Why climate change is a defining issue for 2020

Climate change is playing a larger — and more polarizing — role than ever before in a presidential election.

Why it matters: In the past, the topic barely registered with voters and candidates were less polarized. Today, all Democratic candidates are treating it as a crisis, with detailed plans and funding sources to address it, while President Trump ignores the problem and bashes those plans.

Driving the news: In the Nov. 20 Democratic presidential debate, Joe Biden called climate change "the" existential threat to humanity while Pete Buttigieg championed the notion of a "carbon-negative" farm. Billionaire Tom Steyer said if elected he would call a state of emergency on his first day in office over climate change.

• Billionaire Michael Bloomberg, who officially announced his candidacy on Sunday, has spent $500 million in recent years on global climate-related efforts and in June committed another $500 million for a Beyond Carbon initiative.

The big picture: The impacts of climate change, like more intense wildfires and more severe flooding, are increasing in frequency. Meanwhile, ways to solve the problem, like renewable energy, are becoming more affordable, even while the science increasingly says the problem is growing more dire.

• These developments taken together are making climate change a tangible issue for broader swaths of the population than in the past — so it’s permeating our politics in newly forceful ways.

Between the lines: Multiple surveys of public opinion show Americans' growing concern about climate change being driven almost entirely by Democrats.

• Democrats are looking to clamp down significantly on fossil fuels and enact ever-more aggressive and expensive plans, embodied around the Green New Deal rhetoric.

Where it stands: Trump mocks and rejects mainstream climate-change science and is repealing virtually everything predecessor Barack Obama's administration did on the matter.

• Trump will bash the ultimate Democratic nominee's climate change plan as radical, while that person will bash the president for denying science. Don’t expect an inch of common ground.

Flashback: Here’s a brief run down memory lane.

• In the 2016 and 2012 presidential contests, climate change didn’t register much with either the candidates or voters.
• In 2008, Republican John McCain and Democrat Barack Obama both acknowledged climate change as a problem and put forward aggressive policies.
• The topic rarely came up in presidential contests before that, largely because it was just beginning to emerge as a public issue. More traditional environmental problems were paramount.

Climate change has received far more attention among Democratic candidates than it ever has in the past.

• Although the topic is still not a top focus in the Democratic primary debates, CNN and MSNBC both hosted forums for the candidates to discuss climate change.
• Several current, former or potential candidates have made the topic a top priority for them, including Steyer and former candidate Jay Inslee.

• These men have never been likely nominees, but their attention on the topic has created pressure on the entire field to respond in kind with similarly aggressive policies.

The other side: Congressional Republicans, who have mostly ignored climate change for the last decade, are looking to respond to what is a growing public opinion trend of young people more worried about climate change than older people.

• House Republican Leader Kevin McCarthy told The Washington Examiner recently that his conference will be introducing a series of bills aimed at responding to the Green New Deal. “Let’s have that debate instead of everybody saying we’re just deniers,” McCarthy said.
• Trump campaign spokeswoman Sarah Matthews criticized the Green New Deal and Democrats' plans to significantly curtail — or even eliminate altogether — fossil fuels.
• "In contrast, President Trump continues to advance realistic solutions to reduce emissions while unleashing American energy like never before," Matthews said.

Reality check: Emissions are going back up under Trump, but expect this talking point in any case.

But, but, but: Climate change is unlikely to be the top issue for most voters in 2020.

• The complexity and decades-long nature of this problem makes it uniquely ill-suited for politics operating on two to six-year cycles and makes it unlikely to ever be the top priority for any sizable portion of the population.
• More imminent concerns, like health care and the economy, will almost always win out with most voters.

The bottom line: That all said, we’re entering a new high water mark for climate change and its political saliency.