Sen. Joe Manchin's (D-W.Va.) declaration Sunday that he opposes President Biden's signature climate and social policy legislation makes the administration's task of meeting its climate goals far more difficult.

Why it matters: The setback to slashing emissions comes as scientists say time is running out to avoid far worse impacts from global warming.

The big picture: The package Manchin rejected contained more than $300 billion in tax incentives for clean energy and vehicles, and other measures to cut greenhouse gases such as a new fee on methane emissions.

• Analysts viewed the bill as vital to achieving the White House's goals of generating 100% clean electricity by 2035 and net-zero emissions by 2050, along with meeting its international climate commitments, including a 50% emissions cut below 2005 levels by the end of the decade.
• Without the policies in the BBBA, "We estimate the United States will fall 1.3 billion tons (CO2-equivalent) short of the nation's 2030 climate commitment, a yawning gap that is unlikely to be bridged by executive action or state policy alone," Jesse Jenkins, a co-author of a major Princeton University analysis of how to get the country to net zero emissions by 2050, told Axios via email.
• The legislation is also the linchpin of America's international standing on climate. At the COP26 summit last month, U.S. officials, particularly climate envoy John Kerry, assured international counterparts that the country's commitments would be met.

What's next: Assuming the bill is dead or "just resting," here are some overlapping ways climate policy could play out from here.

A stronger executive branch push

• That ranges from new urgency around steps like auto and power plant emissions rules to closing off lands to oil and gas drilling to quickly raising the social cost of carbon.
• The latter step would have ripple effects throughout federal regulations.
• However, the Supreme Court has signaled that it may look askance at expansive moves by the EPA to regulate greenhouse gases under the Clean Air Act.
• And a future administration could undo such measures over time, as the Trump administration demonstrated.

A Capitol Hill salvage job

• Several environmental groups, including the League of Conservation Voters, signaled an intent to push for continued negotiations, as did multiple lawmakers. So did White House press secretary Jen Psaki (in between her broadside against the senator),
• It is likely any new version would be less ambitious to bring the price tag down, but it could still advance clean energy priorities.
• The White House could separate out the climate portions of the bill into standalone legislation, but this risks incurring new opposition from Manchin.
• "We would not yet bet against long-term green power tax credit extensions in some form, albeit for shorter durations and/or with less generous provisions," ClearView Energy Partners said in a note.

Reality check: Manchin's statement was noteworthy for throwing cold water on the need to speed up the energy transition, asserting that it is already "well underway."

• He said moving faster would endanger the reliability of the grid and make the country more reliant on "foreign supply chains."
• This adds new doubts to what kinds of tax incentives and other measures he would support in any new legislative text.

The apparent demise of the bill could create other ripple effects.

What we're watching, part 1: Look for pressure on the administration to put climate ideas on the executive agenda that it hasn't previously backed.

• They include more direct efforts by financial regulators to discourage investments in fossil fuels. To date, the focus has been on greater risk disclosures and planning.
• There could also be pressure from environmental groups on the White House to declare a "climate emergency" after a year filled with devastating extreme weather events tied to climate change.
• It's a step Biden hasn't previously endorsed that could provide some flexibility for taking certain administrative actions.

What we're watching, part 2: A cornerstone of special climate envoy John Kerry's work has been putting pressure on China — the world's biggest emitter — to accelerate its climate efforts.

The results have been mixed, and the White House's failure to move sweeping measures through Congress could make his job harder still.

What we're watching, part 3: The markets. Keep an eye on the stock prices of electric vehicles and clean power companies today.

Go deeper: The climate policy effects of Manchin's "no" on Build Back Better