Ask a climatard what greenhouse gas has the biggest impact on temperature of the planet. They will almost invariably say Carbon Dioxide because they're idiots and they're just parroting what they're told.

You, an intellectual, will say "Its Water Vapor. That why deserts are boiling hot during the day and freezing cold overnight, there is no water vapor in the air to regulate the temperature. CO2 is barely a fraction of a fraction of a percentage of the atmosphere."

They'll change the subject fast, or move goalposts, or basically will refuse to admit you're right and they're dumb.