currents.
In this forest, it's cold. It has to be.
Mick: It's only known from the cooler temperate waters of the world. The nutrient levels are ideal for that plant when the temperatures are down around 12, 13 degrees. And the reason for that is the higher nutrient levels in the water drives the system.
Charli: Hidden in the trees and the bushy sea plants on the ocean floor, are thousands of species, from silky seals to teeny tiny organisms, most of them still unknown.
Mick: You've got a lot more phytoplankton and therefore you've got zooplankton, therefore you've got small fish, therefore you've got big fish.
Mick: They've been around for eons of time. They have their own ecosystem. It's a three-dimensional system. So instead of just animals, other plants within a meter or two of the bottom, these things have spread right through to the water column. With all that comes a massive supply of invertebrates all over the leaves.
Charli: These are the giant sea kelp forests, and they're unlike anything else.
Mick: Diving through the kelp forest is a unique experience... [you’re] effectively flying through a tall tree forest. Three dimensional.
Not just looking up, but looking down, looking down on these massive great plants.
And then looking up because it has a canopy as well, it spreads out on the surface, so when it’s really thick you down in 20 meters of water looking up at these massive great trunks effectively and the sunlight dappling through the canopy on the surface.
Mick: It is a very unique experience; there’s no question about that.
Charli: The Great Southern Reef, in the oceans off Tasmania, Australia, was famous for having these rare underwater forests.
Mick: We still get requests for that exact experience.
*phone ringing*
Mick: ‘I'd like to come to Tassie to dive the kelp forest’. Well. We're sorry, at the moment, we can't really help you. There isn't any available on the coast that we frequent.'
*phone hanging up*
Recurring opener:
Charli: Have you heard that climate change is kind of expensive?
Clip montage
Sam: It's true. Repairing the damage wreaked by climate change is already costing us a lot.
Charli: But not doing anything about it? That's going to be even more expensive.
Gernot Wagner: "The costs of not acting are much larger than the costs of acting."
Sam: Like around 38 trillion dollars every year by 2050 just for extreme weather damage.
Charli: In this series from Living Planet, we've being digging into the real costs of climate change…
Syd Kitson: "These storms are getting more unpredictable and they’re certainly getting more violent."
Brent Finlay: "Our feed systems collapsed. Our biodiversity collapsed.”
Dr. Sandy Robertson: "We've seen hospitals have their IT systems completely crash because they've overheated."
Sophus zu Ermgassen: "And those costs are starting to become unacceptable."
Sam: How we can reduce those costs..
Catherine McKenna: "The big polluters need to pay. They’re not paying enough, their emissions continue to rise..."
Charli: And just how much there is to save. This is Living Planet. I'm Charli Shield.
Sam: And I'm Sam Baker.
Charli: This is the final episode in our 5-part series on the Costs of Climate Change. We’ve covered a lot already - from the rising costs of extreme weather and heat-related healthcare, to how much a renewables transition will save us, and who’ll pay.
Sam: If you've missed the previous episodes in the series, don't worry, you can certainly start here. But once you're done with this one, we do recommend going back and listening to the rest!
Charli: In today’s episode, I'm going deep on the cost of losing nature to climate change, and the flipside: what we stand to save if we invest in its protection.
Recurring opener end
Charli: To tell this story and to dig into the costs and the savings, first I'm going to take us back to where we started this episode: Tasmania's east coast. Do you know where Tasmania is, Sam?
Sam: Ah, it’s south of the mainland of Australia.
Charli: Correct!
Sam: Woo.
Charli: For those not already familiar, Tasmania is a small island off the southeastern corner of Australia. And what else do you know?
Sam: That’s where the Tasmanian devil is from – another Looney Tunes reference – and, ah, I think it’s colder than the rest of the country, because it’s further south, so that would make sense?
Charli: That’s right, it is cold, which is relevant for today’s episode actually. And, in general, it’s just incredibly beautiful and rich in biodiversity. People come from all over the world to Tasmania to see something different, something special... And that is of course where I met a man called Mick Baron, who you heard at the top, talking about the giant sea kelp forests.
Hi, my name’s Charli, I’m looking for Mick Baron...
