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The earth is suffering from an ‘insect apocalypse’: Biologist Dave Goulson on why this matters and what to do about it

Podcast & Video

This episode of Hub Dialogues features host Sean Speer in conversation with Dave Goulson, a University of Sussex biologist and a leading scholar on the ecology and conservation of insects, about his thought-provoking bookSilent Earth: Averting the Insect Apocalypse

They discuss why insects are so important to the ecosystem, what is causing the current insect “apocalypse”, and why we should be worried about this mass die-off.

You can listen to this episode of Hub Dialogues on Acast, Amazon, Apple, Google, Spotify, or YouTube. A transcript of the episode is available below. 

SEAN SPEER: Welcome to Hub Dialogues. I’m your host, Sean Speer, editor-at-large at The Hub. I’m honoured to be joined today by Dave Goulson. A professor of biology at Sussex University in the United Kingdom, and a leading scholar on the ecology and conservation of bumblebees and other insects. He’s also the author of the book, Silent Earth: Averting the Insect Apocalypse, which draws on his lifetime of research to outline the causes and risks of the precipitous drop in insect numbers across the world.

I’m grateful to speak with him about the book’s staggering analysis and what we ought to do about it. Dave, thanks for joining us at Hub Dialogues, and congratulations on the book, which has just come out in paperback.

DAVE GOULSON: Thanks, Sean. It’s an absolute pleasure to be here.

SEAN SPEER: What is entomology and what led you to a career in it?

DAVE GOULSON: Entomology is the study of insects, the little six-legged creatures that make up the bulk of life on earth. They’re amazing. I’ve been fascinated by them, sort of obsessed since I was a little kid. I can’t really explain why but when I was five or six years old, I started collecting caterpillars and trying to rear them up. Keeping them in jams jars and occasionally they survived and would turn into moths and butterflies. I just thought that was amazing and I was hooked ever since. I’ve been really lucky, I guess, that I’ve managed to make a career out of my childhood hobby.

SEAN SPEER: Why should we be concerned about insects? What motivates your work, Dave? Are you driven by utilitarian or normative reasons or both?

DAVE GOULSON: I guess I’ve trotted out millions of times the arguments as to why insects are important, and I will share them with you if you want, but basically they make the world go around. They do all sorts of stuff in ecosystems that we may not be aware of but that we need. They recycle, they keep pest numbers under control, they pollinate our crops and wildflowers, and many other things too.

That may be a good argument when you’re talking to a politician, perhaps a policymaker, someone who doesn’t give a damn about nature but might maybe be swung by facts and figures about crop yield losses if we don’t look after insects, but the thing that has always engaged me with insects is that I just think they’re rather cool. They’re beautiful, they’re fascinating, they’re weird. There’s so much we don’t know about them. I don’t really care about their economic value at all. I just think they’re amazing creatures that deserve to be looked after.

SEAN SPEER: The book’s main premise is that the number of insects around the world is in decline. Before we get into the causes and consequences, let me ask a basic question. How do we know? How do we measure or count the number of insects, including over a historical timeframe?

DAVE GOULSON: With great difficulty is the answer. The reality is there are huge knowledge gaps. There are lots of insects in the world that nobody’s counting. We know of more than a million species, but a lot of them are very hard to identify. It’s a very specialist job. There aren’t that many entomologists like me in the world.

All of that said, we do have long-term data sets for some insects. Particularly it tends to be the bigger, more colorful, easier-to-identify ones like butterflies, which are monitored in the U.K. We have a Butterfly Monitoring Scheme that’s been running since 1976 and that shows roughly a 50 percent decline in butterflies since I was a boy running around looking for caterpillars. There was a study from Germany recently published that I was involved in a bit which found a 76 percent decline in the biomass of flying insects in a 27-year period from 1989 onwards.

The monarch butterfly in the United States, which is a kind of iconic, amazing species that migrates from Mexico up to Canada every year, down about 80 percent since the mid-1990s. Those are just a few examples. There are lots and lots of others. Most of this nobody really tends to notice apart from specialists like me, but there’s one anecdotal aspect of this that I think is familiar to anyone of a certain age, which is the windshield phenomenon.

