A deposit for CSIRO’s air bank
Are you a keeper? Is your bedroom full of old magazines, broken toys and socks which have long lost their partner? If so, check to see if you have a forty year old sample of air lying around in the back of your cupboard. The CSIRO would love to get their hands on it.
In 1968, scuba diver John Allport filled a tank with air in Melbourne, readying it for a diving trip. However the tank was never used and has remained the perfect time capsule, storing a sample of the atmosphere from over four decades ago.
Keeping records of our air is not all that new – the CSIRO has been doing it since 1978. For older records researchers have had to look elsewhere for bubbles and pockets of old air, such as those trapped deep in glaciers. Unfortunately some tricky mathematics is required to study such icy air samples, leaving room for mistakes. John’s tank will help scientists to double check their sums.
Atmospheric chemistry is vital to our understanding of how our climate can change. Although carbon dioxide only makes up a tiny fraction of the Earth’s air, it is one of only a few gases that scatter infrared light rather than letting it pass through. Small increases in this ‘greenhouse’ gas can lead to significant increases in the amount of energy staying close to the planet’s surface rather than reflecting into space.
While the word ‘weather’ describes things like the temperature and rainfall on small time scales of days and weeks, ‘climate’ describes similar things over much longer periods. A few warm winter days aren’t evidence of climate change, and a particularly hot, dry year might not be due to global warming. Climatologists need to look over many decades of data to find patterns of increasing concentrations of gases, changing ocean currents, air temperatures and precipitation.
Might there be even older samples of air hidden away in somebody’s shed, in an old time capsule or sealed up in an ancient bottle? Perhaps. It’s amazing what people will keep.
