Megan Evans: How many of you flew here today or have taken a flight recently? Could you raise your hand? And keep your hand up if when you booked your flight you chose the option to offset some of the emissions from your flight. It's no judgement zone, it's okay, you'll all get a prize at the end, metaphorically.

Laughter

Now finally, keep your hand up if you know where your money went to the projects that are meant to offset your emissions. No? I've been researching environmental offsets for about 15 years and honestly, it's really hard to find that out.

Now the idea of offsetting your emissions is that you've got to be neutralising the impacts of those emissions by doing projects that reduce emissions elsewhere. And these projects that withdraw CO2 from the atmosphere, they're issued one carbon credit for every ton of CO2 that's sequestered.

So, when you buy your flight, you contribute to buying some of these credits. Sounds like a win-win, right? Unfortunately, some of my research and research done by many others have shown that a lot of these projects aren't working very well. It's like going to buy a dozen eggs, opening up the carton and finding that you've only received one egg despite paying for 12.

So those of you who chose not to offset your flight might be feeling a little bit smug now, right?

Laughter

And those of you who ticked that box, you probably have made an assumption that your money has been invested wisely and is effectively helping to reduce the climate impacts of your flight, right? That's fair. When you buy a product, you expect it to work.

To help explain why some of these projects aren't working that well, I'll give you an example. Probably the most reliable and recognisable approach to remove CO2 from the atmosphere is to plant trees. Makes sense. They grow, they breathe in CO2, they breathe out oxygen and store carbon as they grow. It's literally what they've been involved to do, and they do it very efficiently. Now it might surprise you to learn that carbon projects that actively involve sticking trees in the ground generate only about 2% of Australia's carbon credits in our market. Most of Australia's carbon credits, over 30%, come from promising to grow forests that otherwise wouldn't exist.

That's quite different to tree planting. It involves letting an area of vegetation grow back by itself when normally it's cleared for cattle pasture, or it's being eaten by livestock or feral animals.

Now these forest regeneration projects span over 40 million hectares in Australia. That's over, that's bigger than the size of Japan. Where are they? They're mostly in quite remote places. I'm guessing you might not have seen some of them.

They're near Alice Springs, Cooper Pedy, the back of Bourke and the Nullarbor Plain. Now you might be thinking, I didn't expect many of these places to contain much forest. And you would be right.

Laughter

The vast majority of these projects are located in semi-arid and arid country. These are boom bust environments where vegetation grows and dies in response to largely rainfall. And the thing with carbon offsets is that they're meant to sequester carbon permanently. So, you're hoping forests will grow back in locations that are semi-arid doesn't seem like a particularly permanent solution.

Now my colleagues and I have analysed a lot of these projects, and the results are shocking. Over the last decade or so about 80% of these projects have either lost forest or grown hardly any forest. Despite that, these projects have earned over 20 million carbon credits. So, they've been paid as if they have sequestered over 20 million tons of CO2. That's about the same amount of CO2 that comes from burning gas and generating electricity in New South Wales in one year.

But our data shows that in reality it's very unlikely that much of this CO2 has actually been sequestered. Put simply, these forest regeneration projects aren't working. They can't possibly work.

They're primarily located in places that have never been cleared of forest and forest can't be permanently sustained because these are semi-arid locations.

I want to pause here and invite you to consider how does this make you feel. You might be depressed. Sorry, I get that a lot when I give my talks.

Laughter

You could feel sad or indifferent, maybe angry. And I want to be clear that I'm not criticising anyone here who has purchased these credits voluntarily.

Laughter

You've bought these credits if you have in good faith, assuming they work. When you buy a dozen eggs, you expect to receive 12 eggs. The carbon market promotes the sale of carbon credits on the premise that they will effectively neutralise the release of carbon emissions and that they'll provide crucial income to farmers and other local communities who manage these natural landscapes. And it's absolutely true that farmers and local communities can financially benefit from these projects, and that is a good thing. But we also have to remember who are the main beneficiaries of this system. Most carbon credits in Australia are purchased by companies who emit a lot of CO2. They are required under legislation to do so. So, these companies are those that are, for example, dealing with landfill and waste, extracting and selling fossil fuels, as well as our two biggest airlines. Now, these companies will buy these carbon credits from these forest projects to offset their emissions, but these projects with these forests, they're not growing anywhere near as much forest as they should, but they're earning carbon credits as if they are.

So, on paper, when big emitters buy these credits, everything is neutral, but in reality, the trade is out of balance. When these forest carbon offset projects don't work properly, we get a net increase in emissions. The trade makes climate change worse.

So, this is why my colleagues and I are so concerned. Our findings have been peer-reviewed and published in a top scientific journal, but there are many who disagree with us. So, the Clean Energy Regulator, which is the body that oversees these markets, has said that the integrity of these projects have been confirmed by other reviews.

