Climate Change Banter

[AvantHiatus]

20 percent of 50ft (Miocene Sea Levels) is 10ft of SLR at least this century. The full commitment is much higher. Forcing the system even harder will make it happen even faster.

 

Everything is so far behind due to climate inertia and aerosols. It's immensely mind boggling.

[Bhs1975]

https://robertscribbler.wordpress.com/2015/03/11/entering-the-middle-miocene-co2-likely-to-hit-404-parts-per-million-by-may/

But what caused the cooling trend during that period?

[AvantHiatus]

But what caused the cooling trend during that period?

That would be due to internal natural variability. It's very unusual for the global temperature to increase 0.2c/decade, even in paleorecords. Thus we are still in uncharted waters if you include the hiatus.

 

Going from 380ppm to 450ppm is a big deal and could flip switches. Say the ocean going from a carbon sink to a releaser, etc. We cannot look at the past and expect it to continue.

 

There was no cooling trend, just a stabilization. This mindset is killing our chances, seriously.

 

The chance of another hiatus decade occuring this century is about 10%. Based on latest research.

 

The animation below shows observations and two simulations with a climate model which only vary in their particular realisation of the weather, i.e. chaotic variability. A previous posthas described how different realisations can produce very different outcomes for regionalclimates. However, the animation shows how global temperatures can evolve differently over the course of a century. For example, the blue simulation matches the observedtrend over the most recent decade but warms more than the red simulation up to 2050. This demonstrates that a temporary slowdown in global surface warming is not inconsistent with future warming projections.

 

[Bhs1975]

That would be due to internal natural variability. It's very unusual for the global temperature to increase 0.2c/decade, even in paleorecords. Thus we are still in uncharted waters if you include the hiatus.

 

Going from 380ppm to 450ppm is a big deal and could flip switches. Say the ocean going from a carbon sink to a releaser, etc. We cannot look at the past and expect it to continue.

 

There was no cooling trend, just a stabilization. This mindset is killing our chances, seriously.

 

The chance of another hiatus decade occuring this century is about 10%. Based on latest research.

 

We're screwed

[ORH_wxman]

10 feet of SLR this century?

Lol.

[AvantHiatus]

10 feet of SLR this century?

Lol.

Seriously? You on the geoengineering train?

 

10ft is nothing my man, however it makes all the difference for many people. The rate of change would be on the edge of acceptable tho. Barely enough time for people to move inland in a efficient manner.

 

Hence the importance of cutting down emissions now.

[StudentOfClimatology]

The chance of another hiatus decade occuring this century is about 10%. Based on latest research.

Statistically speaking, it's too early to declare the end of the current hiatus. We're still within the standard deviations that have punctuated the 2001-present period.

[AvantHiatus]

Statistically speaking, it's too early to declare the end of the current hiatus. We're still within the standard deviations that have punctuated the 2001-present period.

True true. Not liking how this year has started out tho. Looks to be a warm one.

[Sophisticated Skeptic]

Regardless, Republicans will still find some manufactured facts around somewhere...to say everything's normal...as long as money's still being pumped to em...from 'somewhere'. 

 

Just like the $billions$ pumped to em to be against Obamacare.  Same agenda...different topic. 

[LakeEffectKing]

10 feet of SLR this century?

Lol.

....at least!!!!.....lol!

[csnavywx]

I'd definitely put 10 feet as a tail risk instead of "at least", but if we want to discuss feasibility, I think there's enough evidence to at least suggest that it's possible if the WAIS is as unstable as it seems to be recently, particularly through interactions between the retreat of Pine Island and Thwaites' grounding lines.

[ORH_wxman]

Even the most ridiculous IPCC scenario on RCP 8.5 barely gets SLR over 1 meter...about 1.2m on the upper bound of the 8.5 scenario

 

 

 

 

 

 

It's hard to discuss something like SLR seriously when when the numbers being thrown out are not even in the realm of believable.

