May 19, 2018

Island Cropping; Win Some, Lose Some in the Sea Level Rise Game

Timothy Birdnow

If sea levels are rising so dramatically, why are we not seeing disappearing atolls in the Pacific?

That is the big question and I've dealt with it going way back. If I may quote myself from my 2010 Canada Free Press article:

"Of course, there is one catch; your islands actually have to be getting smaller. Sea level rise is immaterial if the, uh, sea level isn’t rising. If you have the same amount of real estate as in bygone years your claim is pathetically slim.

Many of those small islands are actually growing! According to this piece in New Scientist

"For years, people have warned that the smallest nations on the planet - island states that barely rise out of the ocean - face being wiped off the map by rising sea levels. Now the first analysis of the data broadly suggests the opposite: most have remained stable over the last 60 years, while some have even grown.

Paul Kench at the University of Auckland in New Zealand and Arthur Webb at the South Pacific Applied Geoscience Commission in Fiji used historical aerial photos and high-resolution satellite images to study changes in the land surface of 27 Pacific islands over the last 60 years. During that time, local sea levels have risen by 120 millimeters, or 2 millimeters per year on average.

Despite this, Kench and Webb found that just four islands have diminished in size since the 1950s. The area of the remaining 23 has either stayed the same or grown (Global and Planetary Change, DOI: 10.1016/j.gloplacha.2007.11.001).”

End excerpt.

And indeed, the actions of wind and waves and geological activity largely explain erosion of these islands, which are generally made up for in island growth elsewhere (although that's cold comfort to those who lose their homes.)

Well, back in 2016 the Empire struck back with this paper noting the complete disappearance of islands in the Solomon group. (Actually I'm being a bit unfair as the paper was far milder in it's claims that human-caused climate change is the primary driving force, but the paper certainly did avoid the obvious conclusion.)

Here are a few excerpts from the Paper:

Interactions between sea-level rise and wave exposure on reef island dynamics in the Solomon Islands

Simon Albert1, Javier X Leon1,2, Alistair R Grinham1, John A Church3, Badin R Gibbes1 and Colin D Woodroffe4

Published 6 May 2016 • © 2016 IOP Publishing Ltd

El Niño/Southern Oscillation events result in significant interannual variations in sea level in the western equatorial Pacific (Barnard et al 2015) (including the Solomon Islands, figure 6) superimposed on the longer term (multi-decadal) sea-level trends of up to 3 mm yr−1 (Church et al 2006, Becker et al 2012). Merrifield et al (2012) used tide gauge data to demonstrate that the rate of western equatorial Pacific sea-level rise increased significantly from relatively low values over the 1950–1990 period to much larger values since 1990.While there is significant interannual variability, the tide gauge and altimeter data indicate a rapid rise in sea levels in the Solomon Islands between 1994 and 2014 of about 15 cm (average of 7 mm yr−1). Projected sea-levels for the Solomon Islands indicate a rise of 24–89 cm between 1996 and 2090, dependent on future greenhouse gas emissions (Australian Bureau of Meteorology and CSIRO 2014) (figure 6). The higher local rate of historical rise is the result of both a larger global averaged rate of sea-level rise (Church and White 2011) and also stronger trade winds since 1990 (Merrifield and Maltrud 2011) which are directly related to the decreasing Pacific Decadal Oscillation index (Zhang and Church 2012). These PDO and ENSO conditions may ease in the Solomon Islands in coming decades to produce sea-level rise rates closer to the global average. However, as eustatic rates of sea-level rise increase over the course of this century we can expect that many areas will experience sea-level rise rates similar to or larger than the 7 mm yr−1 recently observed in the Solomon Islands for all but the very lowest emission scenarios. Local inter-decadal variability and tectonic movements will be superimposed on these higher rates of global mean sea level, resulting in periods when local rates of rise will be substantially larger than that observed over the last two decades. Therefore, we see the current conditions in the Solomon Islands as providing insight into the future impacts of accelerated sea-level rise.

Relative sea-level rise can also be the result of tectonics, the Solomon Islands are in a particularly tectonically active part of the globe with the convergence of the Pacific Plate, Solomon Arc block and Australian Plate causing localised crustal deformations (Tregoning et al 1998) manifesting as either island subsidence or uplift (Taylor et al 2008). Whilst the Isabel study site is considered to be in a more tectonically benign area, without active volcanoes, the Roviana site experienced an 8.1 megathrust earthquake in 2007 which led to the reef islands of Roviana subsiding by up to 60 cm (Taylor et al 2008). Island subsidence can compound sea-level rise rates and make these tectonically active islands particularly vulnerable under accelerated sea-level rise scenarios. However, the apparent resilience of islands in Roviana to subsidence, despite observed increases in coral cover on adjacent reefs attributed to deeper water (Saunders et al 2015), and only 1 (±1.4) mm yr−1 of vertical tectonic uplift measured in Honiara since 2008 (Jia et al 2015), suggests subsidence is not the primary driver of coastal erosion observed in this study.

