Climate Change and the Food System

Hi, I’m Tom Powell. And we’re here, just up the hill from my house in southwest England, to talk about the relationship between climate change and the food that we eat. Now chances are that you probably recognise at least some of the landscape behind me. Even if the topography, the vegetation, or the colours are completely different to where you’re from, the agricultural landscapes are so familiar to us and so ubiquitous that we hardly even notice they’re there. In fact, this is an environment every bit as man-made as the urban environments in which half of the world’s population lives.

And if we add them together, pasture lands and crops constitute the largest single biome on earth, covering about 40% of the planet’s vegetated land surface. And it’s not just about occupying space. Agriculture has an enormous environmental impact, and is responsible for up to a third of all the anthropogenic greenhouse gas emissions. People are most familiar with methane emissions from cattle, like the ones in the next field, and also from rice production. But we also produce huge amounts of nitrous oxide when we fertilise soils. And the carbon dioxide emissions from deforestation are largely driven by agriculture. And that’s not to mention the huge fossil fuel emissions associated with the modern, mechanised agricultural industry.

We’re going to go down the hill to my garden now, and talk a little bit about how climate change might affect our food security.

So here’s what it’s all about, food. Here in my garden, we try and grow as much of our food as we can. And for a few months each summer, we manage to produce quite a lot of what we eat. We’ve really crammed in the crops, but we also managed to grow plants which promote biodiversity and use techniques which increase the health of the soil. In the friendly climates of southwest England, it’s possible to grow really quite a lot in a small area like this. But it’s incredibly hard work, and I’m really lucky to have several others to share that workload with.

Subsistence farming, whereby each household grows all of the food they need to survive, has been a hugely important part of human history. And for many families across the world, it’s still a crucial part of day to day life. But it leaves very little time for other activities which might bring income to the household, and makes you extremely vulnerable to pests, diseases, droughts and other environmental influences. And in truth, we’re completely reliant on the industrial farming system on the other side of these walls.

In the last century, the invention of synthetic fertilisers, mechanised agricultural machinery, scientific crop breeding, and refrigeration have allowed a Green Revolution in food production, which is one of the driving forces behind the growth in population from two billion people to this roughly seven billion there are today. And along with that has gone the boom in culture, technology, consumption, and environmental degradation of what we call the Great Acceleration. But that’s come at a cost. Decades of ploughing and fertilising our soils has caused soil erosion, and degraded the fungal and microbial communities that keep our cells alive. Irrigation has depleted the world’s freshwater resources, and fertilising has polluted them.

Pesticides, the use of chemical pesticides, and habitat loss has depleted communities of predators and pollinators that keep our crops pest-free and fertile. Add in climate change, and we might have a real problem. You might recognise these plants behind me as maise, one of the world’s most important staple crops. And in fact, in the south of England, we’re just about on the northern limits of maise production. As the climate warms in northern latitudes, the growing season’s getting longer, and farmers will be able to grow maise further and further north. And that’s great, if you’re a farmer in northern Europe who wants a good cattle feed crop. Just as the range of crops is sifting, so too is the range of pests.

Fungal and insect pests are also moving with climate change. And farmers will have a real game of catch up to try and protect their crops. Even more serious, for vulnerable farmers in the developing world especially, is that climate change will bring changes in regular weather patterns. And droughts and increased likelihood of severe rainfall will have really serious implications for crops and for livestock. Going forward to the middle of this century, the global food system is going to have to feed an extra two billion people. And with the system as it now is, that means providing at least 50% more food, if not more.

We’re going to be badly in need of sustainable food systems that are resilient to the changing climate.