As Typhoon Doksuri aimed toward mainland China, major southeast ports were forced to turn away dozens of vessels for days.

The storm — supercharged by the warm July waters of the Pacific — delivered Beijing's worst flooding in more than 50 years, shuttering factories, ruining crops, collapsing homes and displacing tens of thousands of people. China's losses from natural disasters in July and August stood at an estimated $10 billion.

But that official Chinese damage tally reflected only a fraction of the costs wrought by the typhoon. Rebuilding flood-hit areas and climate-proofing infrastructure will cost far more — with China issuing 1 trillion yuan ($139 billion) of sovereign bonds to help.