The meaning of "green" is creatively expanded from the color we associate with plants to encompass the process of photosynthesis and the components of plant cells in which it takes place. Sutton's lush illustrations, naturally featuring many shades of green, fill the pages with tendrils, roots, and leaves at macro and micro scales and portray ecosystems on land and water throughout Earth's history as teeming with plants and animals. --The Horn Book A cogent reminder of the significance of plants, for oxygen breathers of all species. --Kirkus Reviews Green is the color of life in this informative picture book, specifically the green of chloroplasts doing the hard work of photosynthesis. Introduced with a helpful close-up on the layers of a tree leaf, their importance is established with a similarly useful diagram tracing the food sources of various creatures, all of which eventually lead back to plants. Green appropriately dominates the palette, and the gentle blending and dapples of the watercolor and acrylic art have a comfy, welcoming vibe. --The Bulletin of the Center for Children's Books A conservationist ethos infuses this scientific introduction to the critical role that plant life plays in regulating Earth's climate. Beginning with a single tree, Davies's gently scientific text talks through photosynthesis.

A pale-skinned child appears occasionally as a visual guide throughout Sutton's signature-style watercolor and acrylic paintings, which blend varied verdant hues in overgrown scenes of vegetation throughout this appreciative work on the abundant value of "green." --Publishers Weekly Lush landscapes and urgent environmental insights unite in this offering for young readers that emphasizes the critical role plants play in the health of our vulnerable environment. zoologist-author Davies and illustrator Sutton make their message here quite clear: "GREEN is the most important color in the world.". Davies presents green as far more than just a color and offers a time line to contextualize the eons it took to create a healthy ecosystem and the climate-change precipice on which we now teeter. --Booklist.