Other vulnerable countries included Ecuador, Panama, Columbia and Mexico in the Americas, Indonesia in Asia Pacific and New Zealand, Israel and surprisingly, Italy, among advanced economies.
"Looking ahead, climatic perils could intensify in line with past trends as climate change gathers pace. Specifically we view it as possible that storms and floods will become more frequent and more severe as the average global temperature rises and weather patterns shift," Moritz Kraemer, S&P chief sovereign ratings officer, said in the report.
The ratings agency recommended that one way to mitigate the threat from natural disasters was greater investment by governments in catastrophe insurance.
"In the case of the five biggest earthquakes covered in the study, the rating impact would be a downgrade of about one notch if 50 percent of the damage were reinsured, compared with almost two notches for no insurance coverage at all," said S&P in the report.