Massachusetts drought cut marsh methane emissions by 83% but recovery is slow

A 2022 drought in Massachusetts pushed seawater into a coastal freshwater marsh, causing methane emissions to drop by 83%. The study, published after the event, shows that the marsh had not fully recovered more than a year later, even after normal rainfall returned. This suggests that extreme weather can have lasting effects on blue carbon ecosystems, which are usually seen as stable carbon sinks. For carbon markets and climate policy, this is a reminder that natural carbon sinks are not static. A drought or storm can flip a wetland from a methane source to a lower emitter, but the ecological damage may persist. Anyone relying on wetland carbon credits should pay attention to how quickly these systems can change under stress and how slow recovery can be.