Okay, so here are a few scholarly works on the subject:
http://www.sciencedirect.com/science/article/pii/S0022030291783823
Abstract: Raspberry, strawberry, peach, and root beer flavored milks were carbonated at subthreshold, low, and high carbonation levels with mean carbonation volumes of <.60, .74, and 1.42, respectively. The effect of carbonation on perceived aroma and flavor by mouth attributes was determined through evaluation by a trained panel. Panelists detected a significant difference in carbonation intensity between the high carbonation level and the subthreshold and low carbonation levels. Carbonation significantly suppressed cooked milk aroma and flavor by mouth at the low and high carbonation levels, but CO2 significantly enhanced sourness and astringency at the high carbonation level. Chalkiness and bitterness were rated significantly higher at the high carbonation level than at the low or subthreshold levels.
http://chemse.oxfordjournals.org/content/23/4/397.short
Abstract: Previous studies of the effect of carbonation on taste perception have suggested that it may be negligible, manifesting primarily in increases in the perceived intensity of weak salt and sour stimuli. Assuming CO2 solutions in the mouth stimulate only trigeminal nerve endings, this result is not altogether surprising; however, there are neurophysiological data indicating that CO2 stimulates gustatory as well as trigeminal fibers. In that case, carbonation might alter the quality profile of a stimulus without producing substantial changes in overall taste intensitymuch as occurs when qualitatively different taste stimuli are mixed. To address this possibility, subjects were asked to rate the total taste intensity of moderate concentrations of stimuli representing each of the basic tastes and their binary combinations, with and without added carbonation. They then subdivided total taste intensity into the proportions of sweetness, saltiness, sourness, bitterness and other taste qualities they perceived. The addition of carbonation produced only small increases in ratings of total taste intensity. However, rather dramatic alterations in the quality profiles of stimuli were observed, particularly for sweet and salty tastes. The nature of the interaction is consistent with a direct effect of carbonation/CO2 on the gustatory system, although the possibility that at least some of the observed effects reflect trigeminal-gustatory interactions cannot be ruled Out.
http://www.sciencemag.org/content/326/5951/443.short
Abstract: Carbonated beverages are commonly available and immensely popular, but little is known about the cellular and molecular mechanisms underlying the perception of carbonation in the mouth. In mammals, carbonation elicits both somatosensory and chemosensory responses, including activation of taste neurons. We have identified the cellular and molecular substrates for the taste of carbonation. By targeted genetic ablation and the silencing of synapses in defined populations of taste receptor cells, we demonstrated that the sour-sensing cells act as the taste sensors for carbonation, and showed that carbonic anhydrase 4, a glycosylphosphatidylinositol-anchored enzyme, functions as the principal CO2 taste sensor. Together, these studies reveal the basis of the taste of carbonation as well as the contribution of taste cells in the orosensory response to CO2.