Biden signals expanded climate plan as a "key objective"

"I have asked my campaign to commence a process to meaningfully engage with more voices from the climate movement — including environmental justice leaders and worker organizations, and collaborate on additional policies in areas ranging from environmental justice to new, concrete goals we can achieve within a decade, to more investments in a clean energy economy."

Why it matters: It's the second sign in recent days that he is likely to alter his platform, which some green activists see as too modest even though it goes much further than Obama-era initiatives.

• Sen. Bernie Sanders' endorsement of Biden last week included the announcement of plans to form joint policy "task forces," with climate among the topics.

Go deeper: The energy stakes of Bernie vs. Biden