"Companies with the weakest ESG credentials, as captured in low QESG scores, tended to trade with the widest CDS [credit default spreads] spreads, Hermes found – indicating a higher risk of default."

[COMMENTARY] It makes sense that companies with bad ESG characteristics are poor credit risks. And that’s why their financing costs are higher too. As companies understand that good ESG performance means lower financing and human resources’ costs with potentially higher prices for their shares, they’ll increasingly strive to improve their ESG performance.
Hermes finds ’clear relationship’ between ESG and credit spreads, by Susanna Rust, April 19, 2017, Investment & Pensions Europe, UK.