EATING THE SUN

Meticulous but always engaging account of photosynthesis, the process that makes life possible.

Because most readers probably last encountered that word in high-school biology, science writer and Nature chief news editor Morton (Mapping Mars, 2002) faces a tough challenge in making the subject accessible, but he succeeds magnificently. The pace never flags in more than 400 pages recounting the history of life (essentially the history of photosynthesis) and of how plants convert sunlight, water and carbon dioxide into plant tissue, the source of animal flesh and food as well as oxygen and much of our landscape and weather. The author reminds us that the animal kingdom reverses photosynthesis. Animals consume oxygen, plants and each other to live, and then they die, decay and revert to inorganic matter, especially water and carbon dioxide. This cycle, stable for billions of years, is now out of whack, he notes. Humans are reversing photosynthesis on a massive scale by burning immense quantities of organic matter (coal, oil, wood), converting it back into carbon dioxide faster than plants can use it or the oceans and atmosphere can absorb it. That unsurprising bad news comes late in the book. Until then readers will enjoy the author’s biographies of scientists and accounts of research that revealed the specifics of how plants make life happen. Photosynthesis didn’t exist when life appeared well over two billion years ago, but it came soon after; Morton tells us how life probably originated and then delivers a detailed history of plant evolution to the present day. Because he describes these events as well as his scientist subjects’ thoughts, quarrels and experiments in precise detail, this is not a book to skim, but readers willing to take time will not regret it.

Top-notch popular-science writing.