On Africa News Tonight: US Treasury Secretary Janet Yellen is preparing for a 10-day tour of Senegal, Zambia, and South Africa where she will re-affirm Washington’s commitments to the continent. Yellen's tour follows soon after the continent's leaders met with U.S. officials in December during the US-Africa Summit. U.N. Secretary-General Antonio Guterres Wednesday addressed the World Economic Forum where he highlighted that the global community is flirting with climate disaster and challenged leaders to create favorable conditions to address climate change.