The correct response to Chevron being overturned is for every single environmental group to start filing millions of lawsuits, right now, today, arguing that various regulatory decisions didn't go far enough.
Absolutely flood the zone.
Just take every public comment period submission by Greenpeace or Ducks Unlimited or literally any one that the EPA hasn't fully implemented and demand the courts rule.
File everything in the 9th circuit.
Play their game.
Fundraising is the linchpin to this scenario because NGOs simply cannot outspend corporations. David and Goliath asymmetry in regard to legal budgets. How do you craft that message to sustain the flood of suits?
Or you find a lawyer in the Ninth Circuit with a degree in Environmental Science and a whole lot of time who doesn’t mind waiting to get paid. Either one, really.
You don't need to outspend though. You just need enough to keep your own lawyers in court and filing briefs. And activists tend to get their lawyers for a fair bit cheaper, because they don't have to pay the tax of crushing their counsel's soul.
Also, wouldn't the defendants in this matter be the Government, and not the Corporations, because if I'm reading this idea correctly, it would be environmental NGOs suing the administrative state (EPA) for not doing enough.
Yeah they can throw as much "Friend of the court" paperwork bullshit in there, but any judge can just look at it and say "Nah, fuck off with that", and even then those filings have no bearing on decisions anyway. Having them as DEF gives them the option to motion the case to death.
There are thousands of talented under-employed advocacy comms people (waves hand) who would give their eye teeth to work on crafting great messaging for a campaign like that.
Unfortunately, this is exactly what Republicans want. They want our system of government to grind to a halt. They don't want it to work. Asymmetrical warfare.