How a $100 bn hurdle threatens to undermine a global climate breakthrough

A $100 billion dividing line between the world’s richest and poorest countries threatens to undermine any hope for a grand deal at the COP26 climate negotiations.

That’s the amount in annual contributions promised more than a decade ago by developed nations to help less well-off nations cut planet-warming emissions and adapt to climate change. It’s one half of a quid pro quo agreed in 2015 at United Nations-sponsored talks in Paris: Developed countries put up the cash, and in return poor countries invest in clean-energy technologies and resiliency projects such as flood defenses.

Ahead of the next global summit, held