Washington (CNN) Democratic Rep. Alexandria Ocasio-Cortez of New York and Democratic Sen. Ed Markey of Massachusetts unveiled their "Green New Deal" resolution Thursday, which outlines the definition of the massive piece of legislation the two hope will tackle a litany of issues related to the US' role in global climate change.

"Climate change and our environmental challenges are one of the biggest existential threats to our way of life. Not just as a nation, but as a world," Ocasio-Cortez said at a news conference outside of the Capitol Building.

"What this resolution is doing is saying this is our first step. Our first step is to define the problem and define the scope of the solution," she added. "And so we're here to say that small, incremental policy solutions are not enough. They can be part of a solution but they are not the solution unto itself."

The legislation has become a key policy initiative for Ocasio-Cortez, the progressive New Yorker who, shortly after being elected in November, joined the Sunrise Movement to protest over the climate change issue in the office of then-House Minority Leader Nancy Pelosi. She later paired up with Markey, who represents Massachusetts, to begin working on the legislation.

Ocasio-Cortez, surrounded by Markey and other congressional Democrats, said that the resolution is "comprehensive, it is thoughtful, it is compassionate and it is extremely economically strategic as well."

Read More