Finding the best ways to do good. In 2017, climate scientist Kimberly Nicholas coauthored a study trying to answer this question: What are the most effective changes you can make to your lifestyle if you want to reduce your carbon footprint and help save the planet? She found that for individuals in high-emitting countries, choices like flying less, driving less, and eating less meat are all helpful. But there’s another lifestyle choice that is much more effective over the long term: having fewer kids. Yet in her new book, Under the Sky We Make, Nicholas says that if you really want to be a parent, you should go ahead and have kids anyway.