Depending on the day, you might look to the sky and see a sea of pale blue or a radiant sunset creeping toward the horizon. If you’re in a major metropolitan area, though, you might also be met with the characteristic red-brown haze of smog.

Berlin-based artist Macarena Ruiz-Tagle is behind the vibrant Cyanometer and Sunset postcards we’ve featured on Colossal (and that have sold out in our shop several times). But she also created a third version designed for those not-so-bright days.

The World Health Organization estimates that 99 percent of people on Earth breathe unsafe air, making Ruiz-Tagle’s Air Pollution postcard perhaps the most fitting for our era of climate catastrophe. While a stark contrast to the brilliant blues, yellows, and oranges of the other two, this design is awash in pale pinks and grays to match that of a gloomy, and even soiled, atmosphere. Like the others, the idea is to hold the work up to the sky and mark the corresponding hue before dropping it in the mail.

The interactive card shifts in meaning depending on whether the opening reveals a misty fog or air thick with chemicals, and it’s part of a growing movement to track climate data in a tangible, grassroots manner. “Separating the visual delight of being immersed in a cloud from the intoxicating reality of breathing heavily polluted air, the postcard evokes both the smog that engulfs global cities and the ethereal beauty of fog,” the artist writes. “In its mesmerizing aesthetic ambiguity, the work sustains a space for contemplation within our troubled atmosphere.”

Find all three postcards in the Colossal Shop, and explore more of Ruiz-Tagle’s work on her website.