[hrothgar]

 Daniel1960, on 2015-November-03, 10:28, said:

Obviously, you have not read either the posts or the linked articles very well. Try again, and perhaps you will begin to understand how your link supports my contention. I am not surprised by your insults. You seem to prefer that method of argument, rather than presenting evidence to support your stance.

You demonstrated long ago that you aren't worth anything more than insult and derision.

I save my cycles for people who pay me or who provide an interesting diversion.
You're a second rate troll who couldn't hack it on Real Climate and spams bridge groups with crap hoping for some kind of validation.

[Daniel1960]

 hrothgar, on 2015-November-03, 11:24, said:

You demonstrated long ago that you aren't worth anything more than insult and derision.

I save my cycles for people who pay me or who provide an interesting diversion.
You're a second rate troll who couldn't hack it on Real Climate and spams bridge groups with crap hoping for some kind of validation.

Fine then. If all you are interest is in insulting those with whom you disagree, then why even join this discussion board. Perhaps you would be better served arguing in your local pub. Most of us (there are other exceptions) are interested in a real discussion, whether we agree or disagree with each other. Fact check, the rest of us do not get paid either. Perhaps you would like to join us over at Real Climate - I have yet to see you back, since you invited me to join here. We just had an interesting discussion concerning the growth in Antarctic ice. Most of those involved were rather civil, although there are those there too who prefer insults to debates.

[PassedOut]

 Daniel1960, on 2015-November-03, 08:52, said:

Actually those rebuttals reinforce my claims. Specifically that sea level rise accelerated from the 19th century until 1930, but no acceleration has occurred since. The other links corroborated these particular time frames. All the papers [that I have found] show that sea level stopped dropping at the end of the Little Ice Age, and started rising, sometime in the 19th century, when temperatures started to rise. This is when the acceleration occurred.

The rebuttals only reinforce the claim that one can cherry-pick data from particular times and locations that diverge from the long-term trend. But no one disagrees with that, and you had seemed to be saying that that wasn't your intent.

The problem comes when you argue that your cherry-picked data somehow undermines the fact that, long term, the rise in sea levels is accelerating as the earth warms.

Let's look at the conclusion of the paper that you say reinforces your claims:

Quote

In summary, we find that the deceleration in sea-level rise reported by Houston and Dean either applies to a far-too-brief time interval (since 1993), or to a unique and specially selected start date (1930), or only to regional, strongly Northern Hemisphere–biased records that are spatially or temporally averaged in an inappropriate manner. None of this supports a lack of acceleration in global sea-level rise, as compared to what is expected from global warming

I'm not a harsh person (having mellowed over the years), but I have to say that it does hurt your credibility when you link to papers that you know have been refuted, without also linking to the refutations. The same is true when you portray inaccurately the contents of a paper being discussed. (This is not the only time you've done that.) Whether you do these things to deceive or from misunderstanding, they diminish your credibility.

[Daniel1960]

 PassedOut, on 2015-November-03, 12:31, said:

The rebuttals only reinforce the claim that one can cherry-pick data from particular times and locations that diverge from the long-term trend. But no one disagrees with that, and you had seemed to be saying that that wasn't your intent.

The problem comes when you argue that your cherry-picked data somehow undermines the fact that, long term, the rise in sea levels is accelerating as the earth warms.

Let's look at the conclusion of the paper that you say reinforces your claims:


I'm not a harsh person (having mellowed over the years), but I have to say that it does hurt your credibility when you link to papers that you know have been refuted, without also linking to the refutations. The same is true when you portray inaccurately the contents of a paper being discussed. (This is not the only time you've done that.) Whether you do these things to deceive or from misunderstanding, they diminish your credibility.

What cherry-picked data? Are you implying that 85 years of no acceleration is somehow cherry-picking, compared to the past 200 years. If that is the case, why not compare to the past 10,000 years, and conclude that a significant deceleration has occurred?

