When Typhoon Morakot hit indigenous villages in Taiwan's mountains 11 years ago, former army officer Chen Cheng-nan was stunned at the devastation.
"The mountain forest landscape changed overnight. In a blink of an eye, the forested river valleys went bare. It was a terrible sight. The dike broke and Qishan town was completely swept away," he remembered.
But as global temperatures rise due to planet-warming emissions, something odd is happening in Taiwan: devastating typhoons appear to be gradually disappearing.