Natural Forcing Of Arctic Climate
Increasingly Affirmed By Scientists
Three years ago a cogent paper was published in the prestigious scientific journal Nature that was surprisingly candid in its rejection of the position that the substantial warming and sea ice reduction in the Arctic occurring since the late 1970s should be predominantly attributed to anthropogenic forcing.
Dr. Quinhua Ding and 6 co-authors indicated in their paper that internal processes — natural variability associated with planetary waves and the North Atlantic Oscillation — are drivers of the recent Arctic warming and sea ice reduction, concluding that “a substantial portion of recent warming in the northeastern Canada and Greenland sector of the Arctic arises from unforced natural variability.”
Ding et al., 2014
“Rapid Arctic warming and sea-ice reduction in the Arctic Ocean are widely attributed to anthropogenic climate change. The Arctic warming exceeds the global average warming because of feedbacks that include sea-ice reduction and other dynamical and radiative feedbacks. We find that the most prominent annual mean surface and tropospheric warming in the Arctic since 1979 has occurred in northeastern Canada and Greenland. In this region, much of the year-to-year temperature variability is associated with the leading mode of large-scale circulation variability in the North Atlantic, namely, the North Atlantic Oscillation.”
“Here we show that the recent warming in this region is strongly associated with a negative trend in the North Atlantic Oscillation, which is a response to anomalous Rossby wave-train activity [planetary waves related to the Earth’s rotation] originating in the tropical Pacific. Atmospheric model experiments forced by prescribed tropical sea surface temperatures simulate the observed circulation changes and associated tropospheric and surface warming over northeastern Canada and Greenland. Experiments from the Coupled Model Intercomparison Project Phase 5 models with prescribed anthropogenic forcing show no similar circulation changes related to the North Atlantic Oscillation or associated tropospheric warming. This suggests that a substantial portion of recent warming in the northeastern Canada and Greenland sector of the Arctic arises from unforced natural variability.”
Since 2014, there have been several more scientific papers that have been published documenting the significance of natural forcing processes in the Arctic and how they may override a clear detection of an anthropogenic influence.
But 2017 already seems to be an exception. Papers that document the dominance of natural forcing — or that don’t even mention anthropogenic forcing as a factor in the Arctic climate processes — keep on rolling in.
As a case example, in a paper discussing the mechanisms involved in “Arctic amplification” and sea ice loss, Kim et al. (2017) never once mention anthropogenic forcing, or carbon dioxide, as mechanisms affecting the Arctic climate. In fact, in citing several other authors, they acknowledge that the physical processes involved in the forcing of Arctic climate are “subject to debate” and remain “an open question.” In other words, not only is the position that humans exert a dominant influence on the Arctic climate not “settled science”, the anthropogenic influence may be so muted a factor that it is not even worth mentioning in a paper discussing forcing mechanisms.
1. Kim et al., 2017
Understanding the Mechanism of Arctic Amplification and Sea Ice Loss
“Sea ice reduction is accelerating in the Barents and Kara Seas. Several mechanisms are proposed to explain the accelerated loss of polar sea ice, which remains an open question. … Previous studies have proposed the physical mechanisms of Arctic amplification, which involve the effect of atmospheric heat transport (Graversen et al., 2008), oceanic heat transport (Årthun et al., 2012; Chylek et al., 2009; 10 Spielhagen et al., 2011; Onarheim et al., 2015), cloud and water vapor changes (Francis and Hunter, 2007; Schweiger et al., 2008; Park et al., 2015a; Park et al., 2015b), and/or diminishing sea ice cover (Serreze et al., 2009; Screen and Simonds, 2010a; Kim et al., 2016). The accurate physical process of the Arctic amplification, however, is subject to debate.”
“Despite the general consensus that heat transfer between the ocean and atmosphere is a crucial element in the physical mechanism of Arctic amplification and sea ice reduction, a quantitative understanding of individual contributions of heat flux components is still controversial. Further, the role of upward and downward longwave radiations in Arctic amplification is vague and not fully understood. Accurately quantifying the contribution of these different mechanisms, therefore, is required for a complete understanding of the Arctic amplification.”
[CO2 is not mentioned as a mechanism responsible for Arctic amplification or sea ice loss.]
