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Comments 31601 to 31650:

31601. Tom Dayton at 15:35 PM on 21 February 2015
       Models are unreliable
       

       Sangfroid, you wrote "Most scientists do not understand randomness and the role it plays in all aspects of our lives. We exist totally due to randomness."

       You are wrong on both counts.  For example, biological evolution is not "totally random."

       Regarding weather versus climate, see the post "The difference between weather and climate."  After you read the Basic tabbed pane, click the Intermediate tab.

       See also "Chaos theory and global warming: can climate be predicted?" which has Basic and Intermediate tabbed panes.  And "The chaos of confusing the concepts." 

       If after that you still believe most scientists do not understand randomness, read the seven-part series "Natural Variability and Chaos" at ScienceOfDoom.

31602. Stephen Baines at 15:07 PM on 21 February 2015
       Models are unreliable
       

       typos!

31603. Stephen Baines at 15:06 PM on 21 February 2015
       Models are unreliable
       

       Tom's

       That answer is spot on.  I have to write that down.  I think its worth reemphasizing that the models do not make a sngle set of predictions - for example of global temperature. People who question models often talk as if they do, but in fact these models actually make many different predictions about the atmospheric and climate.  Each of these can be compared to observation.  the number of different sorts of predictions actually provides a fairly stringent test of the models

31604. Tom Curtis at 15:06 PM on 21 February 2015
       Models are unreliable
       

       Sangfroid @791:

       "Also, it would be very eye opening to see the source of the actual data, how it is interpreted, and what assumptions are included in their climate models. If we demand openness in government we should also demand it on something as importand as this."

       The assumption here is that the data is not available to the public.  That assumption is false.  For all climate models, the basic assumptions and fundamental equations are specified in the peer reviewed literature, as for example the GISS Model E.  Updates will also result in detailing in the peer reviewed literature, either in seperate papers for major updates, or as part of the paper in which the update is first used for minor updates.  Further, for some models (notably the GISS Model E) full code is available for earlier versions, and considerable effort is made to make the code available to the public in a convenient format, as detailed here.  Nor is NASA alone in granting this level of access to the code.  Indeed, one climate model (CCSM 3.0) was explicitly designed to be available to the public, and is freely downloadable along with all relevant documentation.

       So, the problem is not the availability of code and assumptions for analysis.  It is that so called "skeptics" do not make use of resources made available to them to run their own climate experiments, or to modify the models according to the principles they think will hold.  I presume that is because they are quite aware that the result, if they did, would be a very much poorer fit with the data than is provided by the standard models.

31605. Tom Curtis at 14:37 PM on 21 February 2015
       Models are unreliable
       

       Sangfroid @791, there is a major difference between the stockmarket (or currency trading) models and climate models.  That is, the stockmarket models are entirely statistical.  In contrast, the climate models encode well established physical laws into mathematical representations of the atmosphere.  These are laws such as consevation of energy, conservation of energy, radiative transfer physics, boyles law etc.  Because we cannot represent the atmosphere molecule by molecule, (or indeed, kilometer by kilometer), some of the laws are approximated based on empirical estimates of the effect of the laws in the real atmosphere.  Consequently, when these models retrodict the temperature series, without having been trained on that temperature series, that is a significant prediction.

       The achievement is even more impressive in that the models do not predict just a single time series (again unlike stock market models).  The predict temperature series for a variety of different altitude and depths of the ocean.  The predict major atmospheric and ocean circulations (including ENSO like effects).  The predict precipitation changes, and changes in sea and land ice.  They are not perfect at any of these - indeed do not always agree among themselves at any of these - but they do so with very far above chance accuracy.  This would not be possible if they did not get the fundamental processes right - and if they were not in the right ball park for the subtle effects.

       So, quite frankly, I consider your analogy to be on a par with somebody insisting that because a particular sum cannot be calculated in a reasonable time on an abacus, it cannot be calculated in much better time on a Cray xc-40.

31606. Rob Honeycutt at 14:29 PM on 21 February 2015
       Models are unreliable
       

       Sangfroid...  There's a huge difference between financial models and climate models. Climate models are based on physical processes. Financial models are subject to varying human behavior. Gavin Schmidt has a great TED Talk about climate models that you should listen to.

       "Weather [...] is totally random."

       If weather were totally random then you'd get snow in the summer and sweltering heat waves in the winter. Your statement is patently absurd.

       With regards to the rest of your comment, all the information is there. You just have to dig in and start reading. Understand that the body of scientific research is produced by researchers who've dedicated their lives and careers to getting this stuff as accurate as possible. 

