Nigeria, Feb. 26 -- On his first day in office, United States (US) President Donald Trump signed an executive order to withdraw his country from the United Nations Framework Convention on Climate Change Paris Agreement. This latest plunge of the US climate change rollercoaster may be the most impactful yet.

The latest withdrawal will take effect in one year and continue for at least three more, depending on the 2028 US presidential election outcome. Unlike the previous exit, which lasted only 107 days before Mr Biden rejoined the agreement in 2021, there is now a reasonable time for significant harm to global climate action efforts. These impacts will be felt at multiple levels and in four main areas.

The first is direct funding support...