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Kevin O'Neill

The forecasted temperature increase can now be seen on one of the arctic buoys. Buoy 300234062785480 is at 85.45N latitude and the air temperature has increased by 25C over the past 9 hours and is now above freezing.

Complete datafile here.

Rob Dekker

Quite a storm, isn't it ?

As for the effect on Arctic Sea Ice, I doubt that it has much effect.

The temperature anomaly will probably hold ice growth for a few days, while the wind will create polynia that will cause rapid ice growth in the days after the storm. Not to mention that the precipitation that comes with this storm may actually thicken the ice in the days ahead.

So overall this winter storm will probably have little influence on the total ice mass in the Arctic...

John Christensen

It will definitely be interesting to follow this storm; last night DMI's 60N temps were still reasonably low, but this morning positive temperatures are reaching far North of Svalbard.

To Rob's point above, the DMI forecasting tool (http://ocean.dmi.dk/anim/index.uk.php)shows the central pack being spread out (negative convergence) on Dec. 30-31 and then again on Jan. 1-2 by separate lows.

The high temperatures will definitely stall ice formation in a larger area and should be causing ice melting around Svalbard currently.

However, as mentioned on the solstice thread, the resulting precipitation should have a positive effect (http://www.jpl.nasa.gov/news/news.php?release=2014-281).

Pete Williamson

There is the possibility that the extra snow on the ice will act as an insulator and slow the rate of thickening for some of the remainder of the re-freeze season.

eg this old paper that was 1st on the google search and illustrates the concept nicely


Rob Dekker, John Christensen;

While I respect both of your acumen and expertise, some of what you say seem like pretty extreme rationalizations to put a positive spin on what are really extreme conditions. I find it extraordinarily unlikely the net effect could possibly be positive for ice growth. The arguments you cite for that so far seem pretty anecdotal, and there's a lot of arguments which suggest the contrary.

Now, do I think the storm will have a prompt effect reducing ice? Absolutely not. Will it prevent further refreeze? Absolutely not. Do the storms preclude the return of conditions highly favorable to ice formation? Absolutely not.

The actual effect is I think is both more subtle and more serious - reducing the transfer of heat out of the Arctic ocean to the atmosphere. That's what the massive transfer of energy out of lower latitudes will do. Could rain freeze and thicken ice? Yes; however, the energy lost will come from that precipitation, not ocean, and it's far from inconsiderable.

I don't think the timing of this storm could be much worse. Further, speaking to Rob's point, thickening later on will be dependent on weather, which the forecasts suggest will not be favorable for some time to come; in fact, they suggest more storms, possibly of the same scale.

This is the point where we need a strong polar vortex, and isolated dry air masses over the Arctic to facilitate rapid export of heat out of the Arctic Ocean. Every day of that which we lose that export, or go *backwards* as is the case currently over large swaths of the arctic is that much time we lose while the clock is ticking down to the spring equinox and insolation balancing and reversing that loss.

The ice may thicken to near normal levels, but we won't lose the heat. That's my concern, along with the implication that has for next summer's melt season.

Colorado Bob

From Slate on Tuesday, December 29:

“I contacted a team of climate scientists at the University of Washington who maintain a fleet of weather monitoring equipment near the North Pole. James Morison, the principal investigator of the North Pole Environmental Observatory, said he’s “never heard of” temperatures above freezing in the wintertime there. Looking closer at the weather data, it appears this event is in fact unprecedented during the time period from late December through late April”


Buoy 300234062785480 air temperature: http://gergs.net/wp-content/uploads/2015/12/Buoy_300234062785480.png

Temperatures were close to zero back in November, but that's not midwinter!

Colorado Bob

Wavy air patterns mean UK’s extreme storms are here to stay

“I don’t think there has been a combination of conditions similar to the one we’re seeing now because Arctic sea ice loss along with the very warm Arctic are the ‘new game in town’, caused by high greenhouse gas concentrations,” says Francis. “It’s safe to say we’re in uncharted territory.”


Kevin O'Neill

I've seen a couple different buoys above 85N now that have shown the +25C spike in temperatures. The spike is short-lived, though. 300234062785480 was about 22 hours before it returned back into the -20C region.

All in all, a unique and interesting effect, but more a harbinger of things to come than of real importance vis a vis the current melt-freeze season.

Kevin O'Neill

I should add that several years ago arctic researcher Judah Cohen said:

"In my mind there is no doubt that the globe is getting warmer and this will favour warmer temperatures in all seasons and in all locations; however, I do think that the increasing trend in snow cover has led to regional cooling as discussed in the paper and I see no reason why this won't continue into the near future. Also if it continues to get much warmer in the fall, precipitation that currently falls as snow will fall as rain instead, eliminating the winter cooling."

