2012 Global Temperatures

[PhillipS]

You can not deny that there are forcings that the Foster and Rahmstorf study did not take out that are important, and non-greenhouse gas related. One of the most important are the indirect solar impacts on climate.

Are you referring to the hypothetical solar amplification processes you are so enamored with? If it were real, and as important as you claim, then it would show up in the graph I posted, After all, its period covers several solar cycles. There were solar minimums in 1976, 1986, 1996 and 2008. And solar maximums in 1981, 1991, 2002 and an upcoming one in 2013. If Foster & Rahmstorf failed to account for something truly important then it is still in the adjusted record. Show us where it is, please.

[ORH_wxman]

It's interesting though, I recall back in 2008-09 a graph that supposedly accounted for natural factors (in other words, removed them) over at a very pro-AGW awareness website showing a definite slowing of the warming rate since the early 2000s. And they were using GISS/HadCRU data. I'm sure others that have been following this for awhile know which website (*cough* Gavin Schmidt *cough*) and graph I'm talking about.

The Rahmsdorf graph certainly shows a different trend, and that certainly is important to supporting the underlying premise. But why such changes from previous graphs from like-minded people?

I believe the graph you are referring to only took into account ENSO and not TSI or volcanoes...though volcanoes have been at a minimum recently so it would only make the "real AGW trend" lower in the reconstruction....but the TSI has caused a bit of a dip recently too and that was not in that graph I believe.

The biggest issue I have with the Rahmsdorf graph (or maybe not issue...but incompleteness) is it doesn't seem to take into account the longer term PDO trend...only seasonal ENSO state...which doesn't capture all of the Pacific cooling (or warming in the 1980s/1990s). Maybe they tried to, but it doesn't really match on the graph. Or perhaps their analysis offers generally less forcing of the PDO than others think.

If we assume that the PDO had little effect in the 1980s/1990s...then we should continue to assume it has had little effect in the 2000s/2010s which would argue against the points that:

1. The PDO is responsible for the recent slowdown

2. That solar doesn't have a big effect

3. AGW forcing is contuing to increase

Argument against #3 is not anywhere in recent literature that I'm aware of and those that argue the PDO had little effect in the warming in the 1980s/1990s would certainly not choose to say that AGW forcing is slowing....so we are left with mostly #2 and I haven't seen that argument either except in a few well contested papers. So the question would then be what is the cause of the slowing if the PDO and TSI aren't a big factor and AGW is even stronger in forcing than it was in the 1980s/1990s?

[PhillipS]

I believe the graph you are referring to only took into account ENSO and not TSI or volcanoes...though volcanoes have been at a minimum recently so it would only make the "real AGW trend" lower in the reconstruction....but the TSI has caused a bit of a dip recently too and that was not in that graph I believe.

The biggest issue I have with the Rahmsdorf graph (or maybe not issue...but incompleteness) is it doesn't seem to take into account the longer term PDO trend...only seasonal ENSO state...which doesn't capture all of the Pacific cooling (or warming in the 1980s/1990s). Maybe they tried to, but it doesn't really match on the graph. Or perhaps their analysis offers generally less forcing of the PDO than others think.

If we assume that the PDO had little effect in the 1980s/1990s...then we should continue to assume it has had little effect in the 2000s/2010s which would argue against the points that:

1. The PDO is responsible for the recent slowdown

2. That solar doesn't have a big effect

3. AGW forcing is contuing to increase

#3 is not anywhere in recent literature that I'm aware of and those that argue the PDO had little effect in the warming in the 1980s/1990s would certainly not choose to say that AGW forcing is slowing....so we are left with mostly #2 and I haven't seen that argument either except in a few well contested papers. So the question would then be what is the cause of the slowing if the PDO and TSI aren't a big factor and AGW is even stronger in forcing than it was in the 1980s/1990s?

Just so the discussion is not derailed by a possibly poor choice of wording - when I say that AGW forcing is continuing to increase I mean that global temperatures are continuing to increase. That additional GHGs will increase the magnitude of the GHE. That there is no indication in the data that AGW warming is tapering off as the Earth approaches equilibrium. It's going to get hotter.

Are you saying that:

a. global warming due to AGW has stopped?

b. additional GHGs will have no effect?

c. the Earth has reached, or will soon reach, energy equilibrium?

d. it's not going to get hotter?

