After hearing about different strategies for stabilizing and cooling the atmosphere, this book provided clear answers. First, the use of jets to disperse sulfur dioxide into the stratosphere to create a multi-year semi-reflective sunshade is based on proven science and facts. As the NOVA show "Dimming the Sun" demonstrates, sulfur dioxide and sulfate aerosols can and do provide temporary cooling effects. This is incredibly important to maintain current sea levels, and avoid a massive, multi-trillion dollar misallocation of assets to build seawalls around the world's major cities. It is also extremely important that the world keeps the Arctic sea ice. Some scientists believe that the loss of Arctic sea ice, and a dark ocean surface there instead of a high albedo ice cover, would lead to as much global heating as all of the world's human-made CO2 to date (in the year 2013) -- a fully recognized global "tipping point".Second, Prof. Keith advises a gradual approach, to reduce about half of the global warming in any given year, so that the cooling would take place with minimal disruption of rainfall patterns (this would apparently imitate some of the natural releases of sulfur dioxide, but with less of the natural side-effects seen from events such as the Mt. Pinatubo eruption).Another informative aspect of this book is that it shows the amount of sulfur to be used, cost estimates for jets, and settles the concept of using ultra-long tubes attached to upper atmosphere helium balloons. The book also described technical reasons why the use of jets is far better. The large droplet vs. the small droplet challenge for sulfate aerosols is covered too.Moreover, Prof. Keith clearly argues that sulfur dioxide cooling needs to proceed in combination with the pursuit of ultra-low carbon baseload power stations, and that it is not a substitute for biosphere-friendly energy sources. The approach recommended in this book would buy time for the climate and, significantly, help to maintain the heat balance as coal is hopefully phased out. Few mention that the phase out of coal would result in less sulfur dioxide and aerosols, which would temporarily increase global temperatures (in fact, in the late 1990s as the US and Europe reduced coal pollution this actually happened for a time -- as shown in NOVA's "Dimming the Sun").In summary, this is a valuable book, with a high degree of clarity and eloquence.