The case for technologies that harness renewable resources, improve efficiency, and reduce emissions has never been stronger, and the industry known as clean tech continues to grow at a staggering pace – global revenues for the "Big Three" sectors of wind power, solar PV, and biofuels hit $246.1 billion in 2011 after a decade of annual growth averaging more than 30 percent. But such an all-encompassing classification – spanning clean energy, advanced transportation, advanced materials, and clean water technologies – has lately made the industry an easy target for opposition, especially in the U.S., where divisive national politics have made pragmatism a rare commodity.