Corrected Sunspot History: Climate Change Not Due to Natural Solar Trends

[StudentOfClimatology]

Not seeing that at all. Unless you just mean the top portion of the ocean.

Yes, I'm referring to the upper oceans, surface, and troposphere. The deep oceans will take a long time to equilibrate to any external forcing, hence even if we capped CO^2 emissions now, warming would continue decades into the future.

[Mallow]

You need to examine the period post 2006, as the solar minimum of cycle 23 (a very potent cycle) did not occur until post 2006. Looking closely at the 0-700m OHC graph, if one compares the pentadal average of 2000-2005, versus 2005-2010, there is a noticeable decrease in rate of warming. 2000 was around 4 (X10^22 Joules), rising to approximately 9 (X10^22 Joules) in 2005. The rise from 2005 to 2010 was significantly less. Even the yearly average rate of warming from 1998-2005 was greater than that of 2005-2014. The former (eyeballing) around 4 in 1998 to 10 in 2005, contrasted with 10 in 2005 to about 13 in 2014.

 

That's a stretch. Yes, if you choose the right endpoints you can find just about any trend. But the change you're talking about is statistically indistinguishable from internal variability. I could just as easily argue that the period from 2012 onward has seen a strong acceleration in the 0-700m heat content, which is completely inconsistent with the weaker solar forcing. But I suspect that, too, is just internal climate variability. And why only focus on the 0-700m layer?

[Mallow]

Yes, I'm referring to the upper oceans, surface, and troposphere. The deep oceans will take a long time to equilibrate to any external forcing, hence even if we capped CO^2 emissions now, warming would continue decades into the future.

 

The 0-700m layer is strongly influenced by ENSO. Remove that signal and the increase will be quite steady.

[StudentOfClimatology]

OK, that sounds plausible. Where do we find the evidence of a slowdown caused by a reduction in the sun's influence? Ocean temperatures continue to rise, air temperatures continue to rise. It seems to me, that if the sun's output has been reduced, but the earth continues to warm, then there is some effect overpowering the influence of the sun. I don't see the mechanism for a "lagging" effect that wouldn't show up in some data almost immediately.

I don't think solar forcing is responsible for much of the post-1950 warming (I used to think differently). I'm just explaining what one were to look for if solar forcing were responsible.

If solar is responsible, then what you'll see as we near equilibration (which woul be soon assuming we're in for a grand minimum) is a further slowdown in near surface warming while the deep oceans continue to warm at a relatively faster rate in relation to the surface. When the deep oceans have equilibrated, the surface-TOA boundary will begin to cool.

[StudentOfClimatology]

The 0-700m layer is strongly influenced by ENSO. Remove that signal and the increase will be quite steady.

Even when correcting for ENSO et al, there's still a slowdown (especially in the lower troposphere, less at the surface). I'm not assigning attribution here, just stating what the data shows.

[Mallow]

I don't think solar forcing is responsible for much of the post-1950 warming (I used to think differently). I'm just explaining what one were to look for if solar forcing were responsible.

If solar is responsible, then what you'll see as we near equilibration is a slowdown in near surface warming while the deep oceans continue to warm. Only when the deep oceans have equilibrated will the surface-TOA boundary begin to cool.

 

That's assuming "equilibrium" temperature that would hypothetically be reached by the CURRENT solar forcing is higher than the current global temperature, which is a pretty big assumption given that the current solar forcing is much lower than it was at its peak. If solar forcing was the major driving of the warming, the much lower solar activity now would probably correspond to an equilibrium that's LOWER than the current very warm climate, which would have meant we should have started cooling already.

[Mallow]

Even when correcting for ENSO et al, there's still a slowdown (especially in the lower troposphere, less at the surface). I'm not assigning attribution here, just stating what the data shows.

 

I'm talking about OHC.

[StudentOfClimatology]

That's assuming "equilibrium" temperature that would hypothetically be reached by the CURRENT solar forcing is higher than the current global temperature, which is a pretty big assumption given that the current solar forcing is much lower than it was at its peak. If solar forcing was the major driving of the warming, the much lower solar activity now would probably correspond to an equilibrium that's LOWER than the current very warm climate, which would have meant we should have started cooling already.

I'll play devil's advocate here.

Figure that, with the exception of the 8200 kiloyear event, the LIA was the coldest period during the Holocene. That's a pretty cold starting point. Now figure that 80% of the oceans, in terms of mass, receive no insolation and equilibrate solely via conduction and fluid transport. That's going to take a long, long time and possibly explains most of the early 20th century warming (until 1950).

Obviously, simple radiative transfer physics require that CO^2 forcing be the dominant variable after 1950. However, that doesn't eliminate the possibility that even had there been industrial revolution, the system may still be in an equilibration process today.

[StudentOfClimatology]

I'm talking about OHC.

There is also literature suggesting that ENSO may be a systematic response to low frequency energy imbalance. If so, then the stronger La Niñas during/after the last solar minimum may have been a short term response to solar forcing.

So, do we assume they're mutually exclusive? Or don't we?

