Global investment in clean energy must reach $515 billion per year by 2030 — triple that of last year’s investment — in order to avoid “the catastrophic impact of climate change,” according to a report from the World Economic Forum and New Energy Finance.

Over the next 18 months, President Barack Obama wants to inject $54 billion into renewable energy as part of a larger economic stimulus plan — but that’s a onetime investment. Without question, reaching the Davos investment target will be no easy task. While the report authors argue that every stimulus package should push the cleantech ball forward (with support for educating a new generation of engineers and rolling out a fully digital power grid, for example), they see a necessary partnership between the private and public sectors ...