After years of research, cautious optimism, and pilot programs, General Motors has decided to end development of its next-generation Hydrotec fuel cells. This move, which was quietly undertaken, concludes a long experiment that once carried significant potential for alternative fuel technologies.

Environmental advocates are once again sounding the alarm on “Dieselgate,” urging that scandal-plagued vehicles be taken off the roads for good. Millions of diesel cars continue to emit far more pollution than advertised, fueling calls for urgent policy changes and corporate accountability.