Jeffrey Bennett 
The Wizard Who Saved the World [PDF ebook] 

Diego dreams of being a wizard so he can make the world a better place by fighting global warming. When he realizes that he can»t really perform magic, Diego thinks of ways he can help save the world by considering many potential careers and what it would take to achieve them. Filled with sidebars called “Big Kid Boxes” that explain the crucial scientific concepts that lie behind the scenes depicted, this inspirational story gives children an opportunity to exercise their own magical dreams.