This mobility, both physical and symbolic, is what makes tea so meaningful. "It is a plant with which we have strong interaction. There is the plant and its ecology. It's a metaphor for our Earth."

In the face of climate change, Sigley views tea as a symbol of harmony between people and nature. "If we want our future generations to enjoy tea, we have to make sure the ecology of the plants is preserved and maintained."

Sigley's love for tea also stems from Australia, where it is a daily staple. "Australians really love their tea. Per capita, they drink more than the British," he says.

He recalls the rustic ritual of "bush tea" made by boiling black tea over an open fire in a "billy can". "Sometimes the flavor of the eucalyptus goes into the tea … and you drink it underneath the stars."