Two months ago, Dr. Ding delivered another Nature paper — this time with 10 co-authors — that once again emphasized the Arctic’s natural variability, specifically the internal processes involved in the substantial reduction in Arctic sea ice since 1979. The scientists concluded that as much as 50% of the Arctic sea ice decline in the satellite era has been natural, and that anthropogenic forcing may play a much smaller role than has previously been assumed in climate models.
Many other newly-published papers advance the position that natural, non-anthropogenic processes are significant or even dominant factors in shaping the Arctic climate. A total of 15 are cited here categorically.
A ‘Substantial Chunk’ Of Sea Ice Loss/Warming Due To Internal/Natural Variability
2. Ding et al., 2017 (press release)
“The Arctic has seen rapid sea-ice decline in the past three decades, whilst warming at about twice the global average rate. … Internal variability dominates the Arctic summer circulation trend and may be responsible for about 30–50% of the overall decline in September sea ice since 1979. … [A] substantial chunk of summer sea ice loss in recent decades was due to natural variability in the atmosphere over the Arctic Ocean.”
3. Fan and Yang, 2017
“The wintertime Arctic temperature decreased from 1979 to 1997 and increased rapidly from 1998 to 2012, in contrast to the global mean surface air temperature [which] increased between 1979 and 1997, followed by a hiatus… A recent study suggests a possible role of the Pacific Ocean decadal oscillation in regulating wintertime climate in the Arctic (Screen and Francis 2016).”
“The ‘greenhouse effect’ of water vapor and clouds [CO2 not mentioned as contributing to the GHE] may amplify the effect of winds on Arctic winter climate.”
“The objectives of this study are to assess how much natural–internal variability has contributed to climate changes in these [Arctic] regions from 1979 to 2012 … In summary, the correlation analyses presented in this paper shows a natural mode of Arctic winter variability resulting from the Nordic–Siberian seesaw of meridional winds […] is associated with two-thirds of the interannual variance [cooling-warming] of winter-mean Arctic temperature between 1979 and 2012, and possibly contributed a substantial fraction of the observed Arctic amplification [1998-2012 warming] in this period.”
4. Seviour, 2017
“Weakening and shift of the Arctic stratospheric polar vortex: Internal variability or forced response? … By comparing large ensembles of historical simulations with pre-industrial control simulations for two coupled climate models, the ensemble mean response of the vortex is found to be small relative to internal variability. There is also no relationship between sea-ice decline and trends in either vortex location or strength. Despite this, individual ensemble members are found to have vortex trends similar to those observed, indicating that these trends may be primarily a result of natural internally-generated climate variability.”
Natural Planetary Waves Forcing
5. Baggett and Lee, 2017
“The dynamical mechanisms that lead to wintertime Arctic warming during the planetary-scale wave (PSW) and synoptic-scale wave (SSW) life cycles are identified by performing a composite analysis of ERA-Interim reanalysis data. The PSW life cycle is preceded by localized tropical convection over the Western Pacific. Upon reaching the mid-latitudes, the PSWs amplify as they undergo baroclinic conversion and constructively interfere with the climatological stationary waves. The PSWs [planetary scale waves] flux large quantities of sensible and latent heat into the Arctic which produces a regionally enhanced greenhouse effect that increases downward IR and warms the Arctic two-meter temperature. The SSW life cycle is also capable of increasing downward IR and warming the Arctic two-meter temperature, but the greatest warming is accomplished in the subset of SSW events with the most amplified PSWs. Consequently, during both the PSW and SSW life cycles, wintertime Arctic warming arises from the amplification of the PSWs [planetary scale waves].”
6. Gong et al., 2017
“During the past three decades, the most rapid warming at the surface has occurred during the Arctic winter. By analyzing daily ERA-Interim data, we found that the majority of the winter warming trend north of 70°N can be explained by the trend in the downward infrared radiation (IR). This downward IR trend can be attributed to an enhanced poleward flux of moisture and sensible heat into the Arctic by poleward propagating Rossby waves, which increases the total column water and temperature within this region. This enhanced moisture flux is mostly due to changes in the planetary-scale atmospheric circulation rather than an increase in moisture in lower latitudes.”
