Air
Source Player Core pg. 442
Effects with the air trait either manipulate or conjure air. Those that manipulate air have no effect in a vacuum or an area without air. Creatures with this trait consist primarily of air or have a connection to magical air.
Planes with this trait consist mostly of open spaces and air of various levels of turbulence, though they also contain rare islands of floating stone and other elements and energies. Air planes usually have breathable atmospheres, though they might include clouds of acidic or toxic gas. Earth creatures often find themselves at a disadvantage within air planes, as there's little solid ground for them to gain their bearings, which tends to at least make them uncomfortable.
Planes with this trait consist mostly of open spaces and air of various levels of turbulence, though they also contain rare islands of floating stone and other elements and energies. Air planes usually have breathable atmospheres, though they might include clouds of acidic or toxic gas. Earth creatures often find themselves at a disadvantage within air planes, as there's little solid ground for them to gain their bearings, which tends to at least make them uncomfortable.