31607. Sangfroid at 14:17 PM on 21 February 2015
       Models are unreliable
       

       When I had taken on the task of learning to trade stocks and currency a few years ago, I was amazed at the number of 'models' that were 'back tested' to be accurate. They tended to be somewhat accurate - until they failed.

       Most scientists do not understand randomness and the role it plays in all aspects of our lives. We exist totally due to randomness. Weather - despite how much we think we understand the interactions of everything that affects weather - is totally random. We will never be able to predict, with certainty, the future of weather. 

       Many, if not all, of the so called solutions to curb CO2 emmisions, or to curb sunlight, or to convert to alternate energy sources, - although they may be necessary - do not address the effects on many people in the middle income brackets and below. Some do not address the potential negative effect on our health. 

       I would like to see the data that scientists use to predict the negative effects on our environment, animals and humans. Polar bears are often used as an example. Polar bears can survive without the ice covered artic as they do in parts of eastern Canada. 

       Also, it would be very eye opening to see the source of the actual data, how it is interpreted, and what assumptions are included in their climate models. If we demand openness in government we should also demand it on something as importand as this.

31608. michael sweet at 11:17 AM on 21 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Drebich,

       When you start your post off with "Please don't think that I am trying to be facetious in anyway" and then say "any higher, Man Made Global Warming, any lower,.....well....Man Made Global Warming" you come across as facetious, rude and disrespectfull.  Perhaps you need to check your posts before you post them.  If you cannot abide by your own post why don't you just go away?

       Moderator Response:

       [PS] Would anyone else tempted to comment here please note the "no dogpiling" rule in the comments policy. I think Drebich has been given enough to think about already and will hopefully use the resources to become better informed.

31609. Rob Honeycutt at 10:22 AM on 21 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       drebich...  No offense intended here, but each of your questions is about what "should" each of these aspects of the climate system be. That's an irrelevant question. The problem is related to the rate of change that is being caused by human CO2 emissions and how those change will impact natural and human systems.

       But, please do take the time to read through the relevant materials to fully inform yourself before coming to a firm conclusion one way or another. The science is there, it's very well established, and scientists have a very high degree of certainty that continuing on the emissions path we're on through the 21st century would bring with it severe consequences.

31610. Tom Curtis at 10:17 AM on 21 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       drebich @19, your questions are nonsensical.

       Taking the first question, sea levels change regionally due to changes in wind circulation and ocean heat content.  On top of that, there are tides, waves, and storm surges, all of which contribute to a very variable local sea level.  Finally, different shores are rising, or falling due to plate tectonics, and in some locations, due to an ongoing rebound from the melting of the massive ice sheets of the last glacial.  Consequently, while taking an average of a globally distrubuted collection of tide gauge measurements can unequivocally show that sea levels have rising at a rate inconsistent with the planet not warming (see graph below), no mark on a beach can plausibly be a demarcation point, unless set high enough that it will not be passed for several decades.

       

       Your second question makes even less sense in that you want a demarcation point between ice age and global warming from sea ice.  That is a nonsense request as, first, the cause if ice ages is the spread of ice sheets on land, rather than the sea ice itself; and second because we have just come of 10,000 years of interglacial (colloquially, not an ice age) which was not a period of global warming, let alone anthropogenic global warming.  While the history of sea ice in the NH unequivocally shows the current dearth of sea ice to be astonishing (absent global warming) and unprecedented in recent times (see graph below), there is no limit such as you illogically ask for.

       

       Your third question, unfortunately shows that your post is an entirely rhetorical excercise.  That is unfortunate because, allowing for a small middle range, it is the most easilly answered.  The fact is that Global Mean Surface Temperature (GMST) has not recently varied greatly with time.  Over the last 10, thousand years, the temperature range has been about 1 C, yet we in the last century have seen the temperature rise from near the lowest value in that period to probably the highest:

       

       Again, this rate of temperature increase is unprecedented over the last 10,000 years and probably over the history of the Earth.  Further, that temperature keeps on rising, with new records for GMST having been set in 1973, 1980, 1981, 1987, 1988, 1990, 1995, 1997, 1998, 2005, 2010, and now 2014 (GISS LOTI, other indices will vary slightly), ie, on average once every four years over the last forty odd years.  (In contrast, the last cold record GMST was in 1909.)  If that average rate of new records is maintained, then we have global warming.  If temperatures fall below the 1970s average without major volcanism, a nuclear war or a massive asteroid bombardment, then global warming has stopped.  The evidence currently certainly indicates continuing global warming.

31611. Rob Honeycutt at 10:14 AM on 21 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       I just noticed that link to the biggest control knob video is old. You need to go here now to view that video.

