To protect against rising sea levels in a warming world, coastal cities typically follow a standard playbook with various protective infrastructure options. For example, a seawall could be designed based on the latest climate projections, with the city officials then computing its cost-benefit ratio and proceeding to build, accordingly.
The problem? Future climate conditions might differ substantially from the used projections, according to Ashmita Bhattacharya, a civil engineering doctoral student at Penn State and first author of a study published in Nature Communications by an interdisciplinary team of researchers from Penn State and the University of Pittsburgh. Communities risk either overbuilding too much costly infrastructure - the construction and maintenance of which also contribute excess carbon dioxide into the atmosphere, further exacerbating the rate of climate change - or designing inadequate defenses. This can lead to excessive flood-related damages and even more costly repairs.
"The issue with the current state of practice in climate adaptation is the large uncertainty associated with how the climate demands evolve in the future," said Chris Forest, professor of climate dynamics in the Department of Meteorology and Atmospheric Science at Penn State and co-investigator of the study. Global temperatures shattered records quicker than expected in 2023 and again in 2024.
To help communities avoid making a misinformed, potentially expensive investment, with no ability to re-allocate spent resources if future conditions are not what was expected, the team created a model that provides decision support over time as more information becomes available, while keeping costs as low as possible, according to Gordon Warn, professor in the Department of Civil and Environmental Engineering at Penn State and co-corresponding author.
"Our approach suggests dynamic actions in time, responding to the actual evolving climate, while also considering possible future scenarios in an optimal sense," Warn said.
