For those who follow climate news, James Hansen is working on a paper, called “Global warming in the pipeline,” that examines long-term effects of human-caused climate change, slow feedbacks that when they are triggered, cause sudden change.
Ice-free earth is one of them, since when that occurs, all the white that reflects solar energy back to space will be gone, all of it being converted into heat, not just some of it. Another “slow feedback” is change in the ocean currents, like the Gulf Stream. These changes may be slow to occur, but the results, once present will be fast — in this case, a sudden drop in European temperatures, making Paris in winter like Montreal.
The paper is in draft at the moment and available for comment. The latest version is here.
Hansen and Sea Level Rise
Hansen announced this version of his paper to his mailing list, where he writes, among other things, that:
the present greenhouse gas forcing is 70% of the forcing that made Earth’s temperature in the Early Eocene Climatic Optimum at least +13°C relative to preindustrial temperature
there are 60 m of sea level in the Greenland and Antarctic ice sheets between today and an ice-free planet[.]
In other words, 70% of the planet-wide energy imbalance that drove Earth temperature to 13°C higher than today, is present today.
About sea level rise: For Americans, 60 meters is about 200 feet. (For most of the rest of the world, it’s 60 meters.) Philip Bump, writing in the Atlantic, concurs, by the way; those sea level rise calculations are not in doubt.
The So-Called ‘Asian Century’
The map at the top, courtesy National Geographic, shows North America after all ice melts (archived here). You can view their other maps at your leisure, but I want to draw your attention to Asia.
Notice that Beijing is now a coastal city. Notice also that the North China Plain, the Chinese “breadbasket” and engine of Chinese growth, is now under water. In the image below, the green area south of Beijing is the North China Plain. Green shows how close it is to sea level today. It will flood early in the process.
Needless to say, there won’t be a Asian Century.
But back to Hansen and his latest paper. It’s a fascinating read, especially if you’re interested in what paleoclimate events tell us about where we’re headed and understand the basic language of these papers, terms like “climate sensitivity.”
I’d like to parse just a few of the main points. From the Abstract:
Improved knowledge of glacial-to-interglacial global temperature change implies that fastfeedback equilibrium climate sensitivity (ECS) is 1.2 ± 0.3°C (2σ) per W/m2. Consistent analysis of temperature over the full Cenozoic era – including “slow” feedbacks by ice sheets and trace gases – supports this ECS and implies that CO2 was about 300 ppm in the Pliocene and 400 ppm at transition to a nearly ice-free planet…
Translation: Looking at the full Cenozoic Era — the period from the death of the dinosaurs to today — global temperatures were very high at the start, preventing the formation of ice, much less permanent glaciers. According to Hansen’s latest calculations, the crossing point between an ice-free earth and one where glaciers could form is at roughly 400 ppm CO2.
I’ve marked the graph below with a blue oval to show when this change occurred. Note that the graph’s atmospheric CO2 number, though calculated from earlier data, is in line with Hansen’s current one.
Today’s atmospheric CO2 at Mauna Loa is above 420 ppm, with CO2 rising at a little under 1% per year. You don’t have to do the math to do the math.
Back to Hansen’s Abstract (emphasis added):
Equilibrium global warming including slow feedbacks for today’s human-made greenhouse gas (GHG) climate forcing (4.1 W/m2 ) is 10°C, reduced to 8°C by today’s aerosols. (emphasis added)
He explains this later in the paper (Section 6.6):
[T]he human-made climate forcing exceeds the forcing at transition from a largely ice-free planet to glaciated Antarctica, even with inclusion of a large, negative, aerosol climate forcing [“aerosols,” i.e., air pollution, are a climate cooling agent; without them, earth would be hotter by several degrees]. Equilibrium global warming for today’s GHG level is 10°C for our central estimate ... including the amplifications from disappearing ice sheets and non-CO2 GHGs (Sec. 4.4). Aerosols reduce equilibrium warming to about 8°C. Equilibrium sea level change is + 60 m (about 200 feet).
In other words, the long-term earth will probably be ice-free, all ice will enter the sea, and all those maps above will describe our world, whatever “our” means by then.
