At the launch of the Gigaton Throwdown in DC last week, entrepreneurs and investors adopted a new metric for cleantech businesses other than internal rate of return – something called gigaton scale. The herd mentality that has characterized cleantech over the past three years continues today. In 2007 it was biofuels, in 2008 it was solar, and this year it appears to be smart grid and efficiency (which is ironic because for the longest time investors swore up and down that energy efficiency didn’t fit the VC model). What is so captivating about the Gigaton Throwdown is that it challenges businesses, investors and policymakers alike to focus on the technological pathways that have the potential to abate one gigaton of carbon or GHG equivalent per pathway per year by 2020. And executives with vision appear to be buying in. The CEO of Novozymes, Steen Riisgaard, for example told me during a recent conversation: “Thinking at gigaton scale is helping us identify our ultimate potential. Novozymes has the aim to help our customers achieve a 75 million tons reduction in greenhouse gases by 2015. But we actually believe the potential is much, much higher if you look at the entire industrial biotech space, where we think can reach gigaton scale within 10-20 years.” Similarly, Marty Lagod of Firelake Capital referenced one company, EOS Climate, in his investment portfolio that he bet on precisely because it has the potential to reach gigaton scale. Marc Porat, who has founded three cleantech building companies (Serious Materials, CalStar and ZETA Communities) has focused on building materials and building efficiency for the same reason. In his typical candor, he said that a lot of cleantech businesses in Silicon Valley are “vanities, which will not make a difference”. He’s absolutely right. And while businesses and entrepreneurs seem to be getting it, according to Cathy Zoi, the newly confirmed assistant secretary of energy for energy efficiency and renewable energy, policymakers in DC “don’t fully understand the potential scale of clean energy”. If the Gigaton Throwdown is successful it will change that, and bring all parties involved in the clean economy to the common realization that gigaton scale – besides meaning the possibility of climate stabilization within the necessary timeframe – also means gigadollar scale.