Climate Change Banter

[skierinvermont]

I'm not saying that human induced aerosols are not important, but saying that the contribution of Greenhouse Gases to recent warming trends is over 100% because aerosols are masking some of that warming is most certainly alarmist. In addition, aerosol forcing isn't understood all that well, and is probably one of the largest uncertainties in Climate Science. Aerosols have an impact, but my stance is that anthropogenic aerosols are likely not as significant as you assert.

 

For example, the average lifespan of an anthropogenic aerosol is quite a bit less than the average lifespan of a molecule of CO2, and thus the effects from aerosols are likely to be much more local than the effects from CO2. Most of the anthropogenic aerosols are found in the Northern Hemisphere as a result of this local effect.

 

aerosols northern hemisphere.png

 

Yet, the Northern Hemisphere has actually warmed faster than the Southern Hemisphere according to both satellite measurements and surface temperature measurements. While this doesn't disprove an effect from aerosols, it suggests that the forcing from aerosols may lean more towards 0 in the IPCC's aerosol error range.

 

Also, do you deny that a significant increase in SW radiation has been absorbed at the Earth's surface over the last 30 or so years? This would seem to suggest that anthropogenic aerosols have not masked much warming during the late-20th Century warm period.

 

http://www.atmos-chem-phys.net/13/8505/2013/acp-13-8505-2013.html

 

From the paper:

 

"The 340 nm LER is highly correlated with cloud and aerosol cover because of the low surface reflectivity of the land and oceans (typically 2 to 6 RU, reflectivity units, where 1 RU = 0.01 = 1.0%) relative to the much higher reflectivity of clouds plus nonabsorbing aerosols (typically 10 to 90 RU). Because of the nearly constant seasonal and long-term 340 nm surface reflectivity in areas without snow and ice, the 340 nm LER can be used to estimate changes in cloud plus aerosol amount associated with seasonal and interannual variability and decadal climate change. The annual motion of the Intertropical Convergence Zone (ITCZ), episodic El Niño Southern Oscillation (ENSO), and latitude-dependent seasonal cycles are apparent in the LER time series. LER trend estimates from 5° zonal average and from 2° × 5° , latitude × longitude, time series show that there has been a global net decrease in 340 nm cloud plus aerosol reflectivity. The decrease in cos²(latitude) weighted average LER from 60° S to 60° N is 0.79 ± 0.03 RU over 33 yr, corresponding to a 3.6 ± 0.2% decrease in LER. Applying a 3.6% cloud reflectivity perturbation to the shortwave energy balance partitioning given by Trenberth et al. (2009) corresponds 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, which is partially offset by increased longwave cooling to space."

 

1. Lifespan of aerosols is short so effect must be small.

 

False. Surface and satellite based measurements show solar dimming due to aerosols. Aerosols are short-lived, but emissions are high enough that they accumulate in significant concentrations before the end of their lifespan. If we stopped all aerosol emissions, aerosol concentration would plummet (unlike long-lived GHGs). 

 

2. Faster warming in the northern hemisphere is evidence that aerosols have smaller RF than most scientific studies say.

 

False. The NH is projected to warm faster for numerous reasons which may not be cancelled by aerosol forcing roughly 25% the strength of GHG forcing. In addition, you can observe that within the NH, the areas of highest aerosol concentration have warmed the slowest. In fact, the SE U.S. is one of the slowest warming regions on earth. While warming in Europe has generally been .5-1C, warming in adjacent North Africa, Scandanavia, and eastern Europe has been 1-2C.

[Jonger]

Correct. And these higher dewpoints increase SBCAPE (surface based convective available potential energy) for thunderstorms to potentially get juiced like Arod. The bulk of research suggests nocturnal temperatures are increasing at roughly twice the rate of afternoon temperatures on a global scale. This doesn't seem to apply to the irrigated Plains perhaps because of the artificially high peak transpiration of plants occurs during the afternoon. Clouds may very well have some role as well but I don't have any paper on that subject at my immediate disposal. Whatever climate change AGW is causing in the Plains isn't coming from positive temp anomalies in the region unless you ignore all the data prior to circa 1980.