This was a brief taste of "snow will fall as rain." Though he said in the fall - not dead of winter :)


jdallen has provided what I perceive as the correct overview on this very unusual storm while R. Scribbler and KO'N have provided a start on quantitating rain-to-ice and air-to-ice heat transfer respectively.

However we are still far from any specific numbers on the magnitude of the overall effect -- if the +2ºC rain volume north of Svalbard was extensive and this storm proves not a one-off event, hoping for compensatory feedback is merely whistling in the dark.

Off-season rain-on-ice has proven absolutely catastrophic for western Greenland via an altogether different mechanism: a week of warm wet weather in late August 2011 overwhelmed the ice sheet's basal drainage system for 140 km into the ice sheet interior, literally hydraulically lifting the ice sheet up off its bed, reducing basal friction and sending it on its way to the sea, according to Prof Alun Hubbard [Nature Geoscience, July 2015 DOI: 10.1038/ngeo2482]

The drastic rain-on-snow floods in the western US have yet another physical basis:

“One of the main misconceptions is that either the rain falls and washes the snow away, or that heat from the rain is melting the snow,” said Nicholas Wayand, a UW doctoral student. Instead, it’s the warm, humid air surrounding the drops that is most to blame for the melting -- moisture in the air condenses on the cold snow just like water droplets form on a cold drink can.

The energy released when the humid air condenses is absorbed by the snow. Rainstorms also blows warmer air across the snow to melt its surface. These two processes provide 60 to 90 percent of the energy for melting. http://oregonwater.org/improving-forecasts-rain-on-snow-events-worst-floods/


Spikes in winter temperatures in the Arctic are not particularly unusual. Although we have yet to see the full extent of this spike, 15 - 20 degree spikes in the DMI 80+N index appear to occur regularly in winter. 1958-1960 all saw spikes of this magnitude and many years since have also had rapid changes like this.

This one is unusual because it is starting above the long term average, however the current winter norm is well above the long term average.

Kevin O'Neill

A-Team, yes, Greenland ice is likely the big loser. A momentary event shouldn't affect the sea ice much, but the glaciers are a completely different story.

If this patter becomes more widespread and persistent over the years I think we'll see an acceleration that only James Hansen could have predicted.

Kevin O'Neill

DavidR - while momentary, the event *is* unprecedented. Looking back through the records researchers were only able to find 2 other Decembers when temperatures rose above freezing in the far north - and those were much earlier in December. Never this late in December (and never in January or February).

Rob Dekker

Sometimes with these Arctic storms, Ekman pumping brings up heat from below, causing bottom-melt.
We saw that happen with the August'12 storm, where it contributed to the record low ice extent a month later.

But with this storm that does not seem to happen.
ITPs in the NP region (ITP 91, 92 and 93) show nothing unusual below the surface :

Seems this storm was not strong enough to cause much damage at the bottom of Arctic sea ice.

Rob Dekker

With such an unprecedented temperature anomaly in the NP region, we could expect some of the snow cover to melt, and thus reducing ice "concentration" in satellite observations.

And that seems to be the case :
Arctic sea ice "area" numbers are flat-lining at the moment :

That's the result of top-melt in the middle of winter. Pretty impressive...

Dan Carter

Re Rob Dekker: I am not convinced that temperatures very near or slightly above freezing will cause much melting of snow. It takes a long time for snow to melt, especially in the dark. If the sun were shining, it would be a different story. Those of us that have experienced snowy winters in cold climates know that a 0-2C day in the middle of winter will impact snow pack only very slightly, if even perceptibly...unless it rains or unless it's on the south side of some protruding structure that can absorb a little bit of solar radiation. Snow will melt more quickly near freezing if the ground beneath isn't frozen deeply and it can be melted from below, but that situation is applicable for neither land nor sea in the mid-winter Arctic.


Rob, Dan et al;

Is it possible rain dampened snow could change the signal return to the satellite?


There is definitely more snowfall from all these Cyclonic system penetrations of the once power house of winter which was the Arctic Ocean. But this is not the biggest underlying story, it is the vast reduction of winter extent which matters, and has a certain feedback effect causing further warming incursions.

Sea ice wise, more snow tricks the sensors in misjudging
how much sea ice extent there is. I have learned that Cryosphere folks can't distinguish between snow semi immersed on the sea surface and sea ice. There is also more snow, which automatically increases insulation over existing sea ice, this means less accretion not more. Finally over Cryo lands more snow thickness means again extra layer keeping the grounds warmer.
This means an earlier spring warming.

All ansd all does not look good for sea ice with respect to next year minima, especially and foremost its cloudier from a soon to be equal to 1998 El-Nino, if El-nino peaked over the summer that would have been more favorable, but it looks like El- Nino is peaking now, bad presage, if La-Nina kicks in coming late spring 2016, all records will shatter.