Please clarify what you meant.

[ORH_wxman]

Just so the discussion is not derailed by a possibly poor choice of wording - when I say that AGW forcing is continuing to increase I mean that global temperatures are continuing to increase. That additional GHGs will increase the magnitude of the GHE. That there is no indication in the data that AGW warming is tapering off as the Earth approaches equilibrium. It's going to get hotter.

Are you saying that:

a. global warming due to AGW has stopped?

b. additional GHGs will have no effect?

c. the Earth has reached, or will soon reach, energy equilibrium?

d. it's not going to get hotter?

Please clarify what you meant.

My argument was that if we assume the PDO had very little to do with the temp increase in the 1980s/1990s, then we therefore should assume it has little to do with any temperature trends now since the PDO was fully positive for those two decades (it wasn't half postive and half negative to cancel out)...and if we assume that it has little to do with the slowdown in warming now, then that would actually argue either that solar is the main cause or that AGW itself is slowing down since we are ignoring the PDO as a cause.

I don't see a lot of evidence that solar is the main cause though its definitely contributing a bit...and I certainly do not see any major evidence that AGW forcing would slow since we have higher CO2 concentration compared to the 1980s/1990s. So for those that are arguing that the PDO had very little influence in the 1980s/1990s warming, the question would be what is causing the recent slow down or halting?

[WeatherRusty]

My argument was that if we assume the PDO had very little to do with the temp increase in the 1980s/1990s, then we therefore should assume it has little to do with any temperature trends now since the PDO was fully positive for those two decades (it wasn't half postive and half negative to cancel out)...and if we assume that it has little to do with the slowdown in warming now, then that would actually argue either that solar is the main cause or that AGW itself is slowing down since we are ignoring the PDO as a cause.

I don't see a lot of evidence that solar is the main cause though its definitely contributing a bit...and I certainly do not see any major evidence that AGW forcing would slow since we have higher CO2 concentration compared to the 1980s/1990s. So for those that are arguing that the PDO had very little influence in the 1980s/1990s warming, the question would be what is causing the recent slow down or halting?

If the warming trend has slowed over the past 14 years, and I agree it has, then how much so?

To have maintained the warming at the rate prior to then, I would estimate we are behind about 0.1C or maybe at bit more, that needs to be accounted for.

1998 was very warm compared to its surrounding years, so to start with that year as a benchmark is not the best way to assess the situation, but anyway...........to end with a period dominated by La Ninas may also bias things a bit.

As increasing La Nina may be an expected consequence of a switch to -PDO then maybe by association we should attribute some of the slowing in trend to -PDO? How much may that have resulted in reducing the global temp?

The period in question was dominated by a prolonged solar minimum even as it did contain 1 solar max. How much of a depression in temp has that lead to.

Solar variation can depress temp. about 1/2 (correction 0.05C) degree below the mean.

Could recent predominance of La Nina account for another 1/2 (correction 0.05C) degree?

Since the increase in surface temperature has not kept pace with the increase in anthropogenic forcing, when everything else has average out, the TOA imbalance will necessarily grow and the warming must be made up for later.

[ORH_wxman]

If the warming trend has slowed over the past 14 years, and I agree it has, then how much so?

To have maintained the warming at the rate prior to then, I would estimate we are behind about 0.1C or maybe at bit more, that needs to be accounted for.

1998 was very warm compared to its surrounding years, so to start with that year as a benchmark is not the best way to assess the situation, but anyway...........to end with a period dominated by La Ninas may also bias things a bit.

As increasing La Nina may be an expected consequence of a switch to -PDO then maybe by association we should attribute some of the slowing in trend to -PDO? How much may that have resulted in reducing the global temp?

The period in question was dominated by a prolonged solar minimum even as it did contain 1 solar max. How much of a depression in temp has that lead to.

Solar variation can depress temp. about 1/2 degree below the mean.

Could recent predominance of La Nina account for another 1/2 degree?

Since the increase in surface temperature has not kept pace with the increase in anthropogenic forcing, when everything else has average out, the TOA imbalance will necessarily grow and the warming must be made up for later.