 

Contrails probably matter more than corn fields.

http://en.wikipedia.org/wiki/Global_dimming#Probable_causes

 

http://en.wikipedia.org/wiki/Contrail#Contrails_and_climate

[skierinvermont]

Actually the largest regions that lack warming are the already-industrialized regions...and the lack of warming is almost exclusively coming from a cooling trend in winter in these regions.

 

http://web.mit.edu/jlcohen/www/papers/Cohenetal_GRL2012.pdf

 

 

Essentially the opposite of what you'd expect.

 

It looks like Cohen is only looking at the last 20 years.. most of the brightening occurred before then. If you compare 1950-1970 (aerosols era) vs 1990-2012 (clearer air), there is solid warming over the industrialized areas. Including during winter. In fact, the UK, Germany and northern Europe saw some of the fastest warming in winter on earth (1-2C in the UK and Germany, 2C+ in scandanavia).

[Jonger]

It looks like Cohen is only looking at the last 20 years.. most of the brightening occurred before then. If you compare 1950-1970 (aerosols era) vs 1990-2012 (clearer air), there is solid warming over the industrialized areas. Including during winter. In fact, the UK, Germany and northern Europe saw some of the fastest warming in winter on earth.

 

London notoriously had the most smoggy air on the planet until the middle of last century, I wonder how much of a contribution that might have been to UK warming.

[f2tornado]

Contrails probably matter more than corn fields.

http://en.wikipedia.org/wiki/Global_dimming#Probable_causes

 

http://en.wikipedia.org/wiki/Contrail#Contrails_and_climate

 

I'm sure they play some limited role but am quite comfortable suggesting agriculture is a much bigger player for the region and quite possibly downwind through convective feedback. A couple years ago the dewpoint hit 88F in Moorhead, MN. That is not natural. That air is not gonna heat up or cool down readily. Having lived in various parts of the Plains all my life I can tell you there really aren't that many large contrails.

[Cory]

I'm not saying his science is wrong, but he ripped into Hansen pretty hard (probably a little harder than was scientifically deserved given the great uncertainty in this field) and the way he went about it was beyond normal criticism you see between scientists. For example, when Trenberth criticized Hoerlings studies, he wasn't quite so belligerent about it. i think Hoerling and his co-authors are making good faith efforts to interpret evidence objectively and they are doing good science.

 

I'm just saying that if anybody could find evidence that central U.S. drought would not increase, it would be Hoerling, but even he concludes that there will be a modest increase. Other studies find a larger increase. We shouldn't be so quick to assume either party is right. And we definitely should not ignore the overall probability that drought in the central U.S. will increase with AGW. Rising temperature will cause an increase in drought without a pretty solid increase in rainfall to go with it, which does not appear likely. 

 

Fair enough. 

[ORH_wxman]

It looks like Cohen is only looking at the last 20 years.. most of the brightening occurred before then. If you compare 1950-1970 (aerosols era) vs 1990-2012 (clearer air), there is solid warming over the industrialized areas. Including during winter. In fact, the UK, Germany and northern Europe saw some of the fastest warming in winter on earth (1-2C in the UK and Germany, 2C+ in scandanavia).

 

 

I was responding to your claim that areas that were not previously industrialized but are now going through it are seeing the pause in warming...that hasn't been the case recently. Most of the pause is due to cooling in winter in extratropical northern hemisphere regions (i.e. the nations that have been industrialized for a long time now)

[skierinvermont]

London notoriously had the most smoggy air on the planet until the middle of last century, I wonder how much of a contribution that might have been to UK warming.