[Mallow]

I'll play devil's advocate here.

Figure that, with the exception of the 8200 kiloyear event, the LIA was the coldest period during the Holocene. That's a pretty cold starting point. Now figure that 80% of the oceans, in terms of mass, receive no insolation and equilibrate solely via conduction and fluid transport. That's going to take a long, long time and possibly explains most of the early 20th century warming (until 1950).

Obviously, simple radiative transfer physics require that CO^2 forcing be the dominant variable after 1950. However, that doesn't eliminate the possibility that even had there been industrial revolution, the system may still be in an equilibration process today.

 

How does that explain the 20th century warming? I don't follow.

[StudentOfClimatology]

How does that explain the 20th century warming? I don't follow.

You mean the early 20th century warming? I don't think solar can explain much of anything climate-wise after 1950.

[Mallow]

There is also literature suggesting that ENSO may be a systematic response to low frequency energy imbalance. If so, then the stronger La Niñas during/after the last solar minimum may have been a short term response to solar forcing.

So, do we assume they're mutually exclusive? Or don't we?

 

If that's the main cause, then there should be a strong lag-correlation between ENSO and solar forcing. There's not, unless you force it by reversing the sign of the signal at key times like Landscheidt did.

[Mallow]

You mean the early 20th century warming? I don't think solar can explain much of anything climate-wise after 1950.

 

Oh, I missed that part. I don't think you need to even invoke the deep oceans for that, do you?

[StudentOfClimatology]

If that's the main cause, then there should be a strong lag-correlation between ENSO and solar forcing. There's not, unless you force it by reversing the sign of the signal at key times like Landscheidt did.

There's some good literature using the QBO and the 11yr solar cycle to predict ENSO. This is higher frequency/nearer term stuff. I don't know whether it's physically analogous to the long term solar/climate theories.

[Mallow]

There's some good literature using the QBO and the 11yr solar cycle to predict ENSO. This is higher frequency/nearer term stuff. I don't know whether it's physically analogous to the long term solar/climate theories.

 

I will need to have a look at that research. I suspect the correlations are weak, but I don't know.

 

In any case, if there was a major solar influence wrt the 11-year cycle, shouldn't that imply a reasonably strong 11-year ENSO cycle, as well?

[StudentOfClimatology]

Oh, I missed that part. I don't think you need to even invoke the deep oceans for that, do you?

If you don't invoke the deep oceans, how do you explain the continuous warming after the LIA? The paleoclimate data clearly depicts a gradual (yet non-linear) succession out of the LIA, so I think there has to an inertial aspect to it.

I could obviously be wrong.

[StudentOfClimatology]

I will need to have a look at that research. I suspect the correlations are weak, but I don't know.

In any case, if there was a major solar influence wrt the 11-year cycle, shouldn't that imply a reasonably strong 11-year ENSO cycle, as well?

I'll post the literature when I get home, but basically the theory is that ENSO operates on a frequency or resonance of sorts.

Imagine shaking a flag pole. If you shake it within it's resonance period, you it will sway violently, but if you shake it outside it's resonance period, it won't do much of anything. The literature basically looks at the QBO and the 11yr solar cycle, analyzes the various associated wave patterns, and uses them to depict low frequency biases in tropical forcing/ENSO.

It's fascinating to me.

[Mallow]

If you don't invoke the deep oceans, how do you explain the continuous warming from after the LIA? The paleoclimate data clearly depicts a gradual yet non-linear succession out of the LIA, so I think there has to an inertial aspect to it.

 

I'm no expert on paleoclimatology, so I could be mistaken... but I thought the gradual warming since the LIA matched pretty well with a gradual increase in solar forcing (through the 19th century)?

[Mallow]

I'll post the literature when I get home, but basically the theory is that ENSO operates on a frequency or resonance of sorts.

Imagine shaking a flag pole. If you shake it within it's resonance period, you it will sway violently, but if you shake it outside it's resonance period, it won't do much of anything. The literature basically looks at the QBO and the 11yr solar cycle, analyzes the various associated wave patterns, and uses them to depict low frequency biases in tropical forcing/ENSO.

It's fascinating to me.

 

If the solar forcing is the "shaking" in this analogy, then it would imply that changes in solar cycle length would be key?

[StudentOfClimatology]

I'm no expert on paleoclimatology, so I could be mistaken... but I thought the gradual warming since the LIA matched pretty well with a gradual increase in solar forcing (through the 19th century)?

That's true. I don't have the answers.

In some interpretations of the data record, the Dalton minimum didn't lead to much in the way of global cooling, which has lead some scientists to suggest an underlying energy imbalance was still present.

I have no idea what to think. I was just giving a possible solar explanation for the early-20th century warming.

[StudentOfClimatology]

If the solar forcing is the "shaking" in this analogy, then it would imply that changes in solar cycle length would be key?

There are three papers I know of that use a resonance model to relate ENSO and solar/QBO forcing, I'll have to post them when I get home but I think the relational correlation coefficient was usually above 0.7. From what I read, it's assumed that the QBO plays a vital role in modulating the solar/ENSO relationship.