Four New Papers: Anthropogenic Signal Not Detectable in Sea Level Rise

sea_ocean_shoreIt is widely assumed that sea levels have been rising in recent decades largely in response to anthropogenic global warming. However, due to the inherently large contribution of natural oscillatory influences on sea level fluctuations, this assumption lacks substantiation. Instead, natural factors or internal variability override the detection of an anthropogenic signal and may instead largely explain the patterns in sea level rise in large regions of the global oceans.

Scientists who have recently attempted to detect an anthropogenic signal in regional sea level rise trends have had to admit that there is “no observable sea-level effect of anthropogenic global warming,” or that the “sea level rise pattern does not correspond to externally forced anthropogenic sea level signal,” and that sea level “trends are still within the range of long-term internal decadal variability.”

Below are highlighted summaries from 4 peer-reviewed scientific papers published within the last few months.

1. Hansen et al., 2016

For the convenience of the readers, our basic results are shown in Figure 1. We identified five individual oscillations (upper panel), including a sea-level amplitude of 70 mm (top–bottom [t-b]) of the 18.6-year oscillation caused by the lunar nodal oscillation (LNO) … Together with a general sea-level rise of 1.18 mm/y, the sum of these five sea-level oscillations constitutes a reconstructed or theoretical sea-level curve of the eastern North Sea to the central Baltic Sea (Figure 1, lower panel), which correlates very well with the observed sea-level changes of the 160-year period (1849–2009), from which 26 long tide gauge time series are available from the eastern North Sea to the central Baltic Sea.  Such identification of oscillators and general trends over 160 years would be of great importance for distinguishing long-term, natural developments from possible, more recent anthropogenic sea-level changes. However, we found that a possible candidate for such anthropogenic development, i.e. the large sea-level rise after 1970, is completely contained by the found small residuals, long-term oscillators, and general trend. Thus, we found that there is (yet) no observable sea-level effect of anthropogenic global warming in the world’s best recorded region.

2. Palanisamy, 2016

Building up on the relationship between thermocline and sea level in the tropical region, we show that most of the observed sea level spatial trend pattern in the tropical Pacific can be explained by the wind driven vertical thermocline movement. By performing detection and attribution study on sea level spatial trend patterns in the tropical Pacific and attempting to eliminate signal corresponding to the main internal climate mode, we further show that the remaining residual sea level trend pattern does not correspond to externally forced anthropogenic sea level signal. In addition, we also suggest that satellite altimetry measurement may not still be accurate enough to detect the anthropogenic signal in the 20-year tropical Pacific sea level trends.

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    Charles Higley


    There was a paper out recently that described the observation that sea waterpassing through a reef is actually decreased in pH by the metabolic products of the coral population. [I imagine this was describing night-time effects.] The reef itself acidifies, somewhat, the seawater.

    Also, photosynthesis is an alkalizing process such that the pH in bays or estuaries can rise 1–2 pH units during the course of a sunny day and active photosynthesis. Clearly this does not hurt these organisms as they evolved doing this routine.

    One aspect of the ocean acidification issue that is most often totally ignored is that marine organisms are not directly subject to the seawater pH as they are living and have physiological control of their internal pH. They can carry on in the face of pH changes.

    It should be noted here that carbonic acid produced by dissolution of CO2 into seawater is a weak acid and is not capable of significantly affecting the complex buffer that comprises seawater. Also, as there is an extended equilibrium from CO2 to carbonic acid to bicarbonate to carbonate to calcium carbonate, the protons released by this equilibrium cannot affect themselves. Only an outside source of protons, such as from a bolus of hydrochloric acid, can shift the equilibrium (toward carbonic acid and CO2 release).

    As the warm waters of the tropics are essentially saturated with calcium ions, this is a healthy equilibrium and the addition of more CO2 simply pushes the whole thing toward more calcium carbonate precipitation, completely irregardless of the protons released in this equilibrium. More CO2 more precipitation of calcium carbonate, and more concretion formation of the reefs. This is a win-win situation. The wonderfully tall cliffs of Dover were created during a time when CO2 was many times higher than now—very impressive.


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