Senate Democrats launched a new effort Tuesday to reclaim the political initiative in the climate change debate and create a sense of urgency about mitigating the causes of the planet’s warming atmosphere.

The ultimate goal of Democrats on the Senate Climate Action Task Force is to shift the politics of climate change back in favor of legislating a price on greenhouse gas pollution — for the first time since legislation to cap carbon emissions collapsed in the Senate in late 2010.

Republicans, including a sizable group that rejects the scientific consensus that human activities are warming the planet, captured control of the House in midterm elections that year. Ever since, Democrats have been looking for a strategy to put climate change back on the congressional agenda.

Senate Environment and Public Works Chairwoman Barbara Boxer, D-Calif., and Rhode Island Democrat Sheldon Whitehouse, a co-chairman of the Bicameral Task Force on Climate Change, said the campaign will be coordinated with businesses, universities and other nongovernmental groups to counter fossil fuel industry opposition to taxing or capping carbon emissions.

“We’re very realistic politicians,” Boxer said Tuesday. “We understand that the makeup of Congress now is making it very difficult for us to pass climate change legislation, but we will not sit back and give up. … We will raise the visibility of this issue with the intent of changing minds around here.”

The 18-member group plans to push back aggressively against climate change skeptics in Congress, citing polling that shows a majority of voters think those who reject the link between human activities and global warming are uninformed. A poll commissioned by the League of Conservation Voters last summer found that 74 percent of independents and 53 percent of Republicans younger than 35 would describe climate change deniers as “out of touch” or “crazy.”

“When you have a young demographic that sees this issue that way, clearly the denial strategy is doomed,” Whitehouse said. “And our job is to accelerate its collapse.”

The leading Senate global warming skeptic, Oklahoma Republican James M. Inhofe, took to the Senate floor last week as a polar vortex gripped most of the country, pointing to the unusual cold spell to rebut claims of global warming. Inhofe said a hiatus in warming over the past 15 years is evidence the earth is actually moving through a regular climatic cooling period and that models predicting catastrophic global warming are flawed.

“When you put it all together, it is impossible not to sit back and wonder — if there is this evidence that the temperatures are actually getting colder, should we really pursue cap and trade and other similar regulations and policies that will cost the economy $300 billion to $400 billion a year to implement?” Inhofe asked.

The United Nations’ International Panel on Climate Change says the climate has continued to warm over the past 15 years, albeit at a slower rate. The scientific group attributes the slower rate of warming to fluctuations in the climate and possibly increased absorption of heat by the oceans.

Like thermometer readings, the politics of climate change has also “ebbed and flowed” since the mid-2000s, said Manik Roy, a former aide to California Democratic Rep. Henry A. Waxman, who co-sponsored the cap-and-trade bill that passed the House in 2009.

It wasn’t so long ago that addressing climate change was a bipartisan effort. The first concerted effort to pass legislation capping carbon emissions was spearheaded in 2003 by a Republican — Sen. John McCain of Arizona. Another Republican, Sen. John W. Warner of Virginia, led a later effort to pass cap and trade, and South Carolina Republican Lindsey Graham was involved in the bipartisan negotiations that ultimately blew up in 2010.

But the momentum swung against any legislation to rein in carbon emissions once Republicans won control of the House and narrowed the Democratic Senate majority in the 2010 midterm elections. The Obama administration moved to use its regulatory authority under the Clean Air Act to restrict carbon emissions, and Republican lawmakers focused their attention on blocking EPA regulations they viewed as harmful to job growth.

Roy said President Barack Obama’s surprise invocation of the climate change issue in his 2013 inaugural and State of the Union speeches again shifted the conversation. He said the latest effort by Senate Democrats is “building on that crescendo.”

“If you have the facts on your side, why would you go silent?” asked Roy, who is now vice president for strategic outreach at the Center for Climate and Energy Solutions.

Boxer brushed off the absence of notable oil-state Democrats — such as Mary L. Landrieu of Louisiana and Mark Begich of Alaska — from the task force, instead calling on coastal-state Republicans experiencing the impact of rising seas first-hand to be more vocal about addressing the issue.

“They ought to be with us,” Boxer said. “They ought to be leading the charge.”

A counterpart Safe Climate Caucus in the House has more than 30 members, all Democrats. Waxman also co-chairs the bicameral task force on climate with Whitehouse, who delivers weekly remarks on the Senate floor highlighting the reluctance of congressional Republicans to engage on the issue.

More senators will join Whitehouse by taking to the floor to speak about climate change, and members will push legislative proposals on efficiency and alternative fuels that can still attract bipartisan backing. Ultimately, Republicans must reassert leadership on climate change initiatives, as some did in the early to mid-2000s, to make the issue more politically palatable for congressional action, Roy said.

“Until we return to making this a bipartisan issue, it’s hard to see how we actually tackle it in Congress in a serious way,” he said.

Boxer said Whitehouse reached out to Republicans about joining the climate effort in a letter.

“And not one sent back a positive response,” she said.

Geof Koss contributed to this report.