[AvantHiatus]

Why go way out in the right field with poor risk assessment? Any predictions of SLR this far out will innevitably be massively inaccurate, especially predictions beyond a century. There are so many variables at play.

 

The two most important would be if future humanity invents technology to artificially remove CO2 on a mass scale. The second factor is exponential functions related to fast and slow feedbacks.

 

We know how high it can go, the question is how fast? 1m this century is more than enough to do major damage. The new consensus seems to be at least 4-8 ft by 2100 (Alley, Dawkins, etc. The people you should care about not the idiots at IPCC). This is based on combining thermal expansion contribution with WAIS and Greenland contribution.

 

It's so dang far out tho, who knows how the ice behaves at 1C, 2C, 3C, etc. If IPCC is forecasting 4C of warming by 2100 then how can those SLR prediction be the worst case scenario? The rate of increase only marginally increases to about 15mm a year towards the end of this century according to IPCC.

 

Don't make ridiculous calls. I'll stop if you will. I'm just suggesting that it is possible. I Have no idea how likely it is at this point. If things continue on their current trajectory and if countries stop burning coal and releasing aerosols, things will get ugly very fast.

 

I have my doubts about this. I think we will resort to geoengineering at some point before 2100, this is the only way to escape a catastrophic future without emissions shutdown by 2030 (negative CO2 budget), and there is also the possibility of geoengineering failing and making the siutation even worse. Aside from being massively expensive, especially SRM and CDR methods.

 

Building artificial volcanoes around the planet and operating them indefinitely will exact a massive cost. It will also not solve ocean acidification. Oxygen levels could collapse in several thousand years if ocean life goes completely extinct.

 

You underestimate the gravity of the situation by a large margin, almost existing in a dream-like world. The place where you live is one of the most shielded places on the planet from the effects of AGW.

[ORH_wxman]

 

We know how high it can go, the question is how fast? 1m this century is more than enough to do major damage. The new consensus seems to be at least 3-6 ft by 2100 (Alley, Dawkins, etc. The people you should care about not the idiots at IPCC). This is based on combining thermal expansion contribution with WAIS and Greenland contribution.

 

 

 

Another ridiculous statement in a long string of them.

[AvantHiatus]

Another ridiculous statement in a long string of them.

Do you even read the latest literature? WAIS is in irreversible collapse my man. Greenland was basically non-existent in the pliocene. It's going to be gone very soon when CO2 shoots way past that bencmark. 500ppm atmosphere will turn Greenland into water in a human lifespan.

 

Luckily for us, we will be dead by the time hell freezes over on Earth. 

 

 

New studies in Science and Geophysical Research Letters (GRL) find that glaciers in the Amundsen Sea region of the great Antarctic ice sheet have begun the process of irreversible collapse. That by itself would raise sea levels 4 feet in the coming centuries.

But more importantly these glaciers act “as a linchpin on the rest of the [West Antarctic] ice sheet, which contains enough ice to cause” a total of 12 to 15 feet of global sea level rise, as the University of Washington news releasefor the Science study explains.

What most of the media has failed to emphasize is that 1) this is not a worst-case scenario and 2) failure to curb carbon pollution ASAP will result in vastly higher levels of sea level rise that devastate the world’s coastlines.

 

 

 

 

 

 

[ORH_wxman]

Do you even read the latest literature? WAIS is in irreversible collapse my man. Greenland was basically non-existent in the pliocene. It's going to be gone very soon when CO2 shoots way past that bencmark. 500ppm atmosphere will turn Greenland into water in a human lifespan.

 

Luckily for us, we will be dead by the time hell freezes over on Earth. 

 

 

 

 

 

 

 

 

 

 

Apparently you didn't read the paper...that paper has nothing to do with SLR by 2100. Instability in the Antarctic ice sheets will take much longer to be felt.

 

 

As for Greenland...nothing suggests that we're going to melt it out in a human lifetime. We spent thousands of years in the Eemian period with warmer temperatures than now, and the GIS only melted down to about 25% of it's size now. At the very least, this shows that the melting out of the GIS would take thousands of years.

