It's $100 billion total, for all countries, not per country.
That makes a lot more sense.
From Bloomberg Green:
A blueprint for how developed countries will contribute $100 billion a year to poor nations confronting climate change is set to be unveiled on Monday despite objections from the U.S. and other nations that almost derailed the announcement. The plan is seen as critical to the success of the United Nations COP26 climate summit scheduled to begin Oct. 31 in Glasgow, Scotland. Rich nations have fallen short of their 2009 pledge to collectively deliver $100 billion annually to help poor countries confront climate change, shift to clean energy and build resilience. And without more money, some developing nations, such as Bangladesh and Indonesia, have said they can’t step up their climate pledges. Developed countries were roughly $20 billion below the $100 billion target in 2019, the last year for which totals have been released. The U.S. had objected to a plan to make up for shortfalls in previous donations with higher contributions in future years, according to three people familiar with the matter who asked for anonymity to describe private negotiations. Details of how the matter was settled weren’t immediately available but the people confirmed that an announcement, which had been expected this week, would be made Monday.... President Joe Biden last month committed the U.S. to provide $11.4 billion in climate finance annually by 2024. And Congress is on track to spend between $2.8 billion and $3.1 billion on climate finance in fiscal 2022. Yet that still leaves the U.S. lagging well behind other developed nations in meeting its share of the target. Whether -- and how -- to account for continued shortfalls this year and last so that finance still reaches a $100 billion annual average between 2020 and 2025 has been a major sticking point in negotiations, said the people. The U.S. was among nations concerned about the ability of the group to collectively increase contributions in future years to compensate, the people said.