Joe Biden’s latest climate change and clean energy plan mentions the word union more than it does the climate itself.

Why it matters: Wind and solar energyhave grown immensely across America over the last decade, but associated union jobs have not. The Democrats’ presumptive presidential nominee is trying to change that, which politicians and others say is key to tackling climate change.

What they’re saying: “There’s a halo effect that pertains to the clean energy industry with respect to how those industries treat workers,” said Jason Walsh, executive director of the BlueGreen Alliance, a group backed by labor unions and environmental groups.

• But like other industries, he said, "under our prevailing labor law regime, companies are actively discouraging and in some cases actively blocking the ability of their workers to organize, which includes firing them.”

The big picture: Biden has always had a closer relationship with unions, considered one of the Democratic Party’s most important political constituencies, than some of his more progressive counterparts. Now, the pandemic and resulting economic recession is catapulting worker rights and equity to the forefront of all debates, including energy and climate change.

Where it stands: Biden’s expanded plan on those topics unveiled last week calls for sweeping changes to labor laws, alongside aggressive goals to transition off fossil fuels.

• Workers building clean-energy infrastructure “must have the choice to join a union and collectively bargain,” the plan states.
• The plan supports legislation that makes it easier for workers to collectively bargain. Biden’s plan would go further and hold executives “personally liable” if they interfere.
• The plan also backs a bill by Sen. Jeff Merkley (D-Ore.) thatwould provide greater tax incentives for clean-energy companies meeting tougher labor standards.

By the numbers: Union presence is “an important factor” in job quality, said Phil Jordan, vice president at BW Research, which conducted an annual report about energy jobs on behalf of the Energy Futures Initiative, a think tank led by former Energy Secretary Ernest Moniz.

• Jobs in wind and solar are between 4% and 6% unionized. That’s on par with the national average for all jobs, but far lower than the share of union jobs in other energy sectors.
• Natural gas, nuclear and coal power plants are between 10-12% unionized.
• Transportation, distribution and storage jobs, which are largely in fossil fuel sectors, have among the highest share of union jobs at 17%.
• Salaries vary widely depending on the specific job in any given sector, but solar and wind jobs have lower average salaries compared to their counterparts in oil and gas and nuclear plants, according to Labor Department statistics.

Yes, but: Factors inherent to renewable energy will make it hard for Biden to fulfill his promises on labor and use less fossil fuels, according to officials in the renewable energy sector, different labor unions and experts involved with both.

• Fewer long-term jobs exist in operating and maintaining wind and solar facilities compared to other power sources.
• More jobs exist in supporting oil and gas production (like building pipelines and refineries) compared to wind and solar, and those are highly unionized.
• Construction and installation jobs, which are more common in wind and solar, are less unionized.

“We agree that over the coming decades we’re going to do more transition” to renewable energy, said Sean McGarvey, president of the North America's Building Trades Unions. “But we can’t transition into careers where they take a 50-75% paycheck cut.”

The intrigue: Some renewable energy advocates agree. “Where we are right now is not good enough,” Merkley told Axios in an interview last week.

• His bill offers incentives for stronger labor standards instead of penalties because he thinks that’s more politically viable: “I’m not trying to create a war between unions and renewables. I’m trying to bring them together.”

The other side: Renewable-energy officials say the topic is increasingly on their radar, but they maintain thattheir sector already creates quality jobs.

• “Solar workers have good paying jobs and a safe working environment,” said Erin Duncan, vice president for congressional affairs at the Solar Energy Industries Association. “We welcome conversations with policy makers in both parties and our friends in the labor movement about policy options.”

The bottom line: Higher quality renewable energy jobs will ultimately make it easier to address climate change, Merkley says. "The speed with which we can transition will be affected profoundly if those who have good-paying jobs in the fossil-fuel world hate the idea of the transition to renewable energy.”