The green revolution has led to an increase in food production because it has used scientific knowledge to make food production easier and more efficient. This has been particularly true in many developing countries.
For example, let us look at what was done by the International Rice Research Institute (IRRI) in the Philippines. This institute was mainly funded by aid from private and public sources in the US. IRRI worked on developing strains of rice that would be able to live in flooded fields. It developed strains that would be easier to harvest. It developed strains that would be more perfectly suited for tropical climates. By doing this, IRRI made it much easier for farmers in various areas of the developing world to grow large amounts of rice.
Changes like the ones made by IRRI were also applied to other crops. Typically, it was applied to grain crops like wheat and corn. Since these crops are staples, the green revolution allowed people to have much more of the most important foods in their diets.
Of course, there are some who criticize the green revolution. This is largely because its advances depended to some degree on things like the use of chemical fertilizers. This has led to greater ecological problems due to things like runoff from farm fields.
The green revolution, then, improved food production by applying scientific knowledge of things like breeding and selection of crops to the production of staple foods.