US President Barack Obama delivers remarks during a town hall at the Young African Leaders Initiative (YALI) Mandela Washington Fellowship Presidential Summit in Washington, DC, August 3, 2015. The three-day Summit brings together 500 of sub-Saharan Africas most promising young leaders to meet with the President and leading US entrepreneurs, government officials, and civil society representatives. National Journal

Going directly after Republican climate skeptics, President Obama said Monday that failing to fight climate change would be "shameful," while warning the American public not to believe criticism from "special interests and their allies in Congress" who oppose his environmental agenda.

"It's easy to be cynical and say that climate change is the kind of challenge that's just too big for humanity to solve. I am absolutely convinced that's wrong," Obama said during a speech delivered from the White House, as he heralded his administration's efforts to regulate pollution from power plants.

The speech is one of Obama's most forceful attempts yet to convince the American public that action to combat the Earth's rising temperature is badly needed now.

And he struck back against skepticism from Republican presidential contenders over the threat of global warming, and against criticism of the White House regulatory regime.

"There will be critics of what we are trying to do," Obama said. "Long before the details of this Clean Power Plan were even decided, the special interests and their allies in Congress were already mobilizing to oppose it with everything they've got."

He added: "We only get one home. We only get one planet. There's no Plan B. I don't want my grandkids not to be able to swim in Hawaii, or not to be able to climb a mountain and see a glacier because we didn't do something about it."

Leading Republican 2016 contenders slammed the president's climate agenda on Sunday, with Ted Cruz arguing that global warming is not a threat.

"I think science and facts matter," Cruz told conservative donors at an event in Southern California, adding: "To any power-greedy politician, this is the perfect theory — it can never, ever, ever, be disproven, if it gets hotter, if it gets colder, if it gets wetter, if it gets drier."

Jeb Bush called the regulations "irresponsible and overreaching," saying that the effort "runs over state governments, will throw countless people out of work, and increases everyone's energy prices."

Obama is racing to cement a legacy on climate change and the environment before leaving office, and he needs to sell voters on his administration's massive effort to limit greenhouse-gas emissions from power plants — a regulatory regime rolled out on Monday.

The fate of the president's highly-anticipated and vastly controversial climate policy likely rests in the hands of the next president. And as a result, convincing voters that the policy must be left intact could be crucial to its survival.

Obama also wants to show that his climate policy stands on solid ground even as congressional Republicans and GOP presidential contenders try hard to convince the world that it's a shaky promise at best.

Later this year, White House envoys will tout that policy as the backbone of the administration's pledge to cut emissions during make-it-or-break-it climate talks in Paris.

Senate Majority Leader Mitch McConnell has worked hard to undermine faith in that pledge. McConnell in March called on governors not to comply with the regulations, arguing that they are unlikely to hold up in court.

Speaking on the Senate floor just minutes before Obama's announcement began, McConnell said that the Senate would explore a number of options to strike back at the rules, including the Congressional Review Act, riders on appropriations bills, and a bill from Sen. Shelley Moore Capito that would force the Environmental Protection Agency to scrap the rules.

"I'm not going to sit by while the White House takes aim at the lifeblood of my state's economy," McConnell said. "I'm going to do everything I can to fight them."

Capito's bill appears to have gotten a kick-start; she announced Monday that the Environment and Public Works Committee will hold a vote on it on Wednesday. The bill — which has 35 cosponsors, including McConnell and Democratic Sen. Joe Manchin — would require EPA to ditch the power-plant rules and rewrite them under narrow guidelines, essentially gutting the regulations.


Jason Plautz contributed to this article

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