 

Here's the chart FWIW. The UK's warming looks pretty pronounced compared to the surrounding ocean and much of the rest of the NH. It's also interesting to me that Europe and central Asia warmed faster than the arctic or even norther Asia. Almost like a stripe of aerosols had been lessened blowing across the continent. Usually it seems like the fastest warming is a bit farther north than that.

[Snow_Miser]

1. Lifespan of aerosols is short so effect must be small.

 

False. Surface and satellite based measurements show solar dimming due to aerosols. Aerosols are short-lived, but emissions are high enough that they accumulate in significant concentrations before the end of their lifespan. If we stopped all aerosol emissions, aerosol concentration would plummet (unlike long-lived GHGs). 

 

2. Faster warming in the northern hemisphere is evidence that aerosols have smaller RF than most scientific studies say.

 

False. The NH is projected to warm faster for numerous reasons which may not be cancelled by aerosol forcing roughly 25% the strength of GHG forcing. In addition, you can observe that within the NH, the areas of highest aerosol concentration have warmed the slowest. In fact, the SE U.S. is one of the slowest warming regions on earth. While warming in Europe has generally been .5-1C, warming in adjacent North Africa, Scandanavia, and eastern Europe has been 1-2C.

 

Again, recent satellite measurements indicate that the trend has reversed and an increase in SW Radiation has been absorbed at Earth's surface over the last 30-35 years. This would suggest less "masking" of the warming since there is more SW Radiation being absorbed at the end of the late-20th Century than in the mid-20th Century, representing a radiative forcing.

 

Other studies found that the decrease in Cloudiness is unrelated to anthropogenic aerosols.

 

http://www.ann-geophys.net/30/573/2012/angeo-30-573-2012.pdf

 

"Frequencies of clear sky (cloud cover <20%) and overcast days (cloud cover >80%) were observed to increase by ~2.2 days and decrease by ~3.3 days per decade, respectively, which accounts for ~80% of cloud cover reduction. Larger decreasing trends in cloud cover due to larger increase in clear sky frequency and larger decreases in overcast frequency were observed at stations with lower aerosol optical depth. There is no significant difference in trends regarding cloud cover, clear sky frequency, and overcast frequency between mountain and plain stations. These results are inconsistent with our expectation that larger decreasing trends in cloud cover should have been observed in regions with higher aerosol loading where more aerosols could lead to stronger obscuring effect on ground observation of cloud cover and stronger radiative effect as compared with the mildly polluted regions. Aerosol effect on decreasing cloud cover in China appear not to be supported by this analysis and therefore, further study on this issue is required."

 

Regional warming also correlates to multidecadal variations in the amount of SW radiation being absorbed, as well as to TSI changes, suggesting that some of the variability in the SW changes is due to natural factors, as well as human factors.

 

http://www.sciencedirect.com/science/article/pii/S1364682611002161

 

 

[skierinvermont]

I was responding to your claim that areas that were not previously industrialized but are now going through it are seeing the pause in warming...that hasn't been the case recently. Most of the pause is due to cooling in winter in extratropical northern hemisphere regions (i.e. the nations that have been industrialized for a long time now)

 

Again, all of those phenomenon are the last 10-20 years Cohen is talking about. I was talking about the last 40 years or so.

 

As you can see from my chart above, a lot of the warming since 1970 has come from already industrialized areas (and arctic amplification). 

[skierinvermont]

To back up your point:

 

 

 

This simply reinforces my point. Rapid warming occurred in the industrialized nations after passage of clean air acts during the period 1980-1997. 

My chart also illustrates this by showing how much warming the 1990-2012 period was relative to the 1950-1970 period in the industrialized nations in winter.

