2014 Global Temperatures

[skierinvermont]

They were also able to recreate much of the 20th century prior to the hiatus which made them confident that a hiatus wouldn't happen. We were accelerating the warming trend.  

 

Now, we have a study that uses a subset of 12 out of 262 CMIP 5 simulations that shows that these 12 were able to recreate the hiatus. They say that it would be normal for the mean to be well above the observations because the models didn't capture the natural variability in the mean. Yet, we're supposed to believe the ensemble mean for predictions? I guess this would be believable if we truly believe that the natural variability event we just had was more than 2 sigma.

 

The other study discussed earlier in this thread implies that natural variability masked about 0.3-0.35C of AGW warming...that same study implied that AGW was basically zero once you got back to the 1970s. That doesn't sound very believable...only if the aerosol component is very high. But then that creates its own set of problems...mostly that very high aerosol component should have meant more cooling than we saw in Pinatubo.

 

In short, I'm not convinced at all that using a model with a 3C sensitivity that recreates a hiatus by fine-tuning certain parameters is a robust way of validating the model going forward. We are basically trusting that we are going to warm at something around 0.5C per decade once we flip back to a positive ENSO regime. We are trusting that the natural variability event we saw happened to be so extreme, that only a handful of model runs could reproduce it. I don't buy it. Perhaps in another 10 years if we warm at your 0.25C, then I'll be more convinced.

 

For now, I am more inclined to believe the empirical evidence that suggests a TCR in the 1.3C range...hence I'll go with the less aggressive temperature predictions.

 

Your whole argument appears to rest on rejecting a high AGW component because it requires a strong aerosol cooling effect in the 70s and a strong natural cooling effect in the 2000s. However, the latter is demonstrably occurring as evidence by the high frequency of La Ninas, low solar activity and extremely strong tropical trade winds. The former cannot possibly be ruled out by our current models.

 

You assume that aerosols could not have had such a strong cooling effect in the 70s because we would have seen more cooling with Pinatubo. But I have not seen a study that specifically says the aerosol effect cannot be strong because of the empirical evidence during Pinatubo. Nor do I know how one could conclude that based off the empirical evidence alone.

 

Pinatubo released massive quantities of sulfur dioxide directly into the stratosphere from a point source. Humans release smaller quantities into the troposphere from dispersed sources and regions. There are a number of reasons to believe that the dynamics and effect must be quite different. For one, tropospheric aerosols will have a greater effect on cloud seeding. 

 

So your argument seems to rest almost entirely on Pinatubo, and I don't think that part of your argument is well supported.

 

I do kind of lean towards the lower TCR/ECS for the reasons you've given, but I think you are overstating the case.

[nflwxman]

ORH, I don't believe 0.5C/decade is in our future unless something catastrophic (that we don't foresee) occurs.  It would be terrifying and very hard for the developing world to adapt to that kind of jump IMO.  I do see the natural component adding potentially up to 0.2 degrees C/decade in select time periods (high sun and a switch to at + PDO).  Couple that with a slowly growing anthro component of 0.2 C/decade you might see 0.4C/decade in some periods.  

 

Just pure speculation, but that's all we have right now outside of climate models and paleoclimatic records.

 

EDIT: I know SoC could probably comment on what kind of greenhouse gas forced rates of warming there has been in the distant past.

[skierinvermont]

I believe there are 6-7 year periods of .5C+/decade just in the last 30 years with slower CO2 growth than in the future.

[tacoman25]

I believe there are 6-7 year periods of .5C+/decade just in the last 30 years with slower CO2 growth than in the future.

 

But has there ever been a decade to decade trend that had anything close to that? (1970s to 1980s, 1990s to 2000s).

 

No. I think the warmest was around a .18-.2C decadal jump, depending on what data source you use. 

[nflwxman]

But has there ever been a decade to decade trend that had anything close to that? (1970s to 1980s, 1990s to 2000s).

 

No. I think the warmest was around a .18-.2C decadal jump, depending on what data source you use. 

