Its not only fossil fuels that are being depleted, but also other things such as metals or in this case a gas – helium. Andy and I heard a programme on materials depletion on BBC Radio 4 and much to my amazement helium is mined, mainly in Texas. The problem is it has important uses (apart from in balloons) and as such one scientist has asked for its use to be banned in balloons. I seem to remember from the programme there’s about 20 years supply left at current rates of usage. Once it leaks out into the atmosphere being so light it sloughs off into space. The link to the full article can be seen on our Facebook page.