Dozens of countries could see a credit rating downgrade as a result of climate change, according to a study from researchers at the University of Cambridge, the University of East Anglia and SOAS University of London.
"We find that 63 [nations] suffer climate-induced downgrades of approximately 1.02 notches by 2030, rising to 80 sovereigns facing an average downgrade of 2.48 notches by 2100," the researchers wrote.
The hardest-hit countries range all over the world, with China, Chile, Malaysia and Mexico among those projected to see downgrades of up to six notches by the end of the 21st century. The U.S., along with Germany, Canada, India, Peru and Australia, are among those projected to see closer to four notches.
“Our results show that virtually all countries, whether rich or poor, hot or cold, will suffer downgrades if the current trajectory of carbon emissions is maintained,” the report states.
If the downgrades are accompanied by the typical corresponding increases in international borrowing costs, the downgraded nations would see their debt service payments increase $137 billion to $205 billion by the end of the century, the research states.
The report also indicates that environmental policies in keeping with the Paris climate agreement would prevent the most drastic credit downgrades. With those policies in place, the average downgrade would be only 0.65 notches by 2100, according to the research. In this scenario, the combined added cost would be between $23 billion and $34 billion.
“The key take-home message is that existing climate science and economics are capable of supporting credible, decision-ready green finance indicators,” the researchers wrote. “Governments issue ever-longer dated bonds, of which life insurance companies and pension funds are eager buyers, thus enabling them to match their own long-term liabilities. Therefore, investors should consider the long-term creditworthiness of sovereign issuers.”
The researchers noted that there are unquantifiable factors that could not be factored into their findings, such as how the effects of climate change could affect national and international politics.