Yep.  It's a little over 0.2 in 1990s to 2000s, and that's with Pinatubo in the early 1990s and the tradewind/ENSO drop in the 2000s .  It's very hard to get double that trend in a 10+ year period (although i'm sure it could be possible in the future).

[The_Global_Warmer]

ORH, I don't believe 0.5C/decade is in our future unless something catastrophic (that we don't foresee) occurs.  It would be terrifying and very hard for the developing world to adapt to that kind of jump IMO.  I do see the natural component adding potentially up to 0.2 degrees C/decade in select time periods (high sun and a switch to at + PDO).  Couple that with a slowly growing anthro component of 0.2 C/decade you might see 0.4C/decade in some periods.  

 

Just pure speculation, but that's all we have right now outside of climate models and paleoclimatic records.

 

 

I wonder how much methane will be released when the cryosphere is 5-9C warmer annually then today.

 

When snow cover in Siberia is gone by mid April and the ESS, Laptev, and Beaufort are ice free before the end of June with SSTs in the shallow Laptev and ESS reaching 10-15C+ every summer in water 10-50 meters deep.

 

Not to mention the permafrost continuing to melt down.

 

It's not just having massive methane blowouts.  It's having a general release 10-15x more then we see today every year. 

 

So far it hasn't happened.  But we are talking about a brand new arctic in just 15-20 years.

 

It's going to be a whole lot different when we add another 30 days of peak insolation hitting water and bare land in the arctic versus snow and ice from where we are today.  Not to forget how much warmer the nearby oceans will be. 

 

 

When it's late July and there is 12-15C ssts along the continental shelf in the ESS in water 10-50M deep with a river discharging 20C water and a much warmer then current Pacific current running along the shelf edge from the Bering year after year.

 

Not good.

[The_Global_Warmer]

As GHG forcing gets stronger + feedback's the rate of warming will increase.

[nflwxman]

I wonder how much methane will be released when the cryosphere is 5-9C warmer annually then today.

 

When snow cover in Siberia is gone by mid April and the ESS, Laptev, and Beaufort are ice free before the end of June with SSTs in the shallow Laptev and ESS reaching 10-15C+ every summer in water 10-50 meters deep.

 

Not to mention the permafrost continuing to melt down.

 

It's not just having massive methane blowouts.  It's having a general release 10-15x more then we see today every year. 

 

So far it hasn't happened.  But we are talking about a brand new arctic in just 15-20 years.

 

It's going to be a whole lot different when we add another 30 days of peak insolation hitting water and bare land in the arctic versus snow and ice from where we are today.  Not to forget how much warmer the nearby oceans will be. 

 

 

When it's late July and there is 12-15C ssts along the continental shelf in the ESS in water 10-50M deep with a river discharging 20C water and a much warmer then current Pacific current running along the shelf edge from the Bering year after year.

 

Not good.

Methane is certainly a concern, but is there any evidence that would suggest we would have global methane rates increasing ina logarithmic fashion versus the current rate of rise?  I was always under the impression we were at least a century of very very strong warming before a dramatic increase like that happens.  I guess there's always a reason to expect the unexpected though.  Richard Alley has a lot of expertise in the area, he's seems quite a bit more concerned with CO2 growth.

 

http://thinkprogress.org/climate/2009/12/21/205242/agu-richard-alley-explains-biggest-control-knob-carbon-dioxide-in-earths-climate-history/

[The_Global_Warmer]

Methane is certainly a concern, but is there any evidence that would suggest we would have global methane rates increasing ina logarithmic fashion versus the current rate of rise?  I was always under the impression we were at least a century of very very strong warming before a dramatic increase like that happens.  I guess there's always a reason to expect the unexpected though.  Richard Alley has a lot of expertise in the area, he's seems quite a bit more concerned with CO2 growth.

 

http://thinkprogress.org/climate/2009/12/21/205242/agu-richard-alley-explains-biggest-control-knob-carbon-dioxide-in-earths-climate-history/

 

 

I'd think as the environment that has kept things the way they are radically changes there could be radical consequences.