[skierinvermont]

I linked you to one of your previous posts suggesting the accepted sensitivity to be 3 Degrees C with a lower bound of 2 Degrees C. The models, which have a ECS of 3.2 Degrees C do generally simulate too much cooling when compared to observations during cooling events like Mt. Pinatubo. In addition, the models underestimate the early-20th Century temperature trend, which suggests they are too sensitive to changes in radiative forcing. In addition, in the GCMs, with just changes in Water Vapor, Lapse Rate, and Surface Albedo only produce an ECS of 1.9 Degrees C. This means that if the Cloud Feedback is negative, ECS can easily be lower than 2 Degrees C.

 

sensitivity chart 2.png

 

A lot of recent studies, as I've said have gradually been shifting away from the 2-4.5 Degree C figure. Quite a few have high probability densities between 1-2 Degrees C, with some even lower than that.

 

Pinatubo studies do not provide evidence of lower climate sensitivity. They provide evidence of climate sensitivity within the IPCC range. We've had this discussion before. There are some legitimate studies giving speculative evidence of climate sensitivity 1.5-2C, but there aren't any rigorously reviewed good studies suggesting anything lower than 1.5C is likely. 

[The_Global_Warmer]

Let's clear something up really quick about liking snow.  99.9% of the members of this board who came here because of winter weather "snow" don't just like snow.

 

 

"Seeking" versus "liking"

Kent Berridge and other researchers have argued for a distinction between reward, which is defined in terms of motivation, and pleasure, which is defined in terms of emotional expression. A simpler way of describing this is as a distinction between "seeking" and "liking". "Seeking" occurs when an animal, given access to some stimulus such as food, executes some type of active behavior in order to acquire it. "Liking" occurs when an animal shows expressions of happiness or satisfaction while consuming something. There is considerable evidence that the dopamine system is part of the brain system that mediates seeking but not part of the system that mediates liking. Drugs that increase the effects of dopamine (most notably stimulants such as methamphetamine or cocaine) produce corresponding increases in seeking behaviors, but do not greatly alter expressions of pleasure. Conversely, opiate drugs such as heroin or morphine produce increases in expressions of pleasure but do not greatly alter seeking behaviors. Animals in which the VTA dopamine system has been rendered inactive do not seek food, and will starve to death if left to themselves, but if food is placed in their mouths they will consume it and show facial expressions indicative of pleasure.^[21]

 

 

 

 

The overwhelming majority of the snow addiction is Seeking behavior.  After the snow falls and is on the ground the seeking behavior stops.  And the liking takes over.

 

Everyone here knows how incredibly powerful the snow addiction is.  If you deny it you're flat out lying.  And the amount of evidence I can trot out to back it up is enormous.  I don't feel like doing that right now.  But if the posts deny this start flying then it's going to turn into SNOW ANONYMOUS in here.
 

 

The levels of which one person is rewarded for this behavior obviously varies.  But the actions taking by the snow seeker are not only distinct and universal to nearly all of the heavily addicted snow seekers.  They are clearly noticeable to everyone around us as something extraordinary.

 

 

Let's cover a few of them:

 

One of the most powerful ones is Model Worshiping.  As the odds of finding snow(the weather cooperating to bring you snow) start to rise.  The seeking behavior continues to intensify.

 

10 days out- Snow threat becomes possible.  Model checking starts to ramp up to a slight degree.

 

7 days out- Models start showing runs with a big snow storm hitting you're area.  Seeking behavior now emits emotional responses in seeker.  Excitement increases, mood is elevated.  At this stage snow seekers start to rationalize the potential let down with lots of it's still way far out talk to try and temper the uncontrollable excitement that has started because the object they seek is still way out of reach.

 

5 days out- Models are now agreeing a snow storm is coming.  But do not agree on location.  This is the stage where a large region of snow seekers are still in the game.  At this point.  Tempering excitement is moot.  But the practice may still be applied by a few but is less effective.  Model obsessing explodes around this time for those in the cone of uncertainty.  Major rationalization begins for why they will get the snow instead of not.  Mood and excitement are elevated much further.  Sleep starts to become interrupted at this point for many to at least a slight degree.  Anticipation starts to come in at this point as well.  Just another reward trigger further intensifying high.

