America’s carbon dioxide emissions rose by 3.4 percent in 2018, the biggest increase in eight years, according to a preliminary estimate published Tuesday. Strikingly, the sharp uptick in emissions occurred even as a near-record number of coal plants around the United States retired last year, illustrating how difficult it could be for the country to make further progress on climate change in the years to come, particularly as the Trump administration pushes to roll back federal regulations that limit greenhouse gas emissions.

Mr. Trump and his team believe that loosening the regulatory grip on business will help the economy, create jobs and allow Americans “to share in the riches,” as he said during the campaign. But in the energy field, environmentalists, Democrats and even some in the industry fear  the efforts will backfire, harming health and safety without creating much economic benefit.