AvantHiatus

Where is the paper? How can you make such strong claims without circumstantial evidence or analog examples? For all we know, the holocene world might be more prone to overheating beyond certain GHG and Albedo thresholds. We've never had the carbon injection into the atmosphere that we have now. I know you are trying to emotionally cope with having wrecked the Earth for millions of years but this is a science forum.

No, an ice free arctic is permanent in the summer when you have this much CO2. We are still bleeding off the holocene inertia via albedo/ice sheets and ocean absorption. We would have to geo-engineer and go carbon negative to prevent an ice free arctic.

Why didn't the Pliocene and earlier epochs exhibit Milankovitch signals in the climate? It's not about astronomy, it's more about CO2 being permanently sustained and only contained by weathering and geological processes. Positive feedbacks are underestimated in a carbon system sequestered to the rim in the Arctic. The transition problem reveals why Milankovitch cycles are sensitive to small changes in internal climate forcings. The effects of these variations are primarily believed to be due to variations in the intensity of solar radiation upon various parts of the globe. Observations show climate behavior is much more intense than the calculated variations. Various internal characteristics of climate systems are believed to be sensitive to the insolation changes, causing amplification (positive feedback) and damping responses (negative feedback). Over the past 65 Ma, since the beginning of the Cenozoic when temperatures in polar regions were in the neighborhood of 100C, the Earth experienced the erratic global cooling shown in fig. 1(a). This was a consequence primarily of the drifting of the continents with which is associated changes in ocean-basin geometry, mountain-building, volcanic eruptions and other phenomena that affect the two factors that mainly determine globally averaged surface temperatures: the albedo of the planet, and the atmospheric concentration of greenhouse gases. Superimposed on the global cooling were periodic climate cycles in response to Milankovitch forcing. This term refers to modest, perfectly periodic variations in the distribution of sunlight because of periodic variations 3 in orbital parameters such as the tilt (obliquity) of the Earth’s axis. Although this forcing has been relatively constant over the past several million years, the amplitude of the climatic response has changed because, at different times, the long-term global cooling introduced different climate feedbacks The Pliocene Paradox http://www.aos.princeton.edu/WWWPUBLIC/gphlder/pliopar.pdf A. Fedorov1, A. C. Ravelo2, P. S. Dekens2, P. deMenocal3 M. Barreiro4, R. Pacanowski5, S.G. Philander4

I thought the sun was getting stronger on longer timescales, but it's definitely a minor change in the timeframe being discussed above. Unless you're referring to the Milankovitch influence, not sure how potent that is when everything is already melted out. We will have to agree to disagree here. Would be nice to see the paper but since there no paleo analogs for the anthropocene, we can't say for sure how it would play out.

Well if we ever reach a certain SLR threshold, ice ages no longer become possible in a sense of the normal holocene cycle. There would be a massive delay of perhaps 500k to 3 million years if we ever reach CO2 levels of 600-800ppm+ due to feedback systems. Like I said tho, the final outcome likely resides between Hansen and IPCC. A very PETM'ish world where algae blooms prevent runaway greenhouse Venus Earth from ever happening.

Well my man, 250ft SLR rise takes time ya know no matter how much CO2 is discharged. It's not made up at all but may not be necessarily correct. Nobody is capable of predicting the future 100% using logic. I think the middle road approach is the best option but it is the most risky economic/quality of living path because we risk simultaneously investing and collapsing in the short and long-term. The reward is a streamlined capitalistic transition to the new green economy without breaking the bank.

It's possible to do this over a longer period like 10-20 years for about 15% of the US GDP per year. We would just have to take more risks with SLR and accept the loss of some cities and hope abrupt climate change does not occur. It's definitely possible but the willpower is not there yet. Regardless, the US going 100% renewable doesn't solve outside emission sources. I still think it is cheaper in the deep future to fight SLR now rather than adapt but probably more expensive for the next 100-200 years.

We would still have 1-2 years (before cutting emissions) to install a 100% renewable infrastructure in a new-deal on steroids type overhaul but yes it would never happen cause many are not willing to cut their losses and it would be a human/economic rights violation for third world countries that depend on our petroleum exports. The other way to prevent the effects of SLR is simply to build seawalls and drainage systems, but this solution is only feasible for certain cities that can afford it, and it begins to fail in the long-run when SLR really accelerates. We would have to start upgrading before 2020 tho to stop dangerous SLR from kicking in faster than we can adapt in the long-haul. You could say this is the most pivotal decade in the history of human civilization. The cost benefit does not show up until the 22nd or 23rd century but it is cheaper, it's really way out there but I'd say it's better than the collapse of civilization and possibly mass extinction depending on how long we stay on business as usual. It would seem possible to keep current civilization alive after coastal cities have flooded out but such rapid SLR flux is indicative of rapid system change and instability resulting in poor food productions and biosphere collapse.

1.) Yes 2.) By abruptly shutting down all CO2 emissions, not even geoengineering can stop bottom melt. It looks like 1-4ft of SLR is locked in.

