I Ain't Buying It

By: Birthmark , 11:54 PM GMT on September 23, 2013

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I Ain't Buyin' It!

A lot has been made in denialist and media circles about the so-called hiatus in global warming. I ain't buying that there is a hiatus, though there has been a slight slowdown in the upward trend --very slight.

I'll start by posting something I've posted on both Dr. Masters' and Dr. Rood's blogs. I'll simply post the data for the time periods 1980-1997 and 1999-2012. I originally did this because I was curious to see what would the data look like without 1998. I wasn't that surprised by the results. In graphical form, it looks like this:


There is simply no large hiatus in the warming trend if the "freak" El-Nino year of 1998 is left out. Here are the numbers:

GISTEMP
1980-1997 = 0.100 ±0.133 C/decade
1999-2013 = 0.098 ±0.156 C/decade

NOAA
1980-1997 = 0.102 ±0.114 C/decade
1999-2013 = 0.064 ±0.146 C/decade

HADCRUT4
1980-1997 = 0.109 ±0.116 C/decade
1999-2013 = 0.078 ±0.148 C/decade

RSS
1980-1997 = 0.071 ±0.187 C/decade
1999-2013 = 0.038 ±0.239 C/decade

UAH
1980-1997 = 0.031 ±0.197 C/decade
1999-2013 = 0.152 ±0.239 C/decade

------------------------
Land Only data
------------------------

BEST
1980-1997 = 0.161 ±0.286 C/decade
1999-2013 = 0.171 ±0.354 C/decade

NOAA (land only)
1980-1997 = 0.155 ±0.187 C/decade
1999-2013 = 0.138 ±0.252 C/decade

Any change in the trend is pretty minimal.

That's the temperature record, but what happens if we remove the natural factors which cause the noise in the data and look only at the anthropogenic signal, ala Foster and Rahmstorf (2011)?

Adjusted Temperature Trends 1998-2012

GISS 0.212 ±0.097 °C/decade
NCDC 0.153 ±0.081 °C/decade
CRU 0.117 ±0.075 °C/decade
RSS 0.118 ±0.086 °C/decade
UAH 0.176 ±0.099 °C/decade

When corrected for ENSO, solar variability, and volcanic forcing the upward trend continues, even when beginning in 1998. What's more, in all five data sets the trend is statistically significant.

Hiatus in global warming? I ain't buying it!

Neither should you.

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6. WunderAlertBot (Admin)
4:30 PM GMT on October 26, 2013
Birthmark has created a new entry.
5. JohnLonergan
3:06 PM GMT on September 25, 2013
Neither is Stefan Rahmstorf at RealClimate, this is reposted from Dr. Rood"s blog:

The heat content of the oceans is growing and growing. That means that the greenhouse effect has not taken a pause and the cold sun is not noticeably slowing global warming.

NOAA posts regularly updated measurements of the amount of heat stored in the bulk of the oceans. For the upper 2000 m (deeper than that not much happens) it looks like this:


"Change in the heat content in the upper 2000 m of the world’s oceans. Source: NOAA

The amount of heat stored in the oceans is one of the most important diagnostics for global warming, because about 90% of the additional heat is stored there (you can read more about this in the last IPCC report from 2007). The atmosphere stores only about 2% because of its small heat capacity. The surface (including the continental ice masses) can only absorb heat slowly because it is a poor heat conductor. Thus, heat absorbed by the oceans accounts for almost all of the planet’s radiative imbalance.

If the oceans are warming up, this implies that the Earth must absorb more solar energy than it emits longwave radiation into space. This is the only possible heat source. That’s simply the first law of thermodynamics, conservation of energy. This conservation law is why physicists are so interested in looking at the energy balance of anything. Because we understand the energy balance of our Earth, we also know that global warming is caused by greenhouse gases – which have caused the largest imbalance in the radiative energy budget over the last century.

If the greenhouse effect (that checks the exit of longwave radiation from Earth into space) or the amount of absorbed sunlight diminished, one would see a slowing in the heat uptake of the oceans. The measurements show that this is not the case.

The increase in the amount of heat in the oceans amounts to 17 x 1022 Joules over the last 30 years. That is so much energy it is equivalent to exploding a Hiroshima bomb every second in the ocean for thirty years.

The data in the graphs comes from the World Ocean Database. Wikipedia has a fine overview of this database. The data set includes nine million measured temperature profiles from all of the world’s oceans. One of my personal heroes, the oceanographer Syd Levitus, has dedicated much of his life to making these oceanographic data freely available to everyone. During the Cold war that even landed him in a Russian jail for espionage for a while, as he was visiting Russia on his quest for oceanographic data (he once told me of that adventure over breakfast in a Beijing hotel).

How to deny data

Ideologically motivated “climate skeptics” know that these data contradict their claims, and respond … by rejecting the measurements. Millions of stations are dismissed as “negligible” – the work of generations of oceanographers vanish with a journalist’s stroke of a pen because what should not exist, cannot be. “Climate skeptics’” web sites even claim that the measurement uncertainty in the average of 3000 Argo probes is the same as that from each individual one. Thus not only are the results of climate research called into question, but even the elementary rules of uncertainty calculus that every science student learns in their first semester. Anything goes when you have to deny global warming. Even more bizarre is the Star Trek argument – but let me save that for later."...

Read more at RealClimate >>

Note Added the following section:

Beam me up Scotty!


Now to the most amusing attempt of “climate skeptics” to wish these scientific results away. Their argument goes like this: It is not possible that warming of the deep ocean accelerates at the same time as warming of the upper ocean slows down, because the heat must pass through the upper layer to reach the depths. A German journalist put it this way:

Winds can do a lot, but can they beam warm surface waters heated by carbon dioxide 700 meters further down?


