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I only mean that CO2 is adjusting the overall energy budget by perturbing some of the longwave channels as opposed to the other channels. As a result its effect is more pronounced on the Qout side than the Qin side due to its spectral behavior in relation to the precise nature of the Earth/Sun radiation fluxes. I'm not sure what your point was about "there is NO balance never". Anyway, we're starting to digress here as the physical process behind polyatomic molecule's propensity to trap heat isn't directly related to the subject of this thread. We're trying to discuss Arctic sea ice extents here. If you have questions or comments regarding other topics of climate change maybe it would be better to post them in another thread? There's a whole forum dedicated to this.

It's true. The 2007 summer minimum was lower than in 2018. However, if you integrate the sea ice extents over the entire year and assuming 2018 follows the 2017 trajectory the remainder of the year (a reasonable assumption) you'll find that 2018 results in less ice than in 2007. Except that's really moot anyway. Keep in mind that when we say "decline" we are talking about a longterm secular decrease in sea ice extents. We are not in any way implying that every year will necessarily be lower than the previous. Natural variation is still very much in play. And we aren't necessarily even focused on just the summer minimum. The winter maximum and, of course, the yearly mean are equally important metrics. Regarding your second point there may be some confusion as to what a greenhouse gas does. CO2 and other polyatomic molecules (like H20, CH4, and CFCs) aren't sources of heat. What they do is disrupt the balance between Qin (the incoming shortwave radiation) and Qout (the outgoing longwave radiation). This imbalance creates a net positive gain in heat uptake in the geosphere (90% goes into the hydrosphere) until a new equilibrium is achieved such that Qin = Qout once again. It's really not much different at a conceptual level with the insulation in your home. All other things being equal your house will achieve an equilibrium at a lower temperature if there is no insulation. Again, CO2 is not a source of heat. What it does is impede the transmission of heat.

Let me clarify something. Consensus is not itself a form of evidence. Rather it is born out of the abundance of evidence. Specifically it is the consilience of evidence from which a consensus is born. In other words the reality tends to land in the spot where there is the best overlap of available evidence. What I find often in the blogosphere is that they are brainwashing people into believing that consensus is bad and outlier is good. They do this in a variety of guises but the main issue is that they simply don't tell you about the abundance of evidence from which the consensus came and instead focus solely on outlier lines of evidence. Of course it doesn't help that evidence supporting the consensus is often misrepresented or misinterpreted and that the outlier evidence often has significant issues which is also not presented to you. This is actually a big problem with the internet today in general but specifically with climate science. The fact is that the Earth is going to experience a persistent net positive radiative forcing as a result of human activities (including but not limited to CO2). And baring any significant and unpredictable events like significant volcanic eruptions or other cataclysms the entire geosphere will respond with an increase in heat uptake and an increase in temperature. This will put longterm downward pressure on sea ice (especially in the Arctic region) resulting in ice-free conditions in the summer months with the most likely timing being around mid century assuming a business-as-usual representative climate pathway. Different RCPs yield different amounts of warming at different times. Dismissing the abundance of evidence (a mountain of evidence in fact) that has been collected over the last 150+ years isn't going to stop CO2 from producing a positive radiative forcing on the planet or stop the declining trend of Arctic sea ice extents.

I get that, but this thread is focused on Arctic sea ice. Judith Curry makes several points in her blog and none of them were directly related to sea ice. Don't get me wrong. They're good talking points, but they deserve their own thread. That way we can address each talking point via several posts without taking this thread too far off course. That's what the climate change subforum is for afterall. Post another thread and I'll participate as I get time.

Can you post a new thread? I was trying to avoid hijacking the Arctic Sea Ice thread to talk about non sea ice specific stuff.

From the NSIDC... "Why extent remains so low in the Barents Sea is not immediately clear from patterns of atmospheric circulation and temperature. October air temperatures at the 925 hPa level were only 1 to 3 degrees Celsius (2 to 5 degrees Fahrenheit) above average, associated with a trough of low pressure at sea level extending from Iceland into the region. While further investigation is warranted, this lack of ice growth may relate to the observed “Atlantification” of the Barents Sea, in which the cold, low density surface layer of the Arctic Ocean has weakened, allowing the heat from the warm Atlantic waters to more readily inhibit ice formation. It will be instructive to monitor ice growth rates in this area through the coming winter."