31612. drebich at 09:28 AM on 21 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       I am obviously not a scientist. I am just an average working person, but I do have a few questions. Please don't think that I am trying to be facetious in anyway, but I cannot help the fact that "Man Made" Climate Change Scientists come across (to me) as being quite intellectually arrogant (perhaps for good reason).  So, based on the fact that we all are standing on thin, broken slabs of earth floating on a massive ball of molten rock, here are my questions:

       1. Sea levels are rising-Which Scientist is willing to take me down to the beach, draw a line in the sand and say "That is where sea level should be, any higher sea level is rising, any lower, sea level is receding.
       2. The Polar Caps are melting-Which Scientist is willing to declare how many square miles of ice caps the earth is supposed to have, any more, Ice age, any less, Man Made Global Warming.
       3. Man Made Global Warming-Which Scientist is willing to commit to a fixed average temperature of the earth and declare that that is what the temperature has to be, any higher, Man Made Global Warming, any lower,.....well....Man Made Global Warming.

       Again, I am not trying to be rude or disrespectfull in any way, these are just questions an average person would like to have a scientist responde to.  I see alot of data and numbers in the comments on here. Alot of talk about trends, averages, and percentages. But it all seems irrelavent in relation to this huge planet, with all its tremendous power, and with all the monumental changes over billions of years. Continents moving and colliding, ice ages, seas of boiling sulfer.  I mean, it just comes across as almost unintelligent to think that man could possibly have any influence at all.  I do believe in Climate Change because, well...., the climate changes and has been for longer than 200 years. And I didn't even need to be a scientist to know that.

       Regards,

       Daniel

       Moderator Response:

       [RH] Welcome to Skeptical Science! There is an immense amount of reference material discussed here and it can be a bit difficult at first to find an answer to your questions. That's why we recommend that Newcomers, Start Here and then learn The Big Picture.

       I also recommend watching this video on why CO₂ is the biggest climate control knob in Earth's history.

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31613. Tom Curtis at 09:10 AM on 21 February 2015
       Tom Harris' Carleton University Climate Misinformation Class
       

       It turns out that Scholar's and Rogues has an excellent series dissecting Tom Harris's prevarications and hypocrissies.  So far we have:

       Tom Harris – hypocritical peddler of deceitful climate change editorials

       Tom Harris’ recent commentaries rife with errors and illogic

       Tom Harris places absurd limits on scientific truths and elevates ignorance to equal knowledge

       Tom Harris distorts the maturity of global warming science and imagines expertise where little exists

       Tom Harris’ commentaries intended to impede, not advance, public understanding of climate science

       The series has one more post to go, and is written by Brian Angliss.  Tom Harris makes an appearence on comments.

31614. wili at 07:33 AM on 21 February 2015
       A melting Arctic and weird weather: the plot thickens
       

       Another good discussion of these interconnections at robertscribbler: Mangled Jet Stream + Global Warming + Hot Atlantic Water = Boston Buried Under 8 Feet of Snow

31615. hank at 07:15 AM on 21 February 2015
       A melting Arctic and weird weather: the plot thickens
       

       Living in California, I know the area has paleo (lake sediment) proxies showing extreme prolonged dry spells; one academic page has cites: 

       http://blog.lib.umn.edu/stgeorge/geog5426/2010/11/summary-of-megadrought-ii.html —

       quoting from one:

       "Laird PNAS 2003 paper is a story about large-scale moisture shifts across the northern prairies of North America during the past 2000 years. Authors using 6 lake sediments across the North American prairies show that two different types of major shifts in moisture regimes (from wet to dry or from dry to wet) existed for at least the last two millennia.... Such large-scale moisture shifts were thought to be caused by the expansion of the polar vortex, and may be a common phenomenon which may reoccur over longer time frames. The differences in timing of moisture shifts were explained as the fluctuations in the position and shape of the jet stream."

       (They don't say _why_ the jet stream varied in the past, and I'm assuming you'd have to look through a lot of proxies over a large area to guess) 

       Is there enough data on year to year variability over the long term past to say what's happening now is within that "noise" or is a detectable climate signal emerging from the noise?

       Moderator Response:

       [JH] Link activated.

31616. danielbacon at 05:15 AM on 21 February 2015
       A melting Arctic and weird weather: the plot thickens
       

       With the last SSW around the first of this January.

31617. danielbacon at 05:08 AM on 21 February 2015
       A melting Arctic and weird weather: the plot thickens
       

       In your research do you exclude the effects of Planetary-scale wave activity for stratospheric sudden warming events (SSW) that weaken the stratospheric Vortex (SVW)? It would seem that the primary driver for (troposphere) Northern Hemisphere Wintertime Weather is the propagation of the Arctic Oscillation from the stratosphere by SSW and SVW or I am confusing the issue in my head?