 

3 days out-  Models are now agreeing a snow storm is is coming to a smaller area than before.  Some places are now in the jackpot for more than half of the model runs.  Mood and Excitement are elevation 24/7 at this point.  The snow seeker can not get enough information to reinforce that the snow is coming.  Norepinephrine is free-flowing most of the day at intense levels.  Snow seekers now start to become obsessed at times because of the intense high.  Some of this behavior is tracking time closely and obsessively around model runs.  Snow seekers even have routines they use when getting new model data to maximize the anticipation response.  Snow seekers supplement downtime by creating graphics for "fun".  Snow seekers will sit and hit refresh over and over and over and over and over and over and over and over as model runs come out.  Some model seekers get so amped up they can't handle the anxiety in-spite of the intense pleasure.  So they walk away and do something to occupy their time for 10, 15, 20 min so when they get back they have a BIG CACHE OF MODEL IMAGES TO LOOK AT.  Just another way to maximized the high.  Snow seekers typically are getting half of their normal sleep from this point in.  Yet don't feel tired even though days of sleep deprivation are stacking up.  

 

 

I am stopping there.  I have made my point. This is only a fraction of the snow addicts snow seeking behavior.  For most it's a year round thing.  Everyone here knows all of this. 

 

My favorite tell tale sign of a snow addict is paying money to a guy like Joe Bastardi to tell you what you want to hear.  Another one that is in every local market in snow addict land is personal met preference based off how much a Met conveys like or disdain for snow.

 

 

The snow seeking addiction is very unique and probably very modern.  There is no doubt technology has  huge hand in creating this.

[skierinvermont]

Your second study concerns only the land area of China and is written by chinese scientists and I am not sure the quality of the the review.. I tend to be speculative about any academic research coming out of china. Anyways, it only concerns the area of china so it's not all that interesting to this discussion.

 

Your first study claims a 2.7W/m2 increase in solar radiation reaching earth's surface. This is an incredible finding. If this were the case, there should have been a massive amount of warming. Incredible findings require incredible evidence. This paper was just published and nobody has cited or responded to it, although I did find one very critical response by a reviewer.

[tacoman25]

To introduce some facts into this discussion, the IPCC gives the RF from well-mixed GHGs as 2.8+/-.3Wm/2. The RF for aerosols is -.7W/m2, and the AF is -.9W/m2 (-.3 to -1.5W/m2).

 

They say there is "high confidence" that aerosols have offset a substantial portion of GHG forcing. Best guess appears to be 25%. 

 

Right, so even if we go with that estimate, that's only about a .25C reduction. I would not call that "huge" as you did.

[tacoman25]

Again, all of those phenomenon are the last 10-20 years Cohen is talking about. I was talking about the last 40 years or so.

 

As you can see from my chart above, a lot of the warming since 1970 has come from already industrialized areas (and arctic amplification). 

 

And those areas are also some of the most susceptible to regional climate trends due to 1970-mid 2000s going from -PDO/-AMO to +PDO/+AMO. And of course you have the coincidence of global trends leveling off the same decade the +PDO switched back to -PDO.

 

Again, global dimming and subsequent aerosol reduction has likely played some sort of role (especially in certain regions), but I think there is far more evidence for natural ocean/atmospheric phases modulating overall trends.

[Snow_Miser]

Your first study claims a 2.7W/m2 increase in solar radiation reaching earth's surface. This is an incredible finding. If this were the case, there should have been a massive amount of warming. Incredible findings require incredible evidence. This paper was just published and nobody has cited or responded to it, although I did find one very critical response by a reviewer.

 

Keep in mind that this doesn't represent a radiative forcing, since as the paper notes, this value is partially offset by increased longwave radiation being allowed to radiate to the TOA, due to the decreased Cloud Cover. Even if we assume that 50% of the net SW absorbed (2.3 w/m^2) is cancelled out by the longwave cooling, then that is still fairly substantial, and represents a 1.2 w/m^2 forcing. Again, this is just hypothetical.