Solar Forcing Of Arctic Climate, Sea Ice Trends
7. Li et al., 2017
“Correlations between paleotemperature records from the North Atlantic and solar activity suggest that changes in solar output may cause significant shifts in the climate of the North Atlantic region. To test the role of solar activity on summer SST at our study site in West Greenland, we conducted a cross-correlation analysis between our reconstructed summer SST record and a total solar irradiance (TSI) series. The results indicate that the maximum correlation coefficient (0.284) of summer SST [sea surface temperatures] and TSI [total solar irradiance] records is obtained at nearly zero time-lag (-6 time-lag), which means that variations in solar activity affected the summer SST variability in the study area. … A significant positive relationship between summer SSTs on the North Icelandic shelf and solar irradiance reconstructed from 10Be and 14C records during the Holocene was also demonstrated by Jiang et al. … Spectral analyses indicate that significant centennial-scale variations are superimposed on the long-term orbital trend. The dominant periodicities are 529, 410, and 191 years, which may be linked to the well-known 512- and 206-year solar cycles. Cross-correlation analyses between the summer SSTs and total solar irradiance through the last 5000 years indicate that the records are in phase, providing evidence that variations in solar activity impacted regional summer SST variability. Overall, the strong linkage between solar variability and summer SSTs is not only of regional significance, but is also consistent over the entire North Atlantic region.”
8. Stein et al., 2017
“The causes that are controlling the decrease in sea ice are still under discussion. In several studies changes in extent, thickness and drift of Arctic sea ice are related to changes in the overall atmospheric circulation patterns as reflected in the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO). The NAO and AO are influencing changes of the relative position and strength of the two major surface-current systems of the Arctic Ocean. … The increase in sea ice extent during the late Holocene seems to be a circum-Arctic phenomenon, coinciding with major glacier advances on Franz Josef Land, Spitsbergen and Scandinavia. The increase in sea ice may have resulted from the continuing cooling trend due to decreased solar insolation and reduced heat flow from the Pacific. … The increase in sea ice extent during the late Holocene seems to be a circum-Arctic phenomenon as PIP25-based sea ice records from the Fram Strait, Laptev Sea, East Siberian Sea and Chukchi Sea display a generally quite similar evolution, all coinciding with the decrease in solar radiation … The main factors controlling the millennial variability in sea ice and surface-water productivity are probably changes in surface water and heat flow from the Pacific into the Arctic Ocean as well as the long-term decrease in summer insolation, whereas short-term centennial variability observed in the high-resolution middle Holocene record was possibly triggered by solar forcing.”
9. Sha et al., 2017
“The reconstruction indicates warm conditions with reduced sea-ice cover, associated with the Holocene Thermal Maximum, from ca. 6700 to 5000 cal. yr BP. … A distinct increase in sea-ice cover began at 1750 cal. yr BP, with absolute maximum values during the last millennium. … In order to assess the contribution of different potential forcing factors to sea-ice conditions off West Greenland, we evaluated the relationship between our sea-ice reconstruction and solar activity, as well as with the strength of ocean circulation. The observed agreement between the sea-ice record and solar activity suggests that solar forcing may have been an important trigger for sea-ice variability off West Greenland during the last 5000 yr.”
Pacific Decadal Oscillation (PDO) Forcing
10. Lapointe et al., 2017
“This paper investigates an annually-laminated (varved) record from the western Canadian Arctic and finds that the varves are negatively correlated with both the instrumental Pacific Decadal Oscillation (PDO) during the past century and also with reconstructed PDO over the past 700 years, suggesting drier Arctic conditions during high-PDO phases, and vice versa. These results are in agreement with known regional teleconnections, whereby the PDO is negatively and positively correlated with summer precipitation and mean sea level pressure respectively. This pattern is also evident during the positive phase of the North Pacific Index (NPI) in autumn. Reduced sea-ice cover during summer–autumn is observed in the region during PDO− (NPI+) and is associated with low-level southerly winds that originate from the northernmost Pacific across the Bering Strait and can reach as far as the western Canadian Arctic. These climate anomalies are associated with the PDO− (NPI+) phase and are key factors in enhancing evaporation and subsequent precipitation in this region of the Arctic.”
