The European Union has announced a new support of 165 million euros to drought-affected countries in the Horn of Africa.
The world has lost roughly half its coral reefs in the last 30 years.
More than 20 million people in four countries facing starvation and famine, the UN humanitarian chief said Friday.
South Sudan fell into civil war in December 2013, just two years after it won its independence from Sudan.
Libya has descended into chaos since the 2011 civil war, which ended with the killing of longtime dictator Moammar Gadhafi.
An estimated 5 million Somalis, out of population of 10 million, need humanitarian assistance, according to the UN humanitarian office.
The ratifications by Chad, Jordan, Oman and Rwanda means the deal has reached the pre-determined threshold of 110 WTO members required for its immediate entry into force.
Famine has been declared in two counties of South Sudan, according to an announcement by the South Sudan government and three UN agencies.