Last month, Valerie Amos, the UN's humanitarian chief, called for an extra $2bn (£1.25bn) from donors to combat another looming food crisis in the Sahel. Traditionally, these men would be leaving around this time of year to look for jobs in neighbouring Nigeria, but the World Food Programme is paying 25,000 CFA a month ($52) as part of a cash-for-work scheme to clear the lake. "Our research shows that it can take up to three years for people to fully recover from a crisis," said Benoit Thiry, WFP country director. Three droughts across the Sahel in fewer than eight years had severely tested people's coping mechanisms, he added. "We have to act now to make sure that gains we've made in recent years are not lost, so that people have alternatives to just borrowing money again to get themselves through the next crisis."