Global warming discussion III

[bit_pattern]

Ask Miami about accelerating in rate of change

Or NYC even, the sea level there is around a foot higher than 100 years ago - look at the result when it gets hit with a decent storm surge.

 

[a_unique_person]

Question:

Point # 1 - With all this ice melting. 2015 Sept all Arctic ice may be all gone for the first time (summer time).

Point #2 - Most of the carbon goes into the ocean and the heat goes there too.

So why is the ocean rate of rise still growing so slowly, like in millimeters.

Because it's so ***** big. Even that rate of change is already causing problems in florida.

 

[lomiller]

15 years is actually from Jan 2000 to Jan 2015 during which warming has been above the long-term trend. You and I know that 15 years doesn't tell us much but on the other hand we didn't choose to make a big issue of such a short period back in 2013. Those who did can hardly start arguing that it's not a big issue any more, can they?

I was responding to a number given in the WSJ op-ed piece. It’s actually non-specific about exactly what time period the “no warming in the last 15 years” Depending on when the piece was written it could easily refer to a starting point anywhere in the 1998 – 2000 range. Regardless of which one it is, however the basic point i was making doesn’t change. No matter which of these 3 years you choose as a starting point for drawing a trend line, that trend line starts ABOVE the established, statistically significant trend from 1970 – 2014.

I just ran the numbers for HadCRUT4.
Both well within margin of error and far smaller than the 0.02 deg C per year central prediction of the IPCC (and supposed long-term trend).

The fact that even a cherry picked starting point still produces a positive trend strengthens my point. And runs counter to the “no warming in the last 15 years” meme floating around. Regardless I was not addressing the actual trend over this period because it’s not statistically significant.

Both well within margin of error and far smaller than the 0.02 deg C per year central prediction of the IPCC (and supposed long-term trend).

1) The long term average is not an appropriate comparison because most scenarios show acceleration in the trend. If you draw a linear trend line over an accelerating warming it will fall above both observed data and model projections.

2) You are using the wrong error margin. On short time scales realization to realization differences are the dominant source of error. This can only be evaluate by looking at the range in the IPCC scenarios, and finding out if the observed temperature fall in this range. It does.

3) You are still missing the basic point that cherry picking the starting point allows you to pick one ABOVE the IPCC scenario. If you extrapolate a liner trend from this point you insert a systematic error in the resulting “projection”.

 

[CoolSceptic]

If it's such a howler then why doesn't McIntyre or Lewis write up a rebuttal and have it published rather than blogging about it?

I suspect Nic Lewis probably will, but given the paper was only published a week ago, I think expecting him to have a publication out today is unreasonable.

However, given the astonishing (and unthinking) plaudits the paper has received in the press, a highlight of the fundamental problems in the paper is entirely appropriate. Had the paper received no press coverage, it would have been reasonable to respond directly in the scientific press first.

The same was true for the Monckton / Soon / Briggs paper. The fact that the responses appeared in blogs first does not undermine the criticisms of the paper. Such criticisms should stand on their merit, not where they appear.

 

[CoolSceptic]

1) The long term average is not an appropriate comparison because most scenarios show acceleration in the trend.

You should take it up with the IPCC, not me, since they are the ones providing the numbers.

If you draw a linear trend line over an accelerating warming it will fall above both observed data and model projections.

The second derivative can be used for falsification here too, and I'm afraid to say the observations show the warming ain't accelerating at the moment.

2) You are using the wrong error margin.

Actually, nobody knows what the "right" error margin to use is, and every climate scientist I've chatted to about this (including 2 IPCC lead authors) has ultimately agreed with me on this point. But I was giving an indication of relative error margins, which at least gives some understanding of the issues at hand, and the reality is that the difference in error margin between 15 yrs and 30 yrs ain't all that much. Root two, best guess.

 

[lomiller]

You should take it up with the IPCC

Why? The IPCC did it properly, and because they did it properly they reached the correct conclusions.

The second derivative can be used for falsification here too, and I'm afraid to say the observations show the warming ain't accelerating at the moment.

Again you would need to apply that to the model runs not the observations. Doing this would tell you how long a period you would need to look at to observe statistically significant acceleration. This time period is longer than the 20-30 years needed for the first derivative.

Regardless, the trend line you are trying to call "trend from IPCC model results" doesn't match what the model runs show for the period 2000 - 2015. You choose a slope larger than the model results presented in the IPCC reports for that time period and added to the Y intercept from what is actually in the IPCC reports. In the presence of such serious systematic errors the statistical error margins become irrelevant.

