A recent study by Xiong et al titled Holocene sea-level history of the northern coast of South China Sea tells us that sea level rise today is total within the range of natural variability.
The scientists collected and analyzed seven sediment cores from the Pearl River delta, from which they generated 16 new and high-quality sea-level index points.
The paper’s abstract writes that the study “re-checked and re-calibrated the previously published sea-level data from China’s southeast coast with corrections made for tectonic subsidence and sediment compaction factors.”
The results, the authors report:
These sea-level data indicate a rise of relative sea level from −49.3 ± 0.8 m to the present height between 10,500 and 7000 cal. a BP. This sea-level history is similar to those recorded from other far-field locations and ice-volume equivalent sea-level models. The early to early-middle Holocene sea-level history in the study area shows a phase of accelerated rise at a rate increasing rapidly from 16.4 ± 6.1 mm/a at 10,500 cal. a BP to 33.0 ± 7.1 mm/a at 9500 cal. a BP. This phase was followed by a period of rapid decrease in the rate of sea-level rise to 8.8 ± 1.9 mm/a at 8500 cal. a BP and 1.7 ± 1.3 mm/a at 7500 cal. a BP. During the past 7000 years, the relative sea level in the study area changed very little. This new and complete history of Holocene sea-level change supports the following findings: (1) no obvious higher-than-present sea-level highstand in the Holocene is found from the northern South China Sea; (2) certain proportion of the effects of the predicted glacial isostatic adjustment were cancelled out by the effects of the weak upper mantle viscosity in the study area; (3) meltwater pulse 1b likely exists spanning into the early Holocene; (4) there are significant misfit between sea-level data and glacial isostatic adjustment models, and a revision to the existing ice melting history for the early Holocene is possibly needed.”
Overall the study finds: “The rate of relative sea-level rise had varied and peaked at 33.0 ± 7.1 mm/a around 9500 cal. a BP.”
When comparing today’s current sea level rise of just 2 mm/yr as measured from a vast array of tide gauges worldwide, we get the sense that this is puny in comparison to the changes the earth experienced over the Holocene (the past 10,000 years).
Sea levels were higher than today when CO2 was much lower
Also read here how 75 recent scientific publications show sea levels were 2 meters higher than they are today, even though CO2 in the atmosphere was much less at 265 ppm.
via NoTricksZone
October 2, 2018 at 08:53AM