The trend is actually smaller if you start with 2001 or 2002 than 1998. 1998 was warm but 1999-2000 were pretty cool relatively speaking, esp 1999. The trend for 1998-present is +0.07C on GISS using linear regression...2000-present is also +0.07C per decade in GISS....2002-present is -0.02C per decade.

I assume by "1/2 degree" you mean half of a tenth celsius?

[WeatherRusty]

The trend is actually smaller if you start with 2001 or 2002 than 1998. 1998 was warm but 1999-2000 were pretty cool relatively speaking, esp 1999. The trend for 1998-present is +0.07C on GISS using linear regression...2000-present is also +0.07C per decade in GISS....2002-present is -0.02C per decade.

I assume by "1/2 degree" you mean half of a tenth celsius?

Yes

Amazing what one beer can do!

[ORH_wxman]

BTW, here is the plot I said I might continue tonight...I went back to 1930 to catch the running 30 year temperature rate (in degrees C per decade)

A few things stick out (at least to me anyway)....

1.) The cooling that started into the late 1940s didn't produce a negative 30 year temperature trend until 1965. This illustrates that the 30 year temperature trend can remain positive even during a decade (or more) of fairly rapid cooling. The negative running 30 year temperature trend lasted exactly 10 years.

2.) The cooling was extremely abrupt...even a little more abrupt than the warming post-1976.

3.) The fact that the previous downturn in temperature only got to -0.04C per decade 30 year mean despite starting from a lower high point than the current maximum suggest to me that we will not achieve a negative 30 year cooling trend later in the current -PDO cycle without the help of a major volcanic eruption....assuming we are generally accurate with the magnitude of the PDO's cooling (slowing of the warming) ability.

[Snow_Miser]

They account for solar in their paper. In another paper, they discuss the impact that a quieter sun would have on

future warming projections.

http://www.pik-potsdam.de/news/press-releases/archive/2010/weakening-sun-would-hardly-slow-global-warming

They account for one of the sun's least important forcings, the irradiance forcing from a controversial TSI dataset that may not even be correct. The sum of the evidence leans toward ACRIM and not PMOD as being right. The study did not account for any amplification mechanism from the sun either. If they did, the new anthropogenic trend would be much less than before, reducing the anthropogenic contribution to the warming.

[Snow_Miser]

Are you referring to the hypothetical solar amplification processes you are so enamored with? If it were real, and as important as you claim, then it would show up in the graph I posted, After all, its period covers several solar cycles. There were solar minimums in 1976, 1986, 1996 and 2008. And solar maximums in 1981, 1991, 2002 and an upcoming one in 2013. If Foster & Rahmstorf failed to account for something truly important then it is still in the adjusted record. Show us where it is, please.

You would not be able to know the indirect solar effects just by looking at Foster and Rahnstorf's chart. That's silly.

What we can do is look at the total forcing during a solar cycle, and observe it to be 7-8 times larger than the irradiance forcing alone. Then we can extract this amplifying mechanism from the data, and we would be left with a significantly smaller anthropogenic residual trend, especially of ACRIM and not PMOD were to be used for the TSI dataset, since the evidence stacks up as ACRIM being right and not PMOD.

[tacoman25]

I believe the graph you are referring to only took into account ENSO and not TSI or volcanoes...though volcanoes have been at a minimum recently so it would only make the "real AGW trend" lower in the reconstruction....but the TSI has caused a bit of a dip recently too and that was not in that graph I believe.

That is correct, I included that information in the subsequent post with the graph.

I just didn't see how TSI accounted for the large differences in the graphs.

[donsutherland1]

You would not be able to know the indirect solar effects just by looking at Foster and Rahnstorf's chart.

In their paper, they were discussing global temperature changes related to solar forcing. Their global estimates are similar to those contained in an earlier paper on the topic that dealt with the Maunder Minimum. From that paper, where one finds a larger response is on a seasonal and regional basis, even as the net global impact is modest. From that paper:

We examine the climate response to solar irradiance changes between the late 17th-century Maunder Minimum and the late 18th century. Global average temperature changes are small (about 0.3° to 0.4°C) in both a climate model and empirical reconstructions. However, regional temperature changes are quite large. In the model, these occur primarily through a forced shift toward the low index state of the Arctic Oscillation/North Atlantic Oscillation as solar irradiance decreases. This leads to colder temperatures over the Northern Hemisphere continents, especially in winter (1° to 2°C), in agreement with historical records and proxy data for surface temperatures.

