The report, a collaborative effort between leading researchers at UC Berkeley, MIT, University of Michigan, Stanford, and Drexel University, and clean tech leaders, identifies 7 industries capable of creating 5 million clean energy jobs and reducing CO₂ emissions by 5-7 gigatonnes by 2020.

The 7 existing industries - biofuel, nuclear, solar, geothermal, wind, building efficiency, and construction materials - could reach gigaton scale over the next 10 years with new infusions of private capital, says the report. To attain gigaton scale, a single technology must reduce worldwide carbon dioxide and equivalent greenhouse gas emissions by at least 1 billion tons - a gigaton - per year by 2020.

“Investments in clean energy technologies — and policies that encourage those investments — can pay off handsomely with jobs and economic growth while reducing our dependence on foreign oil and tempering the impacts of climate change,” said John P. Holdren, Assistant to the President for Science and Technology and Director of the Office of Science and Technology Policy.

The authors based their analysis on the assumption that CO₂ levels worldwide should be reduced to 450 parts per million by 2020, and to accomplish that, a 5-7 gigaton reduction in CO₂ emissions is needed. The team then investigated what is needed to reach gigaton scale by 2020 for 9 technologies currently attractive to investors.

For an electricity generation technology, this is equivalent to an installed base of 250 gigawatts (GW) of carbon-free energy (at 95% capacity factor). These 9 technologies provide examples of the potential to achieve gigaton scale: biofuels, building efficiency, construction materials, geothermal, nuclear, plug-in hybrids, solar photovoltaic, solar thermal, and wind.