PanThe Washington PostGaia Vince’s Nomad Century is written for all the right reasons. But it comes to the wrong conclusions ... a curious mix of apocalyptic planetary pessimism and unbounded optimism about the better angels of human nature. Vince examines scenarios for the unfolding climate crisis and chooses those nearer to the alarmist end of the spectrum, although remaining, in my view, within the bounds of the plausible ... Vince’s prescription of assisted mass migration, however, is a recipe for political disaster ... Vince recognizes some of the difficulties, noting that for her plan to succeed, humans would first have to abandon racism, chauvinism and nationalism and become citizens of the world. Like John Lennon and Yoko Ono, she cannot be faulted for lack of imagination ... Vince has read widely but often leaves her sources unmentioned. Readers who want to know where she got the notion that ancient Greeks were descended from steppe nomad warriors, or that 40 percent of East Africa’s rainfall comes from groundwater exploitation in India, are left in the dark. This makes it harder than it should be to assess the quality of the science on which she relies ... Vince’s wrongheaded recommendations come from having her heart in the right place. She is deeply, and appropriately, concerned about the likely plight of billions of the world’s least fortunate as our climate continues to warm. And she is right to emphasize the perils that climate change portends. But Nomad Century recommends cures that could easily prove worse than the disease. Her proposals for internationally overseen mass migrations and grand-scale geoengineering require faith in widespread saintliness and wisdom that humankind has yet to show.