The Trump administration’s actions in recent days have cast unprecedented uncertainty upon the climate panel’s work.

A NASA climate scientist is banned from an international meeting, and the agency shuts down a team supporting production of the next global climate asessment.

The Trump administration told US government scientists working on a vital global climate report to stop their work – the president’s latest move to withdraw the US from global climate action and research.

Delegates to a key UN-backed climate meeting this week will be forced to consider what their future work might look like without US government participation.

Representatives of nearly 200 countries gather Monday to continue fraught negotiations on the timing and content of the UN's next blockbuster assessment of global warming science.