This Briefing Note explores the implications for climate change, green finance, and Sustainable Development Goals (SDGs) of the G20 Summit which was held in Hamburg, Germany, on 7-8 July 2017. The previous G20 Summit in Hangzhou, China, held on 4-5 September 2016, appeared to begin a new era of cooperation on climate and sustainable development among the world’s leading countries. The 2016 Hangzhou Summit followed the Paris Agreement on climate change and SDGs, which were global landmark agreements signed in 2015. The US and China jointly announced their ratification of the Paris Agreement on the day before the Summit, and the Summit itself produced a G20 “Action Plan” on the SDGs which included a brief statement of each country’s implementation plans. While there were few concrete measures resulting from the Summit, the overall outlook was generally positive.