Frankly I would not be terribly upset if someone hacked the air conditioning system at their office, so the place heats up to a good 85 degrees Fahrenheit while the thermostats all show 72. That or burn a decent quantity of coal upwind of them for a few days, so they get a whiff of what they’re selling. “Oh P.U.!, what’s that nasty smell? Coal? Really? Eww….”

Realistically the best weapon to use against scum like Heartland is ridicule and sarcasm. For example a billboard showing a background of a photo from the Philippines, with a face-closeup of Pinocchio in the foreground with his nose grown out to a foot in length, the headline “Climate change is a myth,” and a URL such as “heartlandlies.com.” Or send out postal mail to the same mailing list, with postcards offering a chance to win $500 of storm & flood insurance with a “force majeure” exclusion for “acts of God and climate change.”

Don’t even engage these people at the level of reasoning. The goal is to make them look like fatuous liars and quacks, to the undecideds. The way to get there isn’t by arguing facts and theories, but to just go after them as liars, quacks, charlatans, and frauds, deserving of ridicule and scorn.