That kind of outcome is something that could fit with the latest evidence that the recent solar minimum did not eliminate the earth's energy imbalance, meaning warming continued. If one is looking for regional variability within a warming climate from a possible prolonged period of low solar activity, that idea is far more reasonable than expectations of a large global cooling response. The recent severe blocking in 2009-10 and 2010-11 might also have had some relationship to the deep solar minimum. Again, even as the world warmed, some regions saw a colder than normal winter.

In sum, were a Maunder Minimum-type situation to play out in the context of a continuing increase in atmospheric CO2, one might expect:

1. A modest damping of the warming trend on a global basis, with the AGW warming overwhelming the impact of the solar forcing.

2. Some regions seeing a larger impact on temperatures, especially on a seasonal basis, courtesy of increased blockiness.

[skierinvermont]

My argument was that if we assume the PDO had very little to do with the temp increase in the 1980s/1990s, then we therefore should assume it has little to do with any temperature trends now since the PDO was fully positive for those two decades (it wasn't half postive and half negative to cancel out)...and if we assume that it has little to do with the slowdown in warming now, then that would actually argue either that solar is the main cause or that AGW itself is slowing down since we are ignoring the PDO as a cause.

I don't see a lot of evidence that solar is the main cause though its definitely contributing a bit...and I certainly do not see any major evidence that AGW forcing would slow since we have higher CO2 concentration compared to the 1980s/1990s. So for those that are arguing that the PDO had very little influence in the 1980s/1990s warming, the question would be what is causing the recent slow down or halting?

I think you are stuck in a 2008-era mindset. The temp trends to present have become much more positive since. Of course you can always get lower or negative trends by cherrypicking start points.

IIRC a fairly ENSO-neutral estimate of recent warming is a bit over .1C/decade... maybe .12C/decade. That's not too much lower than the agw forcing alone would predict. The recent solar minimum and weak cycle can probably explain most of the difference.

It also should be stressed how Nina-ish the past couple years have been. 24 straight months with a negative ONI. First Nina peaked -1.5 next -1.

1998-present is a negative ENSO trend.

[ORH_wxman]

I think you are stuck in a 2008-era mindset. The temp trends to present have become much more positive since. Of course you can always get lower or negative trends by cherrypicking start points.

IIRC a fairly ENSO-neutral estimate of recent warming is a bit over .1C/decade... maybe .12C/decade. That's not too much lower than the agw forcing alone would predict. The recent solar minimum and weak cycle can probably explain most of the difference.

The 10 year temp trend is at a low right now...2008 itself was colder than any year in the past decade, but the 10 year trend is lower than 2008 ...ENSO neutral figures I'd agree with, but a -PDO is not enso neutral so it supports the idea that the PDO is influencing the temps. We'd expect ENSO to average out negative during -PDO regimes along with a colder Pacific in general.

This goes back to the post you quoted where I was arguing that if you argue that the +PDO didn't reall affect the 1980s/1990s warming, then it canot be blamed for the current slowing.

Maybe we'll see a series of higher years coming up...but given the state of the Pacific, I'm betting La Nina will generally dominate.

[gracetoyou]

I think you are stuck in a 2008-era mindset. The temp trends to present have become much more positive since. Of course you can always get lower or negative trends by cherrypicking start points.

IIRC a fairly ENSO-neutral estimate of recent warming is a bit over .1C/decade... maybe .12C/decade. That's not too much lower than the agw forcing alone would predict. The recent solar minimum and weak cycle can probably explain most of the difference.

It also should be stressed how Nina-ish the past couple years have been. 24 straight months with a negative ONI. First Nina peaked -1.5 next -1.

1998-present is a negative ENSO trend.

I wouldn't call it cherry picking, but just an inconvenient reality. Besides one could just as easily go back to the 1600-1700's little ice age & say that the warming over the last 300yrs is historically consistent with what has happened in other eras when a significant drop in global temps had occurred.

