Bill and Melinda Gates want young people to get involved in solving major world problems, like finding clean energy sources and changing the division of household and childcare labour between men and women. The couple, co-chairs of the largest private foundation in the world, has made a tradition of releasing an annual letter on philanthropy. This year’s edition, released on Monday, called on the young to be a driving force for innovation and change. “Who are the innovators? It’s this next young generation and it’s not going to happen overnight, it’s only through their commitment that we’ll see by 2050 the kind of dramatic change that we need to see,” Gates said.