In the Introduction, Gates explains that his interest in climate change arose through his work with the Gates Foundation, the nonprofit organization he founded to address health and education issues worldwide. While traveling in Africa, he noticed the lack of access to energy for basic needs like cooking and lighting. He saw that improving this access was crucial to improving people’s lives, as he realized “just how critical energy is to modern civilization” (6).

In 2006, he came to see the looming challenge of climate change. Before that, he thought that lowering emissions was the responsibility of rich nations and that this by itself could mitigate the effects of climate change. However, scientists working on the issue showed him data that made the direness of the situation clear. That was enough to get him involved.

As he studied the issue, he learned that existing renewable energy technology wasn’t in wide enough use and could make a difference—but that this technology alone wasn’t enough to solve the problem and get to zero emissions. He concluded that first, we must first reach zero emissions; second, we must make better use of existing renewable energy sources; and third, we must devise and deploy new sources to make up the difference and reach zero.