The 2024 presidential campaign is an electoral environment unlike any other. Families across the country have lived through yet another hottest summer ever. Communities in the southeast have been devastated by hurricanes made more intense and destructive by climate change.

At the same time, Vice President Harris has put climate and supporting communities at the forefront of her campaign. She has run a historic 100-day sprint boosting her numbers across the board, while still introducing herself to some voters and rolling out a forward-looking platform for what she would do over the next four years. This means that her electoral challenge is unique: both persuading swing voters and ensuring that the Democratic coalition embraces her vision and comes out to vote.

Climate is how Harris appeals to both groups. Climate voters played a critical role in determining the 2020 election, and it’s an increasingly important issue for the undecided young and diverse voters that Harris needs to win, specifically in seven key battleground states. 

The Biden-Harris administration delivered the most important climate bill in American history. This cycle, Harris has laid out a vision to take action on climate change and clean energy—and she has sharply contrasted with Trump’s plan to overturn the Inflation Reduction Act (IRA) and forfeit climate policy to special interest fossil fuel companies.

Now, as we head into the final weeks of the 2024 election, climate voters are poised to be decisive once again in the presidential outcome. 

1. Climate Voters Were Key to Victory in 2020

When the Biden-Harris ticket took the White House in a tight race four years ago, climate voters were at the heart of the Democratic path to victory. In the lead-up to election day, Biden voters ranked climate change as their number one issue.

Pew Research Center found that 68 percent of registered voters ranked climate as a “very” or “somewhat” important issue in their presidential choice, and voters across the political spectrum trusted Biden to handle climate change more than any other issue when compared to Trump. And climate voters turned out: An analysis from the University of Colorado Boulder found that voters’ beliefs about climate change had a significant enough effect to swing the election in Biden’s favor.

Climate has consistently been important to key demographic groups in the past few elections. A post-election poll from Navigator Research found that climate was the number one motivating issue among voters under 45, who moved from non-voting or 3rd party voters in 2016 to Biden voters in 2020.

And we’ve seen climate continue to be a significant decision-making factor for voters in the years since: Navigator Research found that “winning swing” voters in the 2022 midterms prioritized climate change as the second most important reason to support Democrats, after only abortion.

The data points to climate being critical to voter choices again this fall. August polling from Data for Progress found that nearly one-third of voters, including more than half of Democrats, say that climate change is more important to their vote choice in 2024 than it was in 2020.

2. Climate Is Harris’ Biggest Advantage Over Trump

Vice President Harris holds a unique edge over Trump on energy and climate issues, and she stands to gain by leaning into that strength. According to nonpartisan polling from Gallup, Harris holds a 26-point advantage over Trump on climate among registered voters, the biggest gap of any issue that they measured.

Trump’s record of climate denial and cozying up to big oil are massively out of touch with what the American people want. Even an outright majority (56 percent) of self-described moderate Republicans want immediate action on climate, according to polling this spring from CBS News and YouGov.

Harris can capitalize on Trump’s relative weakness by leaning in on her vision for a clean energy economy that lifts up the middle class and reduces costs, a proven effective message according to polling from Hart Research. By pressing her advantage on climate, Harris can win over critical swing voters, who are as likely to rank climate change as their number one issue as they are abortion, another platform that Harris has successfully campaigned on.