Vast portions of west and central Africa have become so dry that they can't support crops, livestock and the millions of people who live there.
The Sahel - a belt of arid land that stretches across Africa below the Sahara Desert - is a zone prone to cycles of drought, and eight countries are seeing the worst of it this time.
The United Nations estimates that more than 10 million people are in danger of starving to death. Aid workers on the ground say it's getting worse quickly.
In response, UNICEF is launching a 24-hour social media campaign on Tuesday to raise awareness about the food crisis in Africa.
Called #SahelNOW, the campaign asks users on Facebook, Twitter and other social media to post messages over the day Tuesday to boost awareness of the problem and the estimated 1 million children in danger.
Aid workers on the ground say the situation is rapidly deteriorating.
"It's related to the lack of rains in 2011 and the drought," said David Gressly, UNICEF's regional director.
"People are trying to cope with that by selling their personal belongings - cattle, livestock," he said. "They're pulling children out of school to adapt to this."
U.S. Secretary of State Hillary Clinton recently announced the U.S. will earmark $120 million in emergency assistance for the humanitarian crisis unfolding in the Sahel.