While twentieth century sea-level rise was dominated by thermal expansion of ocean water, mass loss from glaciers and ice sheets is now a larger annual contributor. There is uncertainty on how ice sheets will respond to further warming, however, reducing confidence in twenty-first century sea-level projections. In 2019, to address the uncertainty, the Intergovernmental Panel on Climate Change (IPCC) reported that sea-level rise from the 1950s levels would likely be within 0.61–1.10 m if warming exceeds 4°C by 2100.
The IPCC acknowledged greater sea-level increases were possible through mechanisms not fully incorporated in models used in the assessment. In this perspective, we discuss challenges faced in projecting sea-level change and discuss why the IPCC’s sea-level range for 2100 under strong warming is focused at the low end of possible outcomes. We argue outcomes above this range are far more probable than below it and discuss how decision makers may benefit from reframing IPCC’s terminology to avoid unintentionally masking worst-case scenarios.
The phrase “Under strong warming” doing a lot of work here.
Let’s see what we can do to avoid that.
Below, Macarthur Genius Grant winner Andrea Dutton PhD on the deceptive nature of sea level rise..
Video not displaying here and no detail to search for.
When the fun of the scientific debate is over, humbly suggest the the following, non precise, attitude.
Sea level is going up, this is bad, what can be done to stop it.
We know what can be done to stop it.
Never suggest to a coastal community that their response to SLR would have any significant effect on global GHG emissions. It is wrong to give these town and city councils any reason to think that their piddling planning and budgeting efforts would be able to keep up with the storms, floods and SLR. There’s too much hysteresis in political responses to keep up with accelerating changes they will be facing.
Rising Oceans would increase inertia of earth and increase Length of Day
The atomic clock is used to measure length of day. 9 leap seconds were added in the seventies and they got a late start, they did not start until 1972 after making an initial adjustment. 6 leap seconds were added in the eighties. 7 leap seconds were added in the nineties. Now, only 5 leap seconds have been added since the end of 1998 and none since 2016. The Length of day has decreased and that would not be true if there was any kind of runaway sea level rise. For whatever reasons, they are lying or just not understanding what they claim to be expert at doing. I have had this discussion with some of you several years ago. It is still holding. I read a story about melting ice and then I go check the atomic clock data, and I relax and just say, not yet.
Watch for it, if runaway sea level rise starts, the Length of Day would increase.
LOD is measured accurately by the atomic clock. There is a lot of uncertainty in measuring and averaging sea level, but not in measuring Length of Day.
that’s quite a theory (edges toward doorway..)
I’ll bet you win a Nobel for that one…!
First off, we need to establish a long-standing tradition of headlines by numbers, to save people the trouble of reading the same damn thing over and over and over, and saving ink. Or electrons. When it’s needed, just the number is published. I can suggest the first few:
1. Democrat Disappoints Progressives, For Uncountableth Time In Row. Most Progressives Completely Surprised Again
2. Effects Of Climate Catastrophe Happening Faster Than Expected
3a. Price Of Wind, Solar, Batteries, Geothermal Energy Falling Faster Than Expected
3b. Wind, Solar, Batteries, Geothermal Energy Being Installed Much Faster Than Expected
4. Once Again, No One Pointed Out That Headlines 3a And 3b Make It A Race, And We’re Losing
https://www.igb.illinois.edu/sites/default/files/inline-images/RedQueen.jpg
“A slow sort of country!” said the Queen. “Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!”
The GHGs that are going to cause SLR and other extremely harmful effects over the next 40 years have already been emitted.
NOT A DAMN THING we can do about them. Those events are going to happen now, and yes, it’s going to be bery bery bad.
What we can do is get that this is an EMERGENCY!
Fuggedabout all the long-term and incremental solutions. One way or another it’s going to be too late for them even if they ever work at all, which is unlikely. Carbon capture, new nukes, old nukes, nonexistent nukes, fusile nukes, hydrogen, carbon prices, Republican-style “innovation’ (aka procrasstination)… are all pointless.
