The financing plan, which calls for $300 billion per year in support for developing nations, was immediately assailed as inadequate by a string of delegates.

Negotiators from nearly 200 nations made a nonbinding commitment that wealthy nations would aim to provide $300 billion annually by 2035 to help poorer nations.

Just as a simple lever can move heavy objects, rich nations are hoping another kind of leverage — the financial sort — can help them come up with the money that poorer nations need to cope with climate change.