What happens when the earth's climate warms by several degrees? Mark Lynas's latest book discusses changes predicted at various levels of global warming. By assigning each of the six chapters to degree of warming, Lynas illustrates the range of scenarios from one degree to six degrees. Some ideas presented will be familiar (rising ocean levels, crop failures, violent storms), but many more will come as a shock (more rainfall predicted for the Sahara desert, the Amazon rainforest easily become a vast empty desert). Lynas carefully supports all his claims with peer-reviewed scientific articles, but discusses the science in plain English.
The book is accessible, easy-to-read, and fascinating for a general reader. No previous knowledge is assumed.
The scenarios that Lynas depicts gradually get more and more unsettling. The first half of the book is discomforting, but the second half is positively terrifying. Chapters one to three are of interest to any reader. Chapters four to six are wonderfully researched and brilliantly written, but I wouldn't recommend them unless you have a strong constitution.
It may come as a surprise to learn that Lynas writes with restraint, deliberately avoiding exaggeration or carelessly frightening the reader. Nevertheless, the final three chapters of the book read like frenzied apocalyptic science fiction. This is because after 3 degrees of warming, many scientifically-predicted feedback loops emerge which could cause catastrophic rises in climate temperatures (eg thawing of the Siberian swampland, releasing vast amounts of methane).
Lynas's conclusion is one of hope - it is likely that today we can still prevent global warming from exceeding three degrees, but we must act now, and we must make dramatic changes.