Sustainable debt is a $7 trillion market with uneven growth

Sustainable debt is now a nearly $7 trillion market, but Q1 2026 showed that growth is becoming more uneven. Green bonds held up; the weakness was concentrated in sustainability-linked debt, sustainability bonds, and emerging-market issuance.

The divergence inside the numbers is more informative than the headline. Instruments with a clear use of proceeds continued to find buyers. Instruments whose value depends on a promise about future performance did not. Investors are asking what the money paid for, and they are rewarding structures that can answer.

That is the same test a Scope 3 claim has to pass. A supplier reduction that is measured where it happens, verified independently and allocated once to the buyers who financed it is the kind of evidence that keeps capital in place. Structures that cannot show the reduction will face the same discount the market is now applying to sustainability-linked debt.