This week's long read: more food for you.

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Is the climate change food crisis even worse than we imagined?

Extreme weather and a growing population are driving a food security crisis. What can we do to break the vicious cycle of carbon emissions, climate change and soaring food costs – or is it already too late?

By Michael Le Page

11 November 2024

Роман Заворотный/Adobe Stock

 

You have probably already noticed that the price of many of the foods in your grocery basket has risen – a lot. In the UK, the cost of white potatoes is up 20 per cent in the past year, with carrots up 38 per cent and olive oil up 40 per cent. And while that means the expense of putting together a roast dinner is soaring, specialty items are suffering even bigger hikes – you will now pay nearly double for some bars of chocolate.

What is driving prices up is complex, but one of the biggest factors is climate change. In the short term, extreme weather caused by a warming climate has had devastating consequences for growers. In northern Europe, for instance, torrential rains in spring 2024 left fields too sodden to harvest vegetables or plant new crops. Meanwhile, a drought in Morocco, which typically exports a lot of vegetables to Europe, meant there wasn’t enough water for irrigation. The result was soaring prices for potatoes and carrots.

As the average global temperature zooms past 1.5°C above pre-industrial levels in the coming years, heatwaves, droughts and extreme storms are going to become even more common and severe, causing greater disruption to food production. But current efforts to compensate for the impact of poor harvests – such as clearing forests to grow more crops – make many other problems worse, from biodiversity loss to increasing carbon dioxide levels. With such big impacts on so many foods already happening, have we underestimated how bad the effect will be? And what can we do about it if we have?

 

Every crop needs particular conditions to thrive – too hot or too cold, too wet or too dry, and yields will be lower. To understand how global warming will affect yields, climate scientists use computer models to work out how conditions might change in growing regions. Early versions of these models suggested yields could fall in areas near the equator, where crops are already near their heat tolerance limits, but rise in areas further north or south. In fact, a 2007 report by the Intergovernmental Panel on Climate Change (IPCC) concluded that, thanks in part to the fertilising effects of higher atmospheric CO₂ on plants, food production would rise overall until the increase in global temperature exceeded 3°C, after which it would begin to fall.

Farming in crisis

The forecast now, based on improved modelling, is less optimistic. The latest IPCC report, issued in 2022, warned that food security will be increasingly affected by global warming and the climate events associated with it, creating the “possibility for surprises”.

Not only are newer climate models projecting much stronger effects, both positive and negative, but the latest crop models also suggest the impact on yields will be much greater too, says Jonas Jägermeyr, a climate scientist at NASA’s Goddard Institute for Space Studies in New York. A recent modelling study by his team projected that wheat yields could rise by up to 18 per cent by 2100 in a high emissions scenario, while maize yields could fall by 24 per cent. These figures aren’t forecasts, but rather give us an idea of what would happen if farmers keep doing what they are doing now.

 

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But current models also have some serious limitations. “Realistic projections probably would be a little bit less optimistic,” says Jägermeyr, noting that climate models aren’t good at projecting extreme events and that crop models tend to underestimate impact.

Another major limitation is that these models don’t consider the risk of pests and diseases. As the planet warms and becomes more humid, some pathogens will spread to areas where they haven’t been able to survive before.

“Where the crops are doing better, their pests and diseases will tend to do better as well,” says Dan Bebber at the University of Exeter in the UK. “We need to be prepared for invasions of new pests and pathogens that we haven’t seen before.” For example, one factor behind soaring olive oil prices is a devastating bacterium called Xylella fastidiosa, which, after being found in Puglia, Italy, in 2013, went on to kill more than a third of the region’s olive trees within a decade. Warmer temperatures are helping it spread in Europe.

 

Another issue with the model studies, according to David Lobell at Stanford University in California, is that they often focus on staples such as wheat and maize, rather than also considering specialised crops like cocoa and coffee. Because these grow in fewer places, their supply has proven more vulnerable to extreme weather. Most of the world’s cocoa comes from just four countries in West Africa, where recent harvests have been devastated by drought, heavy rainfall and a disease called swollen shoot virus. Prices of chocolate have risen precipitously in the past few years in response. “We didn’t really have a good sense of what was going to happen there,” says Lobell of specialty crops.

The real cost of food production

So far, it is also proving harder for farmers to adapt to the changing climate than we thought – which is deeply worrying, given that the changes now are small compared with those expected in the next few decades. “Earlier studies did show the potential for negative impacts, but they were quite optimistic on how easy it would be to avoid those impacts by just making shifts in the types of varieties that are being grown,” says Lobell. “It’s not going to get any easier if the changes are bigger.”

