The top 10 Democrats running for president will go into deep detail Wednesday night on something that could define their presidencies: climate change.

During a seven-hour CNN town hall, the candidates will take turns spending 40 minutes talking about the issue. Former housing secretary Julián Castro is the first onstage, at 5 p.m., and New Jersey Sen. Cory Booker is last at 11:20 p.m.

Most of the candidates only released detailed climate plans in recent days and weeks, with South Bend, Indiana, Mayor Pete Buttigieg and California Sen. Kamala Harris releasing plans Wednesday. So this will be the first time that many candidates detail and are questioned about their sweeping proposals in front of a national audience.

Although it’s not the climate debate youth activists with the Sunrise Movement and former candidate Washington Gov. Jay Inslee pushed for, the marathon event will offer waaaaaaaay more air time devoted to climate than the past two Democratic primary debates combined.

Expect to hear about how climate change is already affecting the US today, from extreme hurricanes to raging wildfires, and how the crisis bleeds into other top issues from health care to immigration. And expect to hear some real differences in how candidates want to try to solve one of the toughest problems facing the planet. Here are some of the biggest questions going into the night:

Does anyone want to be the climate candidate?

The only person to frame their entire campaign on climate change has dropped out. And while every candidate has a multi-page plan out declaring climate an urgent issue, it remains to be seen who, if anyone, will make this the centerpiece of their campaign going forward. For example, former Texas representative Beto O’Rourke rolled out the first climate plan back in April, proposing $5 trillion in spending to get the US to have net-zero emissions by 2050 at the latest. Now he’s refocused his campaign on gun control, though he still frequently raises the issue of climate change.

So far, Massachusetts Sen. Elizabeth Warren is the only candidate to openly announce that she’s not only embracing former climate candidate Inslee’s policies but also “challenging every other candidate for president to do the same.” But Warren and every other candidate has a ton they want to do as president, with a limited amount of time and political capital to actually do it. The town hall could give a clue to who, if anyone, would be willing to start with climate.

Who is championing a Green New Deal, and what does that even look like?

Earlier this year, members of Congress introduced the Green New Deal resolution, a broad vision for responding to the climate emergency in a way that simultaneously creates millions of new jobs and curbs inequality. The five Democratic senators onstage Wednesday — Booker, Harris, Sen. Amy Klobuchar of Minnesota, Sen. Bernie Sanders of Vermont, and Warren — all cosponsored that resolution. They have since used it as a template for their presidential plans in varying degrees, as have some of the other candidates. Sanders literally named his $16.3 trillion climate plan the Green New Deal.

One main way this is coming through is how so many candidates, from Sanders to Booker to Harris to Castro, have made environmental justice a core pillar of their climate plan. Many have overlapping proposals to boost the Environmental Protection Agency's ability to take down corporate polluters, expand funding for cleaning up Superfund sites, and fund programs to ensure low-income communities and communities of color benefit from new jobs created in the transition away from fossil fuels.

Another way is how creating new jobs in an economy run on a green economy, versus a fossil-fueled one, is central to every plan.

Is the climate tax idea dead?

For years, economists have touted a price on carbon as the best solution for tackling climate change. Yale professor William Nordhaus, who helped champion the idea, won the Nobel Prize in economics for this work last year. But as the Green New Deal took over the climate world, support for a carbon tax or pricing schemes has largely quieted, in part over arguments on the left that a tax could worsen the inequality the Green New Deal is in part meant to address. Depending on whom you talk to, the Green New Deal and climate tax ideas are viewed as either competing or complementary solutions. Only a few top candidates, like Buttigieg and Andrew Yang, have embraced carbon pricing as a big part of their broader climate strategy.

Who wants to kill the fossil fuel industry for good?

While some candidates will bluntly call for the end of Big Oil and Big Coal, others have danced around the question. In Warren’s latest plan, she called for the end of coal by 2030; Castro does the same. Sanders has called for a ban on fracking, mountaintop removal coal mining, and imports and exports of coal, oil, and natural gas.

Meanwhile, Buttigieg offered no hard details about this in his new plan. When asked about it, his campaign said, “He is not in favor of keeping those industries open” and would plan to “transition towards sustainable energy sources.” Candidates like Buttigieg and former vice president Joe Biden could be pushed into taking a sharper stance Wednesday.

Will candidates be able to differentiate themselves?

A quick skim of the candidates’ 10 climate plans reveals tons and tons of overlaps, from specific emission targets to policy proposals. But with 40 minutes each to get wonky and personal, the candidates have an opportunity to set themselves apart on a particular issue, to rip into one another’s plans, or to focus the fight on President Donald Trump.

Here are some possibilities, based on the unique aspects of their plans so far: Biden homes in on his foreign affairs experience and talks up his plan for how the US could lead the rest of the world on climate action; Yang elaborates on his unique support for geoengineering, intervening with the Earth’s system to reverse climate change; Booker, Castro, and Harris jostle to be the environmental justice champion; Warren dives into her detailed plan for how the military can respond to the climate emergency; Castro expands on his call for a new category of refugees called “climate refugees”; Buttigieg and Klobuchar pitch themselves as the Middle American candidates with climate plans that will boost agriculture. And Sanders comes out against carbon capture, which Buttigieg and Yang want to heavily fund.