The man who went from cancer to carbon and climate

When Peter Macreadie calls me, he’s walking home from work. He does this every single day — an hour to Australia’s Deakin University in the Melbourne suburb of Burwood, and an hour home. In his easy, friendly manner, Peter tells me that although he’s “definitely not a saint” he tries hard to reduce his personal carbon footprint, because working as a marine ecologist has made him acutely aware of our warming world.

He grew up in Melbourne’s wealthy eastern suburbs, but spent a lot of his childhood in the US as his microbiologist father worked in various labs. Becoming a scientist, however, was more nature than nurture; from an early age Peter found the ocean “magical”.

He arrived at university with a bright-eyed dream of studying marine biology, but come graduation, his parchment read “biochemistry and molecular biology” instead.

“I picked up a job for a couple of years working in my father’s lab at the CSIRO, developing new drugs to treat malaria and Alzheimer’s disease,” Peter says.

Then in his early twenties, he was diagnosed with cancer.

“The doctors said that if I hadn’t had come in when I did, I would have been dead within one month,” he reflects.

“So, in the recovery process — after a couple of operations, six months chemotherapy and daily radiotherapy for a month — I thought if I’m going to be doing something for 50 hours a week for the rest of my life as a career, I might as well make it something I’m particularly passionate about.”

So Peter returned to marine science, completing his PhD at the University of Melbourne on how fish respond to habitat fragmentation.

“It was kind of cool from a quirky science point of view,” he says. “But it wasn’t changing the everyday lives of Australians.”

Then, in 2009, he read a report that coined the phrase “blue carbon”.

“I thought ‘Even if this is just half right, this is a really big deal’,” he explains. “This was a new potential weapon in the fight against climate change.”

Blue carbon is carbon that is captured and stored by coastal ecosystems, namely seagrass meadows, salt marshes and mangroves. Even though they occupy less than 1% of the sea floor, these ecosystems hold onto around half the ocean’s carbon — and they can capture and store it up to 40 times faster than tropical rainforests.

Even better for the long-term climate change game, blue carbon ecosystems can trap carbon in a watery grave for thousands of years — far longer than trees can manage.

“Australia has more blue carbon ecosystems than anywhere else in the world,” Peter tells me. “Think about our national anthem — our home is girt by sea, our land abounds in nature’s gifts … One of these gifts is really blue carbon.”

But this fantastic resource in the fight against climate change is also a liability: human activity has destroyed about half of the world’s blue carbon ecosystems. Their destruction means thousands of years of stored carbon can leak back into the atmosphere — a so-called “carbon bomb”.

Today, Peter is head of the Blue Carbon Lab at Deakin University. His team is not only focused on understanding blue carbon ecosystems, but also putting the science in action to save them.

In their approach, he and his colleagues first have to figure out exactly where these ecosystems are — sometimes using seagrass-eating turtles and dugongs as scouts, since techniques such as remote sensing and satellite imaging don’t reveal what’s on the seabed.

Then, they have to figure out which areas are best at keeping carbon locked up. For this they use another grassroots method: teabags.

Teabags, it turns out, contain a consistent amount of carbon across brands, so Peter’s lab has kickstarted a citizen science project to use them as a cheap, standardised way of measuring the rate of carbon breakdown in soil.

“At the moment it’s operating in 350 sites in over 30 countries, and there have been about 40,000 teabags deployed globally,” Peter says.

The results are generating a map of places great at sequestering carbon, which will help prioritise which ecosystems to conserve and restore.

The biggest problem is how to get people to value blue carbon ecosystems. Compared to the Great Barrier Reef, they’re not much to look at, often regarded as the “armpits” of the coastal environment.

But Peter points out that “there are a lot of people and industries around the world that are trying to offset their emissions. Can we then use that money to restore and rehabilitate the best kinds of wetlands for carbon preservation?”

His lab is currently working with marine-based industries who want to offset their carbon emissions by investing in the environments they have an impact on.

His team has also recently partnered with Qantas to offset Deakin’s travel emissions, as well as to restore blue carbon ecosystems near the Great Barrier Reef — environments that aren’t just critical for carbon sequestration but also for coastal protection, fisheries and biodiversity.

