My guest is Dr Muireann Lynch of the economic and social research institute here in Ireland. She very carefully guides me an idiot on my first tour of the c-word. Carbon. How much it costs to use it, how much it costs, the maths of optimisation, Lagrange multipliers, carbon offsets, what happens when carbon has an infinite price.

Warning – this contains traces of calculus that some listeners may find upsetting. But stick with it and we eventually get onto lighter topics like making twixes or other nougat-biscuit equivlants and then of course the end of habitable earth.