BY FREIDERIKE OTTO/ JASPER VERSCHUUR Food security is a growing concern globally, with two billion people being subject to moderate to severe food insecurity in 2019 according to the United Nation’s Food and Agriculture Organisation. Food security consists of four interconnected pillars: food availability (how much is produced), food access (can people afford food), food use (how is food prepared and consumed) and stability (how stable is the food supply and consumption). Large-scale droughts can have cascading impacts on all these four pillars. They can reduce yield which may result in food price spikes, trigger changes in consumption, and lead to unstable supply and consumption of food. The impacts of such climate extremes are often felt hardest by subsistence farmers who become less self-sufficient and are therefore forced to buy their staple foods at local markets. In case of price spikes during low yield years, food may become too expensive for them, pushing poor households in a food insecure situation. So far, scientists have mainly focused on estimating how climate change has affected droughts and agriculture yields. It’s less well known if and how climate change is influencing the other three pillars of food security. By analysing the case of the 2007 food crisis in Lesotho, we found that climate change was indeed a critical driver of this food crisis, although not straight forward. What we found The food security situation in Lesotho can be classified as precarious. The country produces only 30% of maize — the main staple food — domestically. The predominantly rainfed agriculture makes it vulnerable to drought impacts. The remaining maize to meet domestic food demand is being imported from neighbouring country South Africa, with maize prices in Lesotho strongly influenced by maize prices in South Africa. Given the close proximity between both countries, a drought affecting Lesotho is also likely to affect South Africa. This would result in lower production in both countries. This happened in 2007, when the most severe drought on satellite record hit both countries simultaneously. The drought led to a crop failure in both countries, resulting in a steep drop in exports of maize to Lesotho. This was coupled with an increase in the maize price, which rose to double what they were two years before the event. In total, emergency food assistance for 20% of the Lesotho population was needed. To explore how climate change altered the likelihood of a drought of this severity happening, we used an “extreme event attribution” methodology. While extreme events are expected to occur from time to time because of the natural variability in the climate system, some types of extremes are occurring more frequent in a warming world. Event attribution methodologies, based on both observed weather data and climate models, help to estimate how often a type of extreme event is occurring in the warmer world we live in today (factual world). This is then followed by comparing this to occurrences of a similar event in a world as cool