Yeah, cool. Mick is right over there. Awesome, thanks! Cheers.
Hi Mick! How’s it going... Let’s go out on the verandah, want a hot drink?
Mick: My name is Mick Baron. I'm living down here in the southeastern corner of Tasmania. I run a little business called the Eagle Hawk Dive Centre. Been here for over 30 years.
Charli: Mick is a diver and a business owner, with a background in biology. He's based at a place called Eaglehawk Neck — it's a narrow strip of land connecting two bits of Tasmania at the very bottom of its southeastern end. It's named after the eagle hawks that soar overhead in this very exquisite strip of coastline.
Charli: Mick started diving in the giant sea kelp forests off Tasmania's east coast 50 years ago. In that time, he's documented the rapid decline of this quiet powerhouse of an ecosystem.
Mick: When we first started this business back in 1991, we had forests everywhere. 10 kilometres to the north in the bays, all the way down to this last one, which is 20 kilometres to the south.
Charli: Back then, the kelp forests were thick and healthy. Kelp is a type of seaweed, by the way. And the idea that these forests might one day vanish was not really something on people's minds 30 years ago.
Mick: You couldn't put a net through it. You couldn't drive your boat through it. You couldn't set a pot inside it. I mean, we're talking serious areas of coverage and dense, I mean, just dense forest.
Mick: The last one, we call it Munro Bight Kelp Forest, that was the last one to disappear.
Charli: The loss of the kelp forests was as fast as it was unexpected.
Mick: I would never have believed anybody that would tell me this story. But I saw it over a period of three to four months.
Mick: In early December of 15, the temperatures were about right, 14 and a half degrees at that time of the year. And then normally it takes up till February and March for the temperatures to get up over 17 to 18. I actually saw it, it went from 14 and a half degrees to over 17 degrees in less than 10 days.
Charli: That's about 63 degrees Fahrenheit. Mick's talking about an ocean heatwave that happened at the end of 2015, caused in part by a particularly strong El Niño.
Mick: Now that was a major, major shift, sudden shift in the water temperatures. And over the period of three months, by the end of March in 16, that whole big forest — at that time in December, it was over 200 metres long, 50 metres wide, between 10 and 20 metres depth. By the end of March, there was not one plant left. Not one. Just took it out.
Charli: But even before then, though it might not have been as visible, things had started to change. The reasons, Mick explains, start, fairly and squarely, with climate change — which, as it tends to do, set off a chain reaction in this environment.
Mick: One degree in winter off the east coast of Tasmania has changed our ecosystems. The giant kelp is another victim of the warmer water...
Charli: The giant kelp can't survive in warm waters. They're not nutritious enough.
Mick: Everyone loves diving in warm water. For obvious reasons, it’s very easy, very relaxing and the water is generally quite clear. But it’s clear because there’s nothing in the water. When you have a look at all the big fisheries of the world, the big biomass fisheries of the world, they’re all in cold water.
Charli: The giant sea kelp forests are just a drop in the ocean when it comes to the ecosystems being reshaped and erased by climate change. You can probably think of one in your own part of the world.
News montage
Charli: From vanishing coral reefs in the tropics to thawing permafrost in the Arctic, drying wetlands to burning rainforests, rising temperatures are causing widespread harm. And when habitats disappear, the wildlife inhabiting them go, too — on average, wildlife populations are 73% smaller than they were in 1970. Scientists call this 'sixth mass extinction' — because, for the sixth time in Earth's history, more than three quarters of its species are disappearing in a geologically short period.
And when ecosystems and species disappear, so do the things they quietly provide: pollination for our food crops; carbon storage in forests and wetlands, natural flood barriers, clean water, and even the biological compounds used in medicines. Some researchers have coined a name for these things — they call them 'ecosystem services'. It's a term used in a couple of different ways. Mostly to describe how nature does stuff for us and provides things that we need.
Sophus: The whole idea behind ecosystem services is to kind of give the value of nature some kind of form, some kind of form that you can then use to account for in your models, you can use to quantify the value of nature's contributions to the human economy.
Charli: Sophus zu Ermgassen is an ecological economist at the University of Oxford. He says there are thousands of things that could be classed as ecosystem services. But pollination — from bees, birds, butterflies, bats, beetles and moths — that’s one of the clearer examples.