It may be humbling but there is still so much us humans do not know about our climate that it's ridiculous to make dogmatic statements. We should hopefully learn a whole lot more over the next 100yrs. I think the AGW debate has done a lot of good in that it has brought a lot of focused attention & research to the earth's climate but we have a long way to go. This needs to be admitted because the smug dogmatism from both sides in this debate in the public arena doesn't help matters at all (not talking about this board...this is good discussion I think).

Humble pie is needed for everyone when talking about this issue.

[donsutherland1]

To expand upon my point in Message #920 regarding the AO, an important caveat is in order, as I don't think I was sufficiently clear with regard to the solar-AO connection:

The increased tendency for an AO- during the winter is a response to low solar activity over the long-term. There is little or no correlation with the 11-year solar cycle. Since 1976, there has been an ongoing decline in solar activity. Moreover, the AO- is not present for all winters during a long-term period of low solar activity.

The 2009-10 and 2010-11 episodes of extreme blocking could be a response to a combination of that long-term trend during a time when solar activity was abnormally low. Given the literature, it is unlikely that those episodes of extreme blocking were a response to the solar cycle itself. Additional factors likely also contributed.

The chart based on the 81-day moving average beginning 1/5/2012. As the x-axis was cluttered with all the dates, I suppressed it, as the purpose was to show the trend in solar activity over the past 36 years.

The relevant dataset can be found at: ftp://ftp.pmodwrc.ch/pub/data/irradiance/composite/DataPlots/ext_composite_d41_62_1204.dat

The 81-day moving average is in the 4th column from the left.

[WeatherRusty]

The 10 year temp trend is at a low right now...2008 itself was colder than any year in the past decade, but the 10 year trend is lower than 2008 ...ENSO neutral figures I'd agree with, but a -PDO is not enso neutral so it supports the idea that the PDO is influencing the temps. We'd expect ENSO to average out negative during -PDO regimes along with a colder Pacific in general.

This goes back to the post you quoted where I was arguing that if you argue that the +PDO didn't reall affect the 1980s/1990s warming, then it canot be blamed for the current slowing.

Maybe we'll see a series of higher years coming up...but given the state of the Pacific, I'm betting La Nina will generally dominate.

The most recent La Nina was the warmest such event in recorded history. The background global warming has obviously dominated the mean temperature trend and I bet will continue to do so.

From NOAA:

La Niña, which is defined by cooler-than-normal waters in the eastern and central equatorial Pacific Ocean that affects weather patterns around the globe, was present during much of 2011. A relatively strong phase of La Niña opened the year, dissipated in the spring before re-emerging in October and lasted through the end of the year. When compared to previous La Niña years, the 2011 global surface temperature was the warmest observed.

[ORH_wxman]

The most recent La Nina was the warmest such event in recorded history. The background global warming has obviously dominated the mean temperature trend and I bet will continue to do so.

From NOAA:

Yes it was.

[tacoman25]

The 10 year temp trend is at a low right now...2008 itself was colder than any year in the past decade, but the 10 year trend is lower than 2008 ...ENSO neutral figures I'd agree with, but a -PDO is not enso neutral so it supports the idea that the PDO is influencing the temps. We'd expect ENSO to average out negative during -PDO regimes along with a colder Pacific in general.

This goes back to the post you quoted where I was arguing that if you argue that the +PDO didn't reall affect the 1980s/1990s warming, then it canot be blamed for the current slowing.

Maybe we'll see a series of higher years coming up...but given the state of the Pacific, I'm betting La Nina will generally dominate.

I believe during the 1946-75 -PDO phase, -ENSO years outnumbered +ENSO years 2 to 1.

[Entropy]

The 10 year temp trend is at a low right now...2008 itself was colder than any year in the past decade, but the 10 year trend is lower than 2008 ...ENSO neutral figures I'd agree with, but a -PDO is not enso neutral so it supports the idea that the PDO is influencing the temps. We'd expect ENSO to average out negative during -PDO regimes along with a colder Pacific in general.

This goes back to the post you quoted where I was arguing that if you argue that the +PDO didn't reall affect the 1980s/1990s warming, then it canot be blamed for the current slowing.

Maybe we'll see a series of higher years coming up...but given the state of the Pacific, I'm betting La Nina will generally dominate.

If this keeps up much longer, we might have to rename it "global temperature leveling" instead of global warming.

