<
https://www.theguardian.com/environment/2026/mar/04/global-sea-levels-underestimated-poor-modelling-research>
"Sea levels around the world have been underestimated due to inaccurate
modelling, with research suggesting ocean levels are far higher than previously
understood.
The finding could significantly affect assessments of the future impacts of
global heating and the effects on coastal settlements.
Globally, the research found ocean levels are an average of 30cm higher than
previously believed, but in some areas of the global south, including
south-east Asia and the Indo-Pacific, they may be 100-150cm higher than
previously thought.
Rising sea levels are a major threat to coastal communities across the world,
and the UN Intergovernmental Panel on Climate Change (IPCC) estimates that by
2100 levels may rise by 28-100cm.
The latest research, published in
Nature, combined the analysis of 385 pieces
of peer-reviewed scientific literature released between 2009 and 2025 with
calculations of the difference between the commonly assumed and actual measured
coastal sea levels.
Authors Dr Philip Minderhoud of Wageningen University in the Netherlands and
PhD researcher Katharina Seeger discovered that more than 90% of these studies
did not use local, direct measurements of sea levels but instead used land
elevation measurements referenced against global geoid models.
Geoid models provide an estimate of global sea levels based on the Earth’s
gravity and rotation.
As a consequence, sea levels were undervalued by an average of 24-27cm,
depending on the geoid model used, with some discrepancies as much as
550-760cm.
Minderhoud said: “In reality, sea level is influenced by additional factors
such as winds, ocean currents, seawater temperature and salinity.”
The new calculations reveal that following a relative sea level rise of 1
metre, it is estimated that 37% more coastal areas will fall below sea level,
affecting up to 132 million individuals.
“If sea level is higher for your particular island or coastal city than was
previously assumed, the impacts from sea level rise will happen sooner than
projected before,” said Minderhoud."
Via Susan ****
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
