https://www.scientificamerican.com/article/u-s-science-envoy-resigns-to-protest-trump-policies/

An energy researcher at the University of California, Berkeley, resigned his post as a science envoy for the US Department of State on 21 August, citing US President Donald Trump’s “attacks on the core values of the United States”.

In a resignation letter addressed to Trump, scientist Daniel Kammen joined political leaders from both major parties who have criticized Trump’s equivocal response to violent demonstrations by white supremacists in Charlottesville, Virginia, on 12 August. Kammen also criticized the Trump administration’s “destructive” policies on energy and the environment, which he said have affected his work as a science envoy. Such policies include the president’s decision to pull the United States out of the 2015 Paris climate pact.