Broken Altimetry? 225 Tide Gauges Show Sea Level Rising Only 1.48 mm Per Year …Less Than Half The Satellite-Claimed Rate!

Dave Burton of site here deserves widespread, world-wide exposure.

Hat-tip: Kenneth Richard

The site allows user-friendly observation of sea level rise trends at locations across the world using spreadsheet data direct from NOAA and PSMSL, as it is designed to be similar to Paul Clark’s popular interactive temperature graph site (

Sea levels rising less than half as fast, no acceleration!

Stunningly, contrary to the claims of the modeled reconstructions of sea level rise (with “adjustments” added), actual physical measurements indicate that sea levels are rising at rates well less than half the claimed rates when including GIA “adjustments” and satellite altimetry modeled reconstructions.

The best estimate is a median global mean sea level value of 1.48 mm/yr, or less than 6 inches per century. is a one-stop source for sea-level information. The spreadsheets consolidate data from NOAA, PSMSL and other sources, to simplify examination of tide-gauge data for long term sea-level trend analysis.

The site writes:

One interesting observation is that GIA (PGR) adjustments are often nearly as large as the averaged actual measured sea-level trends! The average of the measured trends for NOAA’s 2012 set of 239 tide gauges is 1.017 mm/year (median 1.280), but the GIA adjustments add an average of 0.665 mm/year, giving a total “adjusted” average trend of 1.682 mm/year, which rounds to 1.7 mm/year, which happens to exactly equal a very widely-quoted figure for 20th century sea-level rise.”

The site here also writes that sea level is not rising everywhere, and:

The measured rate of coastal sea-level change varies from -17.59 mm/yr at Skagway, Alaska to +9.39 mm/yr at Kushiro, Japan. The average, as measured by the world’s best long-term coastal tide gauges, is just under +1.5 mm/yr (about 6 inches per century).”

Satellite altimetry wonders about the often ballyhooed figures of 3.3 mm/yr (13 inches per century), based on satellite altimetry measurements of sea-level, rather than coastal sea-level measured by tide gauges. It writes that satellite altimeters “measure the wrong thing”:

Their measurements are distorted by “sea-level rise” caused by thermal expansion when the upper layer of the ocean warms. But that is a strictly local effect, that doesn’t affect the quantity of water in the oceans, and doesn’t affect sea-level elsewhere (e.g., at the coasts).  Sea-level rise only matters at the coasts, but satellite altimeters are incapable of measuring sea-level at the coasts. They can only measure sea-level in the open ocean. Tide gauges measure sea-level at the coasts, where it matters. Also, tide gauge measurements of sea-level are much higher quality than satellite altimetry measurements. adds that “satellite measurements of sea-level are of questionable reliability, and vary considerably from one satellite to another” and that tide gauges are more reliable because “some of the tide-gauge records of sea-level measurements are nearly ten times as long as the combined satellite measurement record, and twenty times as long as any single satellite measurement record.”

According to, the NOAA has done linear regression analysis on sea-level measurements (relative sea-level) from 225 long term tide gauges around the world, and found that “there’s been no sign of any acceleration (increase in rate) in most of those tide-gauge records, in over three-quarters of a century.”

The site summarizes:

The rate of measured sea-level rise (SLR) varies from -17.59 mm/yr at Skagway, Alaska, to +9.39 mm/yr at Kushiro, Japan. 197 of 225 stations (87.6%) have recorded less than 3.3 mm/yr sea-level rise. At 47 of 225 stations (20.9%) sea level is falling, rather than rising. Just 28 of 225 stations (12.4%) have recorded more than 3.3 mm/yr sea-level rise. The average SLR at those 225 gauges is +0.90 mm/yr. The median is +1.41 mm/yr.

MSL = 1.48 mm/yr


10 responses to “Broken Altimetry? 225 Tide Gauges Show Sea Level Rising Only 1.48 mm Per Year …Less Than Half The Satellite-Claimed Rate!”

  1. handjive

    In Australia we have the Lempriere/Ross mark , an Ordnance Survey Bench Mark engraved into a rock face on a little island near Port Arthur, Tasmania.