IPCC: Corrupt and Comfortable
Why doesn’t the IPCC worry about this issue?
Discussions between the first author (JEH) and field glaciologists 20 years ago revealed a frustration of the glaciologists with the conservative tone of IPCC’s assessment of ice sheets and sea level. One of the glaciologists said – regarding a photo of a moulin (a vertical shaft that carries meltwater to the base of the ice sheet) on Greenland – “the whole ice sheet is going down that damned hole!” Their concern was based on observed ice sheet changes and paleoclimate evidence of sea level rise by several meters in a century, which imply that ice sheet collapse is an exponential process. Thus, as an alternative to the IPCC approach that relies on ice sheet models coupled to atmosphere-ocean GCMs (global climate models), we made a study that avoided use of an ice sheet model, as described in the paper Ice Melt. [here].
I’ll come back to the passages I’ve bolded in the paragraph above.
About the IPCC and the paper Ice Melt, Hansen writes:
Ice Melt was blackballed from IPCC’s AR6 report in a form of censorship, as alternative views normally are acknowledged in science. Science grants ultimate authority to nature, not to a body of scientists. In the opinion of JEH [Hansen], IPCC is comfortable with gradualism and does not want its authority challenged. Caution has merits, but with a climate system characterized by a delayed response and amplifying feedbacks, excessive reticence is a danger, especially for young people. Concern about locking in nonlinearly growing sea level rise is amplified in our present paper by the revelation that the equilibrium response to current atmospheric composition is a nearly ice free Antarctica.
The IPCC is indeed “comfortable with gradualism” if judged by what they do, not what they say.
But there’s more. Hansen’s too polite to add, perhaps, that the IPCC is funded by fossil fuel-controlling nations like Saudi Arabia and fossil fuel-controlled nations like the U.S. This leads them to a kind of censorship that comforts the wealthy at the expense of the victimized poor. (For a look at some of this censorship, see “How Fossil Fuel Governments Control the IPCC,” by yours truly.)
What About the Timing?
What about the timing, you ask? When will this occur? Hansen is unspecific in this paper, but he does mention exponential growth of “ice sheet changes and paleoclimate evidence of sea level rise by several meters in a century” (my emphasis).
It’s true that the rate of increase in CO2 emissions is unprecedented in earth history. It’s also true that very rapid increases in global temperature in the run-up to previous inter-glacial periods (periods like the one we’re living in now, but earlier) have been steep. Here’s a look at temperatures in the previous interglacial, called the Eemian, compared to the present interglacial, the Holocene. (Note that this graph, past to present, reads right to left.)
The steepness of the Eemian temperature rise is striking. In addition, at its peak, global temperatures were roughly 3°C above the Holocene average.
How Much Should We Worry?
So, should we worry about sea level rise of “several meters in a century”? I would answer this way:
Everything in the climate prediction world is wrong to the slow slide. Things are happening faster and sooner than anyone predicts. For example, in a paper titled “Deep Adaptation,” Professor Jem Bendell writes:
For instance, the IPCC previously assigned a probability of 17% for crossing the 1.5 °C global ambient warming mark by 2030, which underestimated a few key factors, which “bring forward the estimated date of 1.5 °C of warming to around 2030, with the 2 °C boundary reached by 2045” (Xu, et al. 2018). The natural fluctuations in the Pacific “raises the odds of blasting through 1.5 °C by 2025 to at least 10%”.
The latest prediction is a 66% chance of crossing at least once above +1.5°C before 2027. I discussed the tendency, to be wrong to the slow side, here: “Erring on the Side of Least Drama.”
Sea level rise of “several meters in a century” places the problem of relocating coastal cities like New York in this generation. If the estimate is wrong and we do act anyway, it’s undeniably good. If it’s right and we don’t act at all, the country collapses before us as we watch.