Cloud Radiative Forcing
11. Solomon et al., 2017
“A number of feedbacks are found that damp the warming effect of the clouds. Thin mixed-phase clouds increase the downward longwave fluxes by 100 W m−2, but upward daytime surface longwave fluxes increase by 20 W m−2 (60 W m−2 at night) and net shortwave fluxes decrease by 40 W m−2 (partially due to a 0.05 increase in surface albedo), leaving only 40 W m−2 available for melt. This 40 W m−2 is distributed between the turbulent and conductive ground fluxes, so it is only at times of weak turbulent fluxes (i.e., at night or during melt) that this energy goes into the conductive ground flux, providing energy for melt. From these results it is concluded that it is the integrated impact of the clouds over the diurnal cycle (the preconditioning of the snowpack by the clouds at night) that made melt possible during this 3-day period. These findings are extended to understand the pattern of melt observed over the GIS. … Mixed-phase clouds are common at Summit (Shupe et al. 2013) and play a critical role in the Arctic surface energy balance (Shupe and Intrieri 2004), radiatively warming the highly reflective surface at Summit year-round (Miller et al. 2015).”
Most Of The Arctic’s Net Warming Occurred Before 1950
The instrumental record (HadCRUT) for Arctic temperatures indicates that there has been no significant net warming in the Arctic during the last ~80 years. Newly published papers also affirm that much of the warming of the Arctic occurred before 1950, or before humans began emitting CO2 in large quantities.
12. Werner et al., 2017
“During the MCA [Medieval Climate Anomaly], the contrast between reconstructed summer temperatures over mid- and high-latitudes in Europe and the European/North Atlantic sector of the Arctic shows a very dynamic expression of the Arctic amplification, with leads and lags between continental and more marine and extreme latitude settings. While our analysis shows that the peak MCA [Medieval Climate Anomaly] summer temperatures were as high as in the late 20th and early 21st century, the spatial coherence of extreme years over the last decades seems unprecedented at least back until 750 CE. However, statistical testing could not provide conclusive support of the contemporary warming to supersede the peak of the MCA in terms of the pan-Arctic mean summer temperatures.”
13. Fernández-Fernández et al., 2017
“The abrupt climatic transition of the early 20th century and the 25-year warm period 1925–1950 triggered the main retreat and volume loss of these glaciers since the end of the ‘Little Ice Age’. Meanwhile, cooling during the 1960s, 1970s and 1980s altered the trend, with advances of the glacier snouts.”
“The trend in Western Tungnahryggsjökull during the first half of the 20th century was a more rapid retreat, showing the highest average rates of the whole period (19.5 m yr−1). By 1946, this glacier had retreated almost 90% of the total recorded between the LIA maximum (1868) and 2005.”
14. Vachula et al., 2017
15. Krawczyk et al., 2017
31 responses to “15 New Papers: Scientists Abandoning Claims Of Dominant Man-Made Influence On Arctic Climate”
Ding et al., 2014 pointed out “The magnitude of the surface and tropospheric warming in the northeastern Canadian-Greenland sector of the Arctic is nearly twice as large as the Arctic-mean warming.” Ding et al., 2017 reads “Internal variability dominates the Arctic summer circulation trend and may be responsible for about 30–50% of the overall decline in September sea ice since 1979.”
In Fan and Yang, 2017 You point out that CO2 was left out as a cause of a greenhouse effect. The reason is just above your quote from the paper. “A reduction of sea ice also increases air temperature, water vapor, and cloudiness, leading to an increase of surface downward longwave radiation and Arctic amplification in winter. The ‘greenhouse effect’ of water vapor and clouds may amplify the effect of winds on Arctic winter climate.”
I have no problem with you being a glass half full kind of person but the 3 papers only show that some, not all of the Arctic warming comes from unforced natural variability. They show that scientists have no problem looking for causes of warming that are natural in origin. They also see “an increase of surface downward longwave radiation” caused by increasing levels of CO2.
“The ‘greenhouse effect’ of water vapor and clouds may amplify the effect of winds on Arctic winter climate.” “
That would be nice if however Science still has no complete, cohesive, and verified model of how water works, without this basic knowledge how can anyone believe that climate can be understood or accurately modeled?
http://phys.sci.hokudai.ac.jp/en/lab-group/a-04.html and http://phys.sci.hokudai.ac.jp/en/lab-group/a-05.html
Yes, water and all it’s attributes are not well understood especially during the transition of vapor to liquid to solid and the reverse. And what exactly happens when ice dissociates to vapor without the usual intervening liquid state.
