The rate of sea-level rise in the northern Gulf of Mexico has accelerated from a pre-industrial average rate of approximately 0.4 millimeters per year to a current rate of at least 2.0 millimeters per year, according to the newly formed Gulf Coastal Science Consortium (GCSC) at Rice University. In a new workshop report, the consortium attributed this fivefold increase to thermal expansion and glacial melting with strong scientific consensus.
The consortium is currently composed of academic scientists whose research and publications focus on the response of modern Gulf Coast environments to global change.
“Subsidence is highly variable across the Gulf Coast, but there are areas where current subsidence rates far exceed the long-term background rates,” said workshop report authors John Anderson, professor of Earth science at Rice University, Torbjörn Törnqvist of Tulane University and John Day of Louisiana State University.
The group indicated that human impact, particularly extraction of fluid from the subsurface level, has led to a combined and increased relative sea-level rise (eustatic rise and subsidence). This movement has worsened, due to loss of sediment supply along the coast. The erosion is a result of changes in climate and human impact to the coastal rivers and shorelines. Hurricanes worsen these impacts, and the scientific consensus is that the intensity of severe storms will increase.
In addition, workshop participants identified four areas where research on this matter is needed:
- The acquisition of more prehistoric hurricane records from sedimentary archives. This information is needed to test numerical models for predicting changes in the frequency and magnitudes of hurricanes in response to global warming.
- The influence of ocean circulation on sea level.
- The river response to climate variability and the manner in which variations in sediment supply influence coastal systems.
- More case studies that can be used to demonstrate the current response of coastal environments to accelerated global change.
The workshop was funded by the Shell Center for Sustainability at Rice University. More information about the Gulf Coastal Science Consortium and its current members is available at https://shellcenter.rice.edu/Content.aspx?id=2147483959. The complete workshop report can be viewed at https://shellcenter.rice.edu/uploadedFiles/Shell_Center/Gulf_Coast_Science_Consortium/GCSC%20EOS-2012.pdf.