Imagine the entire population of China suddenly tripled overnight. How would we feed these extra mouths without driving wildlife and wild places into oblivion?
Although this sounds like the potential plot to a disaster movie flop, over the next thirty years this is the problem that humanity is facing. By 2050, Earth’s population will swell to 10 billion. The first big challenge is finding a way to fill all those new bellies. The second big challenge is filling all these bellies without spawning an ecological apocalypse.
There’s no doubt that the conversion of wild habitats into farmlands has consigned thousands of species to extinction. Human takeover of wild lands to make room for crops, livestock and livestock feed is the leading driver of biodiversity loss worldwide—whether it’s jaguar rich rainforests being swallowed by cattle ranches in Brazil, or the displacement of meadows leading to bee plummets across Europe. As population and food demand explodes, then, how will we save wildlife?
For many years, conservationists have championed the use of low-intensity and wildlife-friendly farming practices to limit the biological downsides of agriculture. Including hedgerows alongside farms, reducing chemical inputs or farming organically all in essence attempt the same thing: to create as much habitat as possible for wildlife sharing the farming landscape. At first glance, this is the sort of farming most of us prefer to see, summoning to mind idealistic images of knobbly carrots growing in Shire. But we need to feed a booming population, not a small band of hobbits.
Andrew Balmford, a University of Cambridge Professor of Conservation used to buy his food organically. Now he goes out of his way to avoid it. Why the sudden change of mind? It turns out that an obvious but often overlooked consequence of low-intensity farming is lower crop yields. Zooming out beyond the borders of a single farm and taking a helicopter view of affairs, low-intensity farming starts to look a lot less rosy.
That’s because to achieve high crop yields, low-intensity farmlands need to be sprawled across a pretty hefty area. Farm your cabbages at low-intensity, and you’ll have to devote more land in total to growing those cabbages, ultimately leaving less place for important natural habitats, like forests or wetlands. The alternative is to increase cabbage yields on existing farmlands as much as possible, in return for protecting or restoring natural environments elsewhere. (The other alternative is to stop eating cabbages, because they’re really quite a disgusting vegetable).
So, we have two conflicting approaches to meeting rising food demands. The first, land sharing, suggests that we should run low-intensity farms made up of a patchwork of natural features, like hedgerows. The second, land sparing, says we should separate agriculture and wildlife preservation across space, increasing yields on current farmlands so that we can spare wildernesses from agriculture altogether.
When the relative biological value of these two strategies is compared, a convincing picture starts to emerge. Sparing almost always beats sharing. And this holds true for most species and in most places. In northern India and southwest Ghana, for 600 species of birds and trees measured along a gradient from farmland to natural habitats, most do better under land sparing than land sharing, with this especially true for more threatened species. This pattern is repeated whether we consider dung beetles, butterflies, or ants, from areas as far-flung as Kazakhstan and the Yucatan.
In a way, the superiority of sparing makes intuitive sense. The vast majority of species have evolved to become specialised to particular habitats, whether that’s the dark, humid interior of a tropical rainforest or the mossy understorey of a temperate woodland. As such, although some species can persist within low-intensity farmlands, the vast majority cannot. Most species, including many of those most at risk of extinction, depend on the specific habitats in which they evolved to thrive. Our priority should therefore be protecting and returning wildernesses, rather than moulding our farmlands to be more wilderness-like.
How to spare.
One deadly pitfall to a land-sparing approach arises if, in practice, the “sparing” part falls through. If lands set-aside for preservation or restoration end up being converted to agriculture anyway, or are left unrestored, then no additional species are being protected. Although some have seized upon this issue as the kryptonite to land sparing, there are tried and tested strategies used all over the world to ensure that areas designated for protection actually receive some. One of these involves being very clear about which areas are going to be spared from the outset. In Costa Rica, for example, after the government zoned forests as off-limits for agricultural expansion, the rate of clearance of mature forests halved.
Promoting land-sparing more generally relies on government dollars pointing in the right direction. Unfortunately, the default tends to be the exact opposite. Across Europe, the Common Agricultural Policy spends several billion a year rewarding farmers that try to support bees, birds and wild plants on their lands. According to the current evidence, this money would be better invested in building new nature reserves instead.
Then there is the question of how to boost crop yields or intensify farming in the first place. For this, there are various possibilities at our fingertips. In many developing countries, the norm is for croplands to be relatively low yielding. In these cases, simple technologies or increased take-up of good agricultural practices can have enormous benefits, both to rural livelihoods and wildlife. In the Philippines, introduction of irrigation helped lowland farmers double their yearly rice production, whilst halving deforestation in upland regions.
Even in developed countries, where farming practices are generally more sophisticated, there is plenty of scope to boost farmland yields. More targeted use of pesticides or insecticides, or the introduction of higher yielding or pest resistant genetically modified crop varieties provide clear opportunities. But land sparing doesn’t necessarily rely on largescale agri-business approaches. To ramp up food production, China is encouraging greater uptake of traditional farming methods. And some of these, such as that where farmers also culture carp within their rice paddies are mighty successful. The fish eat damaging rice pests, the rice provides an ideal water environment for the carp, and together this co-culturing approach maintains rice yields whilst more than halving pesticide inputs.
The upsides to boosting farm yields get bigger when coupled with much needed shifts in human behaviour. And the boons of sparing nature also extend far beyond wildlife protection, also providing a helping hand in the fight against climate change. Across the UK, for instance, combining agricultural intensification with reduced food wastage and meat consumption by the public would free up a land area twice the size of Wales for re-growing forest by 2050, sucking up enormous amounts of CO2 in the process.
Intensifying agriculture to increase yields might seem a counter-intuitive way of saving wildlife and capturing carbon emissions. But with surging human numbers set to be a recipe for disaster, doing so will be a vital ingredient in saving the world without costing the Earth.