Actually, nobody knows what the "right" error margin to use is,

? This makes no sense. You analyse the data properly and that gives you the error margins. This is completely different than inserting a discontinuity into the trend line and hiding the fact by only using the slop to calculate error margin.

 

[Fair Witness]

Emily
Elf Grinder and many others do not understand the difference between forcing and feedback.
...
This is SUCH a fundamental point you would think anyone pretending to be knowledgeable about climate would know the difference between a feedback and a forcing.....rather than face planting in a science forum

What I would like someone to provide an explanation for is...

1) Over most periods of time, the paleoclimate graph being referred to previously shows that CO2 lags temperature change. If CO2 has such a strong forcing capability, how is that historical temperatures ever fall once they've risen above a certain temperature and CO2 levels consequently rise? Why doesn't CO2 act as a forcing mechanism to drive them back up? I've read it many times in this forum that current CO2 levels are at the point now where we've reached the point of no return. Yet, CO2 levels in the past have been at this point or higher and CO2 has not acted as a forcing agent to keep temperatures from falling, or to drive them back up, or to compound warming rates as temperatures were climbing. How is it that today CO2 has this much forcing capability?

2) When considering the paleoclimate record, ocean temperature is not included. We are told that the difference between previous warming cycles and the current warming rate is that the rate of warming has never been as high. Yet, the current slowdown (or pause depending on one's perspective) is explained as being hidden in ocean heat. If so, how can we compare the global warming rates of today that factor in ocean heat with historical warming cycles that do not? Is there something about the heat absorbing capabilities of past oceans that makes their heat content not be a significant factor when considering warming rates?

3) I'm also puzzled how one can conclude that the warming rate in the last 30 years exceeds historical levels when the paleoclimate records do not appear to have that level of granularity. Where does that certainty come from?

 

[Emily's Cat]

Question:

Point # 1 - With all this ice melting. 2015 Sept all Arctic ice may be all gone for the first time (summer time).

Point #2 - Most of the carbon goes into the ocean and the heat goes there too.

So why is the ocean rate of rise still growing so slowly, like in millimeters.

The ocean is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to The ocean.

 

[CapelDodger]

Originally by lomiller

I was responding to a number given in the WSJ op-ed piece. It’s actually non-specific about exactly what time period the “no warming in the last 15 years” Depending on when the piece was written it could easily refer to a starting point anywhere in the 1998 – 2000 range. Regardless of which one it is, however the basic point i was making doesn’t change. No matter which of these 3 years you choose as a starting point for drawing a trend line, that trend line starts ABOVE the established, statistically significant trend from 1970 – 2014.

No problem with that, the problem is with "the last x years", which is no way to define a period. Some people will get "no warming for 15 years" into their heads and they'll be repeating it forever. The passage of time escapes them.

AGW deniers have, as we know all to well, made a big thing of a 15 year period. I'm being lenient with that; in 2005 I first heard "no warming for ..." and that was 7 years. That particular victim doesn't post here any more (we've lost a few over the years, haven't we?) but the 15 year thing sticks to all of the extant AGW denialati. I know it's bollocks, you know it's bollocks, but they'll find it hard to argue it's bollocks when the 15 year thing turns against them. There lies the danger in short-term expedients.

Pat Michaels actually warned them against this some years ago at a Heartland bash; "the Pause will come back to bite you" was his message, but they clung to it all the same.

Since then we've seen the retreat from a surface temperature Pause to a UAH lower troposphere Pause to an RSS Pause - which is almost poetic, since the satellite RSS derives from is performing a predictable death-spiral.

Now we have people who used to draw a straight line from 1998 to whenever and declaring an enormously consequential Pause getting into statistics and showing that the Pause was just a slowdown but there's a climate scientist who called it a "Pause" so they'll call a slowdown a Pause as well. Even though we all know it's just a slowdown. And at no point has it even been a statistically significant slowdown.

The 15 year thing is turning against them and I intend to exploit that. The day of the Surge is coming.

 

[bit_pattern]

What I would like someone to provide an explanation for is...

1) Over most periods of time, the paleoclimate graph being referred to previously shows that CO2 lags temperature change. If CO2 has such a strong forcing capability, how is that historical temperatures ever fall once they've risen above a certain temperature and CO2 levels consequently rise? Why doesn't CO2 act as a forcing mechanism to drive them back up? I've read it many times in this forum that current CO2 levels are at the point now where we've reached the point of no return. Yet, CO2 levels in the past have been at this point or higher and CO2 has not acted as a forcing agent to keep temperatures from falling, or to drive them back up, or to compound warming rates as temperatures were climbing. How is it that today CO2 has this much forcing capability?