That many people can recall a time when they were younger when if you drove for a long time in the summer, you’d have to stop every few hours to scrub the windscreen because you just couldn’t see anymore because there were all these poor splattered insect guts all over the windshield. I can remember vividly. I used to have a motorbike, actually, not a car, and the visor on my helmet would just become splattered. That just doesn’t happen anymore. You can drive for hours on a beautiful summer’s day. Yes, there’s a bunch of different lines of evidence, all of which suggest broadly that not every insect but that most insects are in decline, and many of them in a pretty rapid rate of decline.

SEAN SPEER: That begs the obvious question: what’s going on? What are the causes of the insect apocalypse? What’s behind this drop in insect numbers around the world?

DAVE GOULSON: Yes, we think it’s complicated. It’s driven by lots of factors. The biggest is probably still habitat loss. We’re still burning down rainforests, and draining marshes, and destroying insect-rich habitats around the world. Kind of associated with that is the spread of intensive farming, which is often the driver for that habitat loss in the first place. Farming has changed in the last 80 years pretty dramatically. Fields have gotten much bigger, the number of crops we grow has become much smaller. We’ve become very dependent on lots of chemical inputs, particularly insecticides.

Chemicals we’ve invented to kill insects, and we spray them over huge areas of land over and over again. It’s a fairly obvious contributor. There’s more to the story than that. Climate change is starting to kick in. Invasive species have had their impacts. Things like light pollution, which is a more obscure one but is affecting moths and other night-flying insects, and so on and so on.

The world has changed in so many ways really fast. Insects are actually pretty tough on the whole. They’ve been around for 480 million years. They survived the meteor that wiped out the dinosaurs. Now, they’re in trouble. It’s basically down to this perfect storm of stuff that we’ve created.

SEAN SPEER: As you say, there are various factors, but the book and some of your other commentary does focus on agricultural practices as a key source of the problem. I’ll ask you just to elaborate a bit here. What are the trade-offs between agricultural efficiency which one could make a progressive argument for in terms of cheaper and more nutritious food and ecological harm, including for insect populations? How should we think about those trade-offs?

DAVE GOULSON: Yes, that’s a really good question. I would say, this maybe sounds terribly pretentious. For me, I think, possibly the biggest challenge facing humanity in coming decades is how do we feed everybody in a sustainable way that doesn’t destroy the environment and ultimately end in us all starving to death. That sounds dramatic, but you can make a pretty strong argument that what we’ve done to date has done a lot of harm to the world. That’s pretty clear.

We’re changing the climate. We’ve damaged soils. We’re wiping out biodiversity and all of that undermines our capacity to grow food in the future. If we don’t have pollinating insects like bees, if the soil is badly degraded and infertile, if the climate is chaotic, that’s all going to hugely impact crop yields. I think we need to change direction with regard to food production and look for truly sustainable forms of farming, which, for me, well, they have to look after the soil.

They have to have much fewer greenhouse gas emissions associated with them, which really means a big reduction in fertilizer use, and they need to work with nature, essentially, I would say. That all sounds a bit sort of hippie, doesn’t it? Essentially, unless we support healthy populations of pollinators, and predators of insects, pests, and all the little creatures that keep the soil healthy and strong, then ultimately farming is going to collapse.

We really have to stop spraying so many poisons onto the land, in my view. I would go so far as to say we should be trying to phase out poisons entirely from farming. People would challenge that and say, “Well, can we really feed the world with organic pesticide-free farming?” It’s a good question but actually, currently, there’s not a shortage of food in the world. It may seem like it with the Ukraine crisis and so on.

But actually, we still produce roughly three times as many calories in the world as we need to feed the human population. We’re just incredibly wasteful with food. About a third of what we grow is wasted, about another third is fed to animals rather than people. We could be much more efficient. There’s been some big comparisons, big reviews of organic farming versus more conventional farming. Organic produces maybe 80 to 90 percent of the yield. It depends on the crop, but it really isn’t that far behind.