We can get it that we need our full attention and all our resources turned toward more wind and solar, and more, but fewer batteries than most people think will be needed; more geothermal and tidal; more efficiency; more revolutionary change from chemical-industrial agriculture to small-scale, low-meat, organic permaculture than anyone imagines is possible; faster change in domestic and international political and economic equality and our political-economic system than almost anyone thinks possible; more rapid shift from extractive to regenerative forestry than anyone thinks possible (depends mostly on the equality thing); a global standardized publicly owned free or cheap state of the art high speed rail network hooked into even cheaper comprehensive local and regional rail-bus-jitney-bicycle-walking transport networks; taxes to completely get rid of mbillionaires and hundred thousandaires in the next 10 years. Recognition that all our crises are caused by our collective and individual psychological state.
? carbon dividend
I think some kind nuclear breeder LFTR is a good idea, not to generate lots of power, but to burn the radioactive waste and leave a much smaller pile of waste with much shorter toxic life (300 years instead of hundreds of thousands), especially in view of future emergencies and the delusion that we can project millennia of civilized guardianship over this waste.
Some people do think that. But it’s not. It’s a terrible idea that will maybe sort of halfway help fix one problem by creating several more just as bad. The delusion we can do nukes at all has persisted long enough. We need to get sane now.
…
Only 300 years? Heck, that’s hardly any time at all in human terms. Emirite?
Seriously. Know what was happening 300 years ago? Not the French and Indian War, yet. (7 Years War, for you folks across the pond.) Wooden wheels. Horses. Superstition ruling every aspect of life. (OK, some things change very very slowly.) Actual non-misnomered windmills. Not antibiotics or fossil fuels, yet. Or electricity. Nor any scientific awareness of psychology or most other sciences except what the Greeks knew 2200 years ago. Know what’s happened since 1720? Literally hundreds of wars. Multiple upheavals of all kinds in almost every country. Uncountable revolutions and coups.
Know what’s going to happen in the next 300? The complete collapse of civilization if we don’t change everything about the lives of the rich this decade. The difference between 300 and 3000 is minuscule when you’re at the point of no return and will either solve it or not in the next 10.
A carbon dividend is just a carbon price with a populist bribe instead of the usual corporate bribe. Want one? Sure, why not? Sweep up the crumbs. After we get enough power to pass the things that will actually make a difference in time to matter. It’s too late for incremental solutions.
Winning slowly is losing. (McKibben)
You Wrote:
Know what’s happened since 1720? Literally hundreds of wars. Multiple upheavals of all kinds in almost every country. Uncountable revolutions and coups.
I Write:
Know what’s happened since 1945? Literally less major wars between major powers. Of course, that could change at any time.
Still, plenty of upheavals of all kinds in many countries.
oops. #4 should refer to #s 2 & 3, not #a &b.
https://www.nist.gov/pml/time-and-frequency-division/atomic-standards/leap-second-and-ut1-utc-information
No increasing frequency of adding leap seconds, NO INCREASING SEA LEVEL RISE!
THIS IS SIMPLE CONSERVATION OF MOMENTUM. Removing ice from land near the spin axis and increasing sea level around the equator would show up in the Length of Day compared to the atomic clock.
They clearly are wrong about sea level rise, question the rest of their consensus settled science.
On that NIST page there is a link “why we need leap seconds”. If you follow that, you will find that leap seconds are not what you think.
The GHGs have not caused SLR since 1972, the consensus climate alarmists are clearly lying or plain wrong and there is NOT A DAMN THING we can do about what they tell us, but we clearly do not need to believe Sea Level Rise or any other alarmist junk they promote.
Those climate events are not happening due to manmade CO2 but the harm causes by their “so called” fixes are going to happen now, and yes, their man-made harm is going to be very very bad.
