“Future in a Jar" is a series of digital images co-created by a human artist and Artificial Intelligence (A.I.). Each image presents a scenery of a futuristic city in an underwater world of jar. The concept of the "jar" is a metaphor to disclose human's shrinking living space on Earth, but it also represents a fantasy world of living. The project's ideas are rooted in our concern about how environmental issues could affect people's lives in the future. Technology may advance to the point of allowing people to build such complex cities fully underwater, but they are still facing the fate of living in a jar. Using the characteristics of artificial intelligence, which incorporate a large database of human creativity, this work articulates a future we cannot predict. Dystopian or utopian? That is the question for the future.