 

I'm not sure how much the increased longwave cooling associated with decreased Cloud Cover would offset the increased shortwave radiation being absorbed at the surface, and the paper's abstract did not specify. I remember seeing that the IPCC estimated the net anthropogenic radiative forcing during the late-20th Century to be somewhere around 0.9 w/m^2, so thus, assuming that all of the late-20th Century warming was forced, and natural variability didn't play any role (which is unlikely) you can get a sensitivity that is pretty low.. around 1 Degree C. This is all assuming that the study's findings are correct. There are other studies like Pinker et al. that show Global Brightening over the late-20th Century.. though I'm not sure what the magnitude of the increase is compared to this study's.

[skierinvermont]

Oh and the response by the reviewer that I read points out that numerous other surface and satellite sources which have been considered fairly reliable disagree with the findings of major global brightening. 

[Snow_Miser]

Oh and the response by the reviewer that I read points out that numerous other surface and satellite sources which have been considered fairly reliable disagree with the findings of major global brightening. 

 

Pinker et al. found a 0.16 w/m^2/year increase in incoming insolation during the late-20th Century though.. that would be equivalent to 1.6 w/m^2/decade and that would also be comparable to the value found in the Herman et al. study. Again.. this doesn't represent a forcing.. because the longwave cooling still needs to be taken into consideration.

[ORH_wxman]

Again, all of those phenomenon are the last 10-20 years Cohen is talking about. I was talking about the last 40 years or so.

 

As you can see from my chart above, a lot of the warming since 1970 has come from already industrialized areas (and arctic amplification). 

 

 

I agree those areas had a lot of warming from like 1975-2000...what I was emphasizing was that the nations now being industrialized are not the ones holding steady or cooling as we might deduce from the aerosol theory of 1950-1970. Those recently industrialized areas from 1990-present are still warming while the cooling or flat lining is back in the northern hemisphere extra-tropical latitudes...and not only that, its in winter which is even more against conventional theory.

 

None of this is to reject a hypothesis about aerosols outright, but it does paint a fuzzier picture on what exactly is causing these regional swings in temperature. There's likely some large additional components.

[skierinvermont]

I agree those areas had a lot of warming from like 1975-2000...what I was emphasizing was that the nations now being industrialized are not the ones holding steady or cooling as we might deduce from the aerosol theory of 1950-1970. Those recently industrialized areas from 1990-present are still warming while the cooling or flat lining is back in the northern hemisphere extra-tropical latitudes...and not only that, its in winter which is even more against conventional theory.

 

None of this is to reject a hypothesis about aerosols outright, but it does paint a fuzzier picture on what exactly is causing these regional swings in temperature. There's likely some large additional components.

 

It's true that if we look at just the last 15 or 20 years, a little cooling has occurred in U.S. and European winters, but it's a short enough period and a small enough amount a lot of other factors could explain. I don't think there's been much change in aerosols in those places over that period (maybe a small further decrease I'm not sure). 

 

China and SE Asia has also witnessed no winter warming over that period, which could reasonably be explained by the big increase in aerosols there.

 

While one might expect the aerosol effect to be slightly stronger in winter, winter temps are also more effected by weather patterns and we it reduces the time period of data for the analysis from 240 months to 60 months (DJF).

 

Given the above, it still is probably better to use annual trends to look for possible aerosol effects just because you get 4X more data. If we look at annual trends, we definitely see that China and SE Asia has been one of the slowest warming areas the last 20 years (no warming over much of that area). We still see it looking just at winter as I said before, but there's a lot more global spatial variability because of the smaller amount of data. The annual analysis is better because it gives us 4X more data and a clearer picture.