Sophus: So actually a huge proportion of all of the world's agricultural commodities depend on insect pollinators in some way. And so if the human economy implements management measures that destroy pollinators, then it will also have these knock-on impacts on the human economy by undermining the quality of insect pollination in our agricultural systems. And so you can then do lots of cool statistics to work out what the contribution of not killing pollinators is to the human economy.
Charli: To calculate those cool statistics, you have to figure out how much nature is worth...
For decades, ecological economists like Sophus have tried to tally up the value of all the planet's ecosystem services. One of the most-cited estimates comes from a landmark 1997 study in Nature, which put the value of the stuff the natural world gives us at on average minimum $33 trillion each year.If you think that sounds huge, the figure was revised in 2021 — to over $100 trillion. So, more than the value of the entire global economy. But because traditional GDP doesn't count these services or nature in its calculations, ecological economists say it's ignoring the very thing the economy is built on. And if these big numbers seem overwhelming, don't worry, Sophus says the point of them isn’t to be exact, but to offer perspective.
Sophus: The whole purpose of those kind of numbers is to make a really strong point. It's not necessarily that you should view nature in this way, but it's to point out — look, the human economy has got a really big problem. The contributions of nature to our economies are really, really big. And they're currently, basically just not systematically accounted for in economic policymaking. And that is crazy.
Charli: So, what are we missing when we fail to account for the value of a kelp forest?
Mick: You might not see a great big whale swimming through it, but when you get down to the micro level, it's absolutely teeming with invertebrates that most people would never see…
Charli: Giant kelp is a keystone species. Meaning the existence of an enormous number of organisms in the same ecosystem are dependent on it. Mick describes the kelp forests as a kind of nursery for countless species. It's nutrient-rich and protective.
Mick: Two thirds of the species aren’t even identified. We don’t even know all of what’s there!
Charli: It will come as no surprise that all these critters — the crabs, corals, worms, urchins, stars and fish, the octopi, jellyfish, snails and sea plants — are important for healthy underwater ecosystems, which are effectively their own little universes, in which everyone has a role to play. Including species as strange and wonderful as the 'majestic weedy sea dragon'. A species only found in Australia, that Sir David Attenborough himself once described as one of the most incredible animals you could ever see.
Mick: Imagine a seahorse. But these things are much bigger. And they don't have a prehensile tail. Seahorses can go in and grab hold and sit on the stalk of a kelp, brown seaweed. This dragon, he grows to 45 centimeters, and the colours are just fantastic there. Seahorses generally are brown, relatively drab colour, but the dragons are bright red, yellow, blue, really vibrant colours. And they are very unique, they have little tassels and yeah, they're very iconic little beasts, yeah.
Charli: These weedy sea dragons have evolved to look kinda like seaweed — dangly and delicate — but, sparkly fun seaweed — with stripes and spots in neon yellow, purple and blue.
Mick: The numbers are dropping as well of those animals over the last five years as well. And I've got a gut feeling it's related to the lack of the forest. Because in the places we used to go, there were forests in there, and we'd have no problem finding three, four, five dragons in a dive. No problem. And this year, it's the worst we've had.
Charli: Not only do the kelp forests provide a habitat and serve as a breeding ground for all sorts of marine life, they also help regulate the climate, cycle nutrients and form an important part of coastal protection. One study published in Nature in 2023 estimated the value of three key 'ecosystem services' provided by six of the world's major marine kelp forests to be, on average, $500 billion per year.
Some local people in Tasmania have found ways to benefit from the kelp's disappearance though.
Mick: The fishermen reckon it's great because they can now put gear down where they couldn't put it before.
Charli: But Mick says these economic gains are only enjoyed by a select few, and, ultimately, short-term. They won't make up for the bigger costs of losing the kelp — the ripple effects of which will be felt by many.
Mick: But in the long term, no, it's the opposite effect. It’s a devastating effect, I believe.
Charli: And there are plenty of other examples that illustrate this exact trade off. Where investing in protecting, or reviving things like pollinators, or mangrove forests, delivers much more value to society than by destroying it or exploiting it for short-term profit.