Because there is also an orbital forcing at play. Changes in solar radiation impact the temperature of the oceans which in turn impacts their ability to store/release carbon dioxide.

Also, I would note that while - yes - CO2 has been this high before, but that was 15 million years ago when there were no ice caps, the continents were in a different configuration and the planet was in a hothouse state. Arguably, the end of the Miocene climatic optimum came about because Antarctica became isolated from the rest of the continent and the circumpolar circulation formed, reducing the mixing of warm tropical water with cold polar waters, allowing the latter to build up and begin the formation of the Antarctic ice sheet.

2) When considering the paleoclimate record, ocean temperature is not included. We are told that the difference between previous warming cycles and the current warming rate is that the rate of warming has never been as high. Yet, the current slowdown (or pause depending on one's perspective) is explained as being hidden in ocean heat. If so, how can we compare the global warming rates of today that factor in ocean heat with historical warming cycles that do not? Is there something about the heat absorbing capabilities of past oceans that makes their heat content not be a significant factor when considering warming rates?

That's not actually correct.

Corals for example make excellent ocean temperature proxies due to their temperature sensitivity.

And a quick glance at Google Scholar will turn up lots of results such as this:

Pliocene three-dimensional global ocean temperature reconstruction

3) I'm also puzzled how one can conclude that the warming rate in the last 30 years exceeds historical levels when the paleoclimate records do not appear to have that level of granularity. Where does that certainty come from?

That might be the case with reconstructions going back hundred of thousands of years, but on the thousands of years time scale there are quite high resolution - corals, tree-rings, bore-holes etc. And on that scale the current warming is unprecedented.

But what's more important is the rapid rise in carbon levels, which are undeniably unprecedented. Looking back to see how that planet has responded to change in the past is instructive, but the theory doesn't rely on the recent warming being unprecedented. It is certainly useful to put it into historical context but there is a very sound physical model upon which the theory rests - it is beyond doubt that a rapid increase in carbon will result in a rapid warming, looking back merely gives an indication of the implication of such rapid changes.

 

[bit_pattern]

The ocean is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to The ocean.

Hitchhikers Guide to the Climate

 

[CapelDodger]

3) I'm also puzzled how one can conclude that the warming rate in the last 30 years exceeds historical levels when the paleoclimate records do not appear to have that level of granularity. Where does that certainty come from?

It comes from the fact that a global warming such as we've seen in the last 30 years would have been documented if it was a common occurence. We aren't in the process of a glacial/inter-glacial transition, which is what palaeoclimatology is about, we're in the coasting zone of an interglacial, past the peak and heading very gradually down to the point when I'd need to worry about polar bears.

Anthropogenic global warming is not an explanation conjured up after the event to explain the current warming. AGW predicted the current warming from physical principles; the warming is merely confirmation since there's no other identified explanation for it, and great efforts have been made to find one.

Palaeoclimatology concerns finding an explanation for such things as glacial/inter-glacial transitions and the climate dinosaurs thrived in. It involves processes which take at least tens of thousands of years to have a measurable impact at the time, let alone now.

Stuff is happening, it's happening for a reason, and we're it. You will not find a global industrialised civilisation anywhere in the past because this is the first.

 

[CapelDodger]

The ocean is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to The ocean.

You sit on the beach, or even more so in a boat, and look out on the sea and you think it's big, like really big. And then you realise that's just the top.

 

[CapelDodger]

Also, I would note that while - yes - CO2 has been this high before, but that was 15 million years ago when there were no ice caps, the continents were in a different configuration and the planet was in a hothouse state.

A golden age in many ways. Shame we weren't about to enjoy it.

Arguably, the end of the Miocene climatic optimum came about because Antarctica became isolated from the rest of the continent and the circumpolar circulation formed, reducing the mixing of warm tropical water with cold polar waters, allowing the latter to build up and begin the formation of the Antarctic ice sheet.

We warned them, but did they listen? No, they just let nature take its course.

As for allowing the Panama Ridge to become the Panama Isthmus and cut off the Pacific from the Atlantic, that's when idiocy became criminal idiocy in my book.

 

[bit_pattern]

Very droll

 

[macdoc]

But what's more important is the rapid rise in carbon levels, which are undeniably unprecedented.

Not quite unprecedented....the Deccan traps where the end result was the Permian extinction also saw fossil carbon injected in the atmosphere on a massive scale but the scary part is we are actually increasing it faster than that particular disaster.

http://eapsweb.mit.edu/news/2014/extinction-blink-eye

That took many thousands of years and simply provides evidence to support what occurs when carbon becomes a forcing instead of a feedback.