31618. Roger D at 00:34 AM on 20 February 2015
       LBJ's climate warning 50 years ago - do we have your attention yet?
       

       Thanks for this. Great points to counter the misimpression of many contrarians that concerns over global warming are primarily based on an Inconvenient Truth, or began with the formation IPCC, ideas that the conspiracy minded really want to hold on to. That the reality of today syncs very well with the scientific understanding of half a century ago, forming a foundation for continued understanding is a powerful argument for climate science.

31619. alby at 19:13 PM on 19 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Sorry I wrote 0.017 instead of 0.17

       ...and now I see teh short answer from Kevin C.

       Regarding Gleisner in Fig. 5 they found the arctic influence to global T trend, because on fig. 5 the difference from original HadCRUT4 data (yellow line) and Gleisner (black lien) starts from latitude > 70 N.

       Additionally Kriging (blue line) increase the global T from 0.08 up to apporx. 0.11 but (comparing to Gleisner trend) with a visible contribution (approx. 0.02) coming from latitude < 70

31620. alby at 19:01 PM on 19 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       gregcharles: the articles doesn' t misreports T trends. Look at the right end (right because the graph is cumulative) of fig.5: original data from HadCRUT4 (yellow line) shows  for the period 1997-2012 a trend of 0.05 °C/decade (less than 0.017) as reported in the article before fig. 1  "The trend in HadCRUT4 over that period is about 0.05°C/decade". Now, there are two facts:  the artic trend alone is much higher (approx. 1.5 °C/decade) and the surface of the artic region is roughly 1/10 of the global surface with only a partial coverage from HadCRUT4. Consequently including the "missing region" of the artic in the global trend this will increase, adding 0.03 or 0.04 to 0.05 to, up to 0.08/0.09 (see black line on the right end of fig.5). The "missing region" is (quote from the article)    due to "HadCRUT4 had on average 64% coverage for the region north of 60°N ... This region corresponds to about 6.7% of the planet's surface. Therefore the missing region corresponds to about 2.5% of the planet"

       0.36 x 6.7% = 2,41%% or roughly 2.5%

       and 1.3 °C/decade x 2.5/100 = 0,03 °C/decade (for 1.7 the contribution is 0.4).

        I hope (if I'm right, if not someone will correct) to have been clear.

31621. Kevin C at 18:37 PM on 19 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       No, the trends N of 70N really are around ten times higher than the long term trends for the planet as a whole. That is how 2.5% of the planet can influence the global trend. That may seem incredible, but it is confirmed by us, Berkeley, all of the reanalyses and AVHRR. GISTEMP capture most of it, albeit with poorer coverage and some other problems.

       And actually so does the Gleisner reconstruction, despite the fact that they say they can't find it - that was a bit strange.

31622. gregcharles at 13:10 PM on 19 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Thanks to Firgoose for working out those links. I was also scratching my head after first clicking on the Check It Yourself links.

       Another head-scratcher for me: does it seem like this article consistently misreports temperature trends by a factor of 10? For example, "The rate of Arctic warming in the MERRA for region north of 70°N, where most of the missing coverage occurs, is 1.3°C/decade. The ERA-interim reanalysis shows a higher rate of 1.7°C/decade." Global warming trends are about 0.17°C/decade, right? Maybe, I'm misunderstanding what's being reported here.

31623. jja at 11:13 AM on 19 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Kevin, thank you for your reply, sorry for the late response.  The DMI data that I was referencing is the "north of 80N" series found here:
       
       http://ocean.dmi.dk/arctic/meant80n.uk.php

31624. Tom Dayton at 02:59 AM on 19 February 2015
       We're heading into an ice age
       

       Climate Dialogue has a good and recent overview of the potential effect of a new Maunder Minimum, in its "Introduction" to that topic.

31625. Tom Dayton at 02:57 AM on 19 February 2015
       It's the sun
       

       Climate Dialogue has a good and recent overview of the Sun's potential role in Earth's temperature increase--not just with regard to the effect of a new Maunder Minimum--in its "Introduction" to its New Maunder Minimum topic.

31626. ranyl at 20:17 PM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Thanks Kevin.

31627. One Planet Only Forever at 13:36 PM on 18 February 2015
       Scott Mandia on teaching students to debunk climate misinformation
       

       You should consider ensuring you use the terms 'skeptic' and 'climate denier' accurately in your presentations.

