It's not just humans working to combat global warming. Meet the ecosystem engineers who are improving our planet's health! In this unique look at how one animal can make a difference for the planet, Adrienne Mason, a marine biologist, reveals how whales are ecosystem engineers --- animals that create, modify or maintain a habitat or ecosystem. Whales do this by reducing the amount of carbon dioxide in the atmosphere. They store a large amount of carbon in their bodies for decades, even centuries; when they die, they sink to the ocean floor, taking their carbon with them. Whales also deposit nutrients into the ocean that help feed phytoplankton, which, in turn, draw carbon out of the atmosphere and into the ocean during photosynthesis. More carbon in the ocean means less carbon in the atmosphere --- all thanks to whales! Using a highly visual approach and a slow build of concepts, this fascinating book explores how whales play an essential role in maintaining a healthy ocean and, by extension, a healthy and biodiverse planet. Nearly half the book provides information on whales, including types of whales, what they eat and poop and how they migrate. It then moves on to describe the consequences of a warming planet and the ways that whales can help. Kim Smith's stunning art brings the concepts to life. Part of the Ecosystem Guardians series, this book has strong STEM connections in life and environmental science, with curriculum links to biodiversity, ecosystems, food webs and animal habitats and characteristics. It contains a glossary, resources, information on how children can help and an index.