Our fragile moment How lessons from Earth's past can help us survive the climate crisis

In this sober warning, Mann (The New Climate War), director of the Center for Science, Sustainability and the Media at the University of Pennsylvania, examines epochal climate events of the past to underscore the current threat posed by global warming. The Earth, Mann explains, can self-regulate its temperature (as the sun brightened over billions of years, the greater heat caused more evaporation and rainfall on Earth, washing carbon dioxide from the atmosphere and keeping it cool), but doing so takes time; for example, 56 million years ago volcanoes released carbon into the atmosphere for 10,000 years at such high rates that the Earth's temperature rose by 9˚F and remained elevated for 200,000 years afterward. Mann describes how 250 million years ago the Great Dying, which was caused by a spike in carbon dioxide levels from volcanic eruptions in Siberia, killed 96% of marine species despite playing out "about a hundred times more slowly than the current warming spike," underscoring the urgency of the current crisis. The climate history edifies, though discussions of the physics involved in global warming can get a bit technical ("The Stefan--Boltzmann law of physics... tells us that all objects radiate energy in proportion to the fourth power of their temperature"). Still, this enlightens even as it unsettles. (Sept.)

A renowned climatologist and science journalist casts a hard eye on the probability that climate change is irreversible. There's good news tucked away inside these data-packed pages: An Earth too hot to sustain life is not likely to come about "in any scenario but total inaction." The warming trajectory of the planet's climate is, even by current policies, likely to fall below the worst-case scenarios that have been proposed. Mann, the author of The Hockey Stick and the Climate Wars and The Madhouse Effect, suggests that planetary homeostasis is such that the climate is likely to even out and return to its old "normal." The bad news, of course, is that it's entirely unlikely that the present economy, still heavily reliant on fossil fuels, is going to turn on a dime--not when there are so many dimes to be made in burning them. That economy is the biggest obstacle to battling climate change, and with it comes "a sustained, massive, billions-of-dollars disinformation campaign." The campaign's proponent and main villain is Rupert Murdoch, whose stranglehold on the U.S. is principally confined to Fox News but who has much stronger control over Australia's media. Even so, notes the author, Murdoch was unable to undo the Australian government's pledge to reduce carbon emissions by 43% by 2030, largely because mandatory voting led to greater popular representation. Granted, neither mandatory voting nor gerrymandering, banned in Australia, are likely to take root in the U.S. given right-wing opposition. For all its positive outlook, though, Mann's argument hinges on probabilities and a historical record that shows plenty of evidence of past catastrophes resulting in massive die-offs, and the overarching answer, on the principle of scientific uncertainty, is that we don't really know what will happen--unless, that is, we surrender to inertia. An evenhanded take on a crucial topic. While our goose may not be cooked, it's still time to reduce the heat. Copyright (c) Kirkus Reviews, used with permission.