Barack Obama

President Barack Obama walks the Anhinga Trail at Everglades National Park, Fla., Wednesday, April 22, 2015. Obama visited the Everglades on Earth Day to talk about how global warming threatens the U.S. economy. He says rising sea levels are putting the "economic engine for the South Florida tourism industry" at risk. (AP Photo/Susan Walsh)

(Susan Walsh)

President Barack Obama looked out on the tall grasses of the Florida Everglades Wednesday and declared that the sweeping wetlands illustrate the dangers posed by climate change. "This is a problem now," he said.

Obama visited the South Florida landmark to warn of the damage a warming planet is already inflicting on the nation's environmental treasures -- and to hammer political opponents he says are doing far too little about it.

"Climate change can no longer be denied," he said. "It can't be edited out, it can't be omitted from the conversation and action can no longer be delayed."

Obama's remarks were a not-so-veiled reference to allegations by some former Florida state employees that Gov. Rick Scott's administration had banned them from using the terms "climate change" and "global warming." Scott has denied any such policy, and on Tuesday he accused Obama of cutting millions in his budget to repair an aging dike around Florida's largest freshwater lake, Lake Okechobee.

Obama, dressed casually in a blue shirt and sunglasses, toured the Anhinga Trail in Everglades National Park, where a series of wooden walkways took him through dense shrubbery and over wetlands. A park ranger explained the history of the area to the president as alligators slithered in nearby shallows and small flocks of large birds ducked in and out of the deep-green waters.

In Florida, rising sea levels have allowed salt water to seep inland, threatening drinking water for 1 in 3 Floridians and the extraordinary number of native species and plants that call the Everglades home.

"If we don't act, there may not be an Everglades as we know it," Obama said.

Obama conceded that the past winter was the cold in parts of the United States, including the nation's capital. "But around the world, in the aggregate, it was the warmest winter ever recorded. This is not a problem for another generation, not anymore."