In August, the Pew Research Center released a poll showing a sharp increase in the number of Americans who view climate change as a major threat to the well-being of the country — from 40 percent in 2013 to 57 percent now. And it is of particular concern to Democratic voters, as reflected by the emergence of climate change as a leading issue in the 2020 Democratic presidential primary.
The same poll indicates that of the voters who identify as Democrats or left-leaning independents, 87 percent view climate change as a major concern.
And that view is reflected by many of the top Democratic presidential candidates.
Massachusetts Sen. Elizabeth Warren: "Life on earth is at risk."
Former Vice President Joe Biden: "The single greatest concern for war and disruption in the world."
California Sen. Kamala Harris: "This is a fight against powerful interests."
Vermont Sen. Bernie Sanders: "We are fighting for the survival of the Planet Earth."
Those remarks came during a seven-hour climate forum hosted by CNN this month with the top polling candidates.
There are many similar positions – calls for switching from fossil fuels to renewable energy and for rapidly reducing carbon emissions to coincide with recent recommendations from the United Nations. But there are also significant differences in messaging, strategy and ambition.
"Our campaign has introduced the most far-reaching and comprehensive climate change proposal ever introduced in the history of this country," declared Vermont independent Sen. Bernie Sanders during a rally held in Portland on Labor Day weekend.
Sanders outlined a plan that is ambitious and expensive - some $16 trillion, which Sanders says will come from new taxes on fossil fuels, defense cuts and tax increases on the wealthiest Americans. It would all go to pay for a complete overhaul of the nation's energy and transportation system, with a goal of eliminating all carbon emissions by the year 2050.
Sanders is framing his proposal as a jobs initiative, as is Massachusetts Sen. Elizabeth Warren, who wants to spend $3 trillion to decarbonize buildings, transportation and electricity through investments in research and development.
"And here's the hook in it: Any product that gets produced out of that, all the new green ideas that come from that, any manufacturing has to be done right here in the United States of America," Warren explained in a campaign video.
Attaching new jobs to decarbonizing efforts is a central theme of the Green New Deal, a non-binding resolution introduced in the current Congress. The Green New Deal isn't specific set of policies, but rather a set of goals and priorities. That's why 13 Democratic candidates, including former Vice President Joe Biden, are backing the concept despite having their own climate change plans.
"We're going to invest $1.7 trillion in securing our future so that by 2050 the United States will be 100 percent clean energy economy with net-zero emissions," Biden said in a campaign video.
Biden's bid for net-zero emissions by 2050 is in contrast to Sanders and Warren, who are pledging carbon-free proposals.
Net zero proposals, as embraced by most of the Democratic candidates including California Sen. Kamala Harris and New Jersey Sen. Cory Booker, would allow some CO2 emissions to continue as long they're offset by methods to absorb heat-trapping gases, such as planting trees.
Carbon-free means a total elimination of CO2 emissions — through electric vehicles or completely renewable energy sources — with no offset schemes.
Another contrast point is carbon pricing, a cost applied to carbon pollution to encourage polluters to reduce the amount of greenhouse gases they emit.
Only four of the Democrats running have fully committed to it, including South Bend, Indiana Mayor Pete Buttigieg, who made his pitch during a rally held in Portland in August.
"When we do it we don't suck the money out of the economy. We actually have a dividend that goes right back out to the American people, so that we get the benefits of the economic signals, but most people, if we do it progressively, are made more than whole by the carbon dividend coming back to you. And it helps with the politics of it, too," he said.
Buttigieg's carbon pricing dividend proposal is a bit of an outlier among the Democratic hopefuls.
So is New Jersey Sen. Cory Booker's advocacy for nuclear energy to help the U.S. transition to carbon-neutral energy sources, which he detailed during a recent event in Portland.
"We have to start embracing next-generation nuclear, which doesn't have risks of meltdown and could help bring us to the goals we must have," Booker said.
Booker's plan pledges $20 billion toward advanced nuclear research, which he says will help the U.S. meet carbon-neutral electricity generation by 2045. And if that seems overly optimistic, the same might also be said of many of the other Democrats' climate change plans.
Because while there's near unanimous consensus among Democratic voters that the climate change challenge demands bold initiatives and significant public investment, that’s not a view shared by all Americans, or by the current occupant of the White House.
"All of this with the global warming and the — a lot of it's a hoax. It's a hoax. I mean, it's a money-making industry, ok? It's a hoax. A lot of it," Trump said during a 2015 rally in South Carolina.
President Donald Trump's views illustrate how the issue of climate change continues to be locked at the center of a deep partisan divide.
The same Pew Research poll that showed it to be a top concern among Democrats and left-leaning independents also revealed almost no change in urgency for moderate or conservative Republicans.
And that means the issue could drift to the background – as the eventual Democratic nominee becomes focussed on the next major political hurdle: winning the White House.
This story is part of a week-long reporting project “Covering Climate Now,” by Maine Public and more than 300 other news outlets around the world. The series comes in advance of the United Nations Climate Action Summit on Monday Sept. 23 in New York. More information at MainePublic.org/climatenow.
Originally published Sept. 16, 2019 at 5:42 a.m. ET.