End excerpts.

So, the authors dance around the issue, paying lip service to Global Warming alarmism while admitting that there are numerous other factors in play. But in the modern era a scientist must pay lip service or be shut out of the peer reviewed literature. That is a must, because the Alarmists have largely colonized the editorships of most peer review journals and it only takes one reader to spike an article. In academia it is publish or perish, and if you spent years becoming a climatologist or whatnot you aren't going to dare buck the Establishment.

Ask my brother, who labors in obscurity because he did.

Well, at any rate, a recent paper, well, doesn't overturn the findings of the ballyhooed paper by Alberti et. Al. but it makes the case that there is actually more island growth, at least in French Polynesia.

(Download the PDF of the paper here.

Here is the abstract:

Drivers of shoreline change in atoll reef islands of the Tuamotu Archipelago, French Polynesia
Duvat, Virginie K. E.; Salvat, Bernard; Salmon, Camille
Global and Planetary Change, Volume 158, p. 134-154.

This paper increases by around 30% the sample of atoll reef islands studied from a shoreline change perspective, and covers an under-studied geographical area, i.e. the French Tuamotu Archipelago. It brings new irrefutable evidences on the persistence of reef islands over the last decades, as 77% of the 111 study islands exhibited areal stability while 15% and 8% showed expansion and contraction, respectively. This paper also addresses a key research gap by interpreting the major local drivers controlling recent shoreline and island change, i.e. tropical cyclones and seasonal swells, sediment supply by coral reefs and human activities. The 1983 tropical cyclones had contrasting impacts, depending on the shoreline indicator considered. While they generally caused a marked retreat of the stability line, the base of the beach advanced at some locations, as a result of either sediment reworking or fresh sediment inputs. The post-cyclone fair weather period was characterised by reversed trends indicating island morphological readjustment. Cyclonic waves contributed to island upwards growth, which reached up to 1 m in places, through the transfer of sediments up onto the island surface. However, the steep outer slopes of atolls limited sediment transfers to the reef flat and island system. We found that 57% of the study islands are disturbed by human activities, including 'rural' and uninhabited islands. Twenty-six percent of these islands have lost the capacity to respond to ocean-climate related pressures, including the 'capital' islands concentrating atolls' population, infrastructures and economic activities, which is preoccupying under climate change.

End abstract.

CO2 Science has a nice review of the paper by the French scientists.

According to the article:

"As noted by the researchers, their findings bring "new irrefutable evidences on the persistence of reef islands over the last decades." Over the past three to five decades, the total net land area of the studied atolls "was found to be stable, with 77% of the sample islands maintaining their area, while 15% expanded and 8% contracted." Furthermore, they note that 7 out of the 8 islands that decreased in area were very small in area (less than 3 hectares), whereas "all of the 16 islands larger than 50 hectares were stable in area."

End excerpt.

Now, bear in mind French Polynesia is a different place than the Marshalls, but it shows that there is some growth and some loss occuring.

I would like to point out that islands come and go. In the Mississippi River, for example, there were several Civil War battles fought on now non-existent islands. Granted, those are in a sediment-filled river and not the deep ocean, but these atoll type islands are generally in shallow, reef areas and subject to sedimentation (and erosion).

Many Pacific island cultures practice slash and burn agriculture, which often leads to soil erosion and dissipation of land area.

With the world coming out of the Little Ice Age (and likely entering a new one, or at least a Dalton Minimum type period at least) we witness increased sea levels anyway, and with that changes in isostatic pressure leading to changes in sea levels in volcanic areas. And the is an important point; the sea level isn't so much rising over the islands that are sinking as the sea floor is lowering, dropping the islands down. (After all, we have had no planetary warming in 22 years and ice caps are growing at both poles.) The recent eruption of Hawaii's Kilauea volcano suggests the Pacific Ring of Fire is more active than in the past. And more volcanoes in the region are threatening.

And recent research shows the El-Nino Southern Oscillation (ENSO) which is important in regards to weathering of islands was unusually active during the late 20th century.

By the way, Here is a list of ten new islands formed in the last few years.

So what do we take from this? Changes in solar activity, magnetic effects (the Earth's magnetic field has weakened considerably), and like Milankovitch Cycles - changes in the movement and wobble of the Earth - are probably at the core of this. There have been numerous attempts to explain all of this based on Global Warming theory, but that claim is very weak, especially since we aren't seeing any real heating of the planet. The Sun is in a very dormant period and we know that will influence weather patterns. And when weather patterns change it means changes to coastal regions - and islands are about as coastal as you can get.

In the end, this is a matter of win some/lose some. A few islands have gone, and a few more have come. But what does it say about the climate change hysteria?

The more time passes the less the climate change predictions pan out.

Posted by: Timothy Birdnow at 10:25 AM | No Comments | Add Comment
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