Like, I imagine, most members of CR0, I try to "do my bit" towards saving the planet by recycling what I can

I don't know about any research Phil but I did see Gordon Ramsay reckon that the thin surface layer of oil on a plastic carton helps make it easier for the second use as the food won't stick to the sides so much. This is anecdotal I know.

At home I am able to recycle paper, metal, plastics and food waste, which is a step-forward from where we were 20 years ago. Alas I fear that the world has already embarked on an irreversible path to self-destruction and there is little incentive for those who hold the power to really address fundamental issues like climate change, which Greta Thunberg has highlighted. I can only take comfort in that I won't live to see this. Depressing stuff.

Notwithstanding this, I am all for each of us doing our bit where we can.