Real-world time-travel experiment shows ecosystem collapse due to anthropogenic climate change

Guandong Li; Torbjörn E Törnqvist; Sönke Dangendorf

doi:10.1038/s41467-024-45487-6

Real-world time-travel experiment shows ecosystem collapse due to anthropogenic climate change

Nat Commun. 2024 Feb 15;15(1):1226. doi: 10.1038/s41467-024-45487-6.

Authors

Guandong Li¹, Torbjörn E Törnqvist², Sönke Dangendorf³

Affiliations

¹ Department of Earth and Environmental Sciences, Tulane University, 6823 St. Charles Avenue, New Orleans, LA, 70118-5698, USA. gli4@tulane.edu.
² Department of Earth and Environmental Sciences, Tulane University, 6823 St. Charles Avenue, New Orleans, LA, 70118-5698, USA.
³ Department of River-Coastal Science and Engineering, Tulane University, 6823 St. Charles Avenue, New Orleans, LA, 70118-5698, USA.

Abstract

Predicting climate impacts is challenging and has to date relied on indirect methods, notably modeling. Here we examine coastal ecosystem change during 13 years of unusually rapid, albeit likely temporary, sea-level rise ( > 10 mm yr^-1) in the Gulf of Mexico. Such rates, which may become a persistent feature in the future due to anthropogenic climate change, drove rising water levels of similar magnitude in Louisiana's coastal wetlands. Measurements of surface-elevation change at 253 monitoring sites show that 87% of these sites are unable to keep up with rising water levels. We find no evidence for enhanced wetland elevation gain through ecogeomorphic feedbacks, where more frequent inundation would lead to enhanced biomass accumulation that could counterbalance rising water levels. We attribute this to the exceptionally rapid sea-level rise during this time period. Under the current climate trajectory (SSP2-4.5), drowning of ~75% of Louisiana's coastal wetlands is a plausible outcome by 2070.