How a 'transfarmation' can help the climate

There are a number of ways that agriculture can lessen its environmental impact. Some of these ways you might be familiar with, like reducing food waste or using water sparingly. 

But others might be a little less obvious to consumers, even though their impacts could be far greater. For example, Seaweed Solutions in Portugal are experimenting with seeding kelp forests in the Atlantic Ocean by spraying pebbles with kelp spores and dropping them in the sea. Eventually, these spores will bloom into forests 30m (98ft) high that could provide a source of food, animal feed or medicine and sequester carbon in the process.

Solutions like this sound surprisingly simple, but working out farming's environmental impact can be anything but. Some of the biggest agricultural contributors to climate change are a little less obvious.

One significant source of farming's greenhouse gas emissions comes from land use change, or creating new cropland from natural habitats like forests, peatlands and grassland.

Peat, a thick, dark, gloopy mixture of partially decayed vegetation that accumulates over millennia, is a critical carbon sink. Though they make up only 3% of the world's land, peatlands punch far above their weight when it comes to sequestering carbon. Globally, they store twice as much carbon as all the world's forests, which occupy more than 10 times the area of land.

But when disrupted, this powerful storage system can start spewing carbon dioxide. Agriculture is the main driver for this disruption. If a peat bog is drained of its water, the nutrient-rich soil left behind makes it a perfect environment in which to grow many crops. However, draining the water also enables the stored carbon to be released into the atmosphere. 

In parts of Malaysia, Indonesia and Brunei, it is thought that 90% of peatlands have been disturbed to create agricultural land. Growing populations in Malaysia and Indonesia have raised the demand for more farmland, at the cost of natural peatlands.

Not only is this contributing to more carbon emissions, the dried peatland also becomes inflammable, which has led to hugely lethal peat fires. The polluted haze produced by peat fires in Indonesia during 2015, for example, are estimated to have caused 100,000 premature deaths. 

While peat is no longer commonly mined to be used as a fertiliser in countries like the UK, it is still mined in countries like Canada and Finland. For the same reason it makes good cropland, peat is a desirable additive to soil. In the UK, most peat-based compost is used not by commercial growers, but by amateur gardeners, though this practice might soon be banned. Peat-based compost has many valuable properties: it's versatile and absorbs moisture well, for instance.

Agroforestry, or the integration of forests and farming, has been practised in some form for centuries. With climate change driving more extreme weather, the benefits are mounting for both livestock and crops. 

Trees on agricultural plots reduce landslide risk in China and flooding risk in the UK, for instance. As well, "the right design will provide very good shade for livestock and for crops", says Helen Cheshire, the lead farming advocate for the Woodland Trust, a UK-based conservation charity. "They will help slow the wind and help slow evapotranspiration rates [the combined rate at which water is lost to the atmosphere from the ground and from plants], improving the crop water efficiency. So they act as a bit of an insurance policy against drought." The benefits extend year-round. 

One type of agroforestry, silvopasture, interlaces trees and shrubs with pasture. Such land, including both the trees and the soil beneath the woody biomass, can sequester five to 10 times more carbon. (However, the potential for increasing carbon sequestration depends on the conditions of the site. For instance, it may be less effective in areas that already have large amounts of soil organic carbon.) Because trees are such powerful stores of carbon, their presence on degraded agricultural land makes good use of such land.

The mixture also helps diversify the output of a farm or ranch. The trees can generate other foods like nuts and mushrooms while the livestock graze between the trees.

Southeast Asian countries including Cambodia and Vietnam have traditionally used agrosilvopastoral systems involving rubber, palm trees and acacias. "The systems have the potential to increase forage and wood biomass while promoting income diversification and contributing to food security, the restoration of degraded lands and the reduction of greenhouse gas emissions," explains Sonevilay Nampanya, a livestock development officer for the Food and Agriculture Organization’s Asia and the Pacific Regional Office. But this area remains under-studied.

Dairy and cattle production releases 37% of global methane emissions, making it one of the biggest agricultural greenhouse gases contributors. While lab-grown low-emission milks and beef could one day feature at our kitchen tables, some dairy producers like Wyke Farms, the UK's largest independent cheese and milk processor, are finding ways to use waste methane for good.

By introducing methanogenic bacteria to farm slurry and dairy waste, Wyke Farms can collect biogas to use as a clean fuel, and the remaining waste can be spread on the fields as an alternative fertiliser. 

While livestock farming can be made more climate-friendly, reducing the amount of animal farming – at least in industrialised countries with intensive animal agriculture operations – will make an enormous difference to greenhouse gas emissions.

Germany's new Commission for the Future of Agriculture has recommended reduced consumption and production of animal products, for example. And elsewhere, other farmers are already taking the initiative. Some transition farmers in the US are even betting on cannabis as a more lucrative alternative to poultry.

Meanwhile, movements like Refarm'd in Europe and the Miyoko's Dairy Farm Conversion Program in California have cropped up to support farmers to move away from animal products. But, overhauling the comparatively stable business model of farming meat, and learning an entirely new system of farming, is challenging.

For Sarah Heiligtag, one of the most difficult aspects of the transition hasn't been technical or financial, but social. In 2013, animal lover Heiligtag and her husband took over a livestock farm in Hinteregg, near Zurich, and turned it into an animal refuge and farm called Hof Narr. They started producing oats for oat milk, tomatoes for passata, and other crops. There are over 100 animals now living on Hof Narr, and thousands of visitors each year. In 2017, the Hof Narr team started helping other Swiss farmers to undertake their own "transfarmations". 

Other farmers have been suspicious of these kinds of projects, Heiligtag explains. The tensions can have a generational edge. "In Switzerland [farmers often] take over from their dads. And if the dad has done this for so many years, and suddenly the son comes along and says 'No, I'm not going to kill any animal, I'm going to do something completely different,' this might be a big issue."

Most of the farmers they've supported have been in their 20s and 30s, suggesting that as farming faces an ageing crisis, innovative models like this could be a way to keep younger generations interested.