Aaron Lewis

It is a mile post on a journey.

Before circa 2000, the jetstream intruding into the Arctic was rare. By 2007, the jet stream crossing the Arctic was common. By 2009, we could associate the path of the jetsream across the Arctic with exceptional Atlantic seaboard weather events.

Now, there is no longer (cold) enough sea ice between Greenland and Norway to cool and condense all moisture out of low level intrusions of warm, moist air. Thus, warm moist air can blast into the Arctic proper.

This is a sign of things to come.

A cold, dry Arctic with cold, competent sea ice drives one kind of jet stream behavior, while fractured sea ice with atmospheric water vapor in equilibrium with liquid water at 0C drives another kind of jet stream behavior.

In short, the mile post tells us that we are very close to having Greenland as the Northern Cold Pole, setting up very intense local heat gradients that will drive atmospheric behaviors that we have never seen before


Rob, I'd say the flattening of the area curve has more to do with compaction of the pack in Kara and Barentz due to wind.


I concur Aaron

"Greenland as the Northern Cold Pole"

especially during summer.

Without the usual North Pacific Cold center Northern Siberia makes it possible for continuous intrusions of North Atlantic cyclones as is happening now.

This is also the 3rd time the weighted Arctic Ocean cold temperature air mass has shrunk since beginning of 2015 long night. The current shrink being the most intense I have ever seen.

More in 3 days when NOAA has some processed data.

Rob Dekker

jdallen said

Rob, Dan et al;
Is it possible rain dampened snow could change the signal return to the satellite?

I think so. Bremen's concentration map seems to suggest the same.
Note that on their last map, ice concentration dropped to below 90% across much of the central Arctic
with some streaks of 80% and below.
That would explain the flat-lining of 'area' numbers (anomaly of some 500 k km^2) quite nicely.

navegante said

I'd say the flattening of the area curve has more to do with compaction of the pack in Kara and Barentz due to wind.

Typically, compaction increases ice concentration, and does not reduce area.

Rob Dekker

Happy New Year everybody.
And Neven, thank you again for providing us with such a wonderful and unique platform to exchange thoughts about the Arctic.
Dank je wel !


Thanks, and my pleasure, Rob. All the best to you and all other commenters for 2016 (here and on the forum). Looking forward very much to the upcoming melting season.


There's been a huge southerly fetch to the wind field which has driven enormous waves into the European side of the Arctic ocean. Those waves have been mixing the water and driving back the ice edge in the Barents sea towards the central Arctic.

While there certainly has been an area of compaction north of Greenland, low pressure over the central Arctic tends to disperse and thin the ice in the area of low pressure due to Eckman caused upwelling.

Overall, intense storminess in the Nordic seas will lead to ice loss. However, the intense storminess near the tip of Greenland is positive for the thermohaline circulation and keeping Europe from getting brutally cold winters.


Happy New Year!!

Special thanks to our host Neven for maintaining this most important and valuable blog and forum.

016 is certainly going to be a very interesting year in the Arctic as well as globally. The impacts of unabated AGW/CC will bring even more catastrophic surprises.


Happy 2016 Neven Rob (and all :-) ). Notice that IJIS extent has also stalled in recent days, so it is not a concentration issue. When I said compaction I just meant that the Atlantic side of the ice edge is being drifted Northwards by the strength of the winds. I saw this in Nevens graph page (CICE drift model).

John Christensen

Hi jdallen,

You wrote:

"..some of what you say seem like pretty extreme rationalizations to put a positive spin on what are really extreme conditions. I find it extraordinarily unlikely the net effect could possibly be positive for ice growth."

As you see from my note, I am not assessing the net effect and agree that the net effect of warm humid air inflow to the Arctic will be negative on the sea ice.
The Arctic sea ice fairs much better overall in negative AO conditions, where the jet stream is further south and there will be less incursions of warmer, humid air.

However, as you see currently from temp charts (E.g. DMI 60N temps), the two lows have temperatures at their center of -10 - -18C.
The sea ice in these areas is already too thick to grow much by pure energy exchange with the atmosphere, so convergence is needed for the ice to grow thicker.
Also, the snow on the thicker ice will help protect it, once spring arrives.

That said; yes, these storms/LPs are bad for sea ice.

John Christensen

Hi Pete,

The article you are referring to is dealing with snow cover on FYI:

"..the vertical temperature was measured daily with carefully calibrated thermistors at nine levels through a section of the air-snow-ice system on the young sea ice off Point Barrow."

While it is correct that snows acts as insulator on thin ice, slowing further ice growth, the snow cover makes an insignificant difference in insulation level on ice that is 1.5M or thicker.


This warming at the North Pole may be unprecedented or the beginning of new circulation patterns to come:


It is definitely remarkable, all specialists take note.

