Worried about warming but confused about carbon? Try University of Chicago geophysicist David Archer's The Long Thaw, which tells you nearly everything you need to know with down-to-earth clarity and brevity. Archer is known for his studies of "the long tail" - the lifetime of CO2 released by human activities - which he and his colleagues have shown will continue to heat up the planet for thousands of years to come. He calls it "a climate storm" with an impact that will "last longer than Stonehenge." Yet reading The Long Thaw is sobering and enlightening rather than depressing. It's packed with informative, accessible background on past climate cycles and why they are relevant to assessing today's warming. Ultimately, Archer argues, the fate of our climate depends on what we do with earth's vast coal reserves. If we burn all that coal, it has the potential to take us to a hothouse world last seen not long after the demise of the dinosaurs. Yet Archer doesn't preach or waste much space on climate skeptics. His clear-eyed epilog settles quietly on the issue of ethics. Solutions to warming will only work if the nations that have benefited most from fossil fuels take on most of the burden of fixing the problem. The Long Thaw is published by Princeton University Press (2009, $22.95).