The BlueGreen Alliance, an organization made up of environmental groups and labor unions, is applauding the climate change agreement reached last week in Paris — with some reservations.

“This is a proud moment in world history and a strong step forward to solving the biggest challenge of our time,” said alliance Executive Director Kim Glas. “While not perfect— the Paris agreement urges a just transition for impacted workers and underscores the obligation to protect human rights. The agreement does right by us all because it sets a goal and structure that could keep our world below 1.5°C of warming. The agreement also made significant progress towards helping developing nations fund efforts to reduce greenhouse gas emissions, and in ensuring both transparency and verification of everyone’s commitments. Enforcement and follow through are now key.”

The alliance’s members include the Sheet Metal Workers union.