The IPCC Record on Global Warming Temperature Projections - 2

Fig. 1 (click to enlarge)

Don't you just love good records?

And don't you just love the best?

So, today, we are going to use the "best estimate" of what life and death will be like in 2100.

How the IPCC decided to use "best" and "estimate" in the same sentence about the expected reality (~85 years from now) intrigues me.

For one thing, it intrigues me because I am aware of their conservative inclination to underestimate the size of "the monster under all our kids' beds" ("don't make it too scary").

But I digress, because as it turns out, the IPCC record has proven to be a long lasting "best."

So, I am going to go with their "best estimate," which shows a steep climb in this century up to about 4.25° C at or by the year 2100.

It is a steep climb, which they label "REALISED TEMPERATURE RISE" on their graph (Fig. 1) spanning 1850-2100.

I am also using it because, as we saw in the first post, they hit some balls out of the park on their 1990 report's projections concerning temperature increase.

Further, they still have a ~4 deg. C expectation in their most recent report:

Continuing business-as-usual emissions could mean the very worst-case IPCC scenario, where global temperatures rise by more than 4 degrees Celsius (7.2 degrees Fahrenheit) above pre-industrial levels by 2100.

(5 Major Takeaways from the IPCC Report). That makes the ~4 degrees Celsius figure one of their longest held data points (1990-2014 = 24 years).

This helps to emphasize what I have been writing about models that project into the future: stick with the best foundational data.

Anyway, back to today's post.

The IPCC's 1990 assessment did not complete their sea level rise (SLR) projections in those reports.

So, those projections ended up being wild underestimations (Rising Waters: How Fast: "We all think that we’re committed to a meter of sea level rise. We just don’t know exactly how quickly").

Anyway, that 1990 temperature rise projection indicated that by circa 2100, we will have reached ~4.25° C of increased global average temperature.

To complete the missing SLR part of the IPCC report, we will use two very recent papers that can help fill in those blanks.

One is the Potsdam formula, which helps to convert temperature increase into meters of SLR, beginning with:

One paper found that for each 1°C of global average temperature rise there would, as a direct result, be a 2.3 meter sea level rise (SLR), according to Potsdam Institute.

(The IPCC Record on Global Warming Temperature Projections, cf. 5 Most Sobering AGW Facts). The simple arithmetic involved here is 2.3 * 4.25 = 9.775 (i.e., 9.775 meters of SLR by 2100).

It is more sobering to Americans if we convert meters to something we more readily relate to, which is "feet."

Let's render the 9.775 meters into feet: 3.280839895 * 9.775 = 32.070209974 feet.

That is ~32 ft. of SLR caused by a ~4.25° C temperature rise.

Next, the mysterious "law of when" comes into play here:

"The First Law of 'When': the more critical an issue is to the future of our civilization, the difficulty of determining when that critical issue will take effect tends to increase exponentially.

The Second Law of 'When': the greater the amount of time it takes for that critical issue to play out completely tends to exponentially diminish Civilization's grasp of that critical issue.

The Third Law of 'When': the more destructive the impact which that critical issue would have on civilization tends to exponentially increase the time when that critical event will be understood to have begun to take place."

(Quotes Page). We can talk formulas, impacts, and results all day, so long as the "when it will take place" is not too close for comfort.

Perhaps, that is why the Potsdam Study did not elaborate in a detailed manner about "when" their 2.3 m SLR per 1°C rise formula would substantially manifest ("2.3 m °C−1 within the next 2,000 y").

So, we must resort to other papers, such as "Maximum Warming Occurs About One Decade After a Carbon Dioxide Emission," which gives some direction as to "when," as was noted in the post Time Keeps on Slippin' Slippin' Slippin' In From The Past.

Their research paper noted a ~10 year time lag from the time when CO² is injected into the atmosphere, until 90% of its temperature impact takes place (with the remaining 10% of impact playing out over up to ~40 years).

But there is something else about Arctic and Antarctic areas that needs to be dealt with too.

That something else is that they are warming faster than other areas of the globe:

In the Arctic, temperature has increased at twice the rate as the rest of the globe, and could increase by another 8°C (14°F) by the end of this century. The warming atmosphere along with new weather pattern extremes is causing Arctic sea ice to melt at an alarming rate—12% per decade—that suggests the Arctic will be ice-free by 2030. The impacts of dwindling ice cover in the Arctic are far-reaching, from species endangerment to enhanced global warming, to the weakening or shut-down of global ocean circulation.

