More than 100 countries were set to pledge Tuesday to end deforestation, which scientists say is a major driver of climate change.

Britain hailed the commitment as the first big achievement of the UN climate conference in Glasgow. But campaigners say they need to see the detail — such promises have been made, and broken, before.

The UK government said it has received commitments from leaders representing more than 85% of the world’s forests to halt and reverse deforestation by 2030.

More than $19 billion in public and private funds have been pledged toward the plan, which is backed by countries including Brazil, China, Colombia, Congo, Indonesia, Russia and the United States.