The global economy may be sagging, but residents of the Pacific Northwest should take heart: A study released late last week suggests that the region will benefit from a boom in the next 20 years in the clean energy industry. In Washington, Oregon, and British Columbia, clean energy is currently a $1.4 billion business; the report predicts that in two decades it could nearly triple, to $4 billion, and employ 12,000 more people. Next year, construction may be completed on the largest wind-energy source in the world, at the Columbia River Gorge, on the border between Washington and Oregon.