I guess where I was going with my post was that if we are to accept that sea ice was broadly lower in the holocene when temperature were also likely lower than that supports or is at least consistent with future sea ice decline predictions. Afterall, if we can show that sea ice was lower with lower temperatures in the past then there's no reason to think sea ice can't be at least equally as low or even lower with higher temperatures today. In other words, that's not really a good line of evidence to present if the point is to challenge sea ice decline predictions. Also, there may be some confusion as to what AGW actually is. Modern climate science has built a consensus around the idea that there are a lot of physical processes in play that modulate the climate and that these process ebb and flow with respect to their individual radiative forcings. AGW is just the moniker given to how the accepted model plays out in regards to the state of the climate system today. It doesn't ignore any physical process that is modulated wholly by natural cycles. It's just that the natural modulation has been dwarfed by the anthroprogenic modulation mainly after WWII. Remember, the laws of physics don't really care if a CO2 molecule was emitted by man or by nature. It still gets it's molecular vibrational modes activated and send radiation back to the surface all the same. It's the same with any greenhouse gas species or aerosol particle. They behave the same and with the same magnitude regardless of how they entered the atmosphere. That's why modern climate science theory can be applied equally to both the past and the present. Don't get me wrong. I'm not under any illusion that the current model is perfect. It isn't and it never will be. That's par for the course in any scientific discipline. However, the current model does have demonstrable explanatory and predictive power. It works very well all things considered. And if you remove a component (say CO2) from consideration the usefulness of the accepted model is weakened. Afterall, ignoring CO2 or even assuming the climate sensitivity to it is lower than the accepted consensus just makes it more difficult to explain both past and present climate change. If you have a proposal for lessening the radiative forcing or sensitivity of CO2 then it needs to be replaced with something else. Can that something else explain the faint young Sun problem? Can it explain the cooling stratosphere simultaneous with a warming troposphere? Can it explain heat uptake by the geosphere (mostly hydrosphere) in the presence of flat to declining total solar irradation? Nevermind that we'd still need a good reason to replace CO2 in the first place. Those are just some of the questions that need to be answered convincingly if you want to me dispense with 120 years of research culminating in a mountain of evidence that supports the idea that CO2 really can have a significant influence in climate change today.

Let's assume for a moment that this new biomarker proxy evidence for global sea ice extents can be accepted as consensus. That's a big if by the way, but let's go with it for now. What do you think this would suggest in terms of explaining the aggressive declines in the Arctic and the relatively flat trend in the Antarctic in recent decades? Even more importantly what would it say about future trend trajectories?

Note that Comiso does not include data after 2015 which saw anomalously low sea ice extents. And to provide some balance to the quote above this also appears in the article. "The positive trend, however, should not be regarded as unexpected despite global warming and the strong negative trend in the Arctic ice cover because the distribution of global surface temperature trend is not uniform." The authors note that the positive trend from 1979 to 2015 could be linked to 1) higher frequency of cool phase ENSO cycles 2) freshening of sea water and/or 3) ozone depletion by CFCs. It seems as though there are two mains points to the publication. First, the positive trend is real. Second, it's difficult to test the various hypothesis to explain the trend because the CMIP5 suite of models does not adequately predict the trend as-is in the first place.

The Euro has some similar eye candy as well.

That's a great writeup bluewave. It's interesting how the variability in OHC declines through the years. By the 2000's the upward trend is very steady with little variation. Is there an explanation for this effect?

Last night's Euro run was +4.5 SD at 168 right over the pole.

Anyone have low down as to how Mangkhut figured out a way to break the HWRF?

Sahara Air Layer Also, I hadn't heard the phrase "atmosphere depletion" either, but enhanced ocean heat uptake at the expense of less atmospheric heat uptake is the way I understood Vice-Regent's definition. Obviously the harder your compress the spring the more it fights back. In other words, the atmosphere will eventually respond to the ocean heat uptake. It always does.

Saturday might be a player as well in Missouri.

That is a huge powerhouse trough and upper level low showing up on the 12Z EPS. By 18Z on Friday (hour 174) it has 3 fully closed 500mb isohypses and that's just an ensemble mean. The 12Z GEFS also shows big troughing during this period. That's a pretty strong signal for a big weather maker. And it's that time of year so...

We may see some accumulating snow in MO this weekend.

Using 1981-2010 as the baseline GISS comes in at +0.33C for January while the NCEP reanalysis is +0.28C.

No. First, just to clarify, the academic jargon of "ice free" typically means less than 1 million sq km of extent. Second, based on the stuff I've read the consensus seems to be in 2040-2060 timeframe in which the probabilities of "ice free" go likely. At this point though I think we're going to be lucky to make it to 2040.

It's still more than week out so a lot could change. But, the EPS and GEFS means for the QPF swaths are not encouraging for Oklahoma.

The Feb 1st timeframe has been hinted at by the EPS and GEFS for a couple of days now. The weekend of the 27th is a different trough.

St. Louis has been in a snow drought as well. It's been 4 years since we last saw a bona-fide (6"+) winter storm. And as we move into February things get more depressing. St. Louis hasn't had a 6"+ snow in February in over 20 years! So I'm not holding my breath that February will bring anything of interest, but who knows. The trend has break at some point.

It looks like the ZR product on the COD site is messed up. I'm thinking it's scaled too high by a factor of 10.

Euro is really rockin' the cold air next weekend. There is a 40F temperature swing from Thursday afternoon to Friday morning.