Even if it takes a century or longer for these predictions to come true, they will come true. No one with power is slowing climate change. They’re offering excuses instead, or appealing to the manly virtues of “energy independence” — meaning, more fracked oil to sell; more money for the rich who control it; more warming for everyone else as the price of that wealth. The day will come when children of earth will scramble like mice from a burning barn, which they set on fire themselves — into a burning world they also lit up. Disbelieve that prediction when our betters act differently.
Even if this generation escapes and successfully passes the whole climate disaster on to its children, how is that not a world-historical act of shame? What does it say of us, if we condemn our kin to chaos and slavery so our own ability to eat more than we need, drive more than we should, consume the goods of the earth just to throw them away, can be preserved till we ourselves are dead? Nero on his couch of gold deserves more honor than a generation that sells out its own to save a life of excess for those who have it.
But frankly and ultimately, I don’t blame the many — the billions who struggle to walk the earth each day — for the state of our world. I blame the few — the thousands who live to control — for blocking the rest of us from fixing it.
We live to serve the few in so many ways. We’ll serve them in this as well, till we decide to stop.
The IPCC does not and never has assigned distinct numerical probability numbers for temperature (or any other) climactic outcomes. They specifically use the terms low, medium, high probability. The 17% number is certainly cherry picked from an individual IPCC study or GCM model.
Secondly, the longer CO2/temperature record clearly shows CO2 levels triple or quadruple that of today. Where is the CO2 to do that going to come from now? It isn't going to come from fossil fuels. Mauna Loa data from 1959 to 2022 show an increase of a bit over 100 ppm over that 83 years - note that the US (and likely Europe's) oil consumption, for example, has been more or less flat since the early 1970s. Note also how Hansen - or at least the quotes put forward - carefully don't mention at what CO2 levels did historically ice free Antarctica occur. That's because a CO2 level of say, 800 would require 200 years to achieve even at the fastest annual atmospheric CO2 increase rates in modern history.
Thirdly, the typical alarmist trick: "transition to an ice free world". The "Eemian" scare graph is accurately noted to be backwards - but that graph is literally indistinguishable in the longer time vs. temperature vs. CO2 graph. The graph also conveniently hides the various warm and cold periods in human history - the Medieval Warm Period which is constantly attempted to be disappeared, the Roman Warm Period, the Little Ice Age that literally ended around the time of the founding of the United States and which conveniently is right around the time that "Its different this time" global temperature doomsayers pick their "rising temperature" starting point (LIA end 1850, man-made CO2 cause temperature increases compared vs. 1880s).
I particularly like the assumptive close that Hansen employs: "climate system characterized by a delayed response and amplifying feedbacks". Any systems designer in areas where amplifying feedbacks can occur, knows that such systems are inherently unstable. The climate, in contrast, is anything but unstable: the temperature differences in a single day are typically greater than the (now acknowledged by IPCC) nonsense of RCP 8.5 - which in turn is even more pessimistic than Hansen attempts to paint future CO2 emissions.
So while I am all for conservation and research to find better ways to generate/use energy - it is far from clear that these fast and loose interpretations of impending climate temperature increase doom, much less the garbage economic models based on top of these climate models, show any skill beyond agenda promotion.
The one positive I can say for Hansen is that he is not rabidly against nuclear power unlike the vast majority of his climate ideological brethren.
It's terrifying to have learned much of this in 1964. Then hear virtue signaling conversations between our betters in NYC a couple days ago, at the Museum O' Natural History ; clutching desperately at any raggedy shard of denial they could snip from Guardian, The Atlantic or NewYorker? We were drilling wells to 37K' with 2 1/4" wall Q125 & titanium casing, or from floating platforms in 6,900' by the mid-90s before Katrina laid waste to MARS platform & Macondo (MC252) blow-out enabled slickwater fracking & bitumen pyramid schemes, we're picking trade war with Russia, to perpetuate? Like overlapping, unannounced novel COVID variants or exponential precariate income disparity, it's an offhanded conversation-stopper, right up there with police shootings & all us boomers becoming selectively senile, simultaneously? I'm guessing we're programmed by 70s disaster movies, into recognizing the foreshadowing snippets, from Invasion of the Body Snatchers, through Shaun of the Dead? API knew "time was running out," by 1965?