The Truth Behind Rising Sea Levels and Global Warming
By Vijay Jayaraj
On January 3, 2020, 13 states in the U.S. joined Rhode Island in a lawsuit against oil companies for contributing to climate change and the dangers it poses.
The reason: They believe sea-level rise from climate change threatens their low-lying coastal regions.
An alarmist news site in Honolulu claims, “Warmer air temperatures are causing our oceans to thermally expand and glaciers around the world to melt. This combination leads to global sea level rise.”
However, the real-world situation differs dramatically from these hyped-up, sensationalist claims.
Manmade Global Warming: Not the Primary Driver of Sea-Level Rise
Doomsday proponents suggest that glacial melt induced by global warming can contribute significantly to the rise in sea levels. But a growing number of scientific studies (like this one in 2018) find that manmade global warming is not a primary driver of global sea-level rise.
The reason? Contrary to the media narrative, more factors than glacial melt drive sea-level rise.
Three major sets of natural factors control the rise and fall of sea levels: water temperature and salinity changes (steric), cryosphere/glacial changes (glacio-eustatic), and geological changes in continents and ocean basins (isostatic).
Despite multiple influences on sea levels, some alarmist narratives focus exclusively on glacial melt. Why? To make people panic about melting glaciers in the Arctic and Antarctic.
Moreover, sea-level doomsday reports seldom address sea-level rise in previous centuries and millennia. Avoiding that supports the alarmist narrative, as it portrays the current rise as new and unprecedented.
Sea-Level Rise: Higher and Faster in the Past
A 2014 scientific study did a comprehensive analysis of sea-level measurements from 1,277 tide gauge records since 1807 to estimate trends and acceleration in sea-level rise. In the 20th century, global sea-level rise displayed a linear trend of 1.9 ± 0.3 millimeters (mm) per year.
Sea levels have been much higher in the past and varies regionally.
Whoever has been feeding you false information on unprecedented sea-level rise needs to be redirected to research that documents not only higher sea levels in the past but also more rapid sea-level rise.
Long-term historical analysis of sea-level rise (from around 14,000 BC to the present) in Europe, Australia, Russia, Canada, Eurasia, China, India, Thailand, the Caribbean Islands, Bolivia, and various other places indicates that sea levels were much higher in the past than today.
During the early Holocene (11,719 to 7069 calibrated years before 2019) the sea level rose by 55 to 60 meters and the rate of sea-level rise was 11 to 12 mm/year. In Tahiti, the largest French Polynesian Island in the South Pacific, the sea-level rise was “11.7 mm/year for the period 8950-11,650 before 1950.”
Besides, scientific publications published in the 1980s, before the advent of the global-warming craze, reveal that “many parts of the world provide evidence of higher than present strand lines dating from the late Holocene.”
Is Future Sea-Level Rise a Threat to Islands?
In contrast to the early Holocene period, the global sea-level rise since 1958 has been just around 1.3 to 1.5 mm per year, much lower than the 20th-century average.
We cannot blindly assume that islands will get submerged by future sea-level rise of around 2 mm per year or 0.2 meters (m) per century.
Because even if sea levels around islands or along coastlines go up, the coastal regions may still remain unsubmerged, and might even grow in some cases, due to accretion, i.e., geological changes that increase elevation and extension of landmass by accumulation of sediments, growth of coral, or uplift of the landmass itself.
In order to evaluate the same, scientists conducted studies to analyze the impact of sea-level rise on the Pacific islands — like Tuvalu, Tokelau, and Kiribati — which are often projected by climate alarmists as the first victims of rising sea levels.
The study found out that even with a 0.5 meter and 1 meter rise in the sea level (much higher than the 0.2 meters observed during the entire 20th century), the islands remained unaffected.
The scientists attribute this adaptability to “physical changes in island structure, including both vertical adjustments that influenced island topography and planform movement.” The study concluded that the “islands have the capability to morphodynamically respond to rising sea level through island accretion.”
The impact of relative sea-level rise on any coast can only be discerned after considering the vertical crustal motion, and the accretion of sediments, in the coastal region. The assertions of these scientific studies can also be observed in some islands.
For example, in the Grande Glorieuse Islands, the landmass grew by 7.5 ha (1989–2003) despite an absolute sea-level rise around the island and a 28% erosion of shoreline.
So, it is evident from scientific literature that sea levels have not risen dramatically in the recent past; they have been much higher in the past; and the ongoing rise (and potentially faster ones) poses no problem to the islands and other landmass.
Sadly, the mainstream media and climate activists pay no attention to these peer-reviewed and universally accepted scientific facts about sea levels.
Vijay Jayaraj (M.Sc., Environmental Science, University of East Anglia, England), Research Contributor for the Cornwall Alliance for the Stewardship of Creation.