Isabella Tree
Author of the award-winning Wilding: the return of nature to a British farmCreator of the Knepp Wildland and author of Wilding explains that the answers to the biodiversity crisis often apply to the climate crisis as well.
The revival of wildlife at Knepp – on 3,500 acres of West Sussex – over the past 20 years, has gone beyond my wildest imagination. Since we turned our unprofitable arable and dairy farm into a rewilding project in 2000, the abundance of life that has returned, of its own volition, has been – literally – breathtaking. Walking out through thorny thickets early on a spring morning, the volume of birdsong is so loud it reverberates in your lungs. Amongst the chorus are red-listed cuckoos, yellowhammers, and critically endangered nightingales. Knepp is probably the only place in the UK where the numbers of turtle doves – prolific when I was a child but now on the verge of extinction – continue to rise. Last year, the large tortoiseshell – a butterfly thought to have been extinct in Britain for fifty years – was found breeding at Knepp.
For those who watched David Attenborough’s Wild Isles, it may have come as a surprise that the UK is one of the most nature-depleted countries on the planet, ranked twenty-ninth lowest out of 218 countries – the worst in the G7. Shockingly, more than one in seven of our native species face extinction and more than 40 per cent are in decline. Knepp, and other rewilding projects like it, show how easy, quick, and relatively inexpensive it is to reverse those wildlife declines. Nature bounces back – if you let it.
But rewilding is not just about the joy of seeing wildlife again. Restoring ecosystems cleans the air, decontaminates polluted water sources, prevents flooding and contributes dramatically to mental health – all ‘public goods’ that society desperately needs but the Government is struggling to fund by conventional means.
Though vilified by the NFU, rewilding should also be welcomed by farmers and championed as agriculture’s greatest ally. It provides the life-support system for food production at a time when our industrialised farming systems are facing collapse. It restores soil and water tables, creates physical buffers to protect agricultural land from storms and droughts and provides insects for pollinating crops. Studies show that creating margins for nature around fields increases crop yields, even in conventional agriculture. It provides natural pest control – reducing the need for pesticides. Creating space for nature within and around productive farmland is, arguably, the most important action we can take for food security.
But restoring ecosystems has another vital string to its bow. It stores carbon. And here is one of the oddest disconnects of modern times. As the COP summits demonstrate, we have, somehow, separated the crisis of climate change from that of biodiversity loss. We believe we can address them separately and while we continue to do this, we will never stand a chance of solving either. The two are inextricably intertwined.
A new paper, published in the leading journal Nature Climate Change and co-authored by 15 scientists from eight countries, shows that wildlife populations directly influence carbon capture. Protecting or restoring populations of just nine species, or groups of species – marine fish, whales, sharks, grey wolf, wildebeest, sea otter, musk ox, African forest elephants, and American bison – could collectively result in the additional capture of 6.4 billion tons of carbon dioxide annually. This is more than 95 per cent of the amount needed every year to meet the global target of removing 500 billion tons of carbon dioxide from the atmosphere by 2100. “There may be an opportunity to draw down CO2 even faster,” the lead author of the paper, Professor Oswald Schmitz of the Yale School of the Environment, says, “if we consider and study a wider range of species and work to restore and protect the intactness of habitats across landscapes and seascapes”.
At Knepp, where free-roaming ponies, cattle, pigs, and deer have been driving the creation of dynamic new habitats, something astonishing is happening in our soil. Last year, as part of a study co-funded by government, the soil carbon company Agricarbon tested more than 1,000 core soil samples in our rewilding project. They found quantities of stored carbon, in their words, “of astonishing proportions” – between 3.3-4.8 tonnes per hectare per year. The carbon captured under rewilding, it seems, is way higher than carbon levels in the soil of adjacent areas that have simply been left fallow or that are under regenerative agriculture. We don’t yet know the reasons for this. Perhaps it’s the diversity of life in the soil – the year-round action of dung beetles, earthworms, and all the other healthy soil biota – or the actions of our free-roaming animals – trampling vegetation into the soil, where it is broken down and converted into stored carbon – or the stimulating root growth and mycorrhizal networks underground. Potentially, it is a combination of all of the above. We already know that our restored wetlands and habitats created by our beavers are storing carbon, as are our ancient oaks; and Oxford University is currently measuring carbon in our regenerating scrub and naturally colonising new trees. But these soil carbon figures, alone, should put rewilding firmly on the map as one of the most powerful solutions there is to address climate change.
Despite these exciting, world-changing solutions presenting themselves, however, morale amongst those of us involved in nature restoration is plummeting. The optimism that followed the passing of the UK Environment Act in 2021, with its vision for landscape recovery, Net Zero ambition, and targets for waste reduction, and the post-Brexit emergence of environment land management (ELM) as a nature-positive alternative to the perverse, anachronistic, and environmentally destructive farm subsidies of the Common Agricultural Policy, has waned. As ever, Ministers embrace the green rhetoric but baulk when it comes to taking the decisions needed to actually meet the targets they’ve set. As we approach a general election, ambitions for nature are pushed back. Talk of a healthy environment being vital for meeting social and economic goals shrinks to simplistic policies, such as tree-planting. Though our health and prosperity, our very survival, depends on it, nature restoration is attacked and demonised by farmers, developers, and others with opposing, commercial, and short-term interests. The future of ELM, itself, is in doubt. This is not a party-political statement. The Labour Party, despite its rhetoric on climate change, shows no sign of genuine interest in nature recovery and has no credible environmental plan. The Lib Dems suggest they would actually pull back on promoting responsible, nature-positive farming and landscape recovery.
Never has there been a more critical time to embrace rewilding and nature recovery. Never, it seems, has there been less political will to do so.