Climate change will affect food production, but here are the things we can do to adapt

Climate change could have large impacts on food production across the world.

I explored this in my previous two articles, looking at the impact of climate change on food production so far, and what we might expect in the future.

In short, it might boost crop yields at high latitudes but negatively impact yields in the tropics and subtropics. Wheat and rice — which benefit from more carbon dioxide (CO2) in the atmosphere — could see yields increase, while maize, sorghum, and millet could see a decline with warmer temperatures. If you want to know more, you can read the previous two articles to get some grounding in the scale and distribution of climate impacts.

This article is the third and final one in this series. It examines whether the world can adapt its food systems to climate change. What are those changes, and can the negative impacts on yields be offset?

These answers are crucial to ensure that countries can further improve food security in a warmer world.

What, where, when, and how: the four ways to adapt crop production

Farmers can adjust their practices in four key ways. They can change:

Farmers can change what they plant. This could be an entirely different type of crop: maize instead of wheat, for example.1 Or a different variety of a specific crop. There isn’t just one variety of maize or rice; scientists breed various "cultivars" with different characteristics and grow best in different conditions. Some are more drought-tolerant than others, for example. Or they take shorter or longer periods to mature and be ready to harvest.

This means farmers can pick crop varieties best suited to different climate conditions.

Farmers can change where crops are planted. If temperatures rise or fall, crop production can shift north or southwards towards more optimal temperatures. In mountainous areas, it can move up and down the slopes. Agriculture can also shift to drier or wetter regions of a country, depending on the local conditions.

Farmers can change when they plant and harvest. Farmers can plant earlier or later in the year, depending on when spring arrives. The same applies to winter crops: they might choose to plant earlier or later in autumn.

Farmers can change how crops are managed. Crops need the right amount of water, nutrients, and protection from pests and disease. Making sure that they have enough through the use of irrigation, fertilizers, and pesticides can help offset some impacts of climate change.

In the following sections, I’ll look at whether these changes can make food systems more resilient to rising temperatures in the future. However, it’s important to note that farmers have already implemented many of these strategies. For example, an extensive study by Lindsey Sloat and colleagues showed that the movement of farming and more irrigation has already offset most of the negative impacts that we’d expect from the 1.3°C of warming that the world has already seen.2

Adaptation can offset many, if not all, of the negative impacts of climate change on crop yields

Before I jump into the specific changes and investments that will allow us to adapt, it’s worth looking at the opportunity we have to make our food system more resilient at a global level.

Here, I’ll focus on a recent study by Sara Minoli, Jonas Jägermeyr, and colleagues.3

The study looks at the impact of climate change on yields of key staple crops — maize, rice, sorghum, soybean, and rice — towards the end of the century under a pretty high (i.e., bad) climate scenario called “RCP6.0”. In this scenario, the world would warm by around 3°C by 2100.4

They look at global yields for each crop (I’ll come on to some regional impacts later) under scenarios with and without adaptation. Adaptation in their study involves farmers changing the when and what — the timing of planting and harvesting — and picking more climate-suited breeds of crops.

They find that adaptation could offset climate impacts, at least at a global level. Crops such as maize would see yield losses without adaptation but could see an increase in yields with a change in practices and investments in the right places.

Let’s look at what these adaptation measures would mean in practice.

Planting and harvesting crops at different times and using more suitable crop types can improve yields

Sara Minoli and colleagues modeled two adaptation methods. The first is changing the dates that farmers planted their crops — in the chart, this is shown in brown.

There are two key stages in the year when farmers plant their crops: either at the start of warm weather for spring crops or the beginning of colder weather for winter crops, such as winter wheat. Climate change will affect the optimal time to plant. Warmer temperatures mean that in many countries, spring crops can be planted earlier.5 For the scenario of 3°C warming, The researchers estimate that toward the end of the century, spring crops in many places should be planted 10 to 30 days earlier than they are today. On the other hand, winter wheat should be planted 10 to 30 days later so the crop doesn’t develop too early or too quickly when it’s vulnerable to damaging conditions like frost.

In the chart below, you can see the estimated impact of changing the sowing date and adopting different crop varieties on crop yields at the end of the century under the RCP6.0 scenario that we looked at before.

At high latitudes — especially across Northern Europe and Canada — farmers who grow spring wheat might benefit from switching to winter wheat.

The second adaptation measure is choosing better-suited crop strains — in the chart this is shown in purple. Through plant breeding, scientists have adapted crop varieties to suit the local climatic conditions. Some varieties will need longer or shorter periods to reach maturity, will be more adapted to warmer, drier, or wetter conditions, have different optimal day lengths, and need different exposures to cold conditions to flower properly. Farmers can, therefore, select better-suited crop varieties over time as the climate changes. They already do this.6

Both measures help farmers to adapt, although changing crop varieties is expected to have a bigger impact on improving yields for all crops. The adaptation benefits for maize, rice, and sorghum are much larger than for wheat and soybean. This is good news because maize, millet, and sorghum could suffer the most from higher temperatures and don’t benefit much from higher levels of CO2. Wheat yields, on the other hand, are projected to increase under climate change regardless of adaptation.