    It is the oldest known sea level mark.

    It was put there in 1841 by the famous Antarctic explorer Captain Sir James Clark Ross and amateur meteorologist Thomas Lempriere to mark mean sea level.

    “Ross put it in an ideal location which is both geologically stable and open to the vast Southern ocean, with no local estuary effects to distort the tides.”

    “In April 1842, he (distinguished naval officer and polar explorer James Clark Ross) stopped at Port Louis, primarily to make magnetic field and other measurements, but also to make repairs to his ships which had been badly damaged in the Drake Passage.
    Having set up a winter base, he took the opportunity to make careful measurements of sea level relative to two benchmarks cut into the cliffs and marked with brass plaques.

    These marks remain in good condition to this day.”

    The late, great John Daly explains:

  2. Colorado Wellington

    Dave Burton’s site is indispensable to anyone interested in what’s really happening with sea levels around the world.

  3. Josef Boberg

    I myself am inside track to the CO2 issue is a pure bluff – as the 13 global oligarchs = Finance families /hardtruth/the_satanic_bloodlines.htm – that have misguided the world economic = policy for more than 100 years – earn very much with money on.

    1. David Appell

      Decipher — what is it you are actually trying to say?

      1. Josef Boberg

        The CO2 issue is a scam.

  4. tomwys

    The last two items on the “Colderside” media page squarely address Sea-Level in “Tectonically Inert” places around the Globe:

    The following is also intended for the “Level-Headed”among us:

    /Users/Tom/Library/Containers/ Downloads/51E24310-3FE7-44DB-AA7C-0340546AAB33/PastedGraphic-1.pdf

  5. tomwys

    The “pasted” graphic didn’t make it. It showed Portland Maine’s Tide Gauge slowly increasing about 4 inches per century with sea-level in 2015 identical to the millimeter to that in 1912 all during a massive acceleration of CO2, whose signal is nowhere to be found in Sea-Level Rise.

  6. pattcap

    1.4mm, and what is the Standard Deviation?
    Does that account for the 18 year lunar cycle?

    Is that when the wind is blowing east or west?
    Is that on the East coast or the West Coast?
    Is that at the same time of day?

    Does it account for shifts in the Jet Stream… driven Pacific Oscillation?

    Is that 1.4mm at High tide or low tide?
    In Savannah Ga. there is a 9 Foot tidal change, That is 3000mm. It is difficult to argue 1.4mm is statistically relevant there.

    Call me skeptic, climate denier, or realist.
    Anyone can Hype a “Claim” regardless of how ridiculous the shear notion of it is.

    After a lot of rain, when the global atmosphere is dry, it should be higher. If it doesn’t rain and humidity is high, it should be lower.
    Undergrown water in CA is historically low and there is no snow pack in the mountains.
    I know it is more complicated than that, but that is in fact the point.

    But it sure is scary to project a trend out into eternity.
    Which of course is a great way to get funding 🙂

  7. AndyG55

    If you look at NOAA’s sea level trend maps

    You will see that off Sydney, NSW, Australia, the colour indicates 4-6mm/year..

    The tide gauge in Sydney Harbour has a trend of 0.65mm/year.

    Being out by a FACTOR of only 6 to 10 times the real trend.. seems about par for NOAA.

  8. SMS

    Isostatic rebound changes affect sea level, aquifer depletion affects sea level, water impoundment affects sea level and lakes drying up affect sea level, El Ninos/La Ninas affect sea levels etc….

    The University of Colorado attempts to measure sea level change to millimeters with a satellite that has a resolution of 2 cm. And then the University makes adjustments claiming that the bottom of our oceans are dropping.

    Nearly thirty years following James Hansens mumble that sea levels could rise to claim New York City; nothing of consequence has taken place and people are still buying beach front property around the world at a premium.

    Keeping track of what is happening with sea level changes has proven to be very difficult but I think the best conclusion that anyone can come to is that there just isn’t that much happening.

    There are no all-encompassing quality sea level studies that can justify any claim of accelerated sea level rise.

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