Last Wednesday, I was on a panel at Fortune’s Brainstorm Green Conference called "The New Lean Green" with KKR and InterfaceRAISE. At a time when the world is consumed with the global economic crisis, everyone is asking whether green is sustainable; and the verdict from my panel was that while companies are still investing in green, the focus is on prioritization and the economic value. The silver lining in all of this is that the two are not mutually exclusive. The economic challenges have created a silver filter to weed out what my fellow panelist from InterfaceRAISE referred to as "fluff." So if you have not built sustainability into your DNA with a solid governance model, metrics, and ROI models, your green strategy might be first on the cutting floor. Hopefully you all have a robust sustainability agenda that recognizes you can be lean and green.Congress will soon face the same question as it relates to the energy legislation introduced by Chairman Henry A. Waxman of the Energy and Commerce Committee and Chairman Edward J. Markey of the Energy and Environment Subcommittee…The American Clean Energy and Security Act of 2009 (ACES) purports to create jobs, combat global warming and reduce our dependence on foreign oil. The question again will be whether America can afford to pass comprehensive energy and climate change legislation and what will be the cost to business, government and consumers.President’s Clinton’s message to leaders at the Fortune Brainstorm Green on how best to address climate change was simple: It’s about "good economics." He urged all of us to focus less on the "what" and more on the "how." President Clinton outlined a clear strategy on how to make the case with a laundry list of opportunities and measured outcomes around building efficiencies, traffic congestion management, waste management strategies, utility modernization (including SmartGrid), low-income housing strategies and many more.Whether it’s in the U.S. Congress, Copenhagen, our companies, our communities or in our homes, he asked us whether we can afford to wait and urged us all to share the ‘how’ we are going green and to back it up with strong economic data.Tell us what you are doing to be lean and green!