To date, 17 G-20 countries which account for 67 percent of global greenhouse gas pollution have officially joined the Paris Agreement, bringing the pact into effect sooner than anyone expected. If they follow through with their commitments to reduce emissions, it will represent unprecedented progress in the global effort to curb climate change. U.S. President-elect Donald Trump, meanwhile, has suggested a number of actions, including dismantling the Clean Power Plan and pledging to “cancel” the Paris Agreement, that would drive the United States and potentially other countries in the opposite direction. In light of this, the G-20 summit in July 2017 provides an important opportunity for committed major powers to resist backsliding by any and all G-20 countries and even to make some progress in meeting the climate challenge. To its credit, the German government, which officially assumed the G-20 presidency in December 2016, has taken steps that position the summit well for just such an effort. When German Chancellor Angela Merkel announced her three “pillar” objectives for the summit, she explicitly identified climate change as a priority. These pillars include fostering global economic stability; making the global economy viable for the future, including through the Paris Agreement and the 2030 Agenda for Sustainable Development; and establishing the G-20 as a “community of responsibility,” including by promoting a compact with Africa that would address infrastructure investment, among other topics.