       The New York Times recently presented this article "Verbal Warming: Labels in the Climate Debate". (this is also one of the articles in the 2015 SkS Weekly News Roundup #7B)

       The article is about a US scientist, Mark B. Boslough, who objects to calling people who create unjustified attempts to discredit climate science 'skeptics'. His open leter on the matter has spawned a petition to have the media refer to such people as 'climate deniers' rather than 'skeptics'.

31628. jja at 09:56 AM on 18 February 2015
       NASA climate study warns of unprecedented North American drought
       

       Ben Cook's intimation that the current california drought is a natural cycle event is overstated.  His work can only assert this is natural because the regional sea surface temperature anomalies do not show up in the climate models and there is no downward precipitation treand that is statistically significant from the highly variable history data.
       
       It is very likely that the models are simply not adequately addressing regional anthropogenic aerosol patterns, the effects of Hadley expansion in mid-latitudes, the combination with this and arctic amplification effects on the jet stream, shifts in the inter-tropical convergenze zone due to north vs. south hemisphere aerosol loading and (possibly) the effects of deforestation in the south american tropics See:  http://www.accuweather.com/en/weather-news/amazon-climate-change/20184965
       
       

       "All of this has to do with a tipping point," Symington said. "With deforestation, if you go beyond a certain point in the Amazon there's an issue of where the whole system becomes destabilized and you would switch from a tropical, moist forest system, to something that was much drier and more like the Cerrado of central Brazil, sort of a dry forest, savanna system. If that happened it would have a huge impact on species in the Amazon and also on the climate."

       About 20 percent of the fresh river water in the world comes from the Amazon River, and drying of the forest can negatively influence that water source. Symington told Accuweather.com that changes to this freshwater output would affect the entire current off the coast of South America, which could affect the jet stream, which would ripple into a change in weather patterns across the globe.

31629. Tom Curtis at 07:30 AM on 18 February 2015
       NASA climate study warns of unprecedented North American drought
       

       Firgoose @6, BAU may be limping, as you say, but that does not mean the course we follow will be towards less CO2 emissions.  It is very possible that a dirth of sources of liquid fuels will result in replacement by fuels that emit far more CO2 over the entire production process, per liter of fuel used on the road.  That would switch us to a BAU+ path rather than the BAU- path we are currently limping along.

31630. Kevin C at 05:31 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       If there's a way to get the trend in KNMI, I haven't found it either. Click 'raw data' above the third graph and copy it into a spreadsheet. The lack of 700mb trend you can see by eye though.

31631. Firgoose at 05:25 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       For those, like me, who clicked the "Check it yourself" links and came back with a well-scratched head, wondering why both links go to the same place, and what to do with this amazingly complicated looking, scrollfest of an interface anyway? ... the instructions are in a tooltip that shows if you hesitate over "Check it yourself" for long enough before clicking; a fortunate but accidental discovery in my case. ;-) Reading tooltips while clicking widgets on a different page is for magicians so here are the instructions ...

       For the ERA-interim reanalysis rate of Arctic warming in the region north of 70°N : Select ERA or MERRA (show/hide) — click temperature/2m (radiobutton) — click "Select Field" (button) — fill in latitudes 70N-90N — optionally click "convert to Celsius" (radiobutton) — click "Make time series" (button).

       If I did it correctly, this should be a direct link for ERA.

       LINK

       And for MERRA

       LINK

       For the trend "3km into the atmosphere to the 700mb level" it's almost identical to the above : Select ERA (show/hide) — click temperature/700mb (radiobutton) — click "Select Field" (button) — fill in latitudes 70N-90N — optionally click "convert to Celsius" (radiobutton) — click "Make time series" (button).

       LINK

       However, if the results are supposed to draw the trend or and give a value, I've no idea what I missed. :-/

       Moderator Response:

       [RH] Shortened links that were breaking page format.

31632. Kevin C at 05:07 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Ribwoods: Fixed, thanks. (Figure 1 was a late addition)

       jja: The Arctic report card doesn't go into the methodology in detail, but an average to 60N will be dominated by the stations in the 60-70N band. ERA-i, JRA, Berkeley Earth and ourselves all show less extreme temperatures on the region N of 70N in 2013.

       wili: That's something we're hoping to look into, but haven't had a chance to yet.

31633. wili at 04:37 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Thanks for the response, Kevin. "We've seen examples of rapid Arctic warming like this in models, but is is never longlived. That suggests we shouldn't expect the trend to continue"

       So, do we have any idea what drives periods of greater rather less rapid Arctic warming? If we don't, how can we know that this is really something cyclical, especially with all the added forcings and feedbacks of our ever wierder global wierding?

