fueling stations. The book goes on to discuss the hypothetical evolution of the cost of vehicles with fuel cells and with hydrogen-powered internal combustion engines, as well as possible adoption strategies. It then reviews the issue of the greenhouse effect and offers four reasons why hydrogen would not be useful in reducing greenhouse gas emissions: Internal combustion engines continue to improve in efficiency. Since hydrogen is likely to be made from combustion of fossil fuels, it produces CO2 and other greenhouse gases as part of the fuel cycle. Fuel cells are likely to be much more expensive than competing technologies. Fuels used to make hydrogen could achieve larger reductions in greenhouse gas emissions if used to replace the least efficient of the electric power plants. The book then describes pilot projects in Iceland and California. In its conclusion, the book states that hydrogen will not be widely available as a transportation fuel for a long time, and describes other strategies, including energy conservation techniques, to combat global warming. Critical reception The Hype about Hydrogen was named one of the best science and technology books of 2004 by Library Journal. The New York Review of Books stated that the book gives "the most direct answers" to the question on the promise of a near-term hydrogen economy, calling Romm "a hydrogen realist". The environmental community newsletter TerraGreen agrees with Romm in the claim that "the car of the near future is the hybrid vehicle", and cites the book's good reception by Toyota's advanced technologies group. The San Diego Union-Tribunes 2004 review noted that Romm's "clear logic" reaches conclusions similar to an authoritative study issued by the National Academy of Sciences. Three UC Davis scientists who also reviewed the book agreed on its basic premises, but claimed that Romm had made selective use of sources, for example, citing the highest cost estimates, adopting extremely high estimates of efficiency for advanced gasoline vehicles, and giving weight to controversial non-peer-reviewed studies. Romm and Prof. Andrew A. Frank co-authored an article, "Hybrid Vehicles Gain Traction", published in the April 2006 issue of Scientific American, in which they argue that hybrid cars that can be plugged into the electric grid (Plug-in hybrid electric vehicles), rather than hydrogen fuel cell vehicles, will soon become standard in the automobile industry. See also Hydrogen vehicle List of books about energy issues Plug-in hybrid electric vehicle Who Killed the Electric Car?