What happened in 1972 that changed the behavior of greenhouse gases (CO2, CH4, HFCs, etc.) so that they stopped absorbing infrared radiation?
Rather than melting into the seas, where has all that land ice disappeared to in the past few decades?
You Wrote:
Rather than melting into the seas, where has all that land ice disappeared to in the past few decades?
I Write:
Land ice is always dumping into the seas and evaporation and snowfall is always putting ocean water back on the land.
Length of Day is a best indicator on which is ahead, it looks about equal since the last leap second was added, 4 years ago at the end of this month. No new leap seconds added in 48 months.
From 1972, 5 or 6 leap seconds were added in the next 4 years.
There is More Ice on Land and Less Water in the Oceans compared to 1972.
Another year gone by with no additional Leap Seconds Added, now it is more than 5 years since the last leap second and none likely any time soon.
Sea level is down since 1972 and holding
There is extensive literature on changes in day length and its causes. For example:
https://advances.sciencemag.org/content/1/11/e1500679
It is more complicated than you imply.
Of course, they write a bunch of complicated junk and peer review with others who scratch each others back. They start with the view that sea level is rising and make up stuff to support it.
Sea level is hard to measure and even harder to average.
Length of Day Does it Correctly but they can only scare people with sea level rising at an increasing rate.
The year 1998 was a really warm year with much more snowfall than usual.
That resulted in a large reduction of Length of Day. Peer Reviewed Consensus is not any kind of proper science. We are all capable of seeing the data and knowing that the Consensus Kings have no clothes on.
“This melting slowed the Earth’s rotation and increased the duration of a day by about a thousandth of a second over the 20th century, Mitrovica said.”
https://www.reuters.com/article/us-science-rotation-idUSKBN0TU2F720151212
This is orders of magnitude less than your (misunderstood) leap seconds.
Jerry Mitrovica is one of the leading experts on SLR, but we are supposed to believe “pope” who cannot even be bothered to do the math and physics and write it up so we can check his work?
I have done the math myself here:
https://earthscience.stackexchange.com/a/15946/6535
if you want to check it.
As I was told numerous times in school “Show your working” If you cannot supply the mathematics supporting your, frankly, infantile claims then we can laugh in your face
Fact: measured sea level, both by tide gauge and by radar altimetry, is increasing
Fact: the largest influences, by far, on the speed of rotation of the earth are lunar & solar tidal friction (slowing rotation) and redistribution of mass by mantle convection and earthquake (both accelerating rotation). Note: tidal friction does not only apply to water.
Fact: expansion of the oceans and melting of glacial caps is an utterly insignificant redistribution of mass compared to the mass and radius of the earth.
Now go and peddle your stupidity to those who might believe you, such as vaccine/covid deniers, Trump worshippers and other conspiracy theory kooks
The mass of ice and water compared to the mass of the earth’s crust is what matters for length of day.
The crust floats on the core which has the most mass that does not matter because it is spinning at a different rate already.
Fact: Lowering of the oceans and increasing glacial caps is significant redistribution of mass compared to the mass and radius of crust of the earth.
Fact: Length of Day was significantly shorter during the major ice ages when there was much more ice and much lower ocean. Mass of the core of the earth was not and is not part of that change in momentum.
If leap seconds are not added more frequently, sea level is not rising.
The so called slow down due to tidal friction is a really tiny amount compared to the speed up we have had since the atomic clock was put into service in 1972
It is the moment of inertia, not the mass that matters.
The crust floats on the mantle.
You did not read (or understand) your own source (NIST):
“If the atomic second had been defined with respect to the mean solar second, it is likely that leap seconds would have been required much less frequently.”
It is just an arbitrary choice how atomic second was defined. If it had been defined differently your theory would predict differently.
Does not matter how it was defined, leap seconds are adjustments to our time such that the sun is always straight up at noon at the place our standard time reference is located. Adding less and less leap seconds does mean inertia of earth is less and that means sea level has gone down.