This argument reveals once again the shocking lack of understanding of basic physics in “climate skeptic” circles. First the alleged problem is lacking any factual basis – after all, in the last decades the upper layer of the oceans has warmed faster than the deeper (even if recently not quite as fast as before). What is the problem with the heat first warming the upper layer before it penetrates deeper? That is entirely as expected.

Second, physically there is absolutely no problem for wind changes to cool the upper ocean at the same time as they warm the deeper layers. The following figure shows a simple example of how this can happen (there are also other possible mechanisms).



The ocean is known to be thermally stratified, with a warm layer, some hundreds of meters thick, lying on top of a cold deep ocean (a). In the real world the transition is more gradual, not a sharp boundary as in the simplified diagram. Panel (b) shows what happens if the wind is turned on. The surface layer (above the dashed depth level) becomes on average colder (less red), the deep layer warmer. The average temperature changes are not the same (because of the different thickness of the layers), but the changes in heat content are – what the upper layer loses in heat, the lower gains. The First Law of Thermodynamics sends greetings.

Incidentally, that is the well-known mechanism of El Niño: (a) corresponds roughly to El Niño (with a warm eastern tropical Pacific) while (b) is like La Niña (cold eastern tropical Pacific). The winds are the trade winds. The figure greatly exaggerates the slope of the layer interface, because in reality the ocean is paper thin. Even a difference of 1000 m across the width of the Pacific (let’s say 10,000 km) leads to a slope of only 1:10,000 – which no one could distinguish from a perfectly horizontal line without massive vertical exaggeration.

Now if during the transition from (a) to (b) the upper layer is heated by the greenhouse effect, its temperature could remain constant while that of the lower one warmed. Simple classical physics without beaming.

Beam me up Scotty! There is no intelligent life on this planet.


At least not in the deniosphere.
Member Since: June 27, 2012 Posts: 0 Comments: 2764
4. JohnLonergan
12:34 AM GMT on September 24, 2013
About the Lack of Warming… by Dr John Nilson-GannonDr. Nilson-Gannon separated the various years by El Nino, La Nina and neutral:

"I decided to take a simple approach at looking at the effect of ENSO. Using GISTemp Land/Ocean Index values and Niño 3.4 values, I computed 12-month running averages of Niño 3.4 and compared them to the average GISTemp values at lags of 0, 3, and 6 months. Foster and Rahmsdorf used a diferent ENSO index and found optimal lags between 2 and 5 months. So one would guess that a 3-month lag would fit the data best in my case, and indeed it did.

The normal threshold for El Niño or La Niña, as applied by the Climate Prediction Center, is for five consecutive months of at least 0.5 C above or below normal in a key region of the tropical Pacific. For working with annual data, I decided to call an annual average above 0.5 C an El Niño and an annual average below -0.5 C a La Niña. Then I plotted it up, color-coding each year for whether it was El Niño, La Niña, or neither (neutral). Here’s the result:


Somehow, it no longer appears that global temperatures have leveled off in the past decade. That is because, with the color coding according to the phase of ENSO, the eye is able to compare apples to apples: the upward long-term trend during El Niño years (red triangles) is plain, the upward long-term trend during neutral years (green squares) is plain, and the upward long-term trend during La Niña years (blue diamonds) is plain.

Stare hard enough, though, and you see that they have leveled off. The last ten data points have little or no trend. But we see that the lack of trend is at least partly due to the El Niño year near the beginning of the 10-year period and the two La Niña years near the end.

Let’s get quantitative about this. In this case, with the temperature rise being nearly linear, it helps to add trendlines. I’ve excluded the three Pinatubo years from the regressions. Here’s the result:"

"


Remarlable how close the trend lines are.

Also From Dr. N-G:

Lack of Warming: A Followup
Member Since: June 27, 2012 Posts: 0 Comments: 2764
3. JohnLonergan
12:15 AM GMT on September 24, 2013
I was looking for something else and I found this interesting, if off topic, so I thought I'd post it.



Dispatch from AGU: Least Drama

I found myself attending the second of Naomi Oreskes’s talks, having heard the first one yesterday. Her point of departure was a recent paper in which she and her colleagues had analyzed a bunch of climate change predictions made by review articles or committees for which actual verification data was available. They found that all the predictions they could test were either accurate or too conservative. None erred on the side of alarmism.
Oreskes calls this “Erring on the Side of Least Drama”, or ESLD. Steve McIntyre might call it “It’s Worse Than We Thought Syndrome”, or IWTWTS.

Why are climate scientists as a whole too conservative? Oreskes considered the possibility that scientists were afraid of being attacked by skeptics. This was, in fact, why scientists she interviewed said they were conservative in their predictions.

I got to see a real-life example of this at the lunchtime Union Lecture. At the end, a scientist in the audience asked Robert Watson, a former IPCC chair, whether he regretted that the IPCC had been so tentative in connecting man with climate in its first two assessment reports, despite the strong evidence available at the time.

Watson strenuously defended the earlier reports. He said that if they, as scientists, had made even one prediction that turned out to be too extreme, they would have lost all credibility with the general public.
Oreskes thinks a more important issue is cultural peer pressure. She says that scientific culture frowns upon making dramatic predictions, so scientists are conservative to avoid getting vilified by their colleagues.
Member Since: June 27, 2012 Posts: 0 Comments: 2764
2. Patrap
12:15 AM GMT on September 24, 2013
Member Since: July 3, 2005 Posts: 415 Comments: 125628
1. BaltimoreBrian
12:00 AM GMT on September 24, 2013

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About Birthmark

This blog will be for the discussion of whatever takes my fancy at any given time. Primarily, that will be Anthropogenic Global Warming/Climate Change

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