The conclusion in the paper to which Hrothgar linked, discussed deceleration claims since 1993. If you which to argue cherry-picking, would not changes since 1993 be more of a cherry-pick than those since 1930? I contend that sea level rise since 1930 is a better long-term change than your reference to 1993.

You may wish to do a little self-reflection concerning your final comment. How can you say that 22 years of satellite data refutes 85 years of tidal gauge data? Just who is being inaccurate and misleading here?

[PassedOut]

 Daniel1960, on 2015-November-03, 13:15, said:

What cherry-picked data? Are you implying that 85 years of no acceleration is somehow cherry-picking, compared to the past 200 years. If that is the case, why not compare to the past 10,000 years, and conclude that a significant deceleration has occurred?

The 85 years is cherry-picked because 1930 represents the extreme low point following a deceleration in sea level rise caused by a period of unusual global cooling. Sea level rise is strongly correlated with global warming.

When you intentionally pick a starting point at an extreme value instead of a normal value, you intentionally skew your results. That is cherry-picking. 1930 is definitely not a year to use as an honest starting point.

Going back 10,000 years would be senseless because the industrial revolution only started a couple of hundred years ago. The long-term trend starts with the industrial revolution.

 Daniel1960, on 2015-November-03, 13:15, said:

The conclusion in the paper to which Hrothgar linked, discussed deceleration claims since 1993. If you which to argue cherry-picking, would not changes since 1993 be more of a cherry-pick than those since 1930? I contend that sea level rise since 1930 is a better long-term change than your reference to 1993.

That conclusion discusses those specific dates because they were used improperly in the paper by Houston and Dean to dispute the fact that the rise in sea level is accelerating. Neither date is any good for that purpose.

 Daniel1960, on 2015-November-03, 13:15, said:

You may wish to do a little self-reflection concerning your final comment. How can you say that 22 years of satellite data refutes 85 years of tidal gauge data? Just who is being inaccurate and misleading here?

And, of course, I never said anything of the kind. Millimeters are millimeters no matter how they are measured.

Although the satellite measurements are more accurate and more comprehensive, they were not available in the 1880s. But tide gauges are accurate enough that we can be sure that the yearly rise in sea level back then was nowhere close to 3mm.

[Daniel1960]

 PassedOut, on 2015-November-03, 14:23, said:

The 85 years is cherry-picked because 1930 represents the extreme low point following a deceleration in sea level rise caused by a period of unusual global cooling. Sea level rise is strongly correlated with global warming.

When you intentionally pick a starting point at an extreme value instead of a normal value, you intentionally skew your results. That is cherry-picking. 1930 is definitely not a year to use as an honest starting point.

Going back 10,000 years would be senseless because the industrial revolution only started a couple of hundred years ago. The long-term trend starts with the industrial revolution.


That conclusion discusses those specific dates because they were used improperly in the paper by Houston and Dean to dispute the fact that the rise in sea level is accelerating. Neither date is any good for that purpose.


And, of course, I never said anything of the kind. Millimeters are millimeters no matter how they are measured.

Although the satellite measurements are more accurate and more comprehensive, they were not available in the 1880s. But tide gauges are accurate enough that we can be sure that the yearly rise in sea level back then was nowhere close to 3mm.

I think you are confusing cherry-picking data with conclusions based on the data. The link I provided state the following:

1. "We use 1277 tide gauge records since 1807 to provide an improved global sea level reconstruction and analyse the evolution of sea level trend and acceleration. GSL12
shows a linear trend of 1.9 ± 0.3 mm·yr−1 during the 20th century and 1.8 ± 0.5 mm·yr−1 for the period 1970–2008."

2. "In this paper we address the development of the regional and global nonlinear sea level trends over the full length of tide- gauge records, however as pre-20th century records are sparse and geographically very limited, we focus on the 20th century. However, we show that over the last 100 years the rate of 2.5 ± 1.0 mm/yr occurred between 1920 and 1945, is likely to be as large as the 1990s, and resulted in a mean sea level rise of 48 mm"

3. "We consider four observational time series of GMSLR, all obtained by analysis of the worldwide dataset of tide gauge (TG) records collated by the Permanent Service for Mean Sea Level [1880-2010]. The reconstructions account for the observation that the rate of GMSLR was not much larger during the last 50 years than during the twentieth century as a whole, despite the increasing anthropogenic forcing."

