A mix of Beltway action and extreme weather events have brought the fault lines in infrastructure talks and their planetary stakes into sharper focus.

Catch up fast: Senate Democratic leaders pledged to seek big climate measures in a multitrillion-dollar, Democrats-only package that faces a very narrow political path.

Meanwhile, a bipartisan group floated outlines of a smaller plan with some climate measures, but far short of what many Democrats want.

The big picture: It's an uncertain effort. Republicans oppose climate-related spending and tax breaks on the scale President Biden wants, while Democrats' tiny majority features diverging views among progressives and moderates.

Why it matters: Record western U.S. heat and drought offer reminders of global warming's march as scientists warn of a narrowing window to contain temperature's rise.

Democratic leaders, with midterms looming, may be facing their last shot for years at legislation that would pour unprecedented resources into slashing emissions.

Where it stands: Talks on both packages are proceeding and they're intertwined.

• Some lawmakers fear that if a bipartisan bill moves, the reconciliation approach — that is, a Democratic package immune from filibuster — will wither.
• The Hill reports key progressives won't support a bipartisan bill absent "ironclad" assurance on the substance of the reconciliation plan and that it has enough votes.
• Rep. Ro Khanna, a progressive California Democrat, tells Andrew "there's a lot of anxiety" that climate provisions will be "sacrificed." He said the two plans would have to move in tandem to get progressive support in the narrowly divided House.
• Meanwhile, Politico reports on moderate Democrats' concerns about plowing ahead with a multitrillion-dollar reconciliation package of infrastructure and social safety net improvements.

What they're saying: "[W]e interpret recent progress towards a reconciliation package as a further evidence that Democratic Party leadership has already substantially abandoned hopes of a bipartisan bargain," the research firm ClearView Energy Partners said in a note.

• But the same analysis also offers reasons why a bipartisan path may yet emerge in the Senate.
• One reason is that Sen. Joe Manchin (D-W.Va.), a conservative Democrat and crucial vote, "might be able to better explain his support for party-line passage of a reconciliation bill if he voted for it after delivering a conventional infrastructure package on a bipartisan basis."

Here are two other things we're watching...

1. The global fallout from the talks. A deeply reported Bloomberg story this morning explores diplomatic fears critical United Nations climate talks late this year will fail to deliver strong results.

One stumbling block? The White House's power to make big commitments that need Capitol Hill sign-off.

2. The clean electricity standard (CES). Majority Leader Chuck Schumer's office did not list a CES when outlining his priorities for the reconciliation package.

• A CES — which would force utilities to accelerate zero-carbon power deployment — has the potential to be an important climate tool but faces is a very steep uphill climb politically.