Democratic presidential candidates shrunk last night from confronting tough implications of climate change.

Each of the seven candidates on stage for the sixth presidential debate described the climate issue in existential terms, and some promised to declare a national emergency. But most of them avoided giving direct answers about politically perilous outcomes of global warming, like whether some communities should be abandoned because of sea-level rise. At other times, they promoted policies that seemed to clash with their climate priorities, including in foreign affairs.

It amounted to one of the longest discussions on climate change in the half-dozen debates, but the candidates mostly declined to contrast themselves with one another. The exception was billionaire investor Tom Steyer, who twice used climate as an attack line on South Bend Mayor Pete Buttigieg.

Buttigieg threatened diplomatic and economic isolation for China, the world's biggest greenhouse gas emitter, if the Chinese government uses violence against Hong Kong's pro-democracy activists. Steyer responded that such a move would doom international climate action.

That followed a question that almost everybody dodged, on whether the government should relocate people from the cities hit hardest by climate impacts, like Miami or Paradise, Calif., where dozens of people died in 2017 during a wildfire.

Steyer didn't give a direct answer, even as he called on Buttigieg to "prioritize this higher."

Buttigieg tiptoed around that question too, though he noted that he lives near a river that in two years has swelled with 2,000-year floods.

Minnesota Sen. Amy Klobuchar called climate change an "existential crisis" but suggested only individual homes, not entire cities, would need to be moved. In fact, whole towns and villages in Alaska are already trying to do just that, and options for retreat are under discussion in states like Florida, Louisiana and California.

Former Vice President Joe Biden turned the question of relocation into one of rebuilding, saying new infrastructure needs stronger standards for resiliency and energy efficiency.

Vermont Sen. Bernie Sanders rejected the question, saying that scientists have underestimated the rate of climate change: "It is not an issue of relocating people and towns. The issue now is whether we save the planet for our children and our grandchildren."

Tech entrepreneur Andrew Yang, whose climate platform includes a plank titled "Move to Higher Ground," was the only candidate with a direct answer.

"We should obviously be paying to relocate Americans away from places that are hit by climate change," Yang said, adding that affluent residents are already moving while people with less money are stuck.

"The question is, do you leave that town on its own to fend for itself, or do you come together as a country and say we need to protect our people from climate change?" he said.

His plan has few details beyond noting it would cost billions of dollars.

Overall, the candidates set aside climate policy in favor of climate politics. They mostly stuck to the plans posted on their websites, using them as a springboard to talk about how they would break through the gridlock that's stalled climate policy for decades.

Massachusetts Sen. Elizabeth Warren used a question about nuclear energy — she wants to keep existing plants but build no new ones — to talk about corruption.

"Understand, the biggest climate problem we face is the politicians in Washington who keep saying the right thing but continue to take money from the oil industry, continue to bow down to the lobbyists, to the lawyers, to the think tanks, to the bought-and-paid-for experts," she said.

"If we don't attack the corruption first ... then we're not going to be able to make the changes we need to make on climate, on gun safety, on drug pricing, on all of the big problems," Warren said.

Buttigieg and Klobuchar pulled a similar maneuver, using a climate question to frame themselves as electable Midwesterners.

"The way we take on climate change in a big way is by, yes, talking about what's happening on the coasts ... but also talking about what's happening [in the] Midwest, where I'm from," Klobuchar said.

"It's not flyover country to me — I live there," she said. "And what we're seeing there is unprecedented flooding."

Again, Yang distinguished himself with policy. He embraced nuclear power and said its cost, waste and safety concerns could be addressed by replacing uranium with thorium fuel. (The Bulletin of the Atomic Scientists said some of those claims are dubious.)

Climate got to guest-star when the questions turned to other topics. Sanders pivoted to climate twice — stumbling once in the process.

When asked a question about race, Sanders started his answer with "I wanted to get back to the issue of climate change for a moment." Moderator Amna Nawaz of PBS Newshour cut him off and told him to answer the race question, to substantial applause. Nevertheless he continued, saying that people of color would suffer most from climate change.

Sanders offered the night's first climate reference, saying the United States-Mexico-Canada trade agreement had too few climate provisions for him to support it.

Reprinted from ClimateWire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.