Let’s have a very quick lesson about a panic that was going on in a small section of the scientific (and not so scientific) community in the mid-20th century – its name was global cooling. Yes, instead of climate change causing the planet to heat up, there were those who believed the Earth was dangerously close to heading for its next ice age. Most of the reporting and investigation into global cooling did not emerge until the 1970s, but in the decades prior there were already rumblings that temperatures were dropping year after year, and everything from aerosols in the atmosphere to Cold War concerns of a nuclear winter were going to trigger a big freeze. Of course, most of us acknowledge that global warming is the reality we are now facing. Nevertheless, the concept of global cooling was obviously a theme on Alan Fennell’s mind when he was writing both Pink Ice, and the earlier Fireball XL5 episode, The Day The Earth Froze. Whether he actually believed the global cooling theories is neither here nor there, but the predicted doom of another ice age was probably the perfect influence for a science fiction tale of global catastrophe, with more than a little room for some alien interference to trigger the disaster.