Thursday, November 20, 2014

Renewable energy won’t reverse climate change

Ross Koningstein and David Fork, engineers at Google, write at IEEE Spectrum (excerpts):

At the start of RE<C, we had shared the attitude of many stalwart environmentalists: We felt that with steady improvements to today’s renewable energy technologies, our society could stave off catastrophic climate change. We now know that to be a false hope ...

As we reflected on the project, we came to the conclusion that even if Google and others had led the way toward a wholesale adoption of renewable energy, that switch would not have resulted in significant reductions of carbon dioxide emissions. Trying to combat climate change exclusively with today’s renewable energy technologies simply won’t work; we need a fundamentally different approach.

[T]oday’s renewable energy sources are limited by suitable geography and their own intermittent power production. Wind farms, for example, make economic sense only in parts of the country with strong and steady winds. The study also showed continued fossil fuel use in transportation, agriculture, and construction.

RE<C invested in large-scale renewable energy projects and investigated a wide range of innovative technologies .... By 2011, however, it was clear that RE<C would not be able to deliver a technology that could compete economically with coal, and Google officially ended the initiative and shut down the related internal R&D projects. ...

In the energy innovation study’s best-case scenario, rapid advances in renewable energy technology bring down carbon dioxide emissions significantly. Yet because CO₂ lingers in the atmosphere for more than a century, reducing emissions means only that less gas is being added to the existing problem. We decided to combine our energy innovation study’s best-case scenario results with Hansen’s climate model to see whether a 55 percent emission cut by 2050 would bring the world back below that 350-ppm threshold. Our calculations revealed otherwise. Even if every renewable energy technology advanced as quickly as imagined and they were all applied globally, atmospheric CO₂ levels wouldn’t just remain above 350 ppm; they would continue to rise exponentially due to continued fossil fuel use. So our best-case scenario, which was based on our most optimistic forecasts for renewable energy, would still result in severe climate change ...

Suppose for a moment that it had achieved the most extraordinary success possible, and that we had found cheap renewable energy technologies that could gradually replace all the world’s coal plants — a situation roughly equivalent to the energy innovation study’s best-case scenario. Even if that dream had come to pass, it still wouldn’t have solved climate change.

Incremental improvements to existing technologies aren’t enough; we need something truly disruptive to reverse climate change. What, then, is the energy technology that can meet the challenging cost targets? How will we remove CO₂ from the air? We don’t have the answers. Those technologies haven’t been invented yet.

[And then there's methane, with ~25 times the greenhouse gas equivalence of CO₂ and whose reduction would show effect in only a few years. Go vegan, people.]