Sophus: Absolute classic examples are things like: there are many cases where the clearance of mangroves for shrimp aquaculture, for example, might generate more wealth for the individual owner of that particular aquaculture facility, but society is massively worse off because of the obliteration of the ecosystem services provided by those mangroves. And they can include; the way that mangroves attenuate coastal storm surges. So they protect infrastructure that's behind your mangroves. And mangroves are also an incredibly valuable ecosystem in supporting all of our natural fisheries as well, by providing safe harbor and protections from predation and high levels of nutrients, et cetera, for young fish.
Charli: Yet another study published in Nature in 2022 found that the flood protection benefits provided by mangroves are worth about $65 billion per year. And that's just one thing mangroves do.
Sophus: And so we can show many, many tens of case studies where society as a whole generates less economic value from these extractive land uses, but they happen anyway because it tends to be that one person or one organization is the beneficiary of those, whereas society as a whole is the beneficiary of a less extractive model.
Charli: This brings us to another unexpected benefactor of warmer, emptier waters in Tasmania.
Mick: When the big forests are taken out, the canopy, the light to the bottom, opens it all up. So then you've got these other slightly warmer species, they move in really fast because the temperature is high for them at the right time of the year and the nutrients are just right for them.
Charli: Invasive species. And there's one particular invasive species that is thriving in the absence of the forests. Mick calls it a 'beastie'.
Mick: They eat everything. Not just kelp. They'll eat themselves. They are a real survivor. These urchins they will eat the rocks...
Charli: The long-spined sea urchin. As its name suggests, this is an urchin with very, very long, black, moveable spines. The spines contain an irritant toxin that’s released upon pricking. Like Mick says, they eat everything – they can happily survive even after they’ve gobbled up all the kelp – on microalgae and even amino acids in the water.
Mick: It's a native of New South Wales, which is 600 miles to the north of us. And their winter is warmer than ours. So, these little larvae have drifted down the coast...
Charli: Mick says the sites of their destruction – once luscious underwater gardens - now look like asphalt roads.
Mick: So that one-degree temperature shift has changed the whole environment. It's hard to believe, but that's what's happening.
Charli: Interesting fact: you can actually eat parts of this long-spined sea urchin. Its roe is a highly-prized delicacy.
Sam: Mmm. Urchin eggs.
Charli: Not eggs. It’s the reproductive organs...
Sam: Eeee.
Charli: The gonads – which sounds even worse.
Sam: Wow. And who is eating it?
Charli: It’s a very popular delicacy in Asia in particular.
Sam: Interesting. And do you know what these urchin gonads taste like?
Charli: No personal experience, but I watched a YouTube video in which it was being prepared – it’s much bigger than i expected actually, this roe – and she described it as like ’sweet ocean brine’....
Sam: Haha, okay. So many jokes to be made here, but I’ll leave them...
Charli: Haha. Kind of like oysters, apparently.
Sam: Oh, okay.
Charli: You a fan?
Sam: I like oysters, yeah.
Charli: I’m not a big fan personally, but no shame.
Sam: Okay, so this could be one way to deal with the urchins – by farming them?
Charli: Yes absolutely. Harvesting them is one method of combat... it’s kind of already in place. Tasmania already has government-backed sea urchin fishery. But the population is just ballooning, there are more than 20 million on the eastern coastline now. And ultimately Mick says, and these examples we talked about above, the financial gains from this won't make up for the damage done by losing the sea kelp.
Sam: Right it’s still an ecological disaster, the loss of the forests.
Charli: Yeah and that will have a bigger impact on the economy than can be recouped by the harvesting of urchins.
Sam: Got it.
Charli: Alright so, what are our options for avoiding these costs, I hear you ask…
Sam: Yes please.
Charli: We’ll be back with those right after this short break.
TRAILERS
Charli: Okay, so, firstly, there are a bunch of figures out there that estimate how much we need to spend to protect biodiversity, so that it doesn't disappear forever and take us with it... The United Nations Environment Program, for example, came out with an estimate of 8.1 trillion by 2050. So that figure captures what we need to invest in protection for the next 25 years to avoid worst case scenarios of biodiversity and ecosystem loss.