Bill Fothergill

"While it is correct that snows acts as insulator on thin ice, slowing further ice growth, the snow cover makes an insignificant difference in insulation level on ice that is 1.5M or thicker."

There are two reasons why I think it is incorrect to dismiss the insulation effect of snow in such a peremptory fashion.

1) Using the CT figures, Arctic sea ice covered an area of ~ 3.1 million sq kms at the September minimum, and has currently grown to about 11.1 million sq kms. (Latest figure available as at 2015.9945)

Put another way, by the end of December, already about 72% of the total Arctic sea ice area was constituted by First Year Ice. (That number will grow to over 75% by March.) I rather suspect that a goodly portion of this FYI is still considerably less than 1.5 metres in thickness.

2) It is a long, long time since I've done any thermal resistivity calculations, but, unless I'm remembering it all wrong, the overall thermal resistance of a multi-layer barrier (such as this snow-on-ice slab) would be found by adding the resistance of each layer.

Thermal conductivity is inversely related to thermal resistivity, and typical values for both snow and ice can be found here...

Anyone ploughing through that table can see that the conductivity of ice can be between 10 and 50 times greater than that of snow. Even taking the lower value, that means that 6 inches of snow sitting on top of 1.5 metres of ice would effectively halve the energy flow.

Obviously, it doesn't just stay as fresh snow. As time passes, the texture modifies, and the difference in thermal conductivity (or its inverse, thermal resistivity) between the snow and the underlying ice gradually fades away.

However, whilst it is still recognisable as snow, it is acting as a significant insulator, and is hence acting to limit ocean-to-atmosphere energy loss.

As intimated earlier, it's been about 40+ years since I've had to do any of this stuff. If the old grey matter is playing tricks, I'll quite happily be corrected by those whose knowledge is more current.

Rob Dekker

Bill, you are right.
Pure snow is a significant insulator, and should not be discarded so easily. There is an article by the University of Alaska which models snow insulation based of empirical evidence. If I field the link, I'll post it.

However, the crystal structure of snow is very easily broken (and turned to ice) when the temperature of the air (even briefly) is above freezing. The insulation value of snow cover that has been 'broken' by top-melt is much lower than pure snow.

Brief melt of snow over over ice destroys the crystal structure of snow, and we called this "koek-ijs" in Holland. A layer of ice over snow over ice.

That is what just happened with this storm.
And it destroys the insulation value of snow cover.

John Christensen

Hi Bill and Rob,

Please let me clarify my point made on 1/1, which was:

"The sea ice in these areas is already too thick to grow much by pure energy exchange with the atmosphere, so convergence is needed for the ice to grow thicker."

I was referring to the areas, where the LPs were centered at that time.
The models tracking ice thickness are not the most accurate, but it would be reasonable to assume that the ice in those particular areas near the Pole is 1-4 meters (http://ocean.dmi.dk/anim/index.uk.php).
Secondly, we must also assume that some snow has already accumulated in these areas, prior to this most recent storm, so that you may have these layers:
- Snow cover from this recent storm
- Snow cover from earlier precipitation in Nov/Dec
- Mixed ice/snow cover from precipitation Sept/Oct
- Sea ice

It is in this perspective I am saying that another layer of fresh snow on top will not change the overall insulation much.

Of course then, already on Jan. 2, the low pressure deviated from the forecast and moved towards Laptev and ESS, where it encountered much thinner ice and where the added snow layer will have a more significant insulation impact.

Rob Dekker

John Christensen said

I am saying that another layer of fresh snow on top will not change the overall insulation much.

I agree. This storm overall will not have much effect on ice growth.
John also said

"The sea ice in these areas is already too thick to grow much by pure energy exchange with the atmosphere, so convergence is needed for the ice to grow thicker."

I doubt that the ice is "too thick to grow much".
I suspect that ice growth will continue as normal until the maximum March.

Keep an eye out for Neven's PIOMAS reports.


What happened to arctic sea ice extent...? Why is it flatlining??


Very little action on the Atlantic side of the Arctic, Barentsz and Kara area actually going down, most probably due to the storm(s). But the AO is turning highly negative now, so fast growth is a distinct possibility.

Still, with Antarctic sea ice very low, relatively speaking, global sea ice area could see a new record minimum later this month. Not that this is a very useful metric.

Rob Dekker

It may very well be that this storm has a more profound impact than I originally anticipated.

First "area" numbers went flat, which would be expected with the wide area of lower concentration across the Arctic basin, suggesting the initial impact of the storm melted snow, and created polynia.

But then "extent" numbers went flat as well, which is almost certainly due to the storm pushing ice in the Kara and the Barentz towards the NP, just as navegante and Neven suggested.

Now, with the AO turning around, and the polynia freezing up, I second Neven with the expectation that both "area" and "extent" numbers will increase and restore over this and next week.

