Fig. 18

Effect of methane release with a δ13C of − 60‰ over 10 kyr on the δ13C value of present-day preindustrial carbon reservoirs. a Response of δ13C in deep water of the Atlantic, Indian, and Pacific Oceans. Initial values are 0.996‰, 0.620‰, and − 0.508‰, respectively. b Response of δ13C in warm surface water, cold surface water, and the atmosphere (shifted by + 8‰). Initial values are 2.577‰, 1.355‰, and − 6.367‰, respectively (modified from Dickens et al. 2017)