KS34:set up an experiment to mirror global warming. Following safety procedures take a tank and put water in the bottom to about a depth of half way. Colour some very concentrated salt water with red food colouring and very carefully drip it onto the normal water making sure that it stays in a layer above, being less dense than water. Set up a similar control with just normal water. Shine a UV lamp onto both tanks of water. The water with the layer on top gets warmer far more quickly showing that the energy re-radiated at a longer wavelength, lower frequency is bounced back into the water from the salt and can't escape, as it can from the control.
KS4:set up an ideas and evidence debate. Should economic concerns justify procrastination in the understanding and action needed on global warming? How do opposing sides use evidence to justify their argument? Can any scientific theory be accepted as an ultimate truth?