NEW YORK » 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 labor 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 today, 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,” Bill Gates told The Associated Press, speaking about energy solutions.

In her section of the letter, Melinda Gates decried the ongoing disparity in unpaid household labor between men and women. On much of the globe, she wrote, responsibilities for maintaining a home, raising children and caring for the elderly still fall primarily on women and girls, sometimes keeping them from education and paid work.

Young people, she told The AP, can help change cultural norms.

“The way we change societal norms is by role-modeling publicly what the right thing to do is,” she said.

Bill Gates, in his section of the letter, talked about the importance of cheap, clean energy. He called on young people to study hard and come forward with their ideas to come up with what he called “an energy miracle.”

“When I say ‘miracle,’ I don’t mean something’s that impossible,” he wrote. “I’ve seen miracles happen before. The personal computer. The Internet. The polio vaccine. None of them happened by chance. They are the result of research and development and the human capacity to innovate.”

The couple framed the letter around a question once posed to them by a group of high school students: If you could have one superpower, what would it be? Their answers were more energy, and more time.

On a global level, lack of energy and time are some “of the things that lock people into poverty,” Melinda Gates said.