For green finance enthusiasts, a new flavor of debt could emerge this year — nature bonds.

Sales of green bonds — which typically raise money for clean energy projects — are expected to grow by a third this year to record levels, as governments and companies look to capitalize on booming demand at the same time as bolstering their image. Yet academics and activists say this alone isn’t enough to save the planet.

They’re lobbying for securities that more explicitly protect the natural world — and are likely to get a hearing from policymakers when the United Nations meets in coming months to discuss biodiversity and climate change. Those issues are climbing up the agenda as governments decide how to spend trillions to recover from the virus.