And yet, overall food production has been rising. Lobell’s studies suggest that wheat and maize yields would have been a few per cent higher by now in a world without climate change, but we have kept ahead of the climate curve in part by increasing adoption of fertilisers and mechanisation by farmers. However, that means we are having to use more energy to grow the same amount of food, says Bebber. “Once you control for our agricultural technology, the impact of climate change is already with us.”

 

Drought and wildfires are both on the rise, with negative impacts on crop yields

Claudius Thiriet/Biosphoto/Alamy

 

The other reason for rising food production is that the global area used for growing crops is expanding rapidly. This often involves turning forests into farmland, which is catastrophic for biodiversity. Clearing trees also puts a lot more CO₂ into the atmosphere, adding to farming’s already large carbon footprint – about a third of our greenhouse emissions come from agriculture.

A climate change tipping point

Alarmingly, we seem to be at the start of a vicious cycle: global warming is making it harder to grow food, so farming is becoming more emissions-intensive to keep up, leading to yet more warming. The rising temperature will also amplify other threats to world food production, including ocean acidification, groundwater depletion and soil loss, intensifying that cycle further – for instance, hotter temperatures mean farmers need to use more groundwater for irrigation.

“The risk that we face is not a risk just to the food system. The risk we face is to the entire climate system, to the entire ecosystems of the world,” says Lobell. “Problems with food quickly spread to land-use change, biodiversity loss, climate emissions. That’s the scenario that we definitely want to avoid. But in some ways, we’re in that scenario right now.”

 

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The biggest short-term concern isn’t that those on a high income will go hungry, but that we will continue to damage the planet trying to keep supermarkets stocked. To be clear, as the 2022 IPCC reports warns, simultaneous extreme weather events in several parts of the world could lead to major food shocks, but we do have buffers in the form of food reserves and the repurposing of crops currently used for biofuel and meat production for human consumption.

For those on low incomes, things are very different. Estimates say more than 700 million people – 9 per cent of the global population – faced hunger in 2023, 150 million more than in 2019. That number is expected to increase with global warming.

“It’s not just about producing more food,” says Jägermeyr, it is about producing food where it is needed, at a price people can afford.

 

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However, if we pass some potential climate tipping points, maintaining the global food supply for everyone will become even harder – and we may be approaching one fast. Vast areas of the Brazilian rainforest are being burned down to become cattle ranches. Close to 18 per cent of the Amazon has been deforested, says Carlos Nobre at the University of São Paulo in Brazil, making the region hotter and drier and increasing the risk that the Amazon will die.

“Studies indicate that if we reach 20 to 25 per cent deforestation, and global warming exceeds 2°C, we are going to reach the [Amazon rainforest] tipping point,” says Nobre, making it more difficult to grow food. That will have significant negative consequences for all of us – Brazil produces around 10 per cent of the world’s food by weight, including half of global soya bean exports and a third of beef exports.

How can we preserve food security?

So what do we need to do to keep producing enough to eat, without causing even more problems?

“The short answer is everything,” says Lobell. No single solution is a magic bullet – averting the coming food crisis will take a myriad of innovative and scalable responses.

One big answer is eating less meat. A huge proportion of the food we grow, especially maize and soya, is fed to animals rather than eaten directly by us. “If we use land more efficiently and feed humans rather than livestock, then all the problems go away,” says Bebber.

 

Unfortunately, the opposite is happening. Although global beef consumption is down from around 11 kilograms per person per year in the 1970s to just over 9 kg today, population growth has meant that overall beef production has nearly doubled over this time. The global production of dairy and all meats has been rising steadily for decades, with no sign of any change in that trend – as incomes rise around the world, people eat more meat on average. One way to tackle this is to introduce taxes on meat that reflect the environmental damage its production causes. But few voters want that and, so far, no country has tried it.

We can also do more with the food we have. According to a 2024 United Nations report, a fifth of the food that reached shops, restaurants and consumers in 2022 went to waste. Producing that wasted food generated 8 per cent of global greenhouse gas emissions, while gases produced by food rotting in landfills also has a warming effect. Only a few countries are making progress on this: the UK, Europe’s largest waster of food but also a signatory to the UN 2015 voluntary food waste reduction goal, is among them. Between 2007 and 2021, the country saw an 18 per cent reduction in food waste, and new legislation requiring businesses to separate food waste from other streams will come into effect from March 2025, showing that change is possible.

 

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Modifying our behaviours can undoubtedly mitigate the damage (see How you can help solve the food crisis, below), but there are other tools, too. Work to make crops more heat, drought and pest resistant is already under way. Scientists are also trying to design crops capable of making their own nitrogen fertiliser. Legume plants such as peas and beans host bacteria in their roots that convert nitrogen in the air into chemicals that plants can use, but researchers have so far been unable to induce this process in other crops. However, if achieved this would dramatically reduce greenhouse gas emissions caused by the manufacture and use of fertiliser, plus make food cheaper.