 

The biggest thing for me is that we know it's a possibility.

 

If it happens then what are we supposed to do?

[ORH_wxman]

Your whole argument appears to rest on rejecting a high AGW component because it requires a strong aerosol cooling effect in the 70s and a strong natural cooling effect in the 2000s. However, the latter is demonstrably occurring as evidence by the high frequency of La Ninas, low solar activity and extremely strong tropical trade winds. The former cannot possibly be ruled out by our current models.

 

You assume that aerosols could not have had such a strong cooling effect in the 70s because we would have seen more cooling with Pinatubo. But I have not seen a study that specifically says the aerosol effect cannot be strong because of the empirical evidence during Pinatubo. Nor do I know how one could conclude that based off the empirical evidence alone.

 

Pinatubo released massive quantities of sulfur dioxide directly into the stratosphere from a point source. Humans release smaller quantities into the troposphere from dispersed sources and regions. There are a number of reasons to believe that the dynamics and effect must be quite different. For one, tropospheric aerosols will have a greater effect on cloud seeding. 

 

So your argument seems to rest almost entirely on Pinatubo, and I don't think that part of your argument is well supported.

 

I do kind of lean towards the lower TCR/ECS for the reasons you've given, but I think you are overstating the case.

 

You make some good points, but I think you are overstating my certainty...I'm essentially playing the odds.

 

Everything that points to the big aerosol cooling of the 1960s/1970s and the big natural variability cooling event post-2000 is plausible in itself, there's no "smoking gun" to flat out dispute any of them, but when I start adding them up together, I view them as less likely. This isn't saying they didn't happen...obviously they did to some extent, but not on the level being claimed in the higher TCR scenarios. Pinatubo wasn't my main point either...I said it in passing after reading how the CMIP models had over-estimated the cooling effects at some point in the past couple months. There's other factors that support my sketpicism on the larger TCR claims...the most robust being the observation-based estimates of TCR which come in lower, another one being the pretty strong Northern Hemisphere cooling of SSTs during the1960s and 1970s which isn't supported by the aerosol theory. (at least by itself)

 

 

It took me a while to find these since I had forgotten the titles/authors, but these papers I read in the past few years are what convinced me the aerosol theory doesn't explain enough of the cooling....even though it certianly contributed:

 

http://www.nature.com/nature/journal/v467/n7314/full/nature09394.html

 

http://journals.ametsoc.org/doi/abs/10.1175/JAS-D-12-0331.1

 

 

 

BTW, there was a paper on the Pinatubo eruption and TCR earlier this year:

 

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00214.1

 

It points out the issues involved in estimating TCR with volcanic eruptions, and there are many, but it does conclude that it can be useful.

 

They say:

 

 

The upper bound of the interquartile range for individual realizations of the volcanic responses in CM2.1 is slightly less than the GCM's TCR of 1.5K. The range of the TCR in the CMIP3 ensemble is 1.2-2.6K (Randall et al. 2007) and is 1.1-2.6K in CMIP5 (Flato and Coauthors 2013). On this basis, it appears that one can infer with some confidence from single realizations of CM2.1's volcanic response that its TCR lies in the lower half of this model ensemble, so there is potential to use the observed response to Pinatubo to narrow the range of TCR.

 

 

 

 

 

Again, none of these are smoking guns by themselves, but IMHO it makes the alternative scenarios less likely in my book when you start adding up the evidence. Obviously the best test for any of these theories will be with more data over the next decade.

[nflwxman]

Here's my issue with the 1.2C TCR.  Assuming we are defining TCR the same way, you are claiming that we will only warm another 0.4C in 30-40 years?  Assuming we double CO2 from preindustrial estimates by 2040-2050.  That just doesn't seem plausible to me.

[ORH_wxman]

Here's my issue with the 1.2C TCR.  Assuming we are defining TCR the same way, you are claiming that we will only warm another 0.4C in 30-40 years?  Assuming we double CO2 from preindustrial estimates by 2040-2050.  That just doesn't seem plausible to me.

 

You would probably have to up it by a few tenths...unless you are satisfied with saying we were in representative equilibrium in mid/late 1800s...but we probably weren't and some of the early period warming was natural.

[nflwxman]

You would probably have to up it by a few tenths...unless you are satisfied with saying we were in representative equilibrium in mid/late 1800s...but we probably weren't and some of the early period warming was natural.

Even going back to 1860, when the PDO was positive and solar output pretty moderate, we've gained 0.8C.  Since the early 1900s, during low solar and a negative PDO, we've risen almost a full degree celcius.  I'd say 0.8C due to anthropogenic is about right so far (and the IPCC generally agrees).

[ORH_wxman]

Even going back to 1860, when the PDO was positive and solar output pretty moderate, we've gained 0.8C.  Since the early 1900s, during low solar and a negative PDO, we've risen almost a full degree celcius.  I'd say 0.8C due to anthropogenic is about right so far (and the IPCC generally agrees).

 

 

I was not aware the IPCC attributes significantly the early 20th century warming to humans. I recall them saying that humans are responsible for most of the 0.6-0.7C warming since 1950.

[nflwxman]

The IPCC does not attribute much of the 1920-1945 warming to anthropogenic sources, but it attributes most (if not all) of the warming between preindustrial times to present to human sources.  

 

The start and end points are important.  The natural factors that warmed the planet in the early 20th century are no longer present, thus that warming (while important to the science) is somewhat irrelevent to the attribution.  Essentially, they are saying there is no major natural trend since 1880-present that forced the climate a particular way.  And yes, they also make that same claim for 1950-present.

[ORH_wxman]

The IPCC does not attribute much of the 1920-1945 warming to anthropogenic sources, but it attributes most (if not all) of the warming between preindustrial times to present to human sources.  

 

The start and end points are important.  The natural factors that warmed the planet in the early 20th century are no longer present, thus that warming (while important to the science) is somewhat irrelevent to the attribution.  Essentially, they are saying there is no major natural trend since 1880-present that forced the climate a particular way.  And yes, they also make that same claim for 1950-present.

 

 

So the IPCC thinks that we've had equal natural cooling to the natural warming that occurred out of the pre-industrial era.

 

That's a first I've heard...but I admittedly do not use IPCC much for the warming attribution.

[nflwxman]

So the IPCC thinks that we've had equal natural cooling to the natural warming that occurred out of the pre-industrial era.

 

That's a first I've heard...but I admittedly do not use IPCC much for the warming attribution.

Essentially. Theoretically, a 100 year period like we are discussing should not have any major trend in ocean oscillations that wouldn't equal close to zero.  As you can see from the attached summary for policy makers, solar is a small positive forcing in the period mentioned, but likely under 0.1C total attribution.

 

http://ipcc-wg2.gov/AR5/images/uploads/WG2AR5_SPM_FINAL.pdf

[ORH_wxman]

Essentially. Theoretically, a 100 year period like we are discussing should not have any major trend in ocean oscillations that wouldn't equal close to zero.  As you can see from the attached summary for policy makers, solar is a small positive forcing in the period mentioned, but likely under 0.1C total attribution.

 

http://ipcc-wg2.gov/AR5/images/uploads/WG2AR5_SPM_FINAL.pdf

 

 

Thank you for the link.

 

 

If you want to read more about TCR and IPCC AR5 and CMIP5 models...here's an article by Nic Lewis...coauthor of the Otto et al. 2013 paper:

 

http://climateaudit.org/2013/12/09/does-the-observational-evidence-in-ar5-support-itsthe-cmip5-models-tcr-ranges/

[nflwxman]

Thank you for the link.

If you want to read more about TCR and IPCC AR5 and CMIP5 models...here's an article by Nic Lewis...coauthor of the Otto et al. 2013 paper:

http://climateaudit.org/2013/12/09/does-the-observational-evidence-in-ar5-support-itsthe-cmip5-models-tcr-ranges/

Great. I'll read it first thing in the AM, thanks

[The_Global_Warmer]

That is a good point.  At the end of the day.  When things equal out 95% of the warming will be from humans.

 

The data on the image below comes from Chen & Tung (2014). It is updated thru 2011. 

 

The most standout glaring thing is the massive spike in Southern Ocean OHC.  While SSTS there dropped and Sea Ice has gone up considerably.

 

 

Now where does that warmer Southern Ocean water go?

 

 

 

 

 

 

What I find interesting about that.  Is below.  The top graphic is -30 to -60S monthly ssta anomalies.

 

We set the record for this region(Southern Hemisphere mid lats) in 2014.

 

There is a distinct warming trend that slows for periods.  But it's very clear the baseline has continued to warm.  And quite a lot since 2008.

 

 

 

 

Here is -60 to -90S.  Notice they have been dropping.  Remember this is a very small sample size for a large part of the year.  But there has been a distinct downward trend since the PDO flipped.  You can even see a correlation to the PDO in the late 90s early 2000s then th return to positive PDO and back to negative.

 

But as of now there has been no response to the current +PDO. 

 

Which could be lag or could be the way above normal ice area/extent.  Which will cause cooling of the surrounding waters and cooling during the melt season with more cold melt water as well.

 

 

 

Never the less the Southern Ocean near surface has cooled.  While Southern Ocean OHC has sky rocketed.

 

 

Then there is the -30S to 30N region covering the sub tropics and tropics.  We can see a clearly defined warming trend within the ENSO nose back to the early 1980s until the 2000s.  That appears to have slowed or stopped since the PDO flip/big 2008 nina.  

 

 

Since March of 2007.  The ONI index has been:

 

Negative 67 months.

Official Nina 33 months.

-0.5C or colder 38 months.

-0.8C or colder 18 months.

-1.2C or colder 13 months.

 

 

A streak of 26 consecutive months of -0.1C or colder from March of 2007 to April of 2009.

 

Another streak of 24 consecutive months of -0.1C or colder from June of 2010 to May of 2012.

 

Another streak of 17 months of -0.1C or colder from Dec of 2012 to April of 2014.

 

Since June of 2010 the ONI index has been 0.1C or warmer only 7 months.  While being 0.0C or colder 42 months.

 

 

 

Positive 20 months

Official Nino 10 months

0.5C or warmer 12 months

0.8C or warmer 7 months

1.2C or warmer 4 months

 

 

 

Pretty wildly lopsided. 

 

 

 

Here is 30-60N.  We can see since the 1998 super nino there has been noticeable seasonal variance.  that has trended larger overtime.  It's hard to see but 2014's last data point is just shy of 1.0C+ and is the record for this latitude band.  Both the Southern mid lats and Northern mid lats have broken their ssta records in 2014. 

 

The NH tho has broken them for 3 consecutive years. 

 

The winter of 2013/14 also was the warmest(cold season) ssta record as well for this latitude band.

 

 

 

 

This is 60-90N. 

 

You can see arctic amplification working quite well expecially post 2007.

 

Interestingly(mostly from the NPAC and NATL.  2014 has come in pretty warm.

 

 

[CAD_Wedge_NC]

That is a good point.  At the end of the day.  When things equal out 95% of the warming will be from humans.

 

As has been mentioned many times on this board..... we don't know, with any certainty, how much humans have influenced the climate. However, 95% is highly questionable.

[The_Global_Warmer]

As has been mentioned many times on this board..... we don't know, with any certainty, how much humans have influenced the climate. However, 95% is highly questionable.

 

 

That doesn't matter.  Over a long enough period of time.  The natural influences will balance themselves out. 

 

Natural oscillations like the IPO, PDO, AMO, and others only redistribute heat.  The sun is a on a pretty rigid cycle and we can directly measure it's level of forcing so we know it's influence.

 

We have observable records of the influence of volcanoes and all natural and man made gases on forcing.

 

So it all evens out.  Whatever percentage anyone wants to attribute to the last big warming period to natural factors. That is being mitigated

[ORH_wxman]

That doesn't matter.  Over a long enough period of time.  The natural influences will balance themselves out. 

 

Natural oscillations like the IPO, PDO, AMO, and others only redistribute heat.  The sun is a on a pretty rigid cycle and we can directly measure it's level of forcing so we know it's influence.

 

We have observable records of the influence of volcanoes and all natural and man made gases on forcing.

 

So it all evens out.  Whatever percentage anyone wants to attribute to the last big warming period to natural factors. That is being mitigated

 

 

You are being too simplistic here. Eventually the natural oscillations do even out on a long enough timescale, but if we are making attributions based on like 3-4 decade samples, then it does matter how much is natural and how much isn't. 

 

The further you go out in time, the better the natural variability sample...which is why TCR estimates don't change as much for years beyond 1950 as the starting point. Read the link I gave to nflwxman above, and read some of the literature on it.

 

Also, your 2nd to last sentence that says "We have observable records of the influence of volcanoes and all natural and man made gases on forcing." doesn't tell us anything beyond what we already know...we know how much CO2 forces the temperature...about 1.1C per doubling. But we cannot "measure" the feedbacks...those are attempted to be derived from a whole complex of factors.

[chubbs]

The IPCC does not attribute much of the 1920-1945 warming to anthropogenic sources, but it attributes most (if not all) of the warming between preindustrial times to present to human sources.  

 

The start and end points are important.  The natural factors that warmed the planet in the early 20th century are no longer present, thus that warming (while important to the science) is somewhat irrelevent to the attribution.  Essentially, they are saying there is no major natural trend since 1880-present that forced the climate a particular way.  And yes, they also make that same claim for 1950-present.

This seems reasonable to me. While there was natural warming between 1920 and 1945 there was natural cooling from 1880 to 1910 and 1945-1975. Greenhouse gases began increasing in the late 1700s, so warming in the 1800s has an AGW component. An argument can be made that GHG ended the little ice age. They certainly accelerated its demise. 

[The_Global_Warmer]

So there is "natural" warming going on that is much stronger than "natural" cooling?

 

I highly doubt that.

 

Any change between 1870 and whenever global warming peaks will likely be at the most 5% from natural warming.

 

Maybe I am not understanding but it's starting to feel like some people are quick to try and blame 30, 40 , 50% of the warming from the late 70s to the 2000s as natural.

 

But question GHG warming during this short "hiatus" where those natural factors reversed and in a big way.  But they haven't even been able to cool the Earth at all.

 

Remember the Earth warmed dramatically for a few decades there. OHC has gone up steadily and is still going up.  We are at record warmth right now.

 

Going by natural factors alone we should be cooling .2 to .3C from peaking but we haven't cooled at all.  The natural factors that would be cooling the Earth are not capable of overwhelming the ever increasing GHG warming.  So when this natural period of what should have been cooling is over.  The net result is that AGW is responsible for almost all of the warming.

 

 

Trying to model the future warming doesn't change that that natural factors indicate the Earth should be either pretty much steady between ocean oscillations or at this point cooling naturally because of solar changes.

[Msalgado]

As has been mentioned many times on this board..... we don't know, with any certainty, how much humans have influenced the climate. However, 95% is highly questionable.

 

There are many things that are incorrect and frequently mentioned on this board.  Just because something wrong is repeated doesn't change that its wrong.

[nflwxman]

So there is "natural" warming going on that is much stronger than "natural" cooling?

 

I highly doubt that.

 

Any change between 1870 and whenever global warming peaks will likely be at the most 5% from natural warming.

 

Maybe I am not understanding but it's starting to feel like some people are quick to try and blame 30, 40 , 50% of the warming from the late 70s to the 2000s as natural.

 

But question GHG warming during this short "hiatus" where those natural factors reversed and in a big way.  But they haven't even been able to cool the Earth at all.

 

Remember the Earth warmed dramatically for a few decades there. OHC has gone up steadily and is still going up.  We are at record warmth right now.

 

Going by natural factors alone we should be cooling .2 to .3C from peaking but we haven't cooled at all.  The natural factors that would be cooling the Earth are not capable of overwhelming the ever increasing GHG warming.  So when this natural period of what should have been cooling is over.  The net result is that AGW is responsible for almost all of the warming.

 

 

Trying to model the future warming doesn't change that that natural factors indicate the Earth should be either pretty much steady between ocean oscillations or at this point cooling naturally because of solar changes.

There is a lot of confusion in the biosphere on attribution.  It really matters where you start and begin.

 

I'm willing to concede up to 40% of the warming from 1979-1998 was naturally caused (which is generous).  However, for the reasons you just mentioned, the warming from 1979-2013 might be less than 20% naturally induced.  The paper we discussed before gives a pretty good detail on the natural component.  What we do know for sure, is that the natural component to global temperature change is become smaller and smaller as the anthropogenic aspect rises.

[ORH_wxman]

So there is "natural" warming going on that is much stronger than "natural" cooling?

 

I highly doubt that.

 

Any change between 1870 and whenever global warming peaks will likely be at the most 5% from natural warming.

 

Maybe I am not understanding but it's starting to feel like some people are quick to try and blame 30, 40 , 50% of the warming from the late 70s to the 2000s as natural.

 

But question GHG warming during this short "hiatus" where those natural factors reversed and in a big way.  But they haven't even been able to cool the Earth at all.

 

Remember the Earth warmed dramatically for a few decades there. OHC has gone up steadily and is still going up.  We are at record warmth right now.

 

Going by natural factors alone we should be cooling .2 to .3C from peaking but we haven't cooled at all.  The natural factors that would be cooling the Earth are not capable of overwhelming the ever increasing GHG warming.  So when this natural period of what should have been cooling is over.  The net result is that AGW is responsible for almost all of the warming.

 

 

Trying to model the future warming doesn't change that that natural factors indicate the Earth should be either pretty much steady between ocean oscillations or at this point cooling naturally because of solar changes.

 

 

First off....many papers attribute something like 30-40% (I've seen as high as 50%) of the warming from 1975-2000 to natural factors. Read the papers. We've provided them many times...so there's no reason not to read them to understand how they come to these conclusions.

 

There is differing opinion in the literature on the exact magnitude of the hiatus components. Some claim that roughly 0.3C per decade AGW was offset in that time while others are closer to half that when you infer all the math. We discussed one of the papers recently that claimed the higher amount.

 

 

OHC measurements are not exact...we discussed this earlier too. We posted a paper published recently that shows more slowing of OHC than the more popular NODC dataset, even when you account for the NODC error bars. Different methods come to slightly different conclusions...they are all using mostly the same data, but it still doesn't mean the results come out exactly the same. There's a lot of infilling and assumptions made with SLR and such that are required for OHC data. You have to attribute SLR in proper proportions when using it as a proxy. So if one data set shows more flattening of OHC than another, then the components of what drives the hiatus can change. Similarly, you have uncertainties in aerosol forcing. Read the Nic Lewis article I posted above where he breaks down the different aerosol estimates. All this matters.

 

But this is how science works. You have papers written...some are rebutted, some are built upon and improved, and a select few tend to be real ground-breakers...in the end, you get closer to reality. Look how much the science has changed in just a decade or 15 years. The biggest fault in climate science is probably that we tend to over-estimate our certainty. Or rather, perhaps we don't illustrate our uncertainty well enough.

[Isotherm]

There are many things that are incorrect and frequently mentioned on this board.  Just because something wrong is repeated doesn't change that its wrong.

 

 

This statement in and of itself is disputable. The words "incorrect" and "wrong" imply that a known standard of fact / truth has been established, when in reality nothing has been scientifically proven as far as the percent contribution of anthropogenic activities to climate change. There are many hypotheses and educated guesses circulating, but to utilize the words "incorrect and wrong" surely implicates that we're discussing something along the lines of Newton's law of gravity, which can be tested and proven many times over.

[nflwxman]

 The biggest fault in climate science is probably that we tend to over-estimate our certainty. Or rather, perhaps we don't illustrate our uncertainty well enough.

 

Bingo.