Congressional Democrats on Thursday unveiled an unprecedented plan to reverse climate change and eliminate all US carbon emissions within 10 years, by taking drastic steps that would require transformational action across the economy.

The "Green New Deal" introduced by liberal congresswoman Alexandria Ocasio-Cortez, a rising Democratic star in the House, and Senator Ed Markey is a dramatic, potentially unrealistic, statement of intent on a sustainable path forward.

"This is our first step," Ocasio-Cortez told reporters.

"Today is the day we choose to assert ourselves as a global leader in transitioning to 100 percent renewable energy and charting that path."

The plan does not detail exactly how America will wean itself off of fossil fuels, or how much the ambitious transformation will cost.

The Republican Party hammered the deal as a "socialist wish list" which could cost upwards of $2 trillion.

The non-binding resolution is effectively a blueprint of dramatic action -- it proposes "upgrading all existing buildings" in the country, for example -- that could be taken to address climate change.

It is already playing a role on the 2020 presidential campaign trail, with progressive Democratic hopefuls including Senators Kamala Harris and Elizabeth Warren expressing support.

"The green generation has risen up, and they are saying they want this issue solved," Markey said. "So this is going to enter the 2020 election cycle as one of the top two or three issues."

The ambitious goal, according to the measure, is to achieve "net-zero greenhouse gas emissions," in part by meeting 100 percent of the power demand through clean, renewable, and zero-emission energy sources.

House Speaker Nancy Pelosi, who appeared to brush off the resolution as a "green dream" the day before, welcomed the "enthusiasm" with which Democrats were engaging in pushing the framework.

The measure has dozens of sponsors, none of them Republican.

The goal to become carbon neutral within a decade will most likely prove exceedingly ambitious, given the oil and gas industry's deep entrenchment in the global economy.

One critical factor will be the buy-in of President Donald Trump, who pulled the US out of the Paris climate accord, as is seen by Democrats as the world's most prominent climate-change denier.

The Paris deal saw nations agree to limit global temperature rises this century to below two degrees Celsius (3.6 Fahrenheit), and under 1.5C if possible.

Failure to meet those goals, scientists have said, could result in irreversible sea level rise, disastrous droughts and higher temperatures.