Wealthy, progressive Montgomery County on Tuesday became one of the first jurisdictions in the nation to declare a "climate emergency," heeding a call from environmental advocacy groups to counter Trump administration policies by dramatically cutting greenhouse emissions in coming years.

Under the resolution approved by the all-Democratic council, Maryland's most populous jurisdiction aims to reduce greenhouse gas emissions by 80 percent by 2027 — and 100 percent by 2035.

While activists and lawmakers conceded that those benchmarks will be challenging to meet, they said embracing the goal will push the county in the right direction.

"If your goal is 2050, then you'll develop policies that are even slower," said council member Marc Elrich (D-At Large), a lead sponsor of the resolution. "So we're better off trying to do this on a 'short track' rather than a 'long track.' "

Council member George L. Leventhal (D-At Large), another lead sponsor, said the resolution spoke to "goals we should adhere to in our own community," particularly in the face of a federal government that has been hostile to climate change initiatives.

Greenhouse gases, such as carbon dioxide and methane, are emitted through activities including the burning of fossil fuels such as oil and gas. Such emissions contribute to the "greenhouse effect," one cause of global warming, by blocking heat from escaping the atmosphere.

President Trump, as well as Energy Secretary Rick Perry and Environmental Protection Agency Administrator Scott Pruitt, have repeatedly questioned humans' role in spurring global warming. Trump's administration has also taken steps to repeal several federal rules that aimed to reduce the nation's carbon footprint, including those to curb greenhouse gas emissions from power plants and carbon emissions from vehicles. In June, Trump announced that he was withdrawing the United States from the Paris climate accords, a move widely criticized at home and abroad.

A New York-based group called the Climate Mobilization is urging cities and counties to adopt resolutions like the one approved in Montgomery on Tuesday as a way to combat what is happening at the federal level. Margaret Klein Salamon, founder and director of the organization, said local governments must treat global warming as a dire emergency.

"Montgomery County has embraced the mentality that we cannot accomplish any of our objectives unless we solve the climate crisis," Salamon said. "The way to do that is eliminate emissions as soon as possible."

The council intends to gather ideas over the next six months on what types of legislation can most quickly and effectively cut emissions, possibly including increased investment in renewable energy, composting programs and greener building codes, or initiatives to boost the use of electric cars and solar panels.

Local activists are particularly focused on shutting down a trash incinerator and a coal and gas plant in Dickerson, said Jim Driscoll, a Bethesda resident and the coordinator of the local Climate Mobilization chapter.

In order for the county to meet its goal of zero emissions within 20 years, Driscoll said, activists, lawmakers and residents will have to adopt an "all hands on deck" approach. "People are going to have to change," he said.

Salamon said Hoboken, N.J., has adopted an even more ambitious climate-related goal, aiming for zero emissions in the next 10 years. Her group is pushing other jurisdictions to take similar action.

At its meeting Tuesday, the Montgomery council also passed development plans for areas near the White Flint and Grosvenor-Strathmore Metro stations and elected officers for 2018.

The White Flint plan, which passed 8 to 1, covers a 460-acre area in North Bethesda near another White Flint sector plan that includes shopping centers, an office park and residential buildings.

The Grosvenor-Strathmore plan, which passed unanimously, also features transit-oriented development to meet housing demands in an environmentally sustainable way.

Elrich said he voted against the White Flint plan because he thought the targeted area was too far from the Metro station to be reasonably considered a "transit-oriented development."

The council elected at-large member Hans Riemer (D) president and Nancy Navarro (D-Mid-County) vice president for the coming year.

Riemer, a seven-year lawmaker who served as vice president this year under council President Roger Berliner (D-Potomac-Bethesda), said he expects to see strong engagement with the public in the county in 2018, as voters choose a new county executive and several new council members.

"Emotions in our community are charged as our residents reject the destructive politics in D.C. and look to our leadership to provide a light in the storm," Riemer said.