Sam: Doesn't sound too bad, in the grand scheme of figures we have been looking at throughout the series...
Charli: No, that’s true. However, it still might be more expensive than it needs to be.
Sam: Okay?
Charli: I'll explain why. Or I'll get Sophus to help me explain why... So, Sophus says that it's these estimates that we need to be careful about and interrogate what's hidden in them, you know what they're really proposing.
Sophus: So that number is actually much more controversial, I think... I'd say those estimates of exactly how much money is needed to avert biodiversity loss, they're super controversial because they make some assumptions that the way to solve biodiversity loss is basically to run profitable businesses that improve biodiversity. So, it's all about how much money needs to go to acquire or manage areas of land for the delivery of biodiversity outcomes.
Charli: These funding estimates for ‘protecting nature’ are based on the idea that investing in things like buying up land for to hold it for ‘conservation’ or paying farmers to manage their land in more environmentally friendly ways, will end ecological collapse. And even though those things are important, Sophus says this whole approach overlooks a fundamental problem.
Sophus: You can see that that logic, I think, misses quite a large part of the picture, which is that we can actually probably address the majority of biodiversity loss through government regulation to stop those harms happening in the first place.
Charli: In other words, if we just took better care of the environment, of wildlife and their habitats, we wouldn’t need to spend 8 trillion dollars. And, in any case, that money is not aimed at fixing the root causes that are leading to species loss.
Sam: So, in this case climate change...?
Charli: Yes, climate change is one of the roots causes, but it’s not the only one. On land it’s actually the fourth biggest driver of biodiversity loss, after intensive agriculture, harming/exploiting animals through hunting, trade and logging, and pollution – of the air, soil and water. But in the ocean, climate change is the second biggest driver of this loss – after industrial fishing. So basically, we should start by addressing these major drivers - rising temperatures, deforestation, overfishing and industrial farming
Sam: Before forking out more money for some sort band aid solution?
Charli: Exactly – if we don’t deal with those no amount of money will help undo the damage.
Sophus: And all of these things, the answer to those things is not just to necessarily to pay people or to create profitable business models around delivering improvements in biodiversity. You can see that they're all giant complex problems and regulation is definitely a big part of those solutions. And essentially the more regulation you do to restrict the damages of those types of systems, then the less you have to pay to improve biodiversity.
Charli: In fact, one major study published in the journal Science in 2024 found that in a scenario where strong policies to support biodiversity are adopted — such as strong land-use regulations and climate change mitigation — biodiversity loss could be significantly slowed and the loss of ecosystem services could be reversed. Which, the authors said, would be the best-case scenario for human wellbeing.
Charli: Not everyone is on board with the concept of 'ecosystem services'. Some researchers argue this framing reduces nature to a set of commodities, and erases or undermines the cultural, spiritual and deeply personal meanings people attach to the natural world. They fear it can also create a divide — an us versus them mentality, which many see as part of what's driving ecological collapse in the first place. And when you really think about it, the full 'value' of nature is pretty hard to describe.
Sophus: To lose nature is to lose something completely beautiful about the history of the biology of this planet. It would be the loss of a combined evolutionary history that has emerged on earth, that has co-evolved on earth over billions of years...
Charli: Then, there is the politics, and economics, of our current moment. The point of putting a price on nature, its proponents argue, is to emphasize something many are failing to see.
Sophus: If you want to make the kind of the rational economic argument for addressing biodiversity loss, then the things that people normally talk, speak to, are the fundamental ways in which the diversity of nature underpins the human economy. We can't live without it… the human economy is a small subsystem of the overall biosphere of nature and all of its natural interactions. And if we undermine that to the capacity and undermine its capacity to support the human economy, then the human economy won't exist anymore.
Charli: The economic model we’ve had for the last several hundred years isn't built to account for this — the value of nature, or the cost of losing it. And that's part of why we're facing the environmental crises we see today. Sophus says it's kind of understandable that these things weren't taken into account, back when this system was dreamed up.
Sophus: A big chunk of sort contemporary mainstream economics emerged in a world that didn't really consider environmental constraints. And it kind of made sense at the time, because at the time that neoclassical or mainstream economics emerged, the human economy was pretty small relative to the Earth. So, you know, an expansion in the size or the materials consumed by the economy could happen without inflicting major damage on the environment.
