Ten 2020 Democratic candidates took questions at a 7-hour CNN town hall Wednesday night about how to tackle a "climate crisis."

Why it matters: It was their chance to talk to a broad audience about proposals that some of them have unveiled in just the last few days. Scientific reports from the last 2 years suggest the world is at tipping point to confront the effects of global warming.

Sen. Cory Booker

His big picture: Booker emphasized the importance of racial and social justice in his climate change plan, saying the issue is no less urgent than the civil rights movement.

Details: As president, he said he would move to ban offshore drilling and fracking on public lands, and require all federal departments and agencies to create a climate plan. He wants zero-emission electricity by 2030 and a carbon-neutral country by 2035 and supports banning the fossil fuel exports from the U.S.

Read his full climate plan.

Former Rep. Beto O'Rourke

His big picture: O'Rourke saw climate change as a bipartisan issue, insisting it "is more of a popular issue across party lines than I would have imagined."

Details: O'Rourke supports a cap and trade system to price carbon, not a carbon tax. On his first day as president, O'Rourke said he would re-enter the Paris Climate Agreement (which the U.S. cannot actually leave until 2020), aim to reduce greenhouse gas emissions, try to prevent new oil and gas leases on federally protected land, and ban offshore drilling. He would try to provide federal assistance to people who want to move from neighborhoods that repeatedly flood or are affected by other climate events.

Read his full climate plan.

South Bend Mayor Pete Buttigieg

His big picture: Buttigieg pointed to energy efficiency initiatives, like electric vehicle charging points, in his Indiana town to argue that cities have had to step up in the absence of enough federal climate change policy.

Details: Buttigieg supports a carbon tax and a constitutional amendment to reverse Citizens United. He emphasized the need for bipartisanship to address climate change and is interested in decarbonizing fuel for air travel. He said that allowing people to suffer from the effects of climate change — whether from pollution-caused health issues or natural disasters — could be seen as "a kind of sin."

Read his full climate plan.

Sen. Elizabeth Warren

Her big picture: Warren, who has released 5 climate plans on topics from the military to clean energy technology, embraced large-scale climate policy. "This is a moment where we better dream big and fight hard," she said.

Details: Warren endorsed a carbon tax, arguing that there are "3 areas with the most carbon pollution:" in buildings and homes, cars, and the generation of electricity. She wants the U.S. to ween itself off nuclear energy by 2035. She endorsed the Green New Deal's focus on creating jobs in energy and manufacturing. Her plans would spend around $3 trillion over 10 years.

Read her different climate plans.

Sen. Bernie Sanders

His big picture: Sanders billed his $16.3 trillion climate change plan as more comprehensive than any other candidate's proposal.

Details: He argued that federal regulation is the best way to expand solar and wind energy and touted his Green New Deal's focus on creating new jobs in energy and manufacturing. He said that wind, solar and geothermal energy are more cost-effective than nuclear energy. Sanders said he would not give federal assistance to people who rebuild homes in coastal communities after storms or natural disasters.

Read his full climate plan.

Former Vice President Joe Biden

His big picture: Biden focused on what he views as realistic actions to tackle climate change, saying, "We have to start quickly, we have to start and do things that we know can be done immediately and progress from there," he said.

Details: He said, in his first act as president, he would call a meeting of all nations who signed the Paris Climate Agreement, to "up the ante" and discuss "what has to happen quicker." He wants to achieve net-zero emissions by 2050 and he supports a carbon tax. He said the Green New Deal "doesn't have a lot of specifics," but "deserves an enormous amount of credit." He does not think national legislation to ban fracking is realistic.

Read his full climate plan.

Sen. Amy Klobuchar

Her big picture: She emphasized that climate change effects — like fires and flooding — are visible and personal for her in the Midwest, where her constituents live.

Details: On her first day as president, Klobuchar would return the U.S. to the Paris Climate Agreement. On her second day, she said she would try to restore former President Obama's Clean Power Plan, and on Day 3, she would attempt to "bring back" Obama-era gas mileage standards, which President Trump has proposed to freeze. Klobuchar does not support a complete fracking ban, and she pointed to energy efficiency as a bipartisan starting point for climate change policy.

Read her full climate plan.

Sen. Kamala Harris

Her big picture: She said she would support getting rid of the Senate filibuster to pass a Green New Deal, if there is no bipartisan cooperation on the issue. However, this plan assumes a Democratic majority in the Senate. She characterized addressing climate change as a "fight against powerful interests."

Details: On her first day as president, Harris would declare a drinking water emergency to address climate change, try to end any fossil fuel leases on public lands, support ratifying the latest amendment in the Montreal Protocol and rejoin the Paris Climate Agreement. She is also in favor of a fracking ban and wants to have electric buses for schools by 2030.

Read her full climate plan.

Former tech executive Andrew Yang

His big picture: Yang pinned his climate change plan on financial incentives, and he said his plan to give every American $1,000 each month would help people protect themselves in natural disasters.

Details: Yang said he'd rejoin the Paris Climate Agreement and attempt to "upgrade the GDP" with a new scorecard that includes environmental sustainability. He would try to ban offshore oil drilling and eliminate all subsidies for fossil fuels. He said he loves the "vision" of the Green New Deal, but takes issue with its 10-year timeline to make the U.S. carbon neutral.

Read his full climate plan.

Former HUD secretary Julián Castro

His big picture: Castro identified climate change as "the most existential threat to our country's future." He pointed to events like Hurricane Dorian and ongoing fires in the Amazon as evidence of climate change, saying "we don't need climate scientists to tell us what we see with our own eyes."

Details: As president, Castro said his first executive order would be to rejoin the Paris Climate Agreement. He would also aim to bring the U.S. to net-zero emissions by 2050, provide incentives for solar and wind energy production, invest in renewable energy, create a carbon pollution fee and prohibit fossil fuel extraction on federal land.

Read his full climate plan.

Go deeper: 2020 climate plans have lofty goals for energy research and development