The financial risk posed to companies by natural disasters keep growing and growing, and the size of potential losses is just eye-popping.

Moody’s Investors Service says 18 sectors have a combined $7.2 trillion of debt with "high inherent exposure to physical climate risks,” such as devastating wildfires, storms and other calamities. To put that number in perspective, only two countries have a gross domestic product that’s larger: the U.S. and China. Japan, the world’s third-largest economy, has a GDP of about $5 trillion.

For Moody’s, environmental considerations are becoming increasingly relevant when assessing credit quality. "The increased frequency and severity of extreme weather events are causing significant economic losses, hazards for the local population and environmental damage,” the analysts wrote in a 53-page report published last month. Moody’s doesn’t identify the companies or nations that are most at risk-instead, it chose to focus on different business sectors.