 

 

 

The only one trolling is you with a plethora of unsubstantiated claims about SLR and ice sheet collapse. There's much better ways to be concerned about and discuss AGW than embellishing the potential short term effects. This puts you right into the same class as a denier....denying science can work in both directions.

[AvantHiatus]

Temperatures should exceed the Eemian baseline in 20-30 years or so and be massively distant from that regime by 2100 leading to rapid collapse. You once again don't understand exponential factors.

 

I'll eat crow if i'm wrong. It's inconvenient that the hiatus happened, probably a death sentence for us.

 

Knowing that Eemian sea level was 5 meters higher than present day should be all you need to know. That is one heck of a meltwater pulse, probably the largest ever unless a huge negative feedback occurs.

[ORH_wxman]

Temperatures should exceed the Eemian baseline in 20-30 years or so and be massively distant from that regime by 2100 leading to rapid collapse. You once again don't understand exponential factors.

 

I'll eat crow if i'm wrong. It's inconvenient that the hiatus happened, probably a death sentence for us.

 

Knowing that Eemian sea level was 5 meters higher than present day should be all you need to know. That is one heck of a meltwater pulse, probably the largest ever unless a huge negative feedback occurs.

 

 

So, we're going to see Arctic warming exceed 5-8C in the next 20-30 years?

 

That's a bold prediction and about as certain to be wrong as any of the other silly ones made in here. (and the list is long...including 2015 ice free arctic)

[chubbs]

10 feet is too high but the recent IPCC assessment is also too conservative on the upper end. IPCC did not include marine ice sheet instability in Western Antarctic which is now thought to be in the early stages of collapse. Timing for collapse though is unknown.

 

 

[dan11295]

People have to remember ice sheet melting is a long term feedback. Happens on the time scale of centuries not decades. Simply exceeding the Eeemian baseline isn't going to suddenly melt all the the ice in Greenland. Takes heat energy (and time) to convert the ice back into a liquid state. That being said, on our current CO2 emissions path sea levels will rise toward (and potentially beyond) Eemian levels over the next few hundred years.

 

Key point of uncertainty is when chokepoints in places such as the West Antarctic Ice Sheet (WAIS) give way resulting in an acceleration of SLR. The WAIS, not Greenland holds the key here as the volume of water stored is much larger and the factors influencing the SLR contribution are different. Appears we could start to see this acceleration as soon in the latter half of this century but this is still an area of research up for significant debate and even such an acceleration on this time scale is very unlikely to result in an additional 8 ft over 80-90 years.

[nflwxman]

Soon scientists will be publishing papers about why many of them bowed to pressure of a select few over the "hiatus."  While it's premature to declare anything for sure, it really does appear that the surface temperatures are starting their rise to "catch up" with modeled projections.  

[ORH_wxman]

Soon scientists will be publishing papers about why many of them bowed to pressure of a select few over the "hiatus."  While it's premature to declare anything for sure, it really does appear that the surface temperatures are starting their rise to "catch up" with modeled projections.  

 

 

Doubtful...while the hiatus may end...temps will fall again in the next round of La ninas...they need to keep screaming upward to match model projections.

 

Remember that model projections accelerate the warming as we go out in time. So it takes even more warming to "catch up" to them.

 

Unless we are talking about the lower emission scenarios, which are kind of irrelevant since emissions are not low.

[AvantHiatus]

The energy imbalance would continue to increase for no apparent good reason. It's definitely possible to catch up to model projections based on how much we are emitting. 400ppm is really not a big deal but once you start hitting higher numbers, as I've said so many times before.

 

Stuff just starts hitting the fan, and when you are still so far below the temperature baseline for a given CO2 concentration, the rise will be even faster overtime.

 

2015 is the leading edge of the true red meat of AGW. Everyone knows red meat is bad for you, except for LakeEffectKing.

 

It's not a steady climb, more like a series of abrupt stair-stepping.

