William Happer, US President Donald Trump’s deputy assistant for emerging technologies who serves on the National Security Council, once compared the “demonization of carbon dioxide,” a gas which is a cause of global warming, to how Jewish people were treated in Nazi Germany.

"The demonization of carbon dioxide is just like the demonization of the poor Jews under Hitler," Happer, who is a Princeton-educated physicist, said in a 2014 interview with CNBC's "Squawk Box" hosts Joe Kernen and Andrew Ross Sorkin.

​Happer's comments resurfaced in a New York Times article on Monday about how he is leading a "climate review panel" under the Trump administration, with the goal of rolling back emissions-limiting regulations on power plants and vehicles and allowing fossil-fuel development to take place on public land.

— Justice Democrats (@justicedems) May 28, 2019

​In addition, the Trump administration is planning on limiting projections related to carbon dioxide pollution in federal studies to 2040 in an effort to avoid discussion of "worst-case scenarios."

— Perry Gershon (@perrygershon) May 28, 2019

​Philip Duffy, the president of the Woods Hole Research Center in Massachusetts, told the New York Times that the Trump administration's plan to no longer include emissions scenario projections in federal reports like the National Climate Assessment, which summarizes the impact of climate change in the US, is a "blatant attempt to politicize" climate change evidence and "push the science in a direction that's consistent with their politics."

— Aaron Keyak (@akeyak) May 28, 2019

​However, James Hewitt, a spokesperson for the Environmental Protection Agency, an independent agency of the US federal government, defended the Trump administration's push to not include predictions past 2040.

"The previous use of inaccurate modeling that focuses on worst-case emissions scenarios, that does not reflect real-world conditions, needs to be thoroughly re-examined and tested if such information is going to serve as the scientific foundation of nationwide decision-making now and in the future," Hewitt told the Times.