Something that's atmospheric is related to a planet's atmosphere, or the gases that surround it. Atmospheric pollution can sometimes cause asthma and other breathing problems.
All planets have an atmosphere, layers of gas that are held close to them by their gravitational pull. The atmospheric conditions on Earth have allowed many life forms to develop, but global warming is a serious atmospheric problem that is getting worse. Every planet has its own unique atmospheric makeup. The adjective atmospheric comes from atmosphere, which stems from the Greek root words atmos, "steam or vapor," and spharia, "sphere or globe."