[chubbs]

People have to remember ice sheet melting is a long term feedback. Happens on the time scale of centuries not decades. Simply exceeding the Eeemian baseline isn't going to suddenly melt all the the ice in Greenland. Takes heat energy (and time) to convert the ice back into a liquid state. That being said, on our current CO2 emissions path sea levels will rise toward (and potentially beyond) Eemian levels over the next few hundred years.

 

Key point of uncertainty is when chokepoints in places such as the West Antarctic Ice Sheet (WAIS) give way resulting in an acceleration of SLR. The WAIS, not Greenland holds the key here as the volume of water stored is much larger and the factors influencing the SLR contribution are different. Appears we could start to see this acceleration as soon in the latter half of this century but this is still an area of research up for significant debate and even such an acceleration on this time scale is very unlikely to result in an additional 8 ft over 80-90 years.

 Yes its going to take thousands of years for Greenland and Antarctica to come back into equilibrium with the atmosphere and ocean.  Our science isn't good enough to predict with any accuracy future long-term SLR trajectories. Recent work generally indicates that both Greenland and Antarctica are less stable to warming than thought previously. This means that potential sea level rise rates and long-term sea level endpoints are both increasing. All this makes dealing with SLR is a very good field to get into.

[AvantHiatus]

 Yes its going to take thousands of years for Greenland and Antarctica to come back into equilibrium with the atmosphere and ocean.  Our science isn't good enough to predict with any accuracy future long-term SLR trajectories. Recent work generally indicates that both Greenland and Antarctica are less stable to warming than thought previously. This means that potential sea level rise rates and long-term sea level endpoints are both increasing. All this makes dealing with SLR is a very good field to get into.

Good post. Tho, my focus has been how long it takes 20% of WAIS to melt, or how long does it take 20% of Greenland to melt?

 

If you add their contributions together it results in destructive SLR this century, on the order of about 1-2 meters. Complete collapse would result in sea level rises of 50+ meters. That is definitely not going to happen overnight.

 

We just have way too many potential sources of melt, there is really no reason to be conservative unless your view of Earth-Ocean dynamics is flawed.

[LakeEffectKing]

The energy imbalance would continue to increase for no apparent good reason. It's definitely possible to catch up to model projections based on how much we are emitting. 400ppm is really not a big deal but once you start hitting higher numbers, as I've said so many times before.

 

Stuff just starts hitting the fan, and when you are still so far below the temperature baseline for a given CO2 concentration, the rise will be even faster overtime.

 

2015 is the leading edge of the true red meat of AGW. Everyone knows red meat is bad for you, except for LakeEffectKing.

 

It's not a steady climb, more like a series of abrupt stair-stepping.

Been eating red meat everyday for basically 10 years!! My cholesterol went from 300 (with the "good" HDL of 32) to 205 (with the HDL rising to 59!!)

My doctor says "whatever you are doing...keep doing!!" Perfect health!!

As for your assertions regarding AGW....let's say they are on the extreme end of plausibility....

[AvantHiatus]

[Sophisticated Skeptic]

Ben did a nice 20 minute climate change update this morning.  

 

 

 

EDIT:  to my surprise, his piece is mostly about how were due for an extended cooling period. thought he'd be more realistic about what's currently going on.  Regardless, still an interesting clip.

[LakeEffectKing]

Last OT response, but I usually eat at least 1 pound of beef per day...and average around 6 eggs per day (give or take)....throw in an occasional chicken thigh with skin, and some shrimp and there's my way of eating!!! Good stuff!!

[AvantHiatus]

Interesting I suppose, bacon. There are uncertainties in all directions. I have not ruled out negative feedbacks caused by catastrophic meltwater injection into the North Atlantic.

 

At the end of the day, Ben is looking to appear credible at the expense of accuracy. Could be a double edged sword from CO2 and Space Weather, truely unlucky. He is consistently using the traditional denier talking points and comes across as pompous.

 

If it turns out a grand solar minimum is occuring, CO2 emissions might save us from the deep freeze.