(Arctic Sea Ice Decline, emphasis added). I don't see any need to use the "8°C" because civilization goes through at least a severe nervous breakdown at the "4.25°C" figure:

IMO, the answer to the fourth item is: "a three foot SLR would severely damage global civilization as we know it" (The Question Is: How Much Acceleration Is Involved In Sea Level Rise?).

Thus, all we need to know is when the ongoing melt in Greenland and/or Antarctica will result in a 3 ft. global SLR (which is a function of acceleration of SLR).

(The Agnotology of Sea Level Rise Via Ice Melt). Remember that the "4.25°C" figure equates to 32 feet of SLR.

Fig. 2 (click to enlarge)

So, how to we calculate, compute, and project the rendezvous with 3 ft. of SLR?

Fig. 2 is an example I will use to finish out today's post:

It is based on the ~"4.25°C" conservative temperature expectations of the IPCC reports.

I don't have the delay logic implemented (in my SLR software) as well as I would like, yet, but there is a rudimentary 10 yr. delay placed into the years immediately following 2015.

One thing the lag or delay does is cause a limit to the amount of SLR @ 2100 so it is less than the full 32 ft. (the 32 ft is reached later due to the delay).

One thing showing up is that Antarctica takes the lead in generating SLR under the IPCC projection data.

That Antarctica would be the top SLR contributor has been the scientific consensus in several papers.

So, even though the full delay, surge, and feedback is not yet developed or presented in the graph, it is a reasonable beginning landscape for things to come.

For a final look at the 3 Ft. SLR marker concept, let's look in the log file (a csv file) created by the program that generates the SLR projections:

Year, Greenland, Antarctica, Non-polar, Combined
2015, 0.106398, 0.0444488, 0.58813, 0.738976
2016, 0.143898, 0.0544488, 0.59063, 0.788976
2017, 0.181398, 0.0644488, 0.59313, 0.838976
...
2029, 1.61329, 0.446286, 0.688589, 2.74816
2030, 1.89626, 0.521745, 0.707454, 3.12546
...
2097, 10.1968, 16.2361, -, 27.9129
2098, 10.2911, 16.5003, -, 28.2714
2099, 10.3854, 16.7644, -, 28.6298

This indicates a 3ft. SLR marker at ~2030, which is close (~2033) to the calculations that were not based on temperature per se, but rather were based on ice volume loss as reported by the Cryosat-2 ice volume tracking satellite (see Fig. 3 here).

This hypothesis comes at a time when we are "just finding out" some things we should have known about long ago.

That is, assuming we consider our civilization to be intelligent:

Scientific groups, for some time now, have realized that "determinations of when" have been consistently underestimated and/or overlooked:

Changes in the area and volume of the two polar ice sheets in Antarctica ... and Greenland are intricately linked to changes in global climate, and could result in sea-level changes that could severely affect the densely populated coastal regions on Earth. Melting of the West Antarctica part of the Antarctic ice sheet alone could cause a sea-level rise of approximately 6 meters (m). The potential sea-level rise after melting of the entire Antarctic ice sheet is estimated to be about 73 m. In spite of its importance, the mass balance (the net volumetric gain or loss) of the Antarctic ice sheet is poorly known; it is not known whether the ice sheet is growing or shrinking. As a result, measurement of changes in the Antarctic ice sheet has been given a very high priority in recommendations by the Polar Research Board of the National Research Council, by the Scientific Committee on Antarctic Research (SCAR), and by the National Science Foundation’s Office of Polar Programs.

(USGS 2005, emphasis added). Therefore, they are leaning toward changing that defect.

What was "poorly known," as recently as ten years ago, is now becoming known to "a more reasonable degree" (as pointed out by the earlier discussion of Cryosat-2 data).

What we see, then, is that civilization had spent untold trillions in order to make endless war, go to the moon, asteroids, comets, and other planets, but we had not all arrived on Earth yet (You Are Here).

We did not know about the great danger of Antarctic ice melt, which would bring down current civilization (240.53 ft. of SLR, see Fig. 1).

As a result, we do not know exactly when we will destroy our civilization, or ourselves (Civilization Is Now On Suicide Watch, 2, 3, 4, 5, 6, 7, 8).

(The Agnotology of Sea Level Rise Via Ice Melt). We know more about a lot of things than we know about when we are likely to destroy ourselves.

Therefore, the question: What Kind of Intelligence Is A Lethal Mutation? comes to mind.

The next post in this series is here, the previous post in this series is here.