dry country in the outback of Australia

Is rewilding the solution to save the planet?

Rewilding a third of the planet is bold and brave, maybe even essential if humanity is to survive. But is rewilding the solution to save the environment from humanity?

Is rewilding the solution to save nature from humanity is not an everyday question. Only it was asked recently on prime-time Australian television.

Recently I watched an episode of Australian Gogglebox, where people watch TV watching people watching TV—bizarre but hilarious. The Australian viewing public at home on their couches are so funny; their wisecracks and personalities light up the screen far more than the shows they are watching. 

One of the programs was David Attenborough’s A Life on Our Planet

All the Goggleboxers, despite different backgrounds and cultures, had fear in their eyes. Their concern over the messages was palpable. They all recognized what ecologists have known for a long time, that agriculture, fisheries and human land use have decimated wildlife populations across the planet. 

Currently, over 50% of the habitable land area is used for food production. The only true wilderness left is covered with ice, tundra or sand.

infographic showing the proportion of land on earth used for food production

The addition of climate change to land-use change means that even where we haven’t physically altered habitats, the climate will do that for us. Recall that the geological record suggests that four of the five previous mass extinctions of biodiversity on the planet resulted from climate change. Over millennia in those instances, but climate nonetheless. 

The message that Sir David delivers, and he must be commended for finally coming off the fence and telling his audience the truth after so many years of wowing them with the glory of nature, is that life on earth is in big trouble

Natural capital, the engine of all our food production and the iconic biodiversity that relies on it, is being depleted everywhere. And in some places, this capital is mined by the production systems and land uses humans have developed.

Biodiversity, that is, all the variety of life and not just the attractive animals, is declining at rates equivalent to a mass extinction event. 

This biodiversity loss is especially important in soils et al. biology drives the transfer of nutrients to plants.

There is also the matter of 22 trillion kilocalories per day. This is the energy needed in the food supply to keep 8 billion people from going hungry. 

Sir David’s solution to these problems is to rewild a third of the planet. An excellent catchphrase that is attractive and accessible to many people 

Return some of that wilderness that humanity has flattened to somethpast’s ing close to its original state, butrganisms on the planet even as humanity continues to hog most of it. 

Is rewilding the solution to clour mess?

First, we need to know what it was Sir David meant by rewilding. 

What is rewilding?

Rewilding is pretty much what it says on the tin. 

That is a return to the wild by removing human influences and letting nature take care of itself, nudged along by the reintroduction or ia boldof megafauna, such as large grazers or large carnivores, to restore ecosystem processes.

More formally, Pettorelli et al. (2018) define rewilding as

 “the reorganisation of biota and ecosystem processes to set an identified social–ecological system on a preferred trajectory, leading to the self- sustaining provision of ecosystem services with minimal ongoing management.” 

Pettorelli, N., Barlow, J., Stephens, P. A., Durant, S. M., Connor, B., Schulte to Bühne, H., … & du Toit, J. T. (2018). Making rewilding fit for policy. Journal of Applied Ecology, 55(3), 1114-1125.

Rewilding differs from the related idea of ecological restoration, that requires a prescribed endpoint, by being open-ended. Rewilding intervention might try to mirror the ecology and species compliments that were present in the past but reorganisation proceeds according to natural processes to an uncertain endpoint or even an endpoint at all. So long as the ecosystem is resiliently providing ecosystem services and that this is ongoing, then rewilding has succeeded. 

sunlight at dawn through eucalyptus trees. Is rewilding the solution is unlikely when the landscape is already wild
Eucalyptus woodland in eastern Australia is already wild and shaped by fire events but lacks the megaherbivores

Is rewilding the solution?

Rewilding is a courageous idea. 

Formally, it is “the practice of returning areas of land to a wild state, including the reintroduction of animal species that are no longer naturally found there.” And to suggest this happens over a third of the global land area is a huge ask.

As Sir David says, rewilding begins by halting the processes that are degrading the system. Turn around the activities that degrade natural capital and then put extraordinary amounts of effort into rebuilding natural habitat. 

A third of the globe returned to the wild should slow rates of biodiversity loss. 

It will not guarantee the survival of any given species, the iconic rare and endangered will still need individual attention, but enhanced preservation of the many will see ecosystem services maintained with follow-on effects for climate mitigation and water balance.

Rewilding is proposed as a solution to the biodiversity crisis, but that is not humanity’s only grand challenge.

