Here we can see population pyramids for the world, showing a widening youth base, especially in developing countries. It demonstrates the overall increase in the number of young people on the planet. These are people who are currently being fed by a comparatively smaller and aging population of farmers. There are considerably more young people than old, so the already small proportion of farmers (who on average are 60 years and older) will need to pass on their skills and livelihoods to younger persons.
Source: UNCTADstat (Department of Economic and Social Affairs, Population Division. (2019). World Urbanization Prospects: The 2018 Revision. United Nations.)