Sen. Kamala D. Harris followed the release on Wednesday of her $10 trillion climate change plan that aims for a carbon-neutral economy by 2045 with a pledge to end the Senate’s filibuster if needed to pass a “Green New Deal.”

Harris (D-Calif.) made that bold promise during her segment of CNN’s seven-hour, 10-candidate climate change forum, where some of the Democrats vying for the White House offered their climate solutions.

“The U.N. has told us — we’re all very clear — if, over the next 12 years, which is such a short period of time, if we don’t take drastic action, it will be irreversible,” Harris said at the forum.

Harris’s call for an end to the filibuster — a Senate procedural rule that requires 60 votes, rather than a simple majority of 51, to move legislation forward — underscores the urgency many Democrats feel about taking significant steps to address climate change before scientists say it’s too late. (As president, Harris could advocate changing the Senate rule, but only the Senate majority party, which is now the GOP, could make it happen.)

Sen. Bernie Sanders (I-Vt.), who has the Democratic field’s most ambitious climate change plan, with a $16 trillion price tag, wouldn’t endorse ending the filibuster when asked about it, instead saying he would use other procedural workarounds to ensure “it won’t take 60 votes to save the planet.”

In recent days and weeks, other Democratic presidential candidates have rolled out their strategies to fight climate change ahead of the CNN event. Climate activists had called for a Democratic debate focused solely on climate issues, but that idea was rejected by the Democratic National Committee.

Until Wednesday, Harris had been more vague on climate change than on many other major issues. Her stump speech offers broad support for the expansive goals of the Green New Deal promoted by Rep. Alexandria Ocasio-Cortez (D-N.Y.), but she had rarely delved into specifics.

The Green New Deal calls for the United States to “achieve net-zero greenhouse gas emissions . . . through a 10-year national mobilization” that marries climate change and economic inequality. Several candidates released plans with longer target dates this week, an implicit recognition of the difficulty of reaching net-zero emissions in a decade.

A recent report from the Intergovernmental Panel on Climate Change suggested that limiting global warming to less than 1.5 degrees Celsius could reduce its impact. That goal, the group said, “implies reaching net zero [carbon] emissions globally around 2050.”

Sen. Elizabeth Warren (D-Mass.) staked her position on climate policy Tuesday when she embraced the climate change plan offered by Washington Gov. Jay Inslee (D), a former presidential candidate who put the issue at the center of his campaign but recently dropped out. That plan aims to “decarbonize” key parts of the economy within a decade, and Warren said she would also toughen environmental regulations.

South Bend, Ind., Mayor Pete Buttigieg also released a climate plan Wednesday that would require zero emissions for all new passenger vehicles by 2035. Sens. Cory Booker of New Jersey and Amy Klobuchar of Minnesota, as well as former housing secretary Julián Castro, are among other candidates who weighed in with their own strategies this week.

Many Republicans downplay the threat of climate change, and business leaders often argue that plans like those offered by the Democrats are impractical and expensive. Democrats and environmentalists respond that Republicans and “climate deniers” are ignoring or minimizing a threat that jeopardizes the planet’s future.

Democrats say the partisan divide on climate change shows they govern by science and reason while the GOP, they say, is tied to ideology and denialism.

“Is it realistic to not listen to the scientists and to create a situation where the planet that our children and grandchildren and future generations will be living in will be increasingly uninhabitable and unhealthy? Is that realistic?” Sanders said, defending the scope and cost of his plan. “We are dealing with what the scientists call an existential threat to this planet, and we must respond aggressively, we must listen to the scientists. That is what our plan does.”

Meanwhile, former vice president Joe Biden, who introduced a more modest $1.7 trillion climate blueprint in early June, was asked during the forum if his plan is ambitious enough.

Biden argued his more incremental approach was more realistic. He also made the case for why he’s the best equipped to deal with the crisis on a global level.

“We should be organizing the world, demanding the change,” Biden said, adding that the first thing he’d do as president is call a meeting with nations who signed the Paris climate accord to discuss how to “up the ante.”

Biden faced a question about a fundraiser he’s set to attend on Thursday hosted by a co-founder of a natural gas company, Western LNG. First, Biden said Andrew Goldman wasn’t a fossil fuel executive and, when pushed, he said he didn’t know Goldman was.

Goldman doesn’t currently have any day-to-day responsibilities with the company, CNN’s Anderson Cooper later clarified. Biden, who signed a pledge not to take any fossil fuel money, said that’s what he had understood, but that if it turns out Goldman is still involved with the company, then Biden wouldn’t “in any way accept his help.”

Warren, during her portion of the forum, chided the fossil fuel industry and politicians, “You don’t get to ruin the air, water and soil for everyone else just to help giant corporations. We have a Washington that works great for the wealthy and well-connected. It’s just not working for the rest of us.”

Warren also scoffed at a question about the Trump administration’s decision to roll back regulations on energy-efficient lightbulbs. She said the fossil fuel industry wants to distract from the greater climate conversation by talking about “lightbulbs, straws and cheeseburgers” instead of carbon emissions.