They're not just dismissive, they're pretty obviously bad faith arguments. "CO2 is plant food" is a classic climate denier talking point that you hear from your crazy uncle on Facebook, who's parroting something they heard from a pundit on Fox News.

Water is also plant food, but that's not a helpful piece of information if you're in a flood. The world is releasing 97 million barrels of gasoline into the atmosphere per day.