This is a big if and easy to say but hard to do, but if we could substantially reduce food waste and persuade people to eat a little less meat, then actually I would argue that we could comfortably feed everybody with organic farming.

SEAN SPEER: That’s fascinating. Thanks, Dave. We’ve talked about the causes behind these trends. Let’s talk about their consequences. What are the downsides of fewer insects? Why should we care?

DAVE GOULSON: I’m painfully aware as someone who loves insects that most people don’t. They have a pretty bad rap really. Even the name bugs, creepy crawlers, doesn’t really do them any favours. The harsh truth is I think most people just see insects as a pest. If something buzzes near them their usual reaction is to try and swat it. They think it’s going to bite them, sting them, or give them a disease or something.

There are obviously some exceptions. Most people like butterflies and perhaps bumble bees and some of the bigger, furrier, more colorful insects, but on the whole insects are not terribly popular. People should be aware that actually, a world without insects would be a pretty dire place. For many reasons. I’ve touched on some of them already but for one, they’re food for most larger organisms. If you don’t care about insects, you might still quite like to see pretty birds flying around.

Well, most of them eat insects as do bats and lots of frogs, toads, lizards, and so on, and freshwater fish like Trent and salmon that we like to eat, they primarily eat insects. If the insects are gone, then all of these other creatures will be gone. They’re vital in that they recycle dead bodies, cow pats, leaves, tree trunks, pretty much any organic material you like is broken down by insects. That’s a pretty unglamorous thing, getting rid of corpses and cow pats.

It’s important because the nutrients locked up in those things need to be released so that they can go back into the soil so that crops and other plants can grow. Then the one thing that insects do that is moderately well appreciated is pollination. About 80 percent of all the plant species in the world depend upon insects to pollinate, including most of the beautiful wildflowers that we like to see, and roughly three-quarters of the crops we grow in the world wouldn’t give a full harvest without insect pollinators.

That includes everything from apples, cherries, strawberries, raspberries, blueberries through lots of vegetables, squashes, tomatoes, chili peppers, aubergines, eggplants and even things like coffee and chocolate need insect pollination. People who don’t like insects should think on because no insects needs no coffee in the morning and no chocolate. How bad can it get? Even if you live in the middle of a city and the only insects you see are cockroaches, you should still be aware and be thankful for all those insects out in the countryside, in the farmland, that help to produce the food that you eat.

SEAN SPEER: The book paints a grim picture of the future. If we lose a critical mass of insects, you outline potential consequences including starvation, disease, and even poverty. Let me ask you a two-part question. One, what has been the reaction to that picture of the future in the book? Two, why don’t you talk a bit about the decision to include it? Why did you think it was important to effectively convey to people the consequences of the choices that we’re making with regards to insect populations?

DAVE GOULSON: As you say, there’s a chapter in the book where I try to imagine a worst-case scenario viewed from the perspective of my son in 60 years’ time when my oldest son will be 80, and he’s looking back on his life and what’s happened. The reason for writing it was firstly to try to emphasize that this is serious. I think most people do not appreciate the severity of the threat posed by biodiversity loss and climate change, which are two tightly interwoven problems that we’ve created and that they really do threaten our civilization.

I know at this point many people think you’re a nutter, waving a placard, the end of the world is nigh. How ridiculous is that? Surely, it can’t be. Actually, there is pretty clear evidence that life for future generations is going to be tougher unless we can very rapidly change our ways. I’ve already mentioned things like soil loss and the loss of pollinators and so on. It really worries me that my children and potentially one-day grandchildren are going to suffer for the devastation that we’ve reached in my lifetime.

I’m sidetracking myself slightly, but there was a report I just read this morning from the World Wildlife Fund which estimated that global vertebrate populations, birds, fish, reptiles, and amphibians, and mammals, are down 69 percent since 1970. More than two-thirds of all the wild vertebrates on our planet have disappeared. It isn’t obviously just insects that are gone. We really are doing a lot of damage. Many people tend to focus on one issue, but it’s the combination of problems that we’re creating.

