Scott Pruitt appears before the Senate Environment and Public Works Committee for his confirmation hearing in Washington on Jan. 18. (Melina Mara/The Washington Post)

President Trump has tapped Oklahoma Attorney General Scott Pruitt (R) and former Texas governor Rick Perry (R) to lead the agencies at the forefront of the nation’s response to global warming. In their nomination hearings last week, both men downplayed expert warnings about the nature and extent of the crisis.

Mr. Pruitt, the choice to head the Environmental Protection Agency, admitted that “science tells us that the climate is changing, and that human activity in some manner impacts that change,” but he stressed that “the degree and extent of that impact” are “subject to continuing debate and dialogue.” Asked why the climate is changing, Mr. Pruitt replied, “My personal opinion is immaterial.”

Similarly, Mr. Perry, the pick to lead the Energy Department, said that “some of it is naturally occurring, but some of it is also caused by man-made activity.” When pressed further for his views on Earth’s rising temperature, Mr. Perry issued a classic GOP global-warming evasion, telling Sen. Al Franken (D-Minn.) that he is not “a climate scientist,” though he did subsequently pledge to “hire really good scientists.” More evasion came when the nominee was asked whether the science suggests that the world must shift strongly away from fossil fuels; Mr. Perry dismissed the discussion as “academic.”

Questions about how these men view climate science are not “immaterial” or “academic.” Scientists’ overwhelming conclusion is that climate change is happening and human activity is the primary culprit. The causal mechanisms are clear and identifiable, and humanity’s fingerprints are showing up, as predicted, in various lines of data, from the tight correlation between carbon dioxide concentrations and temperature rise to a distribution of warming in the atmosphere that points directly to human-caused changes in atmospheric chemistry. Yet neither Mr. Pruitt nor Mr. Perry will face these observations in their fullness.

Each man invoked his public record to show he has been sensitive to environmental concerns in the past. Here Mr. Perry has some credibility, in that he presided over a massive expansion of wind power in Texas. Mr. Pruitt, on the other hand, has been among the EPA’s most aggressive opponents and offered only mild protest when confronted with evidence of his closeness with the fossil fuel industry.

Both men pledged to keep an open mind. Mr. Perry insisted he would “protect all of the science,” saying that he favors funding for renewable-energy research. Mr. Pruitt promised to “listen to those career staff at the EPA,” pledging not to attempt to roll back the agency finding that carbon dioxide is a pollutant that the federal government has a role in combating. But, given the rest of his presentation, Mr. Pruitt offered little hope that he saw that role to be large.

Indeed, none of the assurances from either man could compensate for waffling on matters of basic science.