When CFs of PET-bottled and tap water were calculated and compared to quantify the contribution of individual patterns of consumption to climate change, the results showed that
choosing substitute goods with lower CFs may avoid a remarkable amount of GHG emissions. An Italian population of 55,000 persons, drinking 2 L of water a day per person, can
prevent emissionof about 9000 t CO2eqper yearbychoosing tap water instead of PET-bottled water. Our analysis suggests that economic incentives schemes, such as voluntary carbon
markets, combined with CF assessments, are a powerful tool available to companies, organizations and consumers to reduce environmental load and to favour private and public economic
competition and improvement. As demonstrated for Italy, drinking tap water instead of PET-bottled mineral water is associated with environmental and economic benefits that are
far from negligible.
However, greater margins of life-cycle improvement can be expected in the BWthanTWsupply chain,
limiting the difference in CF between these substitute goods. Policy makers should seriously consider the role of substitute goods in reducing GHG emissions. Traditional ways
of decreasing the CF have concerned energy production, household efficiency and mobility management. Good results could also be achieved by modifying consumer habits, as our
results suggest in the case of drinking water. Voluntary carbon markets also offer an opportunity to make reduction of the CF pay in economic terms.