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 todays renewable energy technologies simply wont work; we need a fundamentally different approach. So were issuing a call to action. Theres hope to avert disaster if our society takes a hard look at the true scale of the problem and uses that reckoning to shape its priorities.
former director of NASAs Goddard Institute for Space Studies and one of the worlds foremost experts on climate change, showed the true gravity of the situation. In it, Hansen set out to determine what level of atmospheric CO2 society should aim for if humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted. His climate models showed that exceeding 350 parts per million CO2 in the atmosphere would likely have catastrophic effects. Weve already blown past that limit. Right now, environmental monitoring shows concentrations around 400 ppm. Thats particularly problematic because CO2 remains in the atmosphere for more than a century; even if we shut down every fossil-fueled power plant today, existing CO2 will continue to warm the planet.
We decided to combine our energy innovation studys best-case scenario results with Hansens 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 wouldnt 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, with all its dire consequences
Those calculations cast our work at Googles RE<C program in a sobering new light. 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 worlds coal plantsa situation roughly equivalent to the energy innovation studys best-case scenario. Even if that dream had come to pass, it still wouldnt have solved climate change. This realization was frankly shocking: Not only had RE<C failed to reach its goal of creating energy cheaper than coal, but that goal had not been ambitious enough to reverse climate change.
That realization prompted us to reconsider the economics of energy. Whats needed, we concluded, are reliable zero-carbon energy sources so cheap that the operators of power plants and industrial facilities alike have an economic rationale for switching over soonsay, within the next 40 years. Lets face it, businesses wont make sacrifices and pay more for clean energy based on altruism alone.
To bring levels down below the safety threshold, Hansens models show that we must not only cease emitting CO2 as soon as possible but also actively remove the gas from the air and store the carbon in a stable form. Hansen suggests reforestation as a carbon sink. Were all for more trees, and we also exhort scientists and engineers to seek disruptive technologies in carbon storage