So how do they model clouds in the polar regions when H2O goes through all these transition states. They use ‘estimates’, or for the non-scientist, they guess.
What are the energy states operating in and around clouds? Now add the variable atmospheric chemistry of real localities.
And do the models allow for all of water’s anomalies?
Also see http://www1.lsbu.ac.uk/water/water_anomalies.html for a list and explanation of water’s known anomalies.
“They also see “an increase of surface downward longwave radiation” caused by increasing levels of CO2.”
No, CO2 was specifically NOT mentioned.
Stop making stuff-up.!
“that some, not all of the Arctic warming comes from unforced natural variability”
As you say, they only got it part right.
soot, and industrial residues etc, may have a small effect.. as would Russian icebreakers.
But nothing to do with CO2.
Correct. The Arctic sector also cooled by more than twice the global average between the 1940s and 1980s. So what is your point here? Has someone said the Arctic hasn’t warmed since 1979?
I have no idea what your objection is here. Fan and Young didn’t mention CO2 as a factor in the greenhouse effect. Including the preceding sentence doesn’t change anything. It is well known that water vapor and clouds dominate the theoretical greenhouse effect. CO2 only accounts for about 3% to 20% of the total greenhouse effect…so it’s not surprising that it wasn’t mentioned as a dominant factor.
It was never claimed that the papers said that “all” Arctic warming comes from unforced natural variability. In fact, the specific word choices used were quite the opposite of your false characterization. For example:
Using words like “significant” or “dominant” are not synonymous with “all”, Craig. On the other hand, the authors themselves used these very same words that I used. Why would you find it intolerable to think that the Arctic climate would be significantly driven by internal/natural processes, anyway? Why must you believe that humans are the dominant cause of ice melt in the Arctic, and why characterize those who conclude otherwise as “glass-half-full” non-realists?
“I have no idea what your objection is here. Fan and Young didn’t mention CO2 as a factor in the greenhouse effect. Including the preceding sentence doesn’t change anything.”
Fan and Young were not talking about the greenhouse effect in general, but specifically the localized warming caused by the reduction of sea ice in the Arctic. They site Burt et al. 2016:
“As the Arctic sea ice thins and ultimately disappears in a warming climate, its insulating power decreases. This causes the surface air temperature to approach the temperature of the relatively warm ocean water below the ice. The resulting increases in air temperature, water vapor, and cloudiness lead to an increase in the surface downwelling longwave radiation (DLR), which enables a further thinning of the ice.”
Considering our discussions on P Gosselin’s May 14 post, I’m surprised you accept the idea that an increase of surface downward longwave radiation would have a warming effect.
I expect all climate to be subject to internal/natural processes, but that does not disprove the fact that increases in downward longwave radiation from increasing CO2 levels also has an impact.
“I expect all climate to be subject to internal/natural processes, but that does not disprove the fact that increases in downward longwave radiation from increasing CO2 levels also has an impact.”
However there NO observations or experiments that shows downward longwave radiation specifically from increasing CO2 in the lower atmosphere causes any warming. It is very arguable that in a convective atmosphere it can not.
There is only the belief in a theory that keeps such a notion afloat!
Are you disagreeing with the Fan and Young paper that downward longwave radiation warms the Arctic? Or are you saying that the LW radiation from CO2 is special and it alone does not warm? The additional downwell LW radiation from CO2 has been measured in the field.
Observational determination of surface radiative forcing by CO2 from 2000 to 2010
Fan and Young do not mention CO2 as a factor in LW radiative forcing influencing the Arctic. Probably because it is not especially influential. They do mention clouds, though. And clouds do trap heat at the surface and influence ice melt. More clouds in the Arctic region means more warmth stays at the surface. In the tropics and over the oceans, more clouds mean more cooling, as less SW (the source of ocean heat) is absorbed. Because much more of the Earth’s surface is open ocean water and in the middle latitudes, and not the poles, the net global effect (SW + LW) of increased clouds is cooling, and the net effect of decreased clouds is warming. As RealClimate.org itself says, the effects of clouds on both SW and LW forcing completely override the effects of CO2 forcing: “The range of net infrared forcing caused by changing cloud conditions (~100W/m2) is much greater than that caused by increasing levels of greenhouse gases (e.g. doubling pre-industrial CO2 levels will increase the net forcing by ~4W/m2).”
