No return to Eden

Imagine this scenario. You are standing beside a highway and you see a tortoise slowly making its way across. A few hundred metres up the road, a huge truck is bearing down very fast. What do you do? Most people with a beating heart would pick up the tortoise and move it to safety.

Climate change is the biggest, heaviest semi-trailer bearing down on the Earth’s biodiversity, threatening our life support system. We don’t just need to move the odd tortoise, we need to intervene in nature in a far more concerted and proactive way – and do it now.

Climate change is the biggest, heaviest semi-trailer bearing down on the Earth’s biodiversity.

Here’s an example of what can happen when we don’t intervene.

There was once a small native rodent called the Bramble Cay melomys. The entire population of this species was confined to a single, low-lying atoll in the Torres Strait. Several hundred melomys were observed on the atoll in the 1970s, but by early this century only a handful of individuals were left. The melomys was duly listed as an endangered species and a recovery plan was written. But the plan did not contain any practical actions to deal with the threat of rising sea levels and increasingly severe weather. Soon after the plan was published, inundation of the whole island finished off the last few survivors – the first documented extinction of a mammal anywhere in the world attributed to climate change.

We lost the melomys not because we were ignorant of the trouble it was in, but because not even the smallest proactive step was taken to help. It could have been moved somewhere else, but it wasn’t. In fact, our laws that aim to protect species like this one can actually have the opposite effect, because they actively inhibit the interventions needed to prevent extinctions.

Here’s another, more general example. A lot of land in Australia and elsewhere has been cleared or become otherwise degraded. Enormous resources are being devoted to “restore” the original vegetation, planting the same species that were there a few decades ago. But consider that by the middle of the century, the continent may be at least a degree hotter than today, and many places will be drier and more fire-prone. Putting back what was there when Captain Cook sailed in may not be sustainable, even in the medium-term.

We need to intervene in nature in a far more concerted and proactive way.

It’s often occurred to me that our approach to conserving and managing our natural environment is an example of extreme cognitive dissonance. We clear land, dam rivers, introduce all manner of exotic plants to our farms and gardens, and continue to cover an enormous proportion of the continent with methane-belching, hard-hooved exotic animals. Yet positive interventions like moving a native species to a safe refuge beyond its current range, or deliberately creating a new ecological community of plants to provide habitat, often requires so many legislative and regulatory barriers to be overcome that it’s just not done. And it’s not just in Australia. My colleagues and I have recently reviewed the global literature on the incidence of species being deliberately moved to new locations outside their “historic range” as a climate adaptation strategy – often termed “assisted colonisation” or “assisted migration”. We found barely a dozen examples.

Why?

Words are important. “Conservation” comes from the Latin verb conservare. It has lots of meanings, like treasure, cherish, and save. But it also means to keep and to hold. That is, to stay the same as before. Similarly, “restoration” is defined as the action of returning something to a former owner, place or condition.

And there’s the problem. We can’t keep nature as it was before.  What does “before” even mean? Fifty million or so years ago, Australia had a very different climate and was covered in rainforest. It wasn’t a better place, or a worse one, just different. We are now in an era of unprecedented change – change happening faster and at greater scale than at virtually any time in the Earth’s 4.5-billion-year history.

We can’t keep nature as it was before.

No matter how hard we try, we can’t keep nature the same. So what are we to do instead?

I believe we need to get a lot braver if we are to help as many species as possible adapt to the growing risks from the changing climate. We can no longer afford to just be conservationists, or restorationists, trying to turn back the clock to some vision of past Eden. Instead, we need to go forward prepared to intervene, to move, to engineer, and to create. Species won’t be kept safe by just being on a list, or having a recovery plan, or even being currently situated in a national park. Ecosystems won’t be “saved” by just putting back what was there “before”.

Of course, we shouldn’t just be spreading everything everywhere and hoping for the best – we’ve learnt valuable lessons from the cane toad and other introduction disasters. Everything we do should be based on the best possible science that we have at hand, but we don’t have the luxury of time to wait until it’s even better. We knew more than enough to save the Bramble Cay melomys.

At the recent COP26, the leaders of more than 100 countries signed the Glasgow Leaders’ Declaration on Forests & Land Use, pledging to end and reverse global deforestation by 2030. Right alongside the discussions about the need to reduce greenhouse gas emissions and transition from fossil fuels were the buzz words “nature positive”, “natural capital” and “nature-based solutions”.

Nature is having a moment. Let’s not lose the momentum.