Other researchers are working on photosynthesis, the process by which plants harness sunlight to create the energy they need to grow. Photosynthesis is surprisingly inefficient – only about 0.3 per cent of the energy in the light hitting a field of wheat ends up in the harvested grain. In 2022, a team led by Stephen Long at the University of Illinois Urbana-Champaign reported yields up to a third higher in soya beans modified to make them photosynthesise more efficiently. This claim has been disputed, but further trials are ongoing. If it works, the impact would be huge: selective breeding has improved the yields of soya beans and maize by only about 1 to 2 per cent each year, and these are among the highest gains for any crop. But by combining multiple ways of boosting photosynthesis, Long says it might be possible to increase yields by more than 50 per cent.

 

Technology can also improve farming practices: precision agriculture and robotics can, for example, apply nitrogen fertilisers more efficiently, reducing greenhouse gas emissions and the pollution from agrochemicals washed off land into rivers and streams.

Then there is taking the field out of farming. Growing plants in controlled conditions, such as in greenhouses, can protect them from extreme weather and make yields more reliable, but the energy cost to keep conditions controlled can be high. Another not entirely new approach is to grow food in vats – the meat substitute Quorn, for example, is produced this way from a soil fungus. However, the challenges of growing fungal, plant or animal cells in vats means the products can be prohibitively expensive. Those cells also still have to be fed, and because the nutrients used presently come from crops grown in fields, the environmental footprint of the final product isn’t necessarily that much better than the products they replace.

 

Governments should pour money into securing food production, but they are doing the opposite

 

 

But what if we could make nutrients directly using energy and plentiful raw materials, rather than relying on photosynthesis to do the job? Earlier this year, a Finnish company called Solar Foods became the first to produce food commercially this way, using electricity to split water into oxygen and hydrogen, then feeding the latter to bacteria that use it as their main food source. The final product is a yellow protein-rich powder called Solein that can be used as an ingredient in a variety of fare. Snack bars containing Solein are already on sale in Singapore.

 

Compared with producing the same amount of plant proteins, the company claims producing Solein results in a fifth less CO₂ emitted, while requiring a 20th of the land and a 100th of the water. Questions remain whether this can be scaled up and whether people will buy it, but this kind of approach could have a big impact even if it is used only for animal feed.

We do have what it takes to make our food system more productive and resilient and less damaging to the environment. However, at a time when governments should be pouring more money into such efforts, they are actually spending less, says Lobell. “The combination of less innovation and more climate change is a very scary one,” he says. “I think we can do a lot on both of those. But it’s not going to happen overnight.”

 

How you can help solve the food crisis

 

Composting food waste is one way to help reduce emissions

Jim West/Alamy

 

EAT MORE ADVENTUROUSLY

Growing a wider range of crops would make our food system more resilient to weather extremes, pests and diseases. But it is difficult for farmers to switch to crops for which there is little demand. So try some foods you may not have sampled before, such as breadfruit, and if you like them, keep on buying them.

THINK TWICE BEFORE YOU BUY ORGANIC

Organic food is marketed as environmentally friendly, but on average yields are lower. This means we would need a lot more farmland if everyone ate organic, accelerating deforestation and the loss of biodiversity as well as increasing greenhouse emissions related to land clearance.

EMBRACE GM FOOD

To save the rainforests, we need to produce more food on less land. Genetic modification is one of the best tools for achieving this. Take bananas, which have one of the lowest carbon footprints of any food, even when you factor in shipping. The popular Cavendish variety is being hard hit by the spread of a fungal disease, but a resistant variety has been created by gene editing. Its adoption, however, is being slowed by the opposition to genetically modified crops.

FAVOUR LOW-EMISSION FOODS

Producing a kilogram of mutton or cheese results in less than half the greenhouse gas emissions of 1 kg of beef, while 1 kg of pork and chicken results in a 10th of those emissions. So simply picking one kind of animal-derived product over another can make a big difference. Fruits and vegetables usually have much smaller carbon footprints than any animal product, so eating more of them is better and healthier, too.

DON’T WORRY TOO MUCH ABOUT FOOD MILES

Buying local is a long way from being the most important thing when it comes to the sustainability of what you eat. Locally raised beef can have a carbon footprint around 100 times as large as bananas shipped thousands of miles. Focus on what you eat rather than where your food comes from.

WASTE NOT, WANT NOT

An estimated 60 per cent of food waste happens in households, so we all have a part to play in reducing this – which would be a win-win for us and the planet. There are lots of ways to reduce waste, but the biggest, of course, is to avoid buying food you are unlikely to eat before it spoils.