Charli: But that world doesn't exist anymore. And the one we've got is bucking under its own weight.
Sophus: The economic model since the rapid industrialization at beginning of the great acceleration, approximately the 1950s, that model has delivered a huge number of benefits and a huge number of costs. And today, the costs are starting to become unacceptable... the transition to a different economic model that just doesn't cause those harms in the first place and where human society starts developing and flourishing within those environmental constraints. That's the grand challenge for me of the 21st century.
Charli: According to Sophus, to solve these problems, it's not as if we necessarily need to reinvent an entirely new economic system from scratch, because many of the ideas for making it work better, to accommodate for the natural world, have been around for quite a while. Economists like him believe a shift is coming. The question is just whether it will happen in a catastrophic way, or a gentler, smarter, cheaper, more productive way.
Sophus: So just because the future looks radically different, that definitely does not mean worse. I think there's loads of ways in which we can create a more vibrant and interesting economy in the future that also has a much lower environmental impact.
Charli: I'm going to take us back to Tasmania once more before we leave you. Because although the story of the giant sea kelp forests is pretty depressing – miraculously, all hope is not lost. The owners of the Eaglehawk Dive Center don't want this to be the end for Tassie's kelp forests. So, they've been trying something.
Mick: We've got a scientific program underway now to try to do something about it.
Charli: Along with some scientists from a local scientific institute in Hobart, they're trying to revive the kelp.
Mick: We started with a friend of mine back in 2016, 17. He was doing an experiment locally on fish farms with kelp. And he had some strings, we call them strings, with little juvenile spores growing on the strings in the lab. He had a few left over, so he called me up and he said, oh, we'll get a permit to put some out on bricks. So we went out here, just the two of us, two or three of us, a couple of little bays and put them on bricks, labelled them and lo and behold some of them got up to 10 metres high in 12 months. So, we thought, hmm! So, we kept doing it...
Charli: For the last few years, they've been growing juvenile kelps in the lab, and planting them in select places in the ocean on the east coast. At the end of 2022, they conducted Australia's first ever forest-scale restoration of giant kelp, planting an area of 7000 metres squared. Six months after planting, the restored kelps had grown to 5m tall.
Mick: Our role now is to train up amateur divers, your average scuba diver that's really keen on sustainability and the marine environment… And when the temperature drops in winter, we'll hopefully round up a number of them and get out there. It's a numbers game.So, we need a lot of people. So that's the gist of it now. To get these courses up and running and get some mad keen people that are capable of diving in winter.
Charli: They need more people, and more permits, and, ideally, more money of course. But it's a start.
Mick: We'll see how it goes. The next 18 months, two years will be a really interesting time.
Sam: Aside from it being wonderful to bring back the giant kelp forests for the ecosystems they support, we also haven't talked too intensely about how important kelp and the oceans are to suck up all the carbon we’ve been emitting. And if we lose that, it will make climate change a lot worse for us on land.
Charli: Yeah. In a way we can think about it like one of the best insurance policies that we can take out is conserving and protecting what we have, and restoring what's been damaged or lost, like the kelp.
Sam: You might say we need to treat our Earth like a living planet.
Charli: Haha. Thanks Sam.
Charli: This episode of Living Planet was reported and produced by me, Charli Shield. Along with Sam Baker. It was edited and mixed by Neil King. Our studio technicians were Jürgen Kuhn and Simon Berkhahn. This was the final instalment in our five-part series The Cost of Climate Change. If you haven't heard the others, please do go back and give them a listen! We cover the rising costs of extreme weather and what's going on with the bananas insurance premiums we're seeing these days; we also cover the cost of transitioning off fossil fuels to clean energy; how we can reallocate funds to pay for this clean energy; as well as the burden climate change is putting on our healthcare systems. It's all pretty interesting, if I do say so myself. If you've still got questions about the costs of climate change, and to be fair, there are plenty of them, send them through to us at livingplanet@dw.com, in email form or as a voice note, and we'll consider answering them in a future episode. Thank you so much for listening.