San Diego Union Tribune on Environmental Progress

Michael Shellenberger is an environmentalist.

He’s also an advocate for an energy source that many in the green movement deplore — nuclear power.

But that wasn’t always the case.

Shellenberger used to be a rabid anti-nuclear activist who, in his words, tried to “clog the toilet” to stall or shelf nuclear projects such as the Ward Valley radioactive waste dump in the eastern Mojave Desert.But in the face of the ramifications of a warming planet, the 44-year-old father of two has joined a number of greens such as climate scientist James Hansen calling for a reassessment of nuclear energy as the cleanest energy source to combat climate change.

For those who regard nuclear power as inherently dangerous in the wake of the 2011 accident in Fukushima, Japan, and the disaster at Chernobyl 30 years ago, advocating for more nuclear power amounts to almost a form of environmental heresy.