       By the way, I see that temperatures north of Norway now reach into the 40s F (5.5 C).  earth.nullschool.

31634. ribwoods at 03:43 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       And in the second paragraaph after Fig. 5, the fourth sentence starts "The results are shown by the black points in figure 4 ...:, but s/b "... in figure 5 ..."

31635. ribwoods at 03:35 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       In the article, the paragraph just prior to Fig. 3 starts "The errors in the different reconstructions by month are shown in figure 2", but should be "... in figure 3."

       The paragraph just prior to Fig. 4 starts "If we include all three temperature reconstructions in the latitudinal temperature plot, we obtain figure 3", but s/b "... obtain figure 4."

       The second paragraph after Fig. 4 starts "One other feature is shown by the thin grey lines in figure 3", but s/b "... in figure 4."

       The paragraph just before  Fig. 5 ends with "This period is shown in figure 4:", but s/b "... in figure 5:"

31636. jja at 03:28 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Kevin,
       
       WRT your response above, the ARC for 2014 showed that 2013 was near the record high warming (fig 1.1) http://www.arctic.noaa.gov/reportcard/air_temperature.html
       
       and the DMI has winter 2014 as near record high as well.  Please explain?

31637. Firgoose at 03:16 AM on 18 February 2015
       NASA climate study warns of unprecedented North American drought
       

       "If we follow the business-as-usual path, ..."

       Fortunately, this statement will become as redundant, tedious and irrelevant as the apparently mandatory "If all the ice in [Antarctica | Greenland] melts". All of that ice is not going to melt for a very long time and we're not going to follow business as usual. We're already not following that trajectory, as both intention and action increase at the political and corporate levels.

       The writing on the wall is being read, deniers are becoming dinosaurs walking on ever soggier sands, may their bones make interesting fossils. Joe Public is becoming more sympathetic to the plight of the future even if there's still a lot of resistance to actually doing anything personally. Joe will come round, whether stampeded by Gaia saying "Boo!" or herded by the Powers That Be/Will Be.

       Forsooth, we probably won't get to a "below 2°C" but "business as usual" is limping and is going to have to drop out of the race.

31638. Kevin C at 02:10 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Ranyl: Yes, I think you've got the gist of it. I guess you'd call it a cumulative zonal trend plot. The uptick in the last 30 degrees on the right is the Arctic contribution to the global trend. Given the tiny area concerned, you would expect it to be flat. But it isn't, even in the Gleisner reconstruction, showing that the Arctic is playing a role.
       
       The difficulty with the non-cumulative version is that the affect of the different areas of the zones is lost, unless you choose equal area zones.

       Wili: We've seen examples of rapid Arctic warming like this in models, but is is never longlived. That suggests we shouldn't expect the trend to continue. And indeed the last two winters support that expectation.

31639. wili at 01:20 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       If these trends of much faster warming in the Arctic than in equatorial regions continue, at what point do we reach an essentially equable climate for the Northern Hemisphere? What would happen between now and then wrt the Hadley cells? What will be the effects on the ground of these shifts?

31640. One Planet Only Forever at 01:20 AM on 18 February 2015
       NASA climate study warns of unprecedented North American drought
       

       To maintain a more scientific focus I recommend revising the statement "If we follow the business-as-usual path, ..." to more specifically describe the issue. More descriptive alternatives would be:

       • If we do not significantly change the motivations ruling the global social-economic-political systems, ...
       • If we do not significantly limit specific ways that people can succeed in the global social-economic-political system, ...
31641. ranyl at 00:23 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Thanks Kevin,

       Just a question re-figure 2 and those related.

       At first glance it seemed to be showing the decadal warming at different latitudes and was thus surprising that there is no polar tick as you say in both pre and hiatus periods, for both poles are warming reasonably rapidly, as you say, the Arctic up to ~1.7C/decade.

       Then it dawned on me that each segment is actual the temperature trends for each degree of latitude North and South of the equator, so the 10 point represents the region between, 10N to 10S, 20 represents 20N to 20S and so on, and thus by the time you get 90N to 90S, you have the entire globe and therefore the post-hiatus period is showing little to no global warming overall.

       However it seems there is a marked cooling trend in the post hiatus equatorial region (rising at 0.3C to falling at 0.2C figure 2), so quite a shift in trend of -0.5C in a decade or so, which I presume is mainly due to the La Nina predominance and increased oceanic heat uptake in the tropical regions.

       And despite this marked tropical cooling trend the overall globe isn't cooling it is slightly warming figure 2. It does seem as if the regions from 20-50 N/S latitude make the majority of the contribution (~0.2C decade) and then there is a dipped line from 50- 70N/S suggestive of a cooling region (in keeping with cold NH winters recently) and then a further upturn to zero by 90N/S (~0.02decade) looking at the Hadcrut black line.

