https://www.steampoweredfamily.com/the-greenhouse-effect-exp...
An experiment for children isn't going o add anything of value here. Labor or in this case kitchen experiment do not model the real wold. And Correlation does not imply causation.
And finally when you establish a correlation, it does not have to be linear i.e. more of X does not mean it must case more of Y. Complex systems that are in some kind of balance often produce their own counter effect to change. This is the primary reason why such a stable balance could even form over long periods of time. The self correction properties of the whole system is very much a requirement for the balance to exists in a complex system like the climate.
There's a cousin to your comment with a guy refusing to accept that CO2 is a greenhouse gas.
It can be a greenhouse gas in one system or under some conditions and not in another system.
Just like ozone is considered pollution on grown level and its UV radiation shield high up.
>ozone is considered pollution on grown level and its UV radiation shield high up
This is not even a false dichotomy.