In the face of rapidly developing economies, population growth, and rising energy demand, it is clear that technology absolutely must be part of the solution. We will need significantly cleaner energy sources than the ones used today. And we need much faster market penetration than has been the historic norm.
In a 2004 Science magazine article, Princeton professors Rob Socolow and Stephen Pacala introduced the wedge approach to frame this debate. The idea is elegant and simple. To stabilize emissions in the next 50 years, the world must reduce emissions by about 7 gigatons of carbon (not carbon dioxide) compared to “business as usual” scenarios.
So Socolow and Pacala identify 15 stabilization wedges that, if deployed at a significant global scale, could conceivably reduce emissions by 1 gigaton each. At 1 gigaton apiece, each technology wedge still represents a huge investment, but they are nonetheless conceivable. Seven gigatons of reductions are needed to achieve stabilization, so 7 of 15 wedges would, in theory, reach that goal. If deeper reductions become necessary, additional wedges could be added to the mix.