When you take a sip of tea, you’re drinking a beverage that is grounded in a particular time and place. In Yunnan province, southwestern China, which is the source of a highly prized tea known as pu-erh, summer brings monsoon rains, whereas spring is comparatively dry. Tea leaves that are harvested in spring therefore have different qualities to those collected in summer: each tea contains around 50 chemicals that are unique to its season of harvest, says Albert Robbat. The sensitivity of tea plants to the environment makes the crop vulnerable to the effects of climate change. Variations in temperature and precipitation are known to affect tea yield, as well as alter the complex balance of chemicals that gives tea its flavour and potential health benefits.
The primary act of social media—whether Twitter, tumblr, or Instagram—is virtual curation. Around the turn of the 20th century, though, the curation fad was literal: people roamed fields and forests to collect plant specimens and preserve them in plant libraries called herbaria. Now those old specimens are helping scientists reconstruct how trees have responded to shifts in the climate.
Scientists have recently gleaned data from New England herbarium specimens on historical timing of leaf-out—the time in spring when leaves unfurl, an important biological indicator of climate change.