Considering the way we've been treating our planet, testing air quality is crucial. At Kennaook/Cape Grim in Tasmania, the cleanest air in the world blows in from the Southern Ocean. The Cape Grim Baseline Air Pollution Station is constantly testing this air, but they also keep samples in the Cape Grim Air Archive. Every few months a new sample is taken for the archive. Sure, we have air testing results for the last 50 years, but what if, sometime in the future, we need to test for something we never tested before? This historic air will be available for new tests. Tom Scott gives us a look at the archives and explains how these samples are taken, stored, and used.