Climate change is making extreme weather much more likely. As the 2012 drought in the USA shows, extreme weather means extreme food prices. Our failure to slash greenhouse gas emissions presents a future of greater food price volatility, with severe consequences for the precarious lives and livelihoods of people living in poverty. This briefing draws on new research commissioned by Oxfam which models the impact of extreme weather – like droughts, floods and heat waves – on the prices of key international staple crops in 2030. It suggests that existing research, which considers the gradual effects of climate change but does not take account of extreme weather, is significantly underestimating the potential implications of climate change for food prices. This research shows how extreme weather events in a single year could bring about price spikes of comparable magnitude to two decades of long-run price rises. It signals the urgent need for a full stress-testing of the global food system in a warming world.