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Sea level rise hysteria can be cured by looking at tide gauge data

Scaremonger photos of inundation abound in our national news this week. Famous foreshore parks are gone, islands disappear, houses, picnic areas, racecourses, golf courses — all submerged. The water rolls in over Sydney’s Circular Quay, Melbourne’s Docklands, Brisbane Airport, Hindmarsh Island — swamped. Rooned. Today its the satellite photo, tomorrow it’ll be computer generated streetscapes; coming soon, the underwater documentary: Swimming in the Opera House.

Sea level rise, Perth, Fremantle, Australia.

This is a mocked up satellite pic of Perth, WA projecting how much ground we will lose.

If you live in these future washed out zones, email me. I’ll buy your house.

Compare the forecast two metre rise, to actual Tide Gauge Data for Fremantle since 1900 (Fremantle has the second longest record of sea level change in the Southern Hemisphere):

Sea Level rise Fremantle, Perth, Australia.

Sea Level rise Fremantle, Perth, Australia shows about a 20cm rise in 110 years.

So there has been a 20cm rise or so in 100 years. But 200cm is coming. Yeah.  (For details of the way Sea Levels around Perth Coastline change see Chris Gillhams work.)

This slow rate of sea level rise is not just a west coast thing: Sydney’s sea levels are rising at just 6.5cm per century.

The model projections future rate of change is off the scale.

Here’s that current Fremantle trend with a projected 2 metre rise to 2100 added in:

Mean Sea Level, Fremantle, Model Projections, 2100.

A 20cm rise in one hundred years is 2mm per annum. If the forecasts are right that rate must rise immediately to 22mm pa, a tenfold increase.

As it happens, the tide gauge is sinking 2 – 4mm each year (20 -40cm a century).

PARTS of Perth are sinking because too much water is being extracted from the Perth Basin, making those areas more vulnerable to sea level rises.

Professor Will Featherstone said the gauge was sinking at about 2-4mm a year due to groundwater being extracted at a faster rate than it can be replenished, causing the land to subside.

Naturally Featherstone goes on to put in the politically correct caveat, which allows his inconvenient research to be published, but if taken literally, makes no sense at all.

“If the land is subsiding, then the rate of sea level rise measured by a tide gauge appears to be larger than it actually is, which seems to be the case at Fremantle,” he said.

“However this doesn’t mean that we are at a decreased risk of sea level rise, instead we could be at an increased risk, because the land itself is sinking.”

Obviously if the seas were rising due to CO2 then subsidence is “extra-bad”. But if most of the rise so far is due to something else, who cares, the cause and effect link is busted, no disaster is coming?

The big unasked question above: Do CO2 emissions cause Fremantle to sink?

If CO2 emissions are not pushing the port of Fremantle down into the crustal plate then most of the sea-level rise recorded at Fremantle has nothing to do with our emissions. Ergo, reducing or increasing emissions will not cause sea-level rise, nor prevent it, and the forecasts of a 2,000mm rise in the next 90 years are hyperbolic guesstimates based on skill-less models and should be treated accordingly.

At this point, I fully expect someone to say that CO2 emissions indirectly reduce rainfall in South West WA and thus cause people to suck up more groundwater, which drives the local subsidence. I defy anyone to find a climate model that can predict rainfall patterns globally with any measurable skill above random chance. The causal links in the chain between your car exhaust and Fremantle-sinking grow ever longer unto an improbable multi-step narrative that lacks observational support at every point.

Secondly, the real problem in WA is “streamflow” not “rainfall”. While rainfall has fallen, there is research suggesting the decrease has more to do with forest clearance than CO2 possilby thanks to the production of cloud seeding molecules. The point that matters here is not rainfall, but the streamflow reductions which vastly outstrip the loss of rainfall. Rainfall is down in SW WA from 700mm to 600mm. But streamflow has been savaged. Down from 330GL to just 50GL. Unpacking that is another long story, for another day…

Other related posts:


When the warmists are at it again,
Divide their predictions by ten,
Or just use common sense,
For a hundred years hence,
To gauge what sea-level is then.

— Ruairi


Featherstone W. (2015) Nonlinear subsidence at Fremantle, a long-recording tide gauge in the Southern Hemisphere, Journal of Geophysical Research, DOI: 10.1002/2015JC011295

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