Keep this stuff out of the Arctic ice thread, and no I was not trolling but I know your agenda.

If you have doubts, feel free to use NJ Flood-mapper. http://54.243.129.238/SLR.html#

All you need is 1-2ft of SLR to disrupt most coastal communities and at 3-4ft they become totally dysfunctional and real estate/housing would likely begin collapsing. Safe to assume this will occur in our lifetimes without strong policy action unless you are older than 50. Thus we have a two-pronged initiative to act, both for ourselves and future generations. Anything above that range before 2070 would basically solidify future projections like 5-10 meters because of rate hysteresis.

We know more now than we did in 1988, just saying'

So it begins...

That came about because of the failed predictions in the 2000s of Arctic ice lasting until 2080 and Antarctica not contributing to SLR in the 21st century. If we assume this trend of underestimating risks continues, very nasty things will transpire.

True but I don't know of a better way to generate urgent awareness (which is what is required due to climate system inertia). AGW is a perfect risk because it's a human lifetime-scale event but not as close in as 10-20 years which is when people stop caring. How do we propose solutions without explaining implications? Do we make up new reasons for going green? I can claim that my ideas on this subject are usually well-thought out and I don't expect to be wrong. It's just that most on this forum have a false perception of how bad things already are. I can't adapt to what you believe in. I am just stating soon-to-be well known facts. For example, Hurricane Sandy should of been an all hands on deck moment for this generation of people. There will be more storm surges that people just can't brush away and forget about. Largest red tide on record. https://robertscribbler.wordpress.com/2015/06/17/hot-pacific-ocean-runs-bloody-blob-now-features-record-red-tide/

Welcome to trollville. Temperatures follow ocean trends, never forget and you will go far. Don't underestimate the situation we are entering. Most rapid increase of CO2 ever? Unprecedented.

The Earth is going back to the native state. Icehouse Earth has only been around for 20% of the paleo record, and a good chunk of that is pre-Permian when the sun was weaker.

https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/index.html https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/basin_data.html All basins are available. Ocean heat is just exploding everywhere it seems.

Alarmism is more truthful than manipulating someone into a new paradigm for reasons other than to save the planet. I am agreement with the green crowd tho. A more sustainable world is a more human world and people should be eager to reform society in the absence of immediate threats from AGW. Alarmism is just the branch of explaining the implications of said facts. The general public is not informed enough to understand implications on every subject and western civilization encourages specialization, preventing people from seeing the big picture.

It's still barely in the realm of possibility. That would be an insane acceleration tho and that kind of meltwater injection would definitely shut down ocean circulations and end civilization across the board. It also requires that we stay on business as usual indefinitely which is unlikely. The CO2 atmospheric level would be something insane like 600ppm by 2080.

I want to believe you. The only example I can think of is this interview from 2009 where he mentions the topic of tipping points. Otherwise, his warnings are usually vague and far out into the future. In other words, no body really knows if he was right, even if they claim to know, which goes back to having a false perception of the climate. No doubt the cold spell in the US had an effect on maintaining people's opinions despite TWCs heoric efforts. In many ways he was right on the money due to 2012 and the recent occurrences in Antarctica involving the collapse of WAIS. FWIW, James Hansen probably knows more about AGW than anybody else in a hollistic sense. In the grand scheme of things, 2013-2014 does not represent the next 5 years and definitely not the next 20 years.

Possibly, it is a large jump tho. https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/basin_data.html 3-month 0-2000m average reveals 2015 2012.125 5.675 0.251 3.382 0.136 2.294 0.115 2013.125 8.134 0.217 4.125 0.121 4.009 0.096 2014.125 8.404 0.212 4.449 0.121 3.955 0.091 2015.125 8.944 0.217 4.728 0.108 4.216 0.109 According to this, North Atlantic OHC has recovered since 2012. 0-700m shows warming as well. 2012.125 3.385 0.190 2.270 0.102 1.114 0.087 2013.125 5.264 0.166 2.907 0.091 2.357 0.075 2014.125 5.185 0.163 2.907 0.093 2.278 0.070 2015.125 5.736 0.164 3.210 0.081 2.526 0.083

The 0-2000m layer of the Atlantic has begun to warm exponentially. YEAR AO AOse NA NAse SA SAse 2005.500 5.749 0.196 3.606 0.249 2.143 0.307 2006.500 5.875 0.200 3.807 0.129 2.068 0.113 2007.500 5.608 0.192 3.850 0.183 1.757 0.315 2008.500 5.592 0.503 3.530 0.467 2.062 0.136 2009.500 5.537 0.326 3.241 0.264 2.296 0.118 2010.500 5.978 0.226 3.692 0.174 2.286 0.380 2011.500 6.486 0.471 3.903 0.294 2.583 0.242 2012.500 6.375 0.262 3.603 0.171 2.772 0.167 2013.500 7.977 0.408 4.389 0.141 3.588 0.344 2014.500 8.270 0.257 4.451 0.164 3.819 0.165

What about the West Atlantic OHC? Perhaps the two regions are canceling each other out.