Also interesting will be the PIOMAS numbers for Jan once they come out.

John Christensen

On the flat ice extent;

While it is correct that the flat ice extent numbers are due to extent decline and stalling on the Atlantic side due to wind and higher temperatures, from the surface pressure charts it can be seen that the main contributor to the southerly winds in Barents is the high pressure in western Siberia.
This high is still causing warmer air to traverse the Barents in a north-east direction, across northern Kara and near Laptev.

And PIOMAS numbers came out yesterday, which look slightly better than I had expected.

John Christensen

Sorry, let me quality that: The west Siberian high has been the main contributor for the past three-four days..

John Christensen

And regarding ice drifting; it seems like the high in northern CAA could cause significant ice drift from Beaufort towards the Pole in the next couple of days and then possibly towards Fram Strait, as you can see from the Ice Drift on the DMI Forecast:


The lesson I guess is that a strong high can be as bad as a strong low, depending on the location of the high.


The second storm has entered the Arctic basin.

What these storms also do is beat the fragile ice to death.

There is hardly any ice hugging the northern coast of Alaska, for example.

You can watch these storms using the IR satellite images provided by the Canadian Met Office. The view changes every 20-45 minutes or so:


John Christensen

TenneyNaumer said:

"The second storm has entered the Arctic basin"

The lowest pressure in the Arctic basin is about 1008hpa, which can hardly be called a storm..

Is it the storm in the Bering Sea you are referring to?

John Christensen

The ice near the northern coast of Alaska is moved North due to winds caused by the anti-cyclone, which is stronger at about 1035hpa.

The areas with exposed open water along the coast will see higher temperatures (-5 to -10C) until the water has lost enough energy and freezes over again.

John Christensen

It finally happened.. ;-) :


Wayne Kernochan

Not sure this is on-topic but:

The initial estimate for the 2015 yearly increase in CO2 as measured from Mauna Loa, Hawaii, is now available. It set a new record for amount of increase: 3.17 ppm. This was the first increase above 3, and was 0.25 above the second biggest increase (1998). It also represented the first time the increase had surpassed 2 in either three or four consecutive years. Increases in 1959-1964 averaged about 0.6 ppm per year, so that in the last 50 years the yearly increase has more than quintupled – a doubling approximately every 20 years.

Projecting forward 40 years, the increase in 2055 would therefore be in the area of 12 ppm, and the total carbon in the atmosphere would be in the 600 ppm range, or more than double the pre-industrial value. Projecting forward another 40 years, the yearly increase would be in the area of 45 ppm, and the total carbon ppm in the atmosphere would be about 1040 ppm, or four times the preindustrial value. Acorrding to the estimate of James Hansen et al that each doubling of CO2 in the atmosphere historically corresponds in the long run to a 4 degrees C (7.2 degrees F) increase in global land temperature, and twice that in the far north/south, We are therefore talking about an increase of 8 degrees C or 15 degrees F from 1850 to 2100 on average and 16 degrees C or 29 degrees F in the far north/south.


With all due respect, sir, if you think global temps are going to be 8 by 2100, you are seriously informed. No serious estimate has said anything close to 8C and BAU estimates are 4-6C, and even that's unlikely with Paris.

Wayne Kernochan

You are absolutely right. I stated the wrong conclusion from the chain of logic. Because of the lag time between carbon arrival in the atmosphere and the full effects of that arrival, an 8 degrees C rise would happen (assuming, again, continuation of "business as usual"), afaik, in the 2200 to 2300 time frame.

With regard to the Paris climate talks, I share your hope that this marks a significant departure from "business as usual". My concern there is that despite Europe's relative success in achieving rapid decreases in carbon emissions, overall it does not seem to have had a significant effect on "business as usual" global carbon emissions, and therefore whether Paris has a significant effect in the next 10-20 years depends on how much solar displaces oil/coal/natural gas in global transportation and housing over that period. And if it does not do so adequately, we are still on the path of "business as usual" by the only metric that matters -- atmospheric carbon increases.

I should also note, as per Joe Romm, that all estimates, including BAU, do not take into account permafrost melting. My own understanding of Romm's back-of-the-envelope calculation, assuming carbon dioxide rather than methane is the primary emission, is that this would add about 0.6 degrees C in the long run. This is factored into Hansen et al's model, which notes that two previous episodes of carbon atmospheric doubling involving permafrost melting resulted in a 4 degrees C temp increase per doubling.


