On December 12^th, almost 200 nations agreed upon a pathway forward for avoiding the most dangerous impacts of climate change. I join the world in celebrating this historic moment. The United Nations has finally joined the quiet revolution that is already blazing the trail of climate change solutions. The curmudgeon in me is painfully aware of what the Paris Agreement is not. It does not tie the nations of the world to legally-binding reductions in greenhouse gas emissions, nor commit rich nations to mobilize sufficient funds to pay for the transition to low-carbon economies. It does not establish a price on carbon that would unleash market forces and private finance for this transition at the scale that is desperately needed. The optimist in me is thrilled by what the Paris Agreement is—a unified expression of global political will to tackle climate change. The Agreement establishes a shared, ambitious goal—“well below” 2 degrees celsius warming. It establishes a shared commitment and schedule to create a reliable system for measuring progress. It recognizes and begins to plug the financial gap for achieving the target. Finally, it outlines a governance structure, focused on five-year reviews of progress, that should enable a crucial “race-to-the-top” as nations and subnational governments around the world drive progress to announce at their next time on the global stage. In the realm in which Earth Innovation Institute works—supporting political, corporate, and farm leaders to advance towards sustainability in a harmonized and efficient manner—this is as good as it gets. When a region achieves shared goals across its sectors, good monitoring, integrated incentive systems and a transparent, multi-stakeholder governance structure for moving the regional agenda along, the progress towards sustainability—including radical declines in greenhouse gas emissions—can be rapid. Brazil became a global leader in climate change mitigation by slowing Amazon deforestation (the broadly shared goal), through a good monitoring system and only a partial set of incentives (all of them negative). Imagine what will happen when all of the pieces are in place! The global mobilization among sub-national leaders to make a bold announcement in Paris was incredibly powerful and received surprisingly little media coverage. What is particularly interesting about these states, provinces and cities is that they are already making great strides in lowering greenhouse gas emissions. This is the level of government where much of the policy innovation is taking place—innovation that eventually gets pulled into the national policy frameworks. In May of 2015, Governor Jerry Brown of California (USA) and Minister-President Winfried Kreschmann of Baden Württemberg (Germany) launched the “Under 2 MOU”—a global partnership whose signatories all agree to reduce their emissions 80 to 95%--or to below 2 tCO2 per capita—by 2050 to keep the planet from warming beyond two degrees. By December 12^th, the U2MOU had 80 signatories representing a collective GDP of $18.6 trillion—bigger than the US and one-fourth of the global economy.  Part of our support to Governor Brown’s team for this process has been to quantify its potential impacts on climate change—which have now achieved 20 GtCO2 by 2030 and 55 GtCO2 by 2050. Just to put these numbers in context, the US “Clean Power Plan” to scale back emissions from coal-powered electricity would give us 2.7 GtCO2 emissions reductions by 2030. Most of the near-term emissions reductions that could be achieved by the U2MOU come from a handful of tropical forests states and provinces that are themselves organized through a global partnership called the “Governors’ Climate and Forests task force” (the GCF) and have already achieved 4 GtCO2 in emissions reductions. The plan of just one of these states—Mato Grosso in the Brazilian Amazon region—represents 30% of the emissions reductions pledged by the entire U2MOU through 2030. Earth Innovation Institute has been working with the governments, companies and farmer organizations in many of these tropical forest states to help design strategies for the new “low-emission” sustainable development agenda. Bold governors of tropical forest states and provinces are wondering if the world recognizes their contributions to climate change solutions. Paris has responded with a "yes". It will take a few years for the Agreement's specific reference to reductions in emissions from tropical deforestation and CO2 uptake by new forests--also known as "REDD+"--to translate into badly needed finance for these states and provinces. Hopefully, the globally-endorsed mention of forests will stimulate new investments and "pay-for-performance" mechanisms. The Paris Agreement—a unified global expression of political will—promises to energize and embolden the quiet revolution among governors, mayors, spiritual leaders, farmers, activists, indigenous leaders, scientists, and corporate leaders that is already leading the way on climate change solutions. And that is a big deal!