       Which for me sort of implies that the Arctic contribution is there, and quite significant, and in keeping with you estimate of 0.03 to 0.05C (on the Kriging line it seems like definitely 0.05C per decade (figure 4)).

       Therefore for me the graphs seem to imply that there has been a very strong cooling influence the tropics and from 50-70N/S (the dip on the graph) and warming influences between 20-50N/S and from greater than 70N/S.

       Therefore if that is the case the Arctic tick is there and significant it is just lost in a graph whose horizontal scale is cumulative rather than representative of a specific regional areas (the maximum the Arctic can influence the global temperature is 0.05C per decade as you say and that is what it seems to do).

       Is that right or have I missed something?

       It would be interesting to see a plot of 10 degree slices, i.e. 10N to 10S followed by 10-20N and 10-20S and so on; wonder if that would allow the Arctic trend to be seen a lot more readily?? Or to plot it the other way round, from 90 to 0, where 0 N/S is the whole globe to see the tropical influence on the whole globe more?

31642. Kevin C at 00:06 AM on 18 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       The ice melting question is slightly different, although it's worth clarifying.

       Ice melting/freezing anchors arctic air temperatures at around 0C for most of the summer. So the rapid Arctic warming we've seen is purely a winter phenomena. If you plot the Arctic temperature trends for winter alone, the trends are even higher than when looking at the whole year.

       Having said that, since 2012 temperatures have stabilised or retreated a little. I don't think we're seeing any kind of tipping point or runnaway event in the Arctic.

31643. Tom Curtis at 23:42 PM on 17 February 2015
       Human CO2 is a tiny % of CO2 emissions
       

       I am not sure what favourite WUWT graph KR refers to, but I imagine it looks something like this:

       

       As you can see, there is a clear correlation between the CO2 records, and the temperature record.  Of course, these are not the simple records.  What I have done is to take each year from 1964-2009, and divided by the average of the eleven nearest years (inclusive).  The purpose of doing that is that it eliminates any long term trend while retaining the annual variation.  That is a good thing, because it allows me to take a regression of the two time series against each other, thereby determining the natural scale that maximizes similarity between the time series.  In this case, that natural scale is 8.7, as indicated in the title.  That is, for every 1 degree C increase in temperature, from this data we expect an 8.7 ppmv increase in CO2 concentration.

       Put another way, based on the actual temperature and CO2 data, we expect the 1 C increase in Global Mean Surface Temperature (GMST) from 1910 to 2010 to have resulted in an 8.7 ppmv increase in CO2 concentration.  As it happens, it has increased a little more than that.

       Just using the GISS LOTI and Mauna Loa data used in constructing the graph, we can determine the approximate increase in CO2 from 1964 to 2009 was 67.95 ppmv (difference of eleven year means), while the temperature increase was 0.61 C.  From that data, using the regression above, we can determine that just 5.29 ppmv of the increase was due to the increase in GMST, ie, just 7.8%.  

       However, there is still a strong correlation between temperature and CO2 over the period of Mauna Loa observations.  Indeed, the correlation is 0.935 (RSQ = 0.874).  That is not as good as the correlation between CO2 and cumulative emissions I mentioned @269 above.  But it is still impressive.  Very much better, for example than the 0.574 correlation (RSQ = 0.329) between the values once the trend is removed.  That stronger correlation between the trend than the annual values tells us that, most probably, one is significantly responsible for the other.  That is, either temperature is largely responsible for the CO2 trend; or CO2 is largely responsible for the temperature trend.  However, we have excluded the former already with our regression.  Ergo, the correlation between the annual data shows that the increase in CO2 is causing the increase in temperature (or at least, is largely responsible for it.)

       It is no wonder Rickeroo (@266) invites us to have a "cursory look" at the data.  If we only had a cursory look at the data, you might believe his interpretation of it.  Once you analyze, it, however, you can see it conclusively refutes all of his claims.  

31644. Dikran Marsupial at 23:32 PM on 17 February 2015
       Human CO2 is a tiny % of CO2 emissions
       

       Rickeroo wrote: "Any cursory look at two readily available data sets, Mauna Loa CO2 and global temperature by year, clearly shows that temperature is a strong driver in how much CO2 ends up in the atmosphere on a yearly basis."