Other studies that focus specifically on the increased risk of waterlogging find that adaptation using more tolerant crop strains, and changes in planting dates can offset many of the declines expected with warming.7

Data is lacking on impacts and adaptation in the regions that are likely to be most affected

Of course, we don’t only care about crop yields at the global level. If farmers in particular regions — especially those that are most food insecure — cannot adapt to climate change, this is still a major problem.

One extra challenge in assessing the impacts of adaptation in these regions is a lack of data and representative research. Only a fraction of the studies that look at climate change impacts and adaptation strategies are in Sub-Saharan Africa and South Asia. Investment into agricultural research in these regions is essential, given that this is where the most severe climate impacts will be.

What can we say from the small number of high-quality studies that have been done?

Changes in planting dates and the selection of the best crop breeds can already go some way to offsetting climate pressures in countries closer to the equator.

A study looking at agriculture in West Africa found that crop yields could decline by an average of 6% due to climate change.8 But, adaptation through changing planting dates and selecting better crop varieties could offset these declines, resulting in a 13% increase in yields.

Another study focused on the large breadbasket of Punjab in India found that a decline in wheat yields could also be turned into a yield gain by adapting planting dates and using improved crop varieties.9

But in some countries — and for specific crops like maize or millet — these strategies will probably not be enough. They can offset some of the declines in yields but not all of them.

A recent study looked at the potential for adaptation in rainfed cereal crops in West and East Africa.10 It estimated the share of current cereal production that would see increases or decreases in yield — and the stability of those yields from year to year — in 2050 and 2090.11 It then modeled how this would change through adaptation. You can see the results in the chart below.

Without adaptation you can see that a large share of cereal production could see a decline in yield. This is shown in red. But adaptation makes a big difference, especially in East and South Africa. In 2050, more than half of cereal production could see a decline in yield or stability. With adaptation, this shrinks to less than 20%.

There is still some red in the scenarios with adaptation, though. These regions will need to look towards other changes to farming practices and inputs to fully compensate for the impacts of climate change. Increasing access to agricultural inputs will be essential, not just to offset damages from climate change but to feed a growing population over the next 50 years.

Increased access to irrigation, fertilizers, and other inputs will be crucial

Global crop yields have increased dramatically over the last half-century. Improved crop varieties have been one of the big drivers, but increased access to irrigation, fertilizers, and other inputs has also been crucial.

This will still be the case in a changing climate. Perhaps even more so.

A large review of climate impacts on yields by Rezaei et al. (2023) highlights that irrigation and nutrient management (i.e., fertilizer use and efficiency) could be the most effective adaptation options.12

In areas where water stress increases with climate change, the need for more irrigation is obvious. However, a key point is that crop yields in many countries are already limited by poor access to irrigation and fertilizers.

In the two maps below, you can see the large differences in the use of these inputs across the world.

Farmers in richer countries get much higher crop yields. One reason for this is fertilizer use. Some of the world’s poorest countries — particularly across Sub-Saharan Africa — use more than 100 times less fertilizer than farmers in richer countries. Many don’t have access to additional nutrient inputs at all.

Data coverage on the use of irrigation is less complete. But as you can see on the map, there are large differences in rates of irrigation even along the tropics and sub-tropics. More than 75% of farmland in Bangladesh and 40% in India is irrigated, compared to less than 1% in Ethiopia, Nigeria and Niger. It would also be reasonable to assume that countries without available data — particularly across Sub-Saharan Africa — also have very poor access to irrigation.

Of course, the demand for irrigation across the world is not equal. Countries at higher latitudes, such as the United Kingdom, get more rain and don’t have to rely on irrigation as much.

As I mentioned in my previous article, the “yield gap” — the difference between yields that countries currently achieve and could achieve if they had access to best practices and inputs that are already available — in many countries is huge. Crucially, the gap is often far larger than the potential yield reductions due to climate change, even in the worst-case scenarios.

If farmers were given the means to boost yields by improving access to irrigation, fertilizers, and other necessary resources, then countries would be much more resilient and safeguarded against climate impacts. A 0.5 tonnes reduction in crop yields would be much more damaging to food security for a farmer who harvests 1.5 tonnes per hectare than for one who achieves 5 tonnes.

The earlier study looking at climate impacts in West Africa found that increasing fertilizer use alone would not only make crops more resilient to climate impacts but also boost the “baseline” yields.13 Combining climate adaptation measures with better access to fertilizers and irrigation would not only offset yield declines due to climate change but would actually result in much higher yields than farmers achieve today.

The world will need to take investment and innovation seriously to adapt to climate change

All of the studies above have focused on the biophysical potential that we have to build more resilient food systems.

The roadblocks to maintaining food security for 8, 9, or 10 billion people are not technical. With the right crop breeds, access to water and nutrients, and smart decisions around planting, we can offset many of the negative impacts of climate change on agriculture.

That doesn’t mean we should be complacent.

It means we have the chance to build a more productive and resilient food system, but it’s not guaranteed that we will. It depends on whether the seeds, irrigation, and adaptation practices will be available. That will require real and sustained investment from governments, donors, and private companies. Without it, many of these gains will not happen. Climate change will put increasing — and growing — pressure on yields in countries where food insecurity is already high.

The scientific research suggests this is a tractable problem we can tackle. Whether the world commits to making it a reality is up to us.