It is commonly claimed in the scientific literature that the world food production has highly increased since the start Green Revolution. However there are still millions of undernourished people in the world. To make a precise assessement for all countries, scientists Liu et al. reviewed the historical trends of cereal production, pesticide application and fertilizer application from 1961 to 2010. They found that cereal production in 38% of countries and yields in 47% of countries either stagnated or decreased from 1961 to 2010. Countries showing decreasing yields are mainly located in Africa, South America and West Asia.
