Food baskets

Hunger in a changing climate

5 August 2013

Drought, floods, rising sea levels, more intense tropical cyclones. Our changing climate has a direct - and indirect - impact on the availability of food and people's access to it. Food security, as it's known, is an incredibly complex issue - but one that many organisations including the Met Office are tackling head on.

At present, close to one billion people suffer from hunger - and studies suggest that the impact of climate change could increase this figure by between 100 to 200 million people by 2050. But as Kirsty Lewis, Principal Climate Change Consultant and Food Security Team Leader explains, this is just one part of a very complex picture: "We need to look at the contribution of climate change to food security overall."

While there is uncertainty about the impact of climate change on a local scale, climate scientists agree that the global average temperature is rising. In some areas this could increase the length of growing seasons and reduce loss of yields due to frost. But on the other hand, such changes in climate could also bring more extreme weather events such as flooding or drought, damaging crops in the process.

A temperature rise could also affect globally traded food, and hit commodity prices. It may affect people's health which, in turn, affects their ability to absorb nutrients from food. It may also affect the way that food markets operate. And beyond climate, considerations include the impact of demographics, trade markets, economic growth and so on.

As Kirsty explains, "This is why it's so important that the Met Office works with other organisations. The question that policymakers are asking isn't whether crop yields go up or down; it's whether people will be able to afford food and access it securely. They want to know about the bigger picture."

Working in partnership

Over the past two years the Met Office has been working closely with the United Nations World Food Programme (WFP) - the world's largest humanitarian agency fighting hunger worldwide and responding to food insecurity within developing countries. It is a relationship that allows each organisation to work across their respective disciplines, share expertise and deliver knowledge that could help policy makers address the complex issue of food security more effectively.

One of the first joint projects has been the development of a Hunger and Climate Vulnerability Index. This simple diagnostic tool reveals the relationship between climate and food security - identifying those countries most vulnerable. The current index looks at present-day vulnerability by country - but this is just the beginning. Because it's scalable, it can be re-run on a sub-national level, and use future climate projections. It will then be possible to explore how changing one component - such as percentage of grain-fed agriculture, for example - could impact on vulnerability.

Looking ahead, it could prove an invaluable tool for policy and decision makers to design adaptation strategies, build resilience and lower the risk of hunger.

Food security in the UK

The issue of food security is not purely a developing world concern. Closer to home, we have also been working with government bodies and companies, examining the impact of climate change on the price of commodities imported to the UK, such as rice, wheat, barley and other foods. "In the UK it's about standard of living: what proportion of your income goes on food and whether you can afford luxuries like coffee and chocolate," says Kirsty.

To really get to grips with the issues, building long-term relationships and developing a shared language is essential. The challenge is a rewarding one. As Kirsty says, "here's where you get to tackle some real-world problems." And hopefully overcome them, too.

How might climate change affect food security? According to the World Food Summit of 1996, "Food security exists when all people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life." Here are just a few ways climate change could have an impact:

 - The global average temperature is expected to increase, affecting crop production.

 - Although average global rainfall is expected to increase, regional patterns of rainfall will also change, leaving areas dependent on seasonal rainfall, or on rain-fed agriculture particularly vulnerable.

 - Recurrent extreme weather events such as droughts, floods and tropical cyclones worsen livelihoods and undermine the capacity of communities to adapt to even moderate shock.

 - Carbon dioxide (CO2) concentrations are increasing. While the effect of CO2 fertilisation on crop growth is highly uncertain, some evidence suggests that while it could increase crop yields, yield quality may be adversely affected.

 - Heatwaves - one in 20-year extreme temperature events - are projected to be hotter. Even short heatwaves can be critical, especially if they coincide with key stages of crop development.

 - Melting glaciers ultimately cause water availability to become more variable as it increases dependency on seasonal snow and rainfall.

 - Sea-level rise threatens to engulf agricultural lands and salinise groundwater in the coming decades and centuries. It will also increase the impact of storm surges which can cause great devastation.

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