We’re not just destroying biodiversity, we’re damaging the climate, we’re eroding the soils, we’re overfishing the seas, we’re polluting fresh water in the sea with plastics and heavy metals and pesticides and fertilizers and a whole bunch of other things besides. The combination of those has the potential to make life really difficult for all humans into the future for potentially hundreds or thousands of years. Things like the climate isn’t going to be easily fixed.

I wanted to try and paint a picture of what it will be like and as a way to motivate people to do something about this. I don’t want to just depress people. I want ideally to inspire them to think “Wow, this is really serious. I hadn’t really thought about this but now I see it’s going to be bad.” Everybody cares about their children or their grandchildren. We would do anything for them apart from leaving them a decent planet to live on, it seems to me.

It was intended to try and pull together all the different problems that we’re creating and look to see what the end result of that might be. Of course, involving a bit of guesswork. No one can really know exactly how the next 60 years are going to unravel. My agent initially said that I should take it out. He said, “You need to be scientific. You need to stick to the hard facts. You’re a scientist. You shouldn’t be guessing what will happen.”

We argued about it and actually, it was originally the first chapter in the book. The compromise was that it was relegated to near the end of the book, but actually, it’s been really well received. Many people have said they thought it was the most interesting chapter in the whole book. I’m glad I stuck with it, and I think it has an important message.

SEAN SPEER: Let’s pick up that message and talk a bit about what we can do to arrest the insect apocalypse. Before I put that to you directly, let me just ask, are there any particular insect species that are more ecologically important than others? In other words, should we be prioritizing the protection of particular species, or do you think we need an overall agenda to reverse the trends that you outline in the book?

DAVE GOULSON: There are obviously an awful lot of insects: 1.1 million known species. It’s pretty hard to start prioritizing saying, well, how do from that enormous number, how do you pick out which ones are important? The honest truth is we often don’t really know because they exist in complicated communities with lots of interactions with other organisms.

We don’t know which ones will have the biggest impact if they’re lost. Actually, from my perspective, I think they all have a right to live.

Even if they don’t do anything useful from our perspective at all, it seems to me that insects and all life on this planet has been here a long time. Most of it was around long before we appeared. Regardless of whether they pollinate our crops or get rid of cow pats for us or whatever, I think they just deserve our respect and that we need to move away from trying to value nature as a commodity and seeing it as something for us to exploit as we like, and instead regard ourselves as part of nature which we are.

I’m just one species of many. We shouldn’t see ourselves as being more important, I would argue. Maybe I am a crazy hippie, I don’t know, but it seems to me that we have human rights. We should have insect rights. We should have rights for species. Every species on this planet it deserves its place, whatever it does. We should try, I think, to look after them all. That is a challenge, obviously, but I think it comes down to trying to tread more gently on the planet. There are many, many ways we can approach that.

SEAN SPEER: How should we think, Dave, about global solutions versus local solutions? When it comes to insects, are there parts of the world where there is a greater concentration? In other words, how should we collectively support those ecologies where insects are disproportionately found?

DAVE GOULSON: Yes. Big questions there. Firstly on the last part, the most insect rich and the most bio-diverse places on the planet are the tropical forests, as I think pretty much everybody understands these days. One of the great tragedies of the last few decades has been the fact that we haven’t managed to really reign in the destruction of those habitats.

People have been campaigning to protect the rainforest certainly since I was a teenager and probably before that. At least 40 years. But it hasn’t unfortunately succeeded. Somehow, ideally, that would be a real priority, not just for insects, but for the future of life on earth. We really need to try to stem the loss of our tropical forests, particularly in South America but also in Southeast Asia. It’s happening very fast and in Africa. How do you do that? It’s obviously challenging. It could be done if the will was there and if the developed world, which has plenty of wealth if we really wanted to persuade developing countries that have these amazing forest not to chop them down, then we basically need to cut them a deal.

We need to give them a bigger slice of the pie and stop hoarding all the wealth in the North as we have done, which of course is politically challenging to say the very least but it could be done. That really requires political will, top-down decisions, but when it comes to broadly how do we look after the environment and insects better? Much of it could be done from bottom up. We can all do individual stuff to help provide habitat for nature to reduce our impacts, to reduce our carbon emissions, and so on. You could have a mass revolution from the bottom if enough people cared.