[The_Global_Warmer]

2011 took a large drop this week a year ago, 2012 has dropped, but not as much. It's looking more and more like 2012 will finish close to August of 2011

[Snow_Miser]

Global temperatures have plummeted over the last few days.

They are no where even close to 2010, despite the Weak El Nino in the Pacific. 2010 is currently 0.4 Degrees C warmer than 2012 on AMSU at 14,000 feet.

[GaWx]

Global temperatures have plummeted over the last few days.

They are no where even close to 2010, despite the Weak El Nino in the Pacific. 2010 is currently 0.4 Degrees C warmer than 2012 on AMSU at 14,000 feet.

Please provide a link related to this supposed drastic cooling. Are you talking only about 14K feet? If so, what is the significance of cooling at 14K feet vs. the surface? How's the surface been doing the last few days? Links would be appreciated. Thanks.

[ORH_wxman]

Please provide a link related to this supposed drastic cooling. Are you talking only about 14K feet? If so, what is the significance of cooling at 14K feet vs. the surface? How's the surface been doing the last few days? Links would be appreciated. Thanks.

He's talking about this site:

http://discover.itsc.uah.edu/amsutemps/

channel 5 is the basis for the satellite temps (UAH/RSS) but not the only metric. But you can often get a good idea of how the month will shake out looking at them.

[GaWx]

He's talking about this site:

http://discover.itsc....edu/amsutemps/

channel 5 is the basis for the satellite temps (UAH/RSS) but not the only metric. But you can often get a good idea of how the month will shake out looking at them.

I looked at it but am having trouble following it to be honest. What do you think? Is this really of any significance? The way snowlover123 presented it made it sound like a rather big deal. Then again, I may have misinterpreted what he was saying.

[nflwxman]

I looked at it but am having trouble following it to be honest. What do you think? Is this really of any significance? The way snowlover123 presented it made it sound like a rather big deal. Then again, I may have misinterpreted what he was saying.

From what I understand, the AMSU C. 5 temperatures are usually highly correlated to the anomaly results you would expect (at the surface) on a monthly basis (from the sats UAH and RSS). That being said, there are plenty of months in which the surface anomaly seemingly doesn't track at all with AMSU. The data tracks up and down all on a daily basis, thus, it's not prudent to make judgements based on 5 or so days of declining/raising AMSU temps.

[Snow_Miser]

I looked at it but am having trouble following it to be honest. What do you think? Is this really of any significance? The way snowlover123 presented it made it sound like a rather big deal. Then again, I may have misinterpreted what he was saying.

It's a fairly big drop over the last few days, though climo also probably plays some role in the drop.

I think it's unusual that we are running at close to the middle of the pack even though we currently have a weak El Niño. The ONI for 2010 is only 0.8-0.9 Degrees C warmer than 2012, yet global temps are close to 0.4 Degrees C below 2010 currently.

It's interesting to see how cool 2012 will be in relation to 2010 in the near-future.

[Snow_Miser]

From what I understand, the AMSU C. 5 temperatures are usually highly correlated to the anomaly results you would expect (at the surface) on a monthly basis (from the sats UAH and RSS). That being said, there are plenty of months in which the surface anomaly seemingly doesn't track at all with AMSU. The data tracks up and down all on a daily basis, thus, it's not prudent to make judgements based on 5 or so days of declining/raising AMSU temps.

The atmospheric temperatures are largely determined by the surface radiation. Therefore, of the surface is warmer, you would generally expect the atmosphere to be warmer as well.

[nflwxman]

Technically, we are still in ENSO neutral

conditions (correct me if I'm wrong). Also, isn't there generally. 3-6 month lag between ENSO changes and temps?

[Snow_Miser]

Technically, we are still in ENSO neutral

conditions (correct me if I'm wrong). Also, isn't there generally. 3-6 month lag between ENSO changes and temps?

It isn't "officially" a Weak El Nino, because the SSTs in Nino 3.4 have not been higher than 0.5 Degrees C above average for a few months, but they are definitely currently into Weak El Nino territory.

There is also a 3-4 month or so lag in the Climate System, but we should already be seeing the effects of the increase in SSTs in the Nino regions, since they started increasing in late-2011.

I think that temperatures will probably increase some more in relation to the weak-El Nino, but it's interesting to see the temperatures significantly cooler than 2010 so far this year.