4. "the tide gauge records referred to in this paper come from the Permanent Service for mean sea level (PSMSL, Woodworth and Player, 2003, [1880-2010]). the sets display evidence for a positive acceleration, or ‘inflexion’, around 1920–1930 and a negative one around 1960. These inflexions are the main contributors to reported accelerations since the late 19th century, and to decelerations during the mid- to late 20th century."

5. "The global sea-level reconstruction of Church and White (2006) shows a small deceleration since 1930" This is the paper that Hrothgar used to refute. Church and White also state, "little evidence has been found in individual tide gauge records for an ongoing positive acceleration of the sort suggested for the 20th century by climate models."

All these papers showed no acceleration over the past 90 years or so. These conclusions are the same whether the start date was 1930, 1880, or 1807. Those papers using older data did show acceleration up until around 1930. Claiming that they show acceleration over the past two centuries is basically true, but misleading, because all the acceleration occurred in the early portion of the data sets.

One cannot compare satellite measurements to tide gauges, because they are not performing the same measurement.

[PassedOut]

 Daniel1960, on 2015-November-03, 18:35, said:

One cannot compare satellite measurements to tide gauges, because they are not performing the same measurement.

Both measure sea level changes in millimeters, so of course you can compare them. That's the point of using numbers and standard units. The fact that the tide gauges are less accurate doesn't mean that the values they record are worthless.

And of course you can't find evidence for 21st century sea level changes in 20th century records. If the earth keeps warming, sea level increases will accelerate. If the earth cools, they will decelerate.

[Daniel1960]

 PassedOut, on 2015-November-03, 19:07, said:

Both measure sea level changes in millimeters, so of course you can compare them.

And of course you can't find evidence for 21st century sea level changes in 20th century records. If the earth keeps warming, sea level increases will accelerate. If the earth cools, they will decelerate.

Just because they give the measurement in millimeters, does not mean they yield the same results. One calculates sea level from the Earth's center (fixed point), the other measures sea level from the ocean floor (non-fixed). The techniques and reference points are different. Additionally, three different satellites have been used, with three different offsets. I can measure distance driven using my odometer or a yard stick. That does not mean that I will get the same answer.

[PassedOut]

 Daniel1960, on 2015-November-03, 19:50, said:

Just because they give the measurement in millimeters, does not mean they yield the same results. One calculates sea level from the Earth's center (fixed point), the other measures sea level from the ocean floor (non-fixed).

For these comparisons, that is irrelevant. What matters here is the change in sea level, in millimeters, from one year to the next--regardless of the starting point. The measured changes can be compared directly.

Even though the tide gauges are inherently less accurate, they are accurate enough to be sure that sea level rise in the 1880s was around 1mm per year, nowhere near the 3mm+ per year we see today.

[Daniel1960]

 PassedOut, on 2015-November-03, 22:09, said:

For these comparisons, that is irrelevant. What matters here is the change in sea level, in millimeters, from one year to the next--regardless of the starting point. The measured changes can be compared directly.

Even though the tide gauges are inherently less accurate, they are accurate enough to be sure that sea level rise in the 1880s was around 1mm per year, nowhere near the 3mm+ per year we see today.

Yes, and are we in agreement that sea level rise accelerated for the next 50 years, and that sea level rise has been fairly constant since?

[y66]

The Tough Realities of the Paris Climate Talks by Stephen Koonin

Quote

IN less than a month, delegates from more than 190 countries will convene in Paris to finalize a sweeping agreement intended to constrain human influence on the climate. But any post-meeting celebration will be tempered by two sobering scientific realities that will weaken the effectiveness of even the most ambitious emissions reduction plans that are being discussed.