One of my mission in life is to try to drag people on board and get them to care. If we all did our bit, if we all made our gardens, if you’re lucky enough to have one, into mini wildlife preserves, that could make a huge difference. Then we got on to the local council and persuaded them to plant wildflowers in the local parks and along road verges, and so on. These sound small scale but if we were doing this all over the world, then that would really start to add up.

Of course, that requires people in political power. When it comes to voting, if we really want green politicians to look after the planet better then we need to vote for the right people, which we’ve not done particularly well at in this country recently, I must say, but let’s not get into British politics. I’m sure you don’t want to hear it. Politicians could do things really fast if they wanted to.

They could legislate to reduce pesticide use, to direct farming towards more sustainable practices. They could set aside more land for nature. They could do things really fast, or we could do it all from the bottom up with local schemes if enough of us were involved. Or ideally, both would be happening. Then we could really change things pretty fast but we’re not there yet, I’m afraid.

SEAN SPEER: Listeners will hear, Dave, in your voice your passion and commitment to these issues. Your work draws some inspiration from a well-known conservationist named Rachel Carson. Who is she and how has she inspired your work?

DAVE GOULSON: Rachel Carson wrote Silent Spring and it’s not entirely coincidental but my book Silent Earth draws from her book, of course. It’s almost exactly 60 years to the day since Silent Spring was published. I read it when I was at university in the 1980s. It was a really seminal book. It was the first time that anyone really highlighted the peril that the natural world was in. She focused particularly on the use of pesticides in farming, which at the time was still quite a new thing.

They’d only really been around since the Second World War. They’d only been in use for barely 20 years. Already, the problems were emerging, farmers were getting poisoned, livestock was getting poisoned, wildlife was dying, and so on. It was very controversial when it was first published, it created an enormous storm of debate. There was a big backlash from the agro-chemical industry defending their products. They tried to paint her as a lunatic with some success, but in the end she won. I mean, it’s a sad story, because she died two years after the publication of Silent Earth.

Many of the pesticides that she wrote about, things like DDT, were banned eventually. It took another 20 years but they were eventually banned. I think many people thought the problem had been solved, that modern pesticides were much safer, we’d learned our lessons. All was well and conservationists started to turn their attention elsewhere and really forgot about the pesticide issue until pretty recently when it became apparent that we’ve taken our eye off the ball and actually things were not at all well.

Actually, arguably, I think things have gotten a lot worse since her time in terms of the impact that these chemicals we’re making or having. I’ll just give you a few figures. The total amount of pesticides applied to the world has increased by 15 fold since Rachel Carson published Silent Spring. In North America, there were in 1962 about 37 different pesticides available to farmers. Now, there’s about 1,000. Some of them, modern pesticides, just to pick one example, there are a group of insecticides called neonicotinoids, which are neurotoxins that target insect brains, that are about 7,000 times more poisonous to insects than DDT was.

They’re now the most commonly used insecticides in the world. It’s hard to exaggerate how poisonous they are. It’s like novichok for bees. I don’t know whether novichok is a familiar chemical. We had our issues in Britain with Russians poisoning people with this neuro-nerve engine they’d invented.

Anyway, it’s not unrelated to these chemicals that we spray on our farmland all the time. Certainly from an insect’s perspective, it’s similar. I think poor Rachel Carson would turn in her grave if she knew where we’d ended up. It’s rather sad. Really that’s what my book is trying to refocus people’s attention on. Not just the pesticide issue but the broader issues of damaging the environment and the urgency of doing something about it.

SEAN SPEER: I asked earlier, Dave, about trade-offs, and I want to come back to that subject now. There’s a tendency in Canadian political and policy worlds, even for genuine champions of the environment, to diminish trade-offs. The Trudeau government, which I think genuinely has a commitment to environmental progress, often says that the environment and the economy go hand in hand. I wonder what you think about that.

