An urgent examination of a global problem that requires vastly more attention than it currently receives. Despite the pervasive idea that overpopulation is one of the most pressing concerns facing our planet, human fertility rates are dropping fast. Without a concerted global effort to reverse this trend, long-term human survival may be at risk, according to renowned epidemiologist and public health expert Swan. The author made headlines in 2017 when she published a “meta-analysis on sperm-count decline in Western countries.” Her study became one of the most-cited in history, making it a hot topic among scientists as well as the public. Despite the attention, the demonstrated causes of fertility decline—including toxic chemicals that transfer from everyday products and foods into our bodies—remain a problem. In this impeccably researched, cogent book, the author convincingly argues that if society’s trend toward a fertility rate below replacement level continues at the current pace, humans could become an endangered species. “Of five possible criteria for what makes a species endangered,” she writes, “only one needs to be met; the current state of affairs for humans meets at least three.” The author’s passion for her work and access to reams of alarming data make for riveting reading, and her writing is crisp and unfettered by jargon. Writing about the lack of awareness regarding commonly used chemicals that are harming humans and the environment—not to mention policies to limit or eliminate them—she asks with justified anger, “Where is the outrage on this issue?!” Acknowledging the glacial pace of institutional change, Swan outlines how people can take concrete action to protect themselves now and how positive change has long-term ripple effects that benefit future generations. With an advocate’s verve and a scientist’s informed confidence, the author voices “a clarion call for all of us to do what we can to safeguard our fertility, the fate of mankind, and the planet.” An eye-opening, disturbing, empowering, and essential text.