The Emergence of the Forced Response of Climate Change in the Altimeter Sea Level Record

R. Steven Nerem (University of Colorado, United States)


John Fasullo (NCAR, United States); Ben Hamlington (Jet Propulsion Laboratory, United States)

Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)

Session: Science I: Climate data records for understanding the causes of global and regional sea level variability and change

Presentation type: Type Forum

Multiple lines of evidence suggest that the impacts of anthropogenic climate change are now emerging from the 28-year satellite altimeter record of regional sea level change. These lines of evidence include both results from large climate model ensembles, where the forced response (FR) to greenhouse gases (GHG) and aerosols can be isolated from natural variability, as well as data analysis techniques that strive to separate natural variability from long-term changes using statistical approaches. The models reveal that the FRs from greenhouse gases and aerosols are spatially distinct, suggesting that future patterns may look different as GHG increase but aerosols are reduced. Data analysis techniques suggest the observed pattern does not change significantly when natural variability is removed, further supporting the results from the models that the FR has emerged. The models also suggest a path forward for using the observed sea level trends to predict what the future patterns of regional sea level change will look like under a range of possible climate emissions trajectories. Therefore, the satellite-observed pattern of sea level change has major potential applications in assessing future patterns of rise and guiding adaptation along the coasts.
R. Steven Nerem
University of Colorado
United States