Warren's campaign says one of her existing policy proposals would create pressure on major oil-and-gas companies to splinter.

The intrigue: They pointed to her legislation that would require detailed disclosures from publicly traded companies about climate change.

Under her bill, filings with securities regulators would describe risks to the company from policies that would force steep emissions cuts consistent with holding global temperature rise to 1.5°C.

Why it matters: The campaign argues that this would lead to so-called stranded oil and natural gas reserves that would create big financial liabilities for energy companies.

Yes, but: The idea of stranded assets is controversial and beyond the scope of this blurb. And achieving emissions cuts consistent with 1.5°C is looking quite unlikely.

But those huge caveats aside, the campaign argues that this risk would push companies to break apart.

What they're saying: "If oil companies are required to disclose this information to investors, there will be enormous investor pressure on these companies to break up so that the non-fossil fuel parts of these companies would not be taken down by likely losses in the fossil fuel parts," Warren's campaign said.

The state of play: Warren touched on this goal in passing during Tuesday's Democratic debate when she was asked about her goal of breaking up tech giants.

"We need to enforce our antitrust laws, break up these giant companies that are dominating, Big Tech, Big Pharma, Big Oil, all of them," said Warren.

The bottom line: Warren is now the co-frontrunner with Joe Biden. It's another sign of the aggressive posture Warren has staked out.

Go deeper: Elizabeth Warren wants a climate-friendly SEC