One month after the terror attacks that traumatized Paris, the city has produced a climate agreement that is being hailed as a massive expression of hope. On Monday the U.K. Guardian dubbed the Paris Agreement, “the world’s greatest diplomatic success.” Distant observers may be tempted to discount such effusive language as hyperbole, yet there are reasons to be optimistic that last weekend’s climate deal finally sets the world on course towards decisive mutual action against global climate change. The birthing process clearly sets Paris apart from earlier efforts at global climate action, such as the Kyoto Protocol crafted in 1997. Only last-minute intervention by then U.S. Vice President Al Gore clinched a deal at Kyoto, and its impact faded as major polluters declined to ratify the treaty or dropped out. High-level diplomacy to secure a Paris deal, in contrast, began building in earnest last year with a bilateral climate agreement between U.S. President Barack Obama and China’s Xi Jinping—representing the largest climate polluters. Global buy-in grew over the following 12 months as one nation after another anted in with their own emissions reduction plans.