The effects that individual consumption behaviours have on climate change are explored,
focusing on products that satisfy the same need but with different carbon footprints. Two
types of drinking water, produced, distributed and consumed in Italy,were compared as a case
study: tap water and PET-bottled natural mineral water. The first is the one supplied to the
municipality of Siena,while the second is a set of 6 different Italian bottledwater brands. The
results showed that drinking 1.5 L of tap water instead of PET-bottled water saves 0.34 kg
CO2eq. Thus, a PET-bottled water consumer (2 L per day) who changes to tap water may
prevent 163.50 kg CO2eq of greenhouse gas emissions per year. In monetary terms, this
translates into a trad able annual verified emission reduction (VER) between US$ 0.20 and
7.67per drinker.Analyzing a maturebottledwatermarket,such as the Italianone,mayprovide
insights into the growing global bottled-water market and its effects on climate change. The
environmental and economic benefits of changing drinking water habits are also discussed