FW - you need to be careful in your language with forcing and feedback.

An orbital forcing is magnified ( in both cooling and warming ) by the effect of C02. ( and other GHG ...some persistent some not )
The CO2 is not a forcing in that case but rather a feedback.

Examples of a forcing are volcanos or the anthro release of SO2 ( manufacturing ) which dims the planet ( less sunlight reaching the ocean. A volcano is a primary forcing for that reason as it releases aerosols into the stratosphere which can circulate for a couple of years and the cooling is seen in the climate record. Pinatubo notably.
Humans can and do cool the planet by releasing SO2 in manufacturing in which case cooling oceans would absorb more CO2 furthering the cooling...a feedback.

Part of the variability in warming rates over short periods is the offsetting effect of aerosols whose effects are mixed ( carbon black for instance ). Both are anthro..one cooling - the other warming.

Another feedback rarely talked about is water vapor but actually the most powerful which enhances CO2 ( 1.6x I think ) - so we have a warmer and moister atmosphere with knock on consequences for weather.

Fortunately, unlike CO2 ( forever in human terms ) and even methane ( a couple of decades ).....water vapour drops out of the atmosphere quickly.

This is a reasonable visual of the various processes

 

[bit_pattern]

^^ Thanks for the clarification, MD

Came across this before, seems I missed it when it came out but it adds some more texture to the lead/lag issue

http://www.skepticalscience.com/skakun-co2-temp-lag.html

What's Going On?
What appears to have happened, based on global climate model simulations run by Shakun et al., is not all that different from our previous explanation of the supposed CO2 lag - just a bit more nuanced.

• As we already knew, the Earth's orbital cycles trigger the initial warming (starting approximately 19,000 years ago), which is first reflected at the highest latitudes (i.e. Greenland and the Arctic - see "Onset of seesaw" in Figure 4).
• This Arctic warming melted large quantities of ice, causing fresh water to flood into the oceans.
• This influx of fresh water then disrupted the Atlantic meridional overturning circulation (AMOC), in turn causing a seesawing of heat between the hemispheres. The Southern Hemisphere and its oceans warmed first, starting about 18,000 years ago.
• The warming Southern Ocean then released CO2 into the atmosphere starting around 17,500 years ago, which in turn caused the entire planet to warm via the increased greenhouse effect.
• In short, the initial warming was indeed triggered by the Milankovitch cycles, and that small amount of orbital cycle-caused warming eventually triggered the CO2 release, which caused most of the glacial-interglacial warming. So while CO2 did lag behind a small initial temperature change (which mostly occurred in the Southern Hemisphere), it led and was the primary driver behind most of the glacial-interglacial warming.

According to the Shakun et al. data, approximately 7% of the overall glacial-interglacial global temperature increase occurred before the CO2 rise, whereas 93% of the global warming followed the CO2 increase.

 

[Kestrel]

The ocean is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to The ocean.

Mass of the Earth's oceans is 1.4 x 10²¹ kg.
Mass of the Earth's atmosphere is 5.1 x 10¹⁸ kg.

Given this, it is not suppressing that we have screwed up the atmosphere more than the oceans.

 

[bit_pattern]

http://www.theguardian.com/environm...or-australias-record-hottest-year-says-report

Australia’s hottest year on record would not have happened without climate change, according to a new report.

The country experienced its hottest day, month, season and calendar year in 2013, registering a mean temperature 1.2C above the 1961-90 average.

The Climate Council says recent studies show those heat events would have occurred only once every 12,300 years without greenhouse gas emissions from human activities.

 

[Haig]

Mass of the Earth's oceans is 1.4 x 10²¹ kg.
Mass of the Earth's atmosphere is 5.1 x 10¹⁸ kg.

Given this, it is not suppressing that we have screwed up the atmosphere more than the oceans.

You overstate the "we" bit ... it's nature not us as the "climate change" main driver The "we" you refer too are just "statistically insignificant bit players" as this alarmist source admits

It is true that human emissions of CO2 are small compared with natural sources.

add to that the fact that water vapour is a far more potent GHG than Co2 over which we have NO control just confirms it's nature not us driving the climate ... DEAL WITH IT !

Inconvenient study: Seafloor volcano pulses may alter climate – models may be wrong

Tides, Earthquakes, and Volcanoes

Empirical evidence for a celestial origin of the climate oscillations and its implications PDF

Satellites: Warming pause continues & 2014 not the hottest