The first reality is that emissions of carbon dioxide, the greenhouse gas of greatest concern, accumulate in the atmosphere and remain there for centuries as they are slowly absorbed by plants and the oceans. This means modest reductions in emissions will only delay the rise in atmospheric concentration but will not prevent it. Thus, even if global emissions could be reduced by a heroic average 20 percent from their “business as usual” course over the next 50 years, we would be delaying the projected doubling of the concentration by only 10 years, from 2065 to 2075.

Unconditional national commitments made by countries for the Paris meeting are projected to reduce total greenhouse gas emissions through 2030 by an average of only 3 percent below the business-as-usual average rise of 8 percent.

This is why drastic reductions would be needed to stabilize human influences on the climate at supposed “safe” levels. According to scenarios used by the United Nations Intergovernmental Panel on Climate Change, global annual per capita emissions would need to fall from today’s five metric tons to less than one ton by 2075, a level well below what any major country emits today and comparable to the emissions from such countries as Haiti, Yemen and Malawi. For comparison, current annual per capita emissions from the United States, Europe and China are, respectively, about 17, 7 and 6 tons.

The second scientific reality, arising from peculiarities of the carbon dioxide molecule, is that the warming influence of the gas in the atmosphere changes less than proportionately as the concentration changes. As a result, small reductions will have progressively less influence on the climate as the atmospheric concentration increases. The practical implication of this slow logarithmic dependence is that eliminating a ton of emissions in the middle of the 21st century will exert only half of the cooling influence that it would have had in the middle of the 20th century.

These two scientific realities make emissions reductions a sluggish lever for constraining human influences on the climate. At the same time, societal realities conspire to make emissions reductions themselves difficult. Energy demand, which is strongly correlated with rising incomes and living standards, is expected to grow by some 50 percent by midcentury, driven by economic progress in developing countries and by population growth to about 9.7 billion people from the current 7.3 billion.

Fossil fuels, which are not running out anytime soon, supply over 80 percent of the world’s energy today and are usually the least expensive and most convenient means of meeting growing energy demand. They continue to be widely adopted as the developing world builds its energy-supply infrastructure, because whatever the emissions benefits of technologies such as nuclear fission, carbon sequestration, wind and solar, all currently have drawbacks (including cost, land use and intermittence) that hamper their deployment at scale.

And in the developed world, the energy-supply infrastructure of electric generating plants, transmission lines, refineries and pipelines changes slowly because of the large capital costs and long facility lifetimes, and because different parts of the energy system must work together (for example, cars, their fuel and the fueling infrastructure must all be compatible).

Improvements in energy efficiency can help, but even if today’s annual per capita emissions of three tons in the developing world grew by midcentury to only five tons (about 70 percent of Europe’s per capita emissions today), annual global emissions would increase by 60 percent.

And, overarching all this, the tension between emissions reductions and development is complicated by uncertainties in how the climate will change under human and natural influences and how those changes will impact natural and human systems.

These scientific and societal realities compound to make stabilization of the atmospheric concentration of carbon dioxide, let alone its reduction, a distant prospect. As a result, even as the world struggles to reduce emissions, human influences on the climate will not be decreasing for many decades. Thus, adaptation measures such as raising the height of sea walls or shifting to drought-resistant crops become very important. Fortunately, adaptation is on the table in Paris to complement emissions reductions.

Adaptation can be effective. Humans today live in climates ranging from the tropics to the Arctic and have adapted through many climate changes, including the Little Ice Age about 400 years ago.

Adaptation is also indifferent to whether the climate change is natural or human-induced; it can be proportional, depending upon how much or how quickly the climate changes; and it can be politically easier to accomplish because it does not require a global consensus and has demonstrable local and immediate effects. Adaptation will no doubt be more difficult if the climate changes rapidly (as it has done naturally in the past), and, like emissions reductions, it will induce inequalities, as the rich can adapt more easily than the poor. Adapting ecosystems to a changing climate will require a more careful monitoring and deeper understanding of the natural world than we have today.

The critical role of adaptation in responding to the realities of climate change demands a deeper analