Green Economics

This is a follow-up to my last green jobs post. Matthew Kahn, green economist par excellence, asks some questions about green jobs:

I’m still trying to understand what are the exact details of how the “green jobs” push translates into specific policies? Is this simply a relabeling of Keynesian public works projects? Is this a justification for a ramp up in basic research funding (I would support this!)?

I vote for the Keynesian public works option, but feel free to convince me otherwise in the comments.