Just over two years since Egypt's dictator President Hosni Mubarak resigned , little has changed. Cairo's infamous Tahrir Square has remained a continual site of clashes between demonstrators and security forces, despite a newly elected president. It's the same story in Tunisia, and Libya where protests and civil unrest have persisted under now ostensibly democratic governments.

The problem is that the political changes brought about by the Arab spring were largely cosmetic. Scratch beneath the surface, and one finds the same deadly combination of environmental, energy and economic crises.

We now know that the fundamental triggers for the Arab spring were unprecedented food price rises. The first sign things were unravelling hit in 2008, when a global rice shortage coincided with dramatic increases in staple food prices, triggering food riots across the middle east, north Africa and south Asia. A month before the fall of the Egyptian and Tunisian regimes, the UN's Food and Agriculture Organisation (FAO) reported record high food prices for dairy, meat, sugar and cereals.

Since 2008, global food prices have been consistently higher than in preceding decades, despite wild fluctuations. This year, even with prices stabilising, the food price index remains at 210 – which some experts believe is the threshold beyond which civil unrest becomes probable. The FAO warns that 2013 could see prices increase later owing to tight grain stocks from last year's adverse crop weather.

Whether or not those prices materialise this year, food price volatility is only a symptom of deeper systemic problems – namely, that the global industrial food system is increasingly unsustainable. Last year, the world produced 2,241m tonnes of grain, down 75m tonnes or 3% from the 2011 record harvest.