Joe Biden is facing closer scrutiny of his climate plans

The apparent end of the Democratic primary's truly competitive phase will bring closer scrutiny of Joe Biden's climate and energy plans — and new efforts to change them.

The state of play: Bernie Sanders yesterday suggested that his mission in remaining in the race is pushing Biden left, and he name-checked climate change among the policy areas.

• Sanders vowed to confront Biden on the topic at Sunday's debate in Arizona, saying he will ask:

"Joe, how are you going to respond to the scientists who tell us we have seven or eight years remaining to transform our energy system before irreparable harm takes place to this planet because of the ravages of climate change?"

• The pro-Sanders Sunrise Movement, the youth-led group that has played a major role in pushing the Green New Deal into the political bloodstream, also indicated it would work to pressure Biden, per spokesperson Aracely Jimenez:

"It’s never been more important for the next Democratic president — whoever it is — to prioritize an aggressive Green New Deal that overhauls our economy and energy system while stimulating the economy for working people."

The intrigue: It's not clear how much leverage Sanders and the left flanks of the green movement will have.

• That's because Biden isn't just eking out wins — he's running away with many states, which limits the power of Sanders and groups backing him to win concessions.
• Biden's success also limits the incentive to change course, but that said, it's helpful for him to gain as much support as possible across the party's ideological and demographic spectrum.

The big picture: While Biden's wide-ranging climate plan goes much further than Obama-era policies, Sanders' is far more aggressive.

• Sanders' $16 trillion Green New Deal plan includes calls to ban fracking, ban fossil fuel exports, and reach 100% renewables for power and transportation by 2030.

The bottom line: Don't forget that the differences between the plans shrink a lot if you consider what has any chance of getting through Congress and the courts.

Go deeper: Where Joe Biden stands on climate change