All of what you just said sounds right to me, Wayne. And you are right about Europe's emissions reductions not doing much. Once China's emissions start going down, and they probably will soon, and the Clean Power Plan goes into effect, we should start seeing more substantial drops. My theory is that the agreement rests on the outcome of the 2016 election here in the States. I think a Democrat will win, I hope anyway ;)

Bill Fothergill

@ Wayne K
" ... wrong conclusion from the chain of logic"

Wayne, I think there are some problems within your logic chain. Firstly, extrapolation of growth rates is always a dodgy area, especially if one is using a limited number of data points upon which to base the hypothesis.

Secondly, but equally important, there needs to be a sound physical causative basis which underpins the growth rate hypothesis. As you mention, the annual atmospheric CO2 content increment has just topped 3 ppm(v) for the first time. A goodly portion of that can almost certainly be ascribed to the programme of coal-powered electricity generation being undertaken by China and India. However, one cannot simply extrapolate this rapid hike 40 years or more into the future.

That said, it won't be long until we can kiss goodbye to any monthly value below 400ppm(v). Forget Mauna Loa, I'm talking about even from the South Pole monitoring station. Within 2 decades, I fully expect that we'll be kissing goodbye to 450. (And that must seriously worry the folks at 350.org)

Wayne Kernochan

Hi Bill,

I would agree with every point you have made. I would even make another: the alternative (non-Mauna Loa) metric tends to show much less fluctuation from year to year, and therefore will probably wind up less than 3.17. However, I will respectfully and with the utmost deference :) disagree with the conclusions you draw.

Extrapolations from limited data are indeed dodgy. Thing is, they are dodgy upwards as well as downwards. In probability terms, there is an equal probability that I am too optimistic about what will happen if we do not make a significant dent in carbon emissions.

Moreover, measured atmospheric carbon is a far more accurate indication of how things are really going than the per-country and global fossil-fuel emissions measurements you cite. To note a couple of examples, in 2009, because of the global economic recession, global measured emissions were down slightly, and have increased at slower rates since, with a net flat result in 2014 and 2015. During that time, carbon emissions increases have gone from the 1s to the 3s. The point is that our measurements do not capture well even the total of fossil-fuel emissions, while atmospheric carbon measurements capture everything.

On a related but minor point: indications are that China's emissions did indeed go down last year, by the most effective method possible: the central authority told regional authorities to cut it out. And India's coal-use expansion is only beginning. And yet, atmospheric carbon increased a lot more than in previous years.

The "physical causative basis" is not easily summarized, and afaik parts of it are not well understood. However, the point of Hansen et al's paper last year (summarized in a post on my blog as well as I could) is that in the past two episodes of global warming, atmospheric carbon increased or decreased at all points in the ratio (4 degrees C per doubling) I have cited, and other existing models have consistently underestimated that change up to a point, because they show "tipping point" or hysteresis behavior that is not there in the data -- they underestimate the effects up to the tipping point.

So this is my long-winded way of saying that yes, atmospheric-carbon data sucks as a method of extrapolation; but it's the best method we have.

Bill Fothergill


I've just done some quick calculations on both the NOAA and the Scripps Institute data for Mauna Loa, and it would appear we are looking in different places.

The source data I am looking at can be found here...

If you scroll down to the tabular data - and plug in the Dec 2015 value of 401.85 - that gives a 2014-15 annual rise of about 2.2 on the NOAA file and closer to 2.3 on the Scripps data.

This is only marginally above the mean average rise of 2.1 ppm(v) experienced over the 2005-2014 decade, or 1.9 ppm(v) over the previous decade. I'm therefore not sure where you got the rise of 3.17 ppm(v) for 2015.

Setting that aside however, there would need to be a sound physical reason for your hypothesis about the emission levels rising in basically an exponential fashion. Since I was born (1950), the population of the planet has nearly trebled, rising from perhaps 2.5 billion to in excess of 7 billion.

Figures derived from the following US Bureau of Census data... https://www.census.gov/population/international/data/worldpop/graph_population.php

The projection contained therein shows population growth slowing, rather than increasing, and I believe the world population is thought to be on course to reach about 11 million by the end of the century. If per capita energy consumption were to remain approximately the same, then this would imply that the atmospheric CO2 growth rate might increase to somewhere in the 3.5 - 4.5 range.

However, if we get to the stage of clathrate destabilisation or oceanic CO2 degassing, then all bets are off.


I think large-scale clathrate destabilization in the short term is unlikely, but it helps that SRM could be a counter to it.


http://www.esrl.noaa.gov/gmd/ccgg/trends/ and go to the scrollable column at the bottom left. Mauna Loa, btw, is the first and longest-running CO2 measurement. As noted in the comments, variability from the actual atmospheric CO2 increase should not be very large.

Roger Boyd

The NOAA global estimate for 2015 CO2 is 2.73, compared to the 3.17 for Mauna Loa. The difference between the two numbers does bounce around a bit from year to year. These are preliminary numbers and can get revised by a few tenths either way.