Peter’s lab is also working with landowners whose farms were originally built on blue carbon ecosystems. In the inland Murray region, they are working with 41 landowners to rehabilitate 3000 hectares of wetlands through altering grazing practices, planting vegetation and controlling pests.

The lab is also collaborating with Parks Victoria to talk to coastal farmers whose farms have been inundated by seawater, in the hopes that they can help restore their lands and cultivate blue carbon instead of cattle, funded by carbon offset programs.

“I think that, for me, would lead to an early retirement!” Peter laughs.

But when the conversation circles back to the urgency of our situation, he sobers.

“The physics is just so damn simple,” he tells me. “Our planet has a thermostat and it’s been stable within about one degree for 6000 years, and then simply by burning fossil fuel we’ve put more heat-trapping greenhouse gases in the atmosphere.”

The solution, Peter reckons, is simple – grab some of those gases and put them back in the ground.

“I’m not sure that I’m happy with the democratic approach to this, because politicians will do what the people want and that’s how they get re-elected,” he says.

He fantasises about a benevolent dictator who “could basically say ‘You know what? You guys are idiots. I’m going to make some decisions on behalf of the nation that might not be popular but it’s in your best interests.’”

Though he’s not advocating for Australia to fall under a dictatorship, Peter stresses that we need leaders who will look at the data and stick their necks out to make tough decisions.

One of the most pressing decisions, he says, must be to wean the country off coal: “We’re one of the world’s biggest suppliers of coal, often seen as the world’s coal heroin dealer.”

Peter thinks the fastest way to sobriety – to green technologies – is through what he calls the “silver bullet of climate change”: introducing a carbon tax to “pay for our carbon sins”.

“One of the problems with climate change is that people just feel exhausted thinking about it – you don’t want to feel guilty every time to turn on a light or switch on your car,” he observes.

“Tax is often a wonderful way to nudge people in the right direction but also not make them feel guilty.”

He draws a comparison to the taxing of cigarettes in Australia and the impact that had on consumption, in parallel with an education campaign.

Along with many climate scientists, Peter thinks education is another key factor in the fight against climate change: “Every now and again you’ve got to step up for a big issue and say ‘I do this for a living, this is what I study, and I think we really need to be concerned about this.’”

His lab has recently partnered with the environmental non-profit organisation Earthwatch to take key stakeholders from HSBC bank out into the wetlands “to help collect data and hear from the scientists who study the systems firsthand about their importance.”

By getting stakeholders out of their suits and into the mud, Peter is hopeful that they will understand the value of these ecosystems. “Ultimately that is what can help pull these levers towards better management,” he suggests.

He’d love to expand this pilot programme to other businesses and even politicians.

Away from the lab, he enjoys giving school talks, including at his daughter’s school.

“I had one parent come up to me a couple of weeks later and say ‘My son won’t eat meat because of your talk!’” he laughs.

“That’s incredible — here’s a kid who’s in Grade Three hearing somebody make one remark about eating meat and what impact it has on the planet … and he’s made that decision.”

Peter has made a personal decision to reduce his meat consumption, and his fashion consumption, too.

“As daggy as I might sometimes seem in my clothes, fast fashion is pretty bad for climate change,” he says.

I ask whether he’s concerned for his three kids and the future of the next generation, but surprisingly he isn’t.

“To be honest, we’re born in Australia, in a very rich country where we will not feel the first few waves of climate change,” he explains.

“We’re not one of the nine out of 10 farmers in sub-Saharan Africa who aren’t going to be able to put food on their tables. We’re not one of the people living on the islands of Kiribati whose homes are slowly being swallowed by the sea.

“We’re the lucky rich ones. We’re going to be able to survive for a very long time without really feeling those effects.”

And perhaps that’s all the more motivation for him to put his science into action and have a real-world impact.

“I often,” he says, “ask people when they’re approaching retirement, ‘What are you most proud of in your career?’ And it’s usually the policy change they had or the restoration they were responsible for … the stuff that’s really tangible, the high impact stuff.”

He’s already seen some of this impact over the past nine years — the term “blue carbon” has gone from universally drawing blank looks to being talked about by the Intergovernmental Panel on Climate Change (IPCC), the Australian Federal Government, and appears in management plans all around the country.

“I feel like I’m in the game,” Peter says. “I feel like I’ve got this secret weapon to reset the planet’s thermostat.”