The Australian National Audit Office has said that the carbon credit scheme is largely effective. Professor Ian Chubb, former Australian Chief Scientist who led an independent review into the scheme in 2022, has said that the scheme arrangements are essentially sound, and climate change and Energy Minister Chris Bowen, the day after our most recent research was published, said that there's been other checks of these projects which have found that increasing vegetation exists. And finally, the industry body, the peak body that represents carbon market players, has said that our claims amount to a direct attack on farmers, on traditional owners, on conservationists, among others.Strangely, they didn't mention fossil fuel companies or carbon businesses as being attacked when they put out that media release.

So, who to believe? After hearing the names of those organisations and people, you might be thinking, maybe she's wrong, maybe Megan's the one who's wrong, right? Maybe she's overblowing it.

Laughter

But the data is compelling. The science is really clear. I feel compelled to continue speaking about our science, even if it's depressing, and even if it doesn't exactly win me friends in government or industry. And that's because the consequences of these projects not working are more dangerous than the risks of criticising them.

Climate change harms everyone, and some of the people most affected by climate change are the farmers and local communities in these natural landscapes managing them.

I've noticed a pattern that happens whenever we publish our science or speak out about this work, and the typical response from industry and government is to criticise us for being critical. They'll say, don't let the perfect be the enemy of the good, you've paid for 12 eggs, and you've only received one, well, it's better than nothing.

Carbon markets are the only way to address climate change at the scale that we need, so the only choice that we have is to work to improve them rather than point out their flaws. We're not the only scientists who have analysed these kinds of projects and found major problems, and these scientists from places like the US and Europe and the UK, I've observed very similar responses to their work.

Don't let the perfect be the enemy of the good. Don't criticise, because when you criticise, you hurt market confidence, and that means fewer people and organisations are buying these credits, and you're depriving farmers and local communities of crucial income.

But what use is a carbon market if many of these projects don't actually do what they're meant to do, when the net outcome is actually more carbon emissions, not less? Last month, over 80 civil society organisations, including Oxfam, Greenpeace, Amnesty International, signed a joint statement arguing that companies should not be allowed to use carbon offsets to meet their climate targets, largely because of the lack of credible evidence these credits actually work. And while I didn't see this news in the Australian media, the letter was reported on by the financial corporation S&P Global's website as a fresh attack on the voluntary carbon market. Again, the message is don't criticise, don't attack, don't question.

Let's be clear. Criticism is a central part of science and in society more broadly, and we can't figure out how to improve something until we critique and find the problems in the first place. Criticism is the essential first step to identifying solutions. It helps to open up possibilities and allows us to imagine other alternatives, rather than simply accepting that one option is the only way forward. And this is why I think we need to question and even resist those who attempt to close down debates and who do so by characterising criticism as unhelpful, as undermining climate action, or as an attack on vulnerable communities.

Who really benefits from my silence? Who really benefits from your silence?

So where to from here? Now, as I said, I don't want anyone to feel responsible about ticking the box or not ticking the box, because the federal government program that certifies carbon credits that you voluntarily purchase to offset your flight was recently referred to the ACCC and has been described by the Australia Institute as state-sponsored greenwashing. This is a bigger issue than what can be solved by you choosing to tick the box or not.

There are things that can be done to help create a safer climate. The first thing is to produce and sell carbon offsets that actually remove as much carbon as they say they do. I know, revolutionary, right?

Laughter

There's a couple of problems with that. It's actually cheaper to produce and buy credits that are generated by imaginary forests in the desert, and government and industry are quite happy to continue with that trend.

The other issue is that there's simply not enough land on the planet to grow trees to offset the amount of emissions that could be emitted from all of these new fossil fuel developments that are wanting to be developed. The International Energy Agency has said that we cannot have new fossil fuel developments if we want to have a safe climate, and we don't even need them to transition to a net zero economy. The second thing is fossil fuels need to stay in the ground, and there are many people around the world and around the country working to resist these new projects.

These people who care deeply for our collective future are often characterised as out of touch, as attacking business and rural communities, even as criminals, and increasingly being arrested and tried as such. That's deliberate. Don't criticise. Don't question.

Finally, something all of us can do is to ask questions, to think critically, and to criticise, and be wary of those who say this is the only option available. Fake carbon forests, they're the best that we can do. Better isn't possible. Because the truth is, better is possible. We deserve better, and we can and should demand better. And the first step to imagining other possibilities is to criticise what is currently on offer. Thank you.

Applause

Centre for Ideas: Thank you for listening. This event is presented by the Festival of Dangerous Ideas and supported by UNSW Sydney. For more information, visit unswcentreforideas.com and don't forget to subscribe wherever you get your podcasts.