The last big El Nino year (1998), produced a jump in CO2 atmospheric concentrations, so any extrapolations could be very misleading.



Bill, let me run through the math, and then I'm going to drop the topic.

As I understand it, exponential growth over time means that in the equation t * x ** e, e is greater than 1. If e is 1, the growth is linear. In this case, even using the 2014 figure (2.17), the growth percentage (e - 1, in our formulation) goes from approximately 0.6 over 320 ppm in the 1959-1964 time frame to 2.17 over 400 ppm in 2014. And if we average 2012-2015 the difference is even sharper. There is no way that's linear.

This means that exponential growth is the null hypothesis, and projecting linear growth requires a sound physical explanation. As for physical explanations in general, frankly, it's very easy to come up with one for exponential growth and, because of the historical data, not so easy to come up with one that says exponential growth in the past but linear growth in the future. For example, if I simply noted that the population has risen and conjectured that energy consumption had remained constant and would do so in future, I'd wind up with an exponential curve turning linear in the future if and only if population growth percentages/year slowed and then wound up flat/zero.

The explanation you cite simply does not support this: it may be "physical", but it is far from comprehensive, leaving out carbon emissions not the result of energy consumption, such as increased methane from increasing numbers of cows, increased black carbon from melting ice, burning of Amazon rain forests to clear cropland, and so on. And it assumes energy consumption per capita will be flat over time, which historically it has not been. The fact that developing nations begin to use far more energy per capita, and that nations like India and China are now in the developing stage suggests that exponential CO2 growth is, if anything, more likely than linear growth.

Enough already. Btw, I was born in 1950 too. :)

John Christensen

Hi Wayne,

I will need to agree with Bill about the hazard of relying on long-term exponential projections based on historic data.

The future is rarely a repeat of the past, and since the oil crises of the 1970's you have seen many nations working to create local energy programs, for local efficient energy production and energy independence.

Look at the data for Denmark as an example of a developed nation working actively to manage energy and CO2,
(population, CO2 emissions and economic activity in the past decade):

Year___Pop.___CO2 MT_GDP



Jim Hunt

Taking a slightly different tack on the topic of Storm Frank (as he was called here in the UK) the latest numbers from NSIDC and CT reveal that Arctic sea ice extent and area have both now popped above 2011 after spending a few days languishing in the "lowest for the date (since satellite records began" state:

New Year 2016 Arctic Meltdown Update

My own theory is that the brief hiatus in the metrics was more to do with the large swell created by Storm Frank than the anomalously high air temperatures.

Your mileage may vary, but here's some moving pictures of the evidence:


Bill Fothergill

Hi Jim, been enjoying the Devon Drought? ;-)

Re: CT SIA - of course 2016 is still ahead on y-t-d (but not for much longer, I'd warrant)

@ bobcobb
" ... large-scale clathrate destabilization in the short term is unlikely ... "
Yep, completely agree. I only mentioned it as Wayne had already raised the subject in his second post on this thread. My aim was to make it clear that I was talking about direct anthropogenic emissions, as opposed to system feedbacks. Sorry if that caused some confusion. mea culpa

By the way - and I'll probably kick myself here - but what were you meaning by "SRM"? I use that TLA to mean Solar Radiation Management.

@ Wayne & Roger
RE: Annual CO2 rise for 2015

Guys, I'm afraid that there are some serious question marks about the annual rises of 3.17 (ML) or 2.73 (global).

Let's take ML first. Yep, if one scrolls down the drop list, it does indeed state that the 2015 rise was 3.17 However, if you go a couple of lines further down, there is a link to the annual data values.

For 2014 the average annual concentration was 398.61 ppm
For 2015 the value was 400.83

That comes to a difference of 2.22, not 3.17

So which one's right?
Well, try looking at the monthly values now. The largest monthly difference (2014-2015) was in the month of December, and that was 3 dead. The smallest was June, with a rise of just 1.6 ppm. That should constrain the annual average to lie somewhere between these two limits.

As I said earlier, if you take a weighted average across the 12 monthlies for 2015, you get an annual average figure of 2.21 ppm.

There is a similar problem with the global average of 2.73 shown in the relevant drop list. Unfortunately, if one looks at the relevant annual data file, the value for 2015 has not yet been supplied.

However, one can compare the annual growth rates shown on the scrollable list, and compare these with the average annual concentrations shown in the relevant link. One would expect the difference between (say) the 2013 and 2012 annual averages to be the same as the growth shown for 2013.

Dream on.

The mechanism could be as simple as the difference between the daily values on the 31st December each year, but that would introduce a far higher level of inter-annual variability than taking the difference between annual averages.

Look at the following table derived from the global CO2 tab. Column 1 is obviously the year, and Column 2 is the average annual concentration.
Column 3 is the growth in {year x} generated by subtracting the average annual value for {year x-1} from the corresponding {year x} value.

