Structure I (sI) carbon dioxide (CO2) hydrate exhibits markedly different dissociation behavior from sI methane (CH4) hydrate in experiments in which equilibrated samples at 0.1 MPa are heated isobarically at 13 K/h from 210 K through the H2O melting point (273.15 K). The CO2 hydrate samples release only about 3% of their gas content up to temperatures of 240 K, which is 22 K above the hydrate phase boundary. Up to 20% is released by 270 K, and the remaining CO2 is released at 271.0 ± 0.5 K, where the sample temperature is buffered until hydrate dissociation ceases. This reproducible buffering temperature for the dissociation reaction CO2·nH2O = CO2(g) + nH2O(l to s) is measurably distinct from the pure H2O melting point at 273.15 K, which is reached as gas evolution ceases. In contrast, when sI CH4 hydrate is heated at the same rate at 0.1 MPa, >95% of the gas is released within 25 K of the equilibrium temperature (193 K at 0.1 MPa). In conjunction with the dissociation study, a method for efficient and ...