Feeding ourselves on a rewilded planet 

Throwing resources into rewilding through rebuilding nature is only possible if we’re also in good shape. 

There’s an old saying among farmers around these parts “You can’t be green if you’re in the red”. Suppose the human population fails to feed itself or fails to allocate enough resources to maintain the well-being of the majority of the people. In that case, the disruption and unrest that hungry people will unleash on the world will undo any effort put into rewilding or any other conservation action. 

Human instinct is to survive and if the food begins to run out we will do whatever it takes. This has been the case throughout human history. Most of our conflicts are about resources of one sort or another even if they are disguised as political agendas or megalomaniac tendencies. 

Sir David does temper his argument with the requirement to grow food. We are sure a few drones collecting nuts from rainforest trees will not be enough.

There is a 30-year window to grow and then maintain an extraordinary level of food supply, distributed efficiently across the world before the demographic transition passes and there are fewer people to support. 

Researchers differ in their estimate of the challenge but on our current diet trajectory, global food production must grow by roughly 2% per annum for 30 years. This is a second green revolution level of intensification and production efficiency gains. Any rewilding has to go together with food supply at levels never before seen. 

Fortunately, these two things are not as incompatible as they sound. 

Sustainable use of natural capital is easier if an ecological approach is taken. That means understanding the flow of energy, nutrients and carbon into biodiversity and primary production. There are enough linkages between nature and the production of commodities that benefit both. The solution is to think of the food production systems as closed loops running at speed dictated by the innate ecological capacity of the soil and vegetation. 

Where inputs are necessary, they are used with a sensitivity to natural cycling. Think of an organic system more than an intensive one based on fertilisers and tractors. 

Wild areas generate provisioning services, the drone harvesting the nuts from the forest; regulating services, such as controlling climate and disease; supporting services, such as nutrient cycles and oxygen production; and cultural services, such as spiritual and recreational benefits. 

When all these services are integrated into the landscape, they benefit production too.

lone elephant on grassy savanna
Photo by AJ Robbie on Unsplash

Rewilding as part of the solution

The scope of rewilding, as proposed by Sir David is ambitious. It is a global idea—something like the ‘man on the moon’ audacity of the early 1960’s.

Is rewilding the solution? Sure, with a caveat. Rewilding has to include a rewilding of the production system too. Not just the spare land that we don’t currently use. It has to be an integrated approach to food production that maintains ecological processes across the landscape; otherwise rewilding just the parts that are not under production will never work. 

We already know that the reserve systems don’t do enough to halt or even slow biodiversity loss; part of Sir David’s original lament. So the only solution is to integrate wildlife conservation and the management of nature into the production system, making them an integrated connected unit across landscapes, ideally the entire planet. 

At sustainably FED, we believe that rewilding is another term for sustainably using natural capital — that is, maintaining cyclical nutrient and energy processes through the use of ecology alongside human inputs.

It can be done. 

And we would argue it has to be done before humanity eats itself out of existence, but doing it will be hard.

We discuss the many challenges in our long post Key challenges for rewilding 30% of the planet.

What sustainably FED suggests…

Is rewilding the solution? There is no doubt that biodiversity loss will continue at mass extinction rates unless something serious is done. Reserves are not cutting it, nor will any species-level initiatives. Wild animals and plants will need much more space to survive than we have left them.

Rewilding is a bold idea that can potentially integrate and return natural and agricultural landscapes closer to nature and reduce extinction rates.

Rewilding will be the answer in some areas, especially those that have been degraded by human agricultural activity but were not suitable for food production in the long term or those areas that need a rest from production. Abandoned agricultural land is a great place to start.

It may feel unattainable, especially in the form that Sir David Attenborough suggests as a rewilding of one-third of the earth’s land area. But the reality is that humanity has met equally unimaginable challenges in the past, and this one we have to achieve for any kind of sustainable future.

The big question is, if a third of the planet is rewilded, even with multiple use options, can the whole system deliver nutritious food equivalent to 22 trillion kilocalories daily for 100 years?

Hero image modified from a photo by Alloporus


Mark is an ecology nerd who was cursed with an entrepreneurial gene and a big picture view making him a rare beast, uncomfortable in the ivory towers and the disconnected silos of the public service. Despite this he has made it through a 40+ year career as a scientist and for some unknown reason still likes to read scientific papers.

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