       The correlation between temperature and the annual change in atmospheric CO2 is well known and has been since at least the work of Bacastow in the mid 1970s, and is largely due to the effect of ENSO on precipitation in the Americas, which in turn affects the uptake and release of CO2 by land vegetation (as KR mentions).  This is explained in more detail in my article on Prof. Salby's misunderstanding of this correlation, where I show that a correlation with the annual increase has no mathematical relation to the cause of the long term rise (as the correlation is insensitive to the mean value of the annual increase, but it is the mean value that explains the long term rise.   In particular, see the section "What does Mainstream Science say about all this?".

       Some claim that this correlation is due to Henry's law, which suggests that the solubility of CO2 in the oceans depends on ocean temperature.  However this neglects an important fact, which is that Henry's law also tells us that the solubility is proportional to the difference between the partial pressure of CO2 in the atmosphere and the concentration in the surface waters.  Thus as atmospheric CO2 rises, its solubility in the oceans increases and the oceans take up CO2 in opposition to the rise in atmospheric CO2.  It is the constant of proportionality that is sensitive to temperature.  This is a good thing as it is a negative feedback that keeps the climate system more stable than it would otherwise be.  So which factor dominates?  The fact that atmospheric CO2 is rising more slowly than we are emitting CO2 into it shows that the natural environment as a whole is a net carbon sink, which tells us that the long term rise is being opposed by the natural environment, rather than being caused by it.

31645. Esop at 23:23 PM on 17 February 2015
       Missing Arctic warming does contribute to the hiatus, but it is only one piece in the puzzle.
       

       Very interesting discussion, Kevin!

       As was mentioned in the comments on the other thread, the fact that the months with powerful Arctic blasts into lower latitudes (for example February and November 2014) produced a dip in the global average should indicate a very real cool bias due to not properly measuring the changes in Arctic heat. In other words, cold Arctic air flows south where we properly measure its cooling impact, but due to poor Arctic coverage, the impact of the heat flowing north is not properly measured in the Arctic, causing a cool bias due to the shuffling of air masses in the NH.

       We know that surrounding air temperature pretty much stays unchanged when ice is melting. Could the heat partly hide from the measurements by being used to melt sea ice rather than heat the surrounding air?

31646. ryland at 16:05 PM on 17 February 2015
       NASA climate study warns of unprecedented North American drought
       

       Will@3  you may find the public are not as amenable to change as you might like.  Pieces in the MSM such as that  in today's Australian by Garth Paltridge a former CSIRO Chief Scientist and Director of the Antarctic Co-oerative Research Centre,  which has some very critical comments about Climate Change, may well dissuade many from becoming to concerned about the future climate.

31647. ribwoods at 14:43 PM on 17 February 2015
       Newcomers, Start Here
       

       Might moderators find the following response to cagwskeptic helpful?  If not, feel free to delete this post.

       - - - -

       cagwskeptic @245, Are you overlooking that:

       (1) since the Industrial Revolution, manmade machines burning fossil fuels have been emitting more and more CO₂ into the atmosphere,

       (2) these anthropogenic CO₂ emissions are in addition to all the natural processes that governed atmospheric CO₂ levels before the Industrial Revolution, and

       (3) recently our anthropogenic CO₂ emissions have reached a magnitude that is several dozen times the amount of CO₂ that volcanoes emit annually?

31648. ribwoods at 14:24 PM on 17 February 2015
       Newcomers, Start Here
       

       On this page, under "Good starting points for newbies", the first sentence includes "... a good starting point is Warming Indicators which lays out the evidence that warming is happening ..."   However, the link from "Warming Indicators" is to http://www.skepticalscience.com/graphics.php?g=8 which has a graphic but does _not_ lay out the evidence.

       Was that link supposed to go to a different page where evidence is actually laid out?

31649. wili at 12:06 PM on 17 February 2015
       NASA climate study warns of unprecedented North American drought
       

       So, should people be doing anything to prepare for this future?

       This goes for coastal settlement as well. Shouldn't we start planning a de-population of some of these areas? Is that to 'political' to talk about?

       Moderator Response:

       [PS] "Its too hard" would be a more appropriate thread to talk about solutions. There are other blogs to discuss politics. eg http://thinkprogress.org/climate/issue/

31650. KR at 08:42 AM on 17 February 2015
       Human CO2 is a tiny % of CO2 emissions
       

       There is also the yearly cycle of CO2 related to global vegetation, predominately the Northern Hemisphere which has more land (and hence vegetation) absorbing and releasing CO2 over the season. But that is a very small, short term, and essentially zero based variation, despite being a favorite graph of denialists.

       [ I think that particular correlation and corresponding misleading graph, with long term CO2 growth and temperature changes being removed as (ahem) inconvenient facts, shows up at WUWT about once a month... ]

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