[tacoman25]

It's true that if we look at just the last 15 or 20 years, a little cooling has occurred in U.S. and European winters, but it's a short enough period and a small enough amount a lot of other factors could explain. I don't think there's been much change in aerosols in those places over that period (maybe a small further decrease I'm not sure). 

 

China and SE Asia has also witnessed no winter warming over that period, which could reasonably be explained by the big increase in aerosols there.

 

While one might expect the aerosol effect to be slightly stronger in winter, winter temps are also more effected by weather patterns and we it reduces the time period of data for the analysis from 240 months to 60 months (DJF).

 

Given the above, it still is probably better to use annual trends to look for possible aerosol effects just because you get 4X more data. If we look at annual trends, we definitely see that China and SE Asia has been one of the slowest warming areas the last 20 years (no warming over much of that area). We still see it looking just at winter as I said before, but there's a lot more global spatial variability because of the smaller amount of data. The annual analysis is better because it gives us 4X more data and a clearer picture.

 

 

For the U.S. overall, winters have been significantly colder the past 6 years. And I know the same is true for Europe for the past 5 years.

 

 

[ORH_wxman]

It's true that if we look at just the last 15 or 20 years, a little cooling has occurred in U.S. and European winters, but it's a short enough period and a small enough amount a lot of other factors could explain. I don't think there's been much change in aerosols in those places over that period (maybe a small further decrease I'm not sure). 

 

China and SE Asia has also witnessed no winter warming over that period, which could reasonably be explained by the big increase in aerosols there.

 

While one might expect the aerosol effect to be slightly stronger in winter, winter temps are also more effected by weather patterns and we it reduces the time period of data for the analysis from 240 months to 60 months (DJF).

 

Given the above, it still is probably better to use annual trends to look for possible aerosol effects just because you get 4X more data. If we look at annual trends, we definitely see that China and SE Asia has been one of the slowest warming areas the last 20 years (no warming over much of that area). We still see it looking just at winter as I said before, but there's a lot more global spatial variability because of the smaller amount of data. The annual analysis is better because it gives us 4X more data and a clearer picture.

 

 

I guess I just don't see anything noteworthy in SE Asia in context to the rest of the globe....Siberia sticks out for landmasses and perhaps Alaska. 

 

 

 

 

 

 

 

If we narrow it to the last 10 years, SE Asia cools more, but the domination still continues from Siberia/Alaska and of course the ENSO influence in pretty much the entire east Pacific:

 

 

 

 

 

 

 

The Cohen study is good because it tells us where the overall trends are coming from. A steep 25-30 year cooling trend across pretty much all of Siberia/Europe in winter definitely is the opposite of what we would expect. That is long enough to be perplexed. The shorter spacial/seasonal trends of 10-20 years are interesting, but still obviously involve a lot of noise.

[Msalgado]

One of the reasons Siberia and Alaska seem to "stick out more" is because of the way the data is displayed.  The map projections used for many of these maps are always going to make high latitude locations seem much larger than places closer to the equator but that is just an artifact of how the data is projected.

[ORH_wxman]

One of the reasons Siberia and Alaska seem to "stick out more" is because of the way the data is displayed.  The map projections used for many of these maps are always going to make high latitude locations seem much larger than places closer to the equator but that is just an artifact of how the data is projected.

 

Even taking that into account, its still a pretty obvious difference. Siberia is enormous anyway just from a longitude standpoint... and it has same latitude as northern Europe/Canada, so while the area will look a little larger on a flat map like that, its not like its up near the pole where the stuff really gets distorted.

[Tropopause_Fold]

Climate sensitivity (warming per doubling of Co2 concentration) is probably the best way to break down peoples opinions into categories. Since you've all used loaded language in you labels, I'll continue with the tradition:

 

1. Extreme alarmist: believes or focuses solely on the high end or even higher than the scientifically accepted climate sensitivity (>4C). Focuses solely on the worst case consequences and denies or ignores all benefits.

