What will happen to cryogenic applications when helium runs out?
It’s true that most helium in the Earth’s atmosphere escapes into space, and in fact in parts of the upper atmosphere, helium and other lighter gases are the most abundant elements. However, helium is not going to run out. There has always been, and still is a constant (although small) supply of helium on earth due to natural radioactive decay, mainly found in minerals of uranium and thorium (e.g. pitchblende, carnotite and monazite). These decay emitting alpha particles, which are helium nuclei, with which electrons readily combine. There is about 3000 tonnes of helium generated a year throughout the earth’s lithosphere.
