The Question Is: How Much Acceleration Is Involved In Sea Level Rise?

Down town Tomorrow

The question is not "is sea level rise accelerating?"

The consensus is that sea level rise (SLR) is accelerating.

The answer, then, is based on a three-fold spectrum: "how much was there in the past?", "how much is there now?", and "how much will there be in the future?"

Any historical and current data is used to build upon, because we really need to use a known base from which to calculate prospective acceleration.


To set the stage for the reasoning, which is basic to the foundation of the software architecture being constructed and enhanced, I am using the following posts and papers from various sites, to establish the gist of the initial factors involved: Wikipedia, Current Sea Level Rise, Is sea level rise accelerating?, Sea Level Rise Accelerating Faster Than Thought, Discovery, Nature, Study Reveals Scary New Facts About Sea Level Rise, Gulf Stream Impact, Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation.

The purpose for using the three-fold spectrum is to develop a potential for a narrower, and more tightly focused solution.

When contemplating the writing of software algorithms, which can reasonably project expectations of future SLR, it helps to not only properly design the initial system, but further, that design should also facilitate ongoing improvements and enhancements as they become necessary.

IMO that involves a data driven system, with data entry windows, which are used to update a database.

A database from which the values are loaded into the computer, where the software then uses that dynamic data to make SLR projections.

Any software models of future SLR are speculation engines, but that is what all weather forecasting models do quite well, all things considered.


The basic approach I took was to first establish four melt zones for the three melt locations, non-polar, Greenland, and Antarctica.

Fig. 1 (click to enlarge)

The latter two are the major future sources of water from melting ice.

Those four zones were described in earlier posts as Coastal, Inland 1, Inland 2, and No Melt (Will This Float Your Boat - 7).

In this model, each melt zone has its own beginning phase, rate of delay, rate of melt, rate of acceleration of melt, volume of ice, and total possible contribution to SLR.

Those factors are shown in Fig. 1, where X_n is the beginning and delay phase of the sequence, triggered by an initial temperature increase.

Then Y_n represents the end of the delay phase, if any, as well as the beginning of the melt phase.

Finally, Z_n represents the end of the melt phase.

So, X_1,Y_1, and Z₁ represent the Coastal Zone, X_2,Y_2,and Z₂ represent the Inland 1 Zone, X_3,Y_3, and Z₃ represent the Inland 2 Zone, and X_4,Y_4, and Z₄ represent the No Melt Zone.

As you can see, at any time, the four zones could be in separate phases, or could be in the same phase.

They can also be in the same phase at a particular time, then change to separate phases as the environmental factors change.

Each zone's phase sequencing depends on warming, delay, volume, and acceleration impacting that particular zone.

The same goes for the three ice source locations (Non-polar, Greenland, Antarctica), however, not to the same degree.

For example, the Non-polar zone (non polar glaciers, snow capped peaks, high altitude frozen lakes, etc.) went into AGW induced melt phases first, Greenland second, and Antarctica last.


There are four basic rates of melt: "fast", "medium", "low", and "lowest."

In each zone in general, rates at first will tend to be: Coastal=fast, Inland 1=medium, Inland 2=low, and No melt=lowest.

Also, those rates can change as a zone phases through to reach the downhill slope of melt, especially as it nears the end of its ice and melt.

Coastal zones are initially rated as "fast" because they are subject to warmer water and winds, since they are close to the ocean, nearer to sea level, and away from cooler, high altitudes.

In the locations with by far the most ice (Greenland, Antarctica), those factors change more slowly, on a longer time-scale as we move inland.

That is because the height above sea level increases and the ice is thicker, as we move up to higher elevations with colder temperatures.


The four zones were selected based on the notion that the melt, for the most part, is moving from the coast into the interiors of Greenland and Antarctica.

Should that reality change at any time in any location (volcano, earthquake changed heights, etc.), the database can be updated.

Then, the software program can process the newest data to generate more current projections.


The initial values should be produced by a combination of historical values with current values, AND likewise should be produced with an understanding that neither the past world, nor today's world, axiomatically control the future world.

All three (past, present, and future) are distinct, each with its own peculiarities and dynamics.

Future acceleration, then, is a product of how the future is going to be different from the past, and from the present, not how it is going to be the same.

And finally, keep in mind that acceleration, by definition, is an increase over the present rate.

That said, there are times when acceleration can be very near zero, and there are times when there can be deceleration, so do not confuse the two (Good Nomenclature: A Matter of Life and Death).

Frequent updates of data, bringing the database very current and up to date, will insure that any scenario, and subsequent software projection model based on it, is done on a robust location by location, and zone by zone analysis.


I intend to select the initial phase based upon global temperature data compared to and fused with global SLR data (in terms of seeding the data).

In other words, the global temperature increases data and graphs will determine when the initial SLR increases took place year by year.

The initial global warming beginnings (X_n), the subsequent beginning rates of SLR, and finally the rates of acceleration of SLR, will be based on a common sense analysis of both historical and present values.


Having done the above, if the projections cause someone to mess their pants, so be it.

Now, let me go finish the coding so we can try it out and discuss it some more.