Last year, as United Nations scientists were warning of the perils of man-made climate change, this small country of fjords and factories reacted with an extraordinary pledge: by 2050 Norway would be "carbon neutral,' generating no net greenhouse gases into the air. Times Topics: Global WarmingNorway's bold promise raised the bar for other nations, which were mostly still struggling to figure out how to reduce emissions, by even a fraction. Then, in January, the Norwegian government went a step further: Norway would be carbon neutral by 2030, it said. But as the details of the plan have emerged, environmental groups and politicians