E.G. For 2005, 378.8 minus 376.77 implies a growth of 2.03 ppm. However, Column 4 shows the annual growth values shown in the scroll list.

2004 376.77
2005 378.80 ,, 2.03 ,, 2.45
2006 380.93 ,, 2.13 ,, 1.74
2007 382.68 ,, 1.75 ,, 2.11
2008 384.78 ,, 2.10 ,, 1.77
2009 386.29 ,, 1.51 ,, 1.67
2010 388.58 ,, 2.29 ,, 2.39
2011 390.45 ,, 1.87 ,, 1.69
2012 392.48 ,, 2.03 ,, 2.4
2013 395.25 ,, 2.77 ,, 2.51
2014 397.16 ,, 1.91 ,, 1.9

Confused? I know I am, so I've emailed NOAA asking for clarification.

Jim Hunt

Hi Bill,

At the risk of drifting off topic I presume you must be referring to the somewhat colder, clearer weather over the last couple of days?

The Met Office are just down the road, and they've helpfully explained the change:


My trusty cycling jacket is plastered in mud, not to mention the cycle itself. There are plenty of flood warnings still in place as we speak:

All of which reminds me that the Central Pacific Hurricane season has started a few months early:


Just waiting for a nice picture of Pali from Terra!

Jim Hunt

Pali in the Pacific has now been joined by Alex in the Atlantic:


Alex is a mere "subtropical storm", about which the National Hurricane Center point out that:

Alex is the first tropical or subtropical storm to form in January since an unnamed system did so in 1978, and is only the fourth known to form in this month in the historical record that begins in 1851.

They also suggest that:

Interests in the Azores should monitor the progress of Alex.

Rob Dekker

Jim, thank you for that video about the immediate effects of storm Frank, and its aftermath :

That animation shows really well the effects of this storm.
From the (immediate) top-layer effect of water-on-ice (reduced ice concentration) on the ice masses in the Laptev and CAB, to the prolonged effect on the edges in the Kara.

And, yes, I agree that most likely the retreating ice edge had more to do with the waves flushing water over the ice than with temperature/melt.

The quick recovery witnessed by rapidly increasing area and extent numbers over the past week attest to that.

John Christensen

Somewhat off topic regarding Greenland melt water run-off in years following the strong melt of 2012:

AN ICE LID - more greenland meltwater into the oceans:


Alex is now a hurricane:

Wayne Kernochan

Here's the possible effect on Greenland as per Masters:

"Even though Alex will become absorbed in the higher-latitude storm system, its warm, moist air may assist in pushing temperatures over parts of Greenland more than 35°F above average this weekend into early next week."

Jim Hunt

Alex is indeed now a hurricane, and he's heading for the Azores, with Greenland as his next stop.

As a result if we're not snowed in by then I'm planning a surf trip both this weekend and next:

Is the Son of Storm Frank Heading for the Arctic?

Here's the current Arctic Circle surf forecast for January 21st:

Jim Hunt

For those interested in such matters, the buoys have now reported on the most recent"North Pole temperature anomaly (big)". Read all about it at:


John Christensen

Thanks for the update Jim!

Looking at the DMI 80N chart, it doesn't look like this invasion of heat will reach a top 5 spot compared to earlier years.

Jim Hunt

My pleasure John!

What about my point re DMI DeltaT 80N integrated over January? Where does that stand in the league table?

I'm currently sat in an IEC smart grid standards committee meeting at the BSI in London, which for the moment prevents me from doing the necessary sums myself!

John Christensen

The highest winter temperature in 80N I have seen before 2000 was in 1976, where it reached 264K in March, a full nine degrees warmer than the current peak (Average for that time of year being 2-3 degrees warmer than for January).
1974 saw a peak of 260K in January, 5 degrees warmer than this event..

I just signed up at ECMWF and am waiting to be acknowledged.
Once I have access I will try to obtain more detailed data and will share.

Jim Hunt

You can download the latest DMI numbers from:


If it's of interest to you I have the historical ones on file also, if you let me know where to send them.

The 27th came in at 256.294552.

John Christensen

Somewhat off-topic (Sorry!), but I wanted to share an experience of what may be a minor SSW event:
Flying over the north Atlantic today (Sorry again!), I noticed that the jet stream was south of Iceland and that on the east end of Iceland the wind speed was near 0km/h.

At 11,200meters altitude the temperature was -57/-58C just when reaching Iceland, which is normal, but when I had reached the middle of the area of low wind at altitude about 50km later, the temperature had dropped to -70C.

Shortly after the temperature started rising again, and in the middle of the Denmark Strait it was at -56C.

Is this in principle a minor SSW event, or just what occurs with very low wind speed at altitude?

Jim Hunt

Looks like something's going on John?


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