A complete speaking model
Burning fossil fuels increases greenhouse-gas concentrations, while incomplete combustion can produce black carbon. These are related but not identical problems. Black carbon is a component of soot, not another name for carbon dioxide. Reducing unnecessary fuel use helps, yet a school activity must not pretend to solve global warming alone. I suggest an information stand explaining one mechanism and one feasible action, such as reducing unnecessary vehicle idling through the school’s authorised arrangements. We would ask a science teacher to check the source notes before displaying them. We must not burn waste to produce a dramatic demonstration. A drawing can explain a process without exposing people to smoke. We should also distinguish a proposed action from a measured reduction and explain what evidence would be needed to check progress.
Follow-up: Does one smoky morning prove a global climate trend?
Response: No. A brief local event cannot establish a long-term global trend.