China rises while the U.S. recedes, along with the global order it created at the end of World War II. This has become a common narrative. Historian Alfred McCoy put it forward in his 2017 work, In the Shadows of the American Century. But, as McCoy points out in his latest work, China’s day in the sun may be brief, overwhelmed by cataclysmic climate disruption that could shatter world order itself as the century unfolds. The first truly global order originated when Portugal began the European age of exploration around 1420.