 

2. Alarmist: believes or focuses on the high end of scientifically accepted climate sensitivity (3-4.5C). Focuses usually on the worst case consequences and acknowledges few of the benefits. 

 

3. Scientifically grounded: acknowledges the full range of scientifically accepted climate sensitivity (1.5-4.5C). May lean slightly one direction or another within that range based on a good-faith effort to objectively interpret the evidence with assistance of peer-reviewed literature, but acknowledges all of the uncertainty and the lack of concrete evidence. Has a balanced understanding and acceptance of the various consequences and benefits and the evidence that on net the consequences will be negative. A moderate to high level of mitigation is warranted, and adaptation cannot be relied upon solely.

 

4. The biased/arrogant/confused/misled lukewarmer category: believes or focuses solely on the low end or slightly below scientifically accepted climate sensitivity (1-2C). Ignores the evidence that climate sensitivity is probably higher than 2C. Often an undue focus on the benefits of AGW, or downplaying of the consequences. Possibly believes that the benefits of AGW will outweigh the consequences.

 

5. Denier/stupid: believes in a climate sensitivity below the scientifically accepted range (0-1.5C). Usually focuses on the benefits of warming and downplays the consequences. Probably believes that the benefits of warming will outweigh the consequences.

 

6. Extreme denier/stupid: believes CO2 has little to no warming effect. If warming did occur, it would be good.

in the context of this forum...the above may hold some water. but outside of the 20 or so posters who frequent this sub-section of AmericanWx...the above categorization is ridiculous. 

[LocoAko]

A lot of these are open questions that have not been resolved. The "pause" in the warming has shown how poor our understanding of the climate system is. To claim that the science is setlled and we know all, is ignorant and arrogant.

I keep seeing this brought up as some sort of talking point, but who has stated that we "know all"? Seriously.

[tacoman25]

I keep seeing this brought up as some sort of talking point, but who has stated that we "know all"? Seriously.

 

The attitude of many AGW alarmists that I have encountered has tended to be "the science is settled", without wanting to acknowledge the rather large uncertainties that exist about complexities/feedbacks within our climate system. There also seems to be a lack of understanding by many that the science can be solid and well researched, but still wrong about a lot of things.

 

Which is why you often see peer-reviewed studies that are at odds with each other - not everyone can be right, and often the most widely "accepted" view early on in a scientific field does not turn out to be entirely correct.

[LocoAko]

The attitude of many AGW alarmists that I have encountered has tended to be "the science is settled", without wanting to acknowledge the rather large uncertainties that exist about complexities/feedbacks within our climate system. There also seems to be a lack of understanding by many that the science can be solid and well researched, but still wrong about a lot of things.

 

Which is why you often see peer-reviewed studies that are at odds with each other - not everyone can be right, and often the most widely "accepted" view early on in a scientific field does not turn out to be entirely correct.

The bolded is definitely the case (I see it with my friends all the time). I guess I mostly don't care what a lot of alarmists or deniers say, so when I hear statements like this, I think of the scientific community. In that sense, I take "the science is settled" to clearly mean that we ARE warming and it IS anthropogenically-induced, but I don't hear people claim we know everything.

[Isotherm]

Here's the chart FWIW. The UK's warming looks pretty pronounced compared to the surrounding ocean and much of the rest of the NH. It's also interesting to me that Europe and central Asia warmed faster than the arctic or even norther Asia. Almost like a stripe of aerosols had been lessened blowing across the continent. Usually it seems like the fastest warming is a bit farther north than that.

 

 

 

I always get a kick out of images like the above. You're taking the period 1990-2000s and comparing it to the notorious cold cycle -PDO/-AMO of the 1950-1970, thereby skewing the anomalies much warmer than they should be. The comparison time frame should have more years inclusive of a warm cycle (or at least partially - maybe 1950 to 1990) if one is looking to achieve accurate anomalies, but that is not the case.