To fight global warming, a bill in Sacramento would enable Los Angeles County transit officials to increase taxes on motorists. It's a bad idea that may foreshadow even worse to come. Billed as a "climate change mitigation and adaptation fee," the measure would cost motorists either an additional 3 percent motor fuel tax, or up to a $90 annual flat fee, based on vehicle emissions. The new charges would be on top of taxes already paid at the pump. Either option requires a majority approval by a vote of the people. Climate has changed as long as the Earth has...