Negotiators went into record overtime to avoid a complete breakdown at the 25th annual U.N. Climate Change Conference in Madrid, but the deal they eked out evoked disappointment on multiple fronts. Governments failed again to adopt rules for international carbon markets, and bitter struggles over “ambition” and aid for developing countries highlighted deepening tensions as countries prepare to deliver a new round of national targets next year.

The meeting—known formally as the 25th session of the Conference of the Parties (COP) to the U.N. Framework Convention on Climate Change (UNFCCC), or COP 25—was the first since the United States formally initiated its withdrawal from the Paris Agreement. But it was marked even more by the glaring and growing gap between the action needed to stem climate disaster and the still-sluggish response of most major economies.