Table 1 Studies of carbon enrichment with grapevine using temperature growth chambers (GC), greenhouse (GH), temperature gradient greenhouses (TGG), open top chambers (OTC), and Free Air Carbon Enrichment (FACE) with significant findings are summarized here. The contrast in results for photosynthetic response is likely due to the duration of the studies and the material used (fruiting cuttings for the Salazar-Parra et al. [2015] study versus field grown vines for Wohlfahrt et al. [2017, 2018]). Photosynthesis (Anet) increased in response to elevated CO2 in all these studies. However, the downstream effect on phenology has unclear results, as the Edwards FACE studies (2016, 2017) showed a significant effect on the timing of veraison, while the more recent temperature gradient greenhouse study by Arrizabalaga-Arriazu et al. (2020) did not. Few studies document long-term effects on phenology, and there have been no studies in the United States using FACE.