Simple questions can require complex answers. Dr Sam Rose tries to scratch the surface.
I was asked last week by a friend about the link between rewilding and climate change. Can, he asked, rewilding save the planet? Can it have a significant impact on mitigating climate change? Now I had to think carefully for a minute as my puppy-like enthusiasm for ‘nature-process led ecosystem self-restoration’ (rewilding to you and me) wanted to jump up and down and say YES, but it is, of course, more complex than that. It is so complex in fact that this article does not even scratch the surface, so please bear with me!
Rewilding involves allowing nature to choose its own path—and it is pretty good at that. Give it some bare earth, such as a ‘retired’ wheat field on heavy clay, a bit of rain and no herbicides and you will have a patch of thistles, dock, grasses, ragwort and other pioneer species before you can say ‘carbon sequestration’. With those plants comes the insects, and with the insects comes the birds, bats and the small mammals, followed closely by the predators—kestrels, weasels, barn owls, foxes etc—bang, a whole ecosystem brought back to life! Now in terms of climate change, this rich and fast growth of vegetation is great—pioneer species suck up carbon quicker than your average Dyson, so this, followed by the secondary growth of herbs, shrubs and eventually, trees, is a positive thing for the climate.
Of course, ‘letting things go’ is not just the only thing that is good for the climate, and to be fair, very few places adopt that abandonment process for very long anyway before putting a few herbivores onto the land, animals such as hardy old breed cows, pigs and ponies; examples include English Longhorn cows, Tamworth pigs and Exmoor ponies. These herbivores ‘manage’ the system naturally, and as long as their numbers are not too high, their rootling, browsing and grazing, along with that of the wild deer that are invariably present, can really help biodiversity come back, and allow strong and sustained growth of scrubland vegetation.
But the cows that ‘do’ rewilding also have a trick up their hypothetical sleeves for climate change. Research from the Knepp Estate in West Sussex has shown that because the diet of the free-roaming English Longhorn cows is varied and self-selected from what is around them, they eat what is best for their system, and their methane production is significantly lower. Who knew? Well, I guess we all know our own reactions to foods that don’t really agree with us, and it is no different to cows. Intensive farming depends on mainly grass, but cows are naturally browsers as well as grazers and need the woody or thorny material they get from browsing to help their digestion, so perhaps it is no wonder that intensively farmed cows fart so much!
In terms of other aspects of rewilding, carbon is captured and stored in the wetlands created by beaver dams and through other projects to ‘rewiggle’ rivers and create / re-create wet areas. This is through the storage of carbon in sediment, the creation of peatlands and the fast growth of aquatic vegetation. To add to this, and as you will know, carbon is also stored through natural forest regeneration and in the tree planting that is sometimes done in rewilding projects where the soil is so bereft of naturally occurring tree seeds.
If we add in ‘regenerative agriculture’, which will be the subject of another R-word, this approach adopts a soil protection and improvement strategy through not ploughing when planting crops. The amount of carbon in soil organic matter is vast, and when fields are deep ploughed, much of this organic matter is exposed, dried out by wind and the sun, and lost to the atmosphere—not good. Rewilding is at the extreme end of this as growing crops is not part of its system, but where the land is good for growing food, and rewilding is not an option, then a regenerative ‘no-till’ approach can stop a lot of carbon escaping to further heat our planet.
So where am I going with all of this? Well, my friend asked can rewilding save the planet? On its own, no, not really. There are issues of huge concern to the planet’s climate that are possibly an order of magnitude above what rewilding can mitigate—methane emission from melting permafrost, oceanic carbon release, peatland drying, fossil fuel emissions and so on. It’s all a bit doom and gloom, but combined with other changes, nature and rewilding can play a significant role, and that is if the lessons of rewilding (and regenerative agriculture) are adopted globally.
To explain, if livestock that have co-evolved in their location were used instead of imported breeds, and in significantly smaller numbers than now, then methane emissions would come down, and vegetation would not be decimated. If damaged or degraded natural areas were allowed to naturally regenerate, then new scrublands and equivalent areas would lock up carbon. If no-till approaches were adopted rather than deep ploughing then carbon would stay in the soil, and if wetlands were allowed to evolve or come back, they would also lock up carbon, in sediment, plant growth and peat. And in respect of all of this, the people who know this already are those indigenous to their parts of the world, whether in northern Canada, the Amazon or Papua New Guinea. We should listen to them. They know, but they are so often voiceless.
I know that it is all very well me saying this now, but I am under no illusion, it would need seismic global changes in behaviours to meet the changes I suggest above, including changes that impact our own needs and wants. Sadly, I can’t see that happening quickly, but what I can say is that that rewilding and regenerative approaches really can play their parts, and the more places that adopt them, locally and globally, the bigger the combined positive impact on the climate crisis will be.