The U.S. Department of Agriculture building in Washington (Jonathan Newton / The Washington Post) This story has been updated. President Trump on Wednesday nominated Sam Clovis, a former college professor and talk radio host who has challenged the scientific consensus that human activity has been the primary driver of climate change, to serve in the Agriculture Department’s top scientific post. “Dr. Clovis was one of the first people through the door at USDA in January and has become a trusted advisor and steady hand as we continue to work for the people of agriculture,” Agriculture Secretary Sonny Perdue said in a statement Wednesday evening. “He looks at every problem with a critical eye, relying on sound science and data, and will be the facilitator and integrator we need. Dr. Clovis has served this nation proudly since he was a very young man, and I am happy he is continuing […]