Let me put a hypothesis to you. I wonder sometimes if diminishing those trade-offs precludes the type of public buy-in that we’re going to need in order to make genuine environmental progress. If in effect you tell people that they can have environmental progress without economic costs, they’re naturally going to say yes, but isn’t there a healthier conversation that we need to have about those trade-offs? What are the types of costs that we’re prepared to accept in exchange for environmental progress? How do we minimize those costs, particularly for low-income households or developing countries or whatever? I guess in a nutshell, how should we think and talk about the trade-offs between the environment and the economy?

DAVE GOULSON: It’s really complicated, isn’t it? I’m not sure I have the answers here at all. I think ultimately we need to try, or I am trying to explain to people, that the economy depends completely on a healthy ecology. The two are not separate issues. We shouldn’t be trading a one-off against the other. If we grow the economy at all costs and ignore environmental harm, then ultimately the economy will collapse because we’ll all be starving because we’ll have destroyed the environment. We need to keep that in mind.

Although there may be short-term pain involved in looking after the environment, we’re going to have to sacrifice some things. We have to change. Unless we can come up with a cheap energy source suitable for planes that’s environmentally friendly, we need to fly less. We probably need to eat less meat. We need to reduce our footprint. This is all quite tricky because particularly at the moment with the cost of living crisis that’s spreading around the world.

Something I’ve been saying for many years is food is too cheap. We’ve become used to really mass-produced cheap food. That’s part of the reason we’re so wasteful with it. We happily buy food and then throw away a quarter of what we bought, which is absolutely insane. If we really valued food, and one way of making us value food would be if it was more expensive, then we’d be more careful with it. At a time when people are struggling to feed their families and heat their homes saying to them food should be more expensive is not an easy sell.

There isn’t a simple solution here, but, honestly, I think it comes down to inequality. Nobody starves in the world because there isn’t enough food. They starve because they can’t afford it. We live in a world with grotesque inequality and Britain is particularly bad. The United States is one of the worst places in the world. I’m not quite sure where Canada sits in the spectrum but I’m sure there are plenty of poor people and a small number of very rich people as seems to be the norm in this world.

Of course, it’s easy to say and very hard to tackle, but that I think is at the heart of many of the problems we face right now. If we redistributed our vast wealth more evenly, then poor people would be less poor and could afford to eat better and not just need to buy whatever the cheapest option is as they do at present. Really, I’m just a guy who chases insects. How will you address these problems, I really don’t know but I think that is at the heart of it.

SEAN SPEER: Well, let me ask a final question. As a guy who chases insects, what do you think, Dave? Are you optimistic that your message is gaining resonance? I know for instance, that you have done some briefings at the U.K. Parliament and you’ve mentioned the European Parliament. Is there reason to think that, not just the ideas in the book, but the ideas that you’ve pursued throughout your career, are gaining salience with the general public and with policymakers?

DAVE GOULSON: It is happening frustratingly slowly, but bees, for example, most people are now aware that bees are good. They do something. They pollinate crops. People are pretty vague on the details usually but that message has permeated through most people in the developed world and probably the whole world which wasn’t the case 20 years ago when I was a younger scientist studying bees. People are changing and we’ve seen some pretty profound things, the rise of Extinction Rebellion and veganism. Younger people today are much more environmentally aware than they were when I was young.

Politicians are starting to get the idea. They’re talking a good talk now many of them about climate change, but they’re not really taking the actions that we need and biodiversity is still a ways behind climate, I think, in terms of its perceived importance with the decision-makers. It is happening, but not fast enough and it breaks my heart that we are losing so much, so fast.

It’s roughly estimated that we’re losing a species every hour from this planet and so we are going to lose a lot more at the rate we are at. We need to speed it up, basically and that’s why I’m talking to you tonight to reach a bunch of people I might not otherwise have reached. Hopefully, some of the people listening will do something, will perhaps buy the book or at the very least check out my YouTube channel and get some ideas what they can do to at least encourage the insects in their backyard and that seems like a pretty good place to start to me.

SEAN SPEER: And a good place to end. The book is Silent Earth: Averting the Insect Apocalypse. Dave Goulson, thank you for joining us at Hub Dialogues.

DAVE GOULSON: It’s been fun.