Clouds are known to play a pivotal role in regulating the local SEB [Surface Energy Balance], with competing warming and cooling effects on the surface. … The satellite-based cloud observations allow to estimate the cloud impact on the SEB [Surface Energy Balance]. … The annual mean CRE [Cloud Radiative Effect] of 29.5 (±5.2) W m 2 provides enough energy to melt 90 Gt of ice in the GrIS [Greenland Ice Sheet] ablation area during July and August. … The snow model simulations, which capture the evolution of the GrIS SMB [Surface Mass Balance] from 2007 to 2010, indicate that clouds warm the GrIS [Greenland Ice Sheet] surface by 1.2 (±0.1) °C on average over the entire period [2007-2010].
CO2 forcing may have a very modest impact, as cloud radiative forcing dwarfs CO2 forcing in both the shortwave and longwave. Therefore, any 0.000001 change in atmospheric CO2 will be easily overwhelmed by changes in cloud cover, which dominate the changes in the radiation budget. That’s why believers tend to ignore cloud radiative forcing — or pretend it doesn’t exist.
https://www.ncbi.nlm.nih.gov/pubmed/17780422 (1,440 citations)
The size of the observed net cloud forcing is about four times as large as the expected value of radiative forcing from a doubling of CO2. The shortwave and longwave components of cloud forcing are about ten times as large as those for a CO2 doubling.
The additional LW radiation alleged from CO2 for the 2000-2010 period was a mere 0.2 W m-2 for the 22 ppm CO2 change (Feldman et al., 2015). Again, that is a modeled result. In contrast to 0.2 W m-2 of alleged CO2 forcing, the cloud cover changes since the 1980s has elicited a forcing that is several times greater.
The reduction in total cloud cover of 6.8% [between 1984 – 2009] means that 5.4 Wm−2 (6.8% of 79) is no longer being reflected but acts instead as an extra forcing into the atmosphere… To put this [5.4 Wm-2 of solar radiative forcing via cloud cover reduction between 1984-2009] into context, the IPCC Fifth Assessment Report…states that the total anthropogenic radiative forcing for 2011 relative to 1750 is 2.29 Wm−2 for all greenhouse gases and for carbon dioxide alone is 1.68 Wm−2. The increase in radiative forcing caused by the reduction in total cloud cover over 10 years is therefore more than double the IPCC’s estimated radiative forcing for all greenhouse gases and more than three times greater than the forcing by carbon dioxide alone [from 1750 to present].
Atmospheric impacts on climatic variability of surface incident solar radiation
The Earth’s climate is driven by surface incident solar radiation (Rs). Direct measurements have shown that Rs has undergone significant decadal variations. … From this data, the average increase of Rs [surface incident solar radiation] from 1982 to 2008 is estimated to be 0.87 W m−2 per decade [2.3 W/m-2 total]
[T]here has been a global net decrease [of 3.6%] in 340 nm cloud plus aerosol reflectivity [which has led to] an increase of 2.7 W m−2 of solar energy reaching the Earth’s surface and an increase of 1.4% or 2.3 W m−2 absorbed by the surface [between 1979 and 2011].
Traditionally the Earth’s reflectance has been assumed to be roughly constant, but large decadal variability, not reproduced by current climate models, has been reported lately from a variety of sources. There is a consistent picture among all data sets by which the Earth’s albedo has decreased over the 1985-2000 interval. The amplitude of this decrease ranges from 2-3 W/m2 to 6-7 W/m2 but any value inside these ranges is highly climatologically significant and implies major changes in the Earth’s radiation budget.
You’re actually paying attention rather than just ignoring what we say like Sebastian and sod do. There’s hope for you yet.
See, as a true skeptic, when Andy (who is more convinced than I and far more likely to use words that imply certainty) says something about LW causing evaporative cooling at the surface, I am able to cite scientific backing for his claim from a database that I’ve personally compiled. That doesn’t necessarily mean that I agree with what the scientists writing those papers actually wrote, as I am aware that there are others who may disagree. That’s precisely why I do it…I like considering all sides. It’s probably similar to the reasons why someone like Dr. Curry allows guest authors who ascribe to “consensus” science to post on her blog. I love that. I’m probably more aware of the arguments in favor of your views than you are, as I expose myself to all points of view.
Correct, it doesn’t “disprove” that CO2 increases might maybe possibly have an impact on ocean temperatures (although it has never been “proven” in the first place, of course). But, on the other hand, if the degree or magnitude of that alleged/modeled impact is vanishingly small relative to the impact generated from changes in other climate-forcing variables, then I think I can be forgiven for not taking the tiny change in the atmosphere’s CO2 concentration as seriously as people like you do. We’re talking magnitudes here, Craig. Not either/or. IR can have an impact on ocean temperatures, but that impact may be so minimal as to be almost undetectable.
“See, as a true skeptic, when Andy (who is more convinced than I and far more likely to use words that imply certainty) says something about LW causing evaporative cooling at the surface, I am able to cite scientific backing for his claim from a database that I’ve personally compiled.”
Yes, but what the paper said was misapplied. Long range radiation warming the top layer will increase evaporation in the skin layer with the water molecules carrying that energy as latent heat. But as soon as that water vapor condenses the energy is released into the air as heat. The paper also says “The exchange of sensible heat will tend to cool or warm the surface dependent on the air being cooler or warmer than the water.”
This matches the impact of increased downwell LW radiation described by Fan and Young. “The resulting increases in air temperature, water vapor, and cloudiness lead to an increase in the surface downwelling longwave radiation (DLR), which enables a further thinning of the ice.”
Do you have a paper showing the specific wavelengths emitted by CO2 act differently than the rest of the lowngwave radiation known to impact climate?
Clearly shows that low altitude emissions are from H2O, not CO2.
AndyG55 … the graph you are linking to is NOT showing emissions, but heat loss. Do you know the difference?
Here is a graph from the same paper displaying the change in heat loss (e.g. warming in the troposphere) when CO2 concentration is increased: http://4.bp.blogspot.com/-azyymqLnDhE/VITdp5ofIvI/AAAAAAAABBk/D6PTqePKeis/s1600/clough%26iacona95_delta_cooling_rates.png
poor little seb,
with ZERO PROOF OF CO2 WARMING.
yaps yet again !!
CO2 does not emit below 1kkm
CO2 emissions have a maximum path length of 10m or so in the lower atmosphere..
Even a mathematical inebriate like should be able to figure things out !!!
odd.. I thought you said emissions were heat..
Seb eats yet another sock, due to his MANIC foot in mouth disease.
love it seb
the ASSUMED change from 1990 .
oh dearie me..
seb doesn’t even read the figure titles !!!
When did I say that emissions were heat? Heat transfers in only one direction, towards the cold. Emissions (of energy) occur in every direction.
You two (you and Kenneth) still seem to think we (the “AGW scamers”) are saying that backradiation is actually heating the surface. That’s not the case.
Any form of insulation will cause an increase in temperature while the emissions stay the same. It’s pretty basic physics and the atmosphere is Earth’s insulation towards space. Pretty simple.
CO2 is NOT any sort of insulation
In FACT, test have been done in the double glazing industry, and it has been found that normal air is a BETTER insulator than CO2.
That is because CO2 TRANSMITS radiant energy.
That makes it just another conduit for surface and atmospheric cooling, just like convection.
And of course, a tiny change in the balance of different cooling pathways, makes absolutely no difference, because the whole is controlled by the pressure/density gradient.
Your IGNORANCE is yet again, highlighted for all to see, seb
Apparently you don’t know that double glazing (or triple) doesn’t really insulate from radiation losses. That is not their purpose and why would you fill the gap with anything at all? And if you’d do it, why not some monoatomic gas? What kind of industry tests if CO2 is better than normal air for this application?
Anything that is not inert to LW radiation works as an insulator when put between the heat source (surface) and the heat sink (space). Some gases are more efficient insulators than others. But you already knew that and just wanted to troll me, right?
Poor seb .. CO2 doesn’t BLOCK radiation, it transmits it, even better than normal air.
That must REALLY sting, to know that FACT. 🙂
CO2 does NOT warm a convective atmosphere, as you continue to show convincingly with your abject inability at producing even the slightest piece of real science supporting the very basis of your meaningless anti-science AGW religion
So explain how CO2 concentration changes in volumes of + or – 0.000001 affect this process more than, say, changes in other factors affecting transmittance do (i.e., clouds). Did you ever wonder why it is that CO2 isn’t mentioned when scientists discuss heat flux factors? Of course not. That would imply that you are skeptical of what you’re told to believe.
Alexandri et al., 2017
“Using a radiative transfer model and a set of ancillary data, these biases are attributed to the atmospheric parameters that drive the transmission of solar radiation in the atmosphere, namely, clouds, aerosols and water vapor.” [CO2 not mentioned as a factor affecting the transmission of solar radiation.]
Observations of the Infrared Radiative Properties of the Ocean
“[I]t is necessary to understand the physical variables contributing to sea surface emitted and reflected radiation to space.The emissivity of the ocean surface varies with view angle and sea state, the reflection of sky radiation also depends on view angle and sea state, and the absorption of atmospheric constituents such as water vapor, aerosols, and subdivisible clouds affect transmittance.” [CO2 not mentioned as an infrared radiative property of the ocean, a factor affecting transmittance, or anywhere in the paper.]
The heat balance of the global ocean surface layer is calculated using bulk flux formulations. … Incoming solar radiation and latent heat flux are the two dominant components that control net surface energy fluxes. Wind speed, cloud cover, and the gradient of specific humidity are the three most important meteorological parameters in determining surface flux. [CO2 not mentioned as a parameter in determining surface flux, or anywhere in the paper.]
[I]n-water solar fluxes can vary by 40 W/m-2 within the upper few meters of the ocean (based on a climatological surface irradiance of 200 W/m-2) and that a significant portion of the variation can be explained by upper ocean chlorophyll concentration, solar zenith angle, and cloud amount. [CO2 not mentioned as a factor affecting the heat flux variation, or anywhere in the paper.]
Did you notice that Fan and Young do not mention CO2 as a factor leading to an increase in LW radiative forcing? Why do you think it is they failed to include CO2 as a factor…since it is your belief that CO2 is the dominant factor affecting LW forcing? Coincidence?
CO2 is NOT any sort of insulation
In FACT, test have been done in the double glazing industry, and it has been found that normal air is a BETTER insulator than CO2.
That is because CO2 TRANSMITS radiant energy.
That makes it just another conduit for atmospheric cooling.
Arctic sea ice levels have been essentially steady for the last 10 years.
This is totally in line with the flattish top of the AMO cycle. That cycle is starting to head downwards, North Atlantic Ocean is cooling quite fast.
According to Russian charts, “old ice” is above the level of all years since 2008, (borderline equal with 2010 and 2014 iirc)
Both MASIE and NSIDC are showing the slowest melt in the Arctic in over 10 years.
MASIE has Arctic sea ice extent above that of 2006, 2007, 2008, 2009, 2010, 2011, 2014, 2015, and 2016.
ps, There is no doubt that we are still very much in a COLDER period of the Holocene.
The only period that Arctic sea ice extent has been higher than current being the lead-up, during and the partial recovery from the Little Ice Age, the COLDEST period in the last 10,000 years.
It is very pleasant to be rid of the useless, time wasting comments of malevolent trolls
This mechanism is consistent with the above papers:
Refreshing to see real science being done instead of the endless political science, which the left worships.
[…] Remember the Arctic cyclone that busted up sea ice in 2012? It seems such storms are more common than previously thought. Study: Landmass shape affects extent of Arctic sea ice. Polar Vortex Blamed On Global Warming And Global Cooling. Phil Plait says the Polar Vortex is caused by global warming, and cold weather proves the climate is getting hotter. House Science Committee tweets link to climate denial article at Breitbart. Forty years ago, experts blamed the polar vortex on global cooling, and said cold weather proves the climate is getting colder. Cache of historical Arctic sea ice maps discovered. Arctic Ice: An Update – Evidence From the Past is Instructive. Why the Arctic did not have record-low sea ice this winter – Principia Scientific International. Arctic Ice Thickness Measured From Buoys. 15 New Papers: Scientists Abandoning Claims Of Dominant Man-Made Influence On Arctic Climate. […]
What also may be of interest is the difference from today of the nature of the oceanic CO2 gradient levels as reported in Glacial-to-Holocene Redistribution of Carbonate Ion Glacial-to-Holocene Redistribution of Carbonate Ion in the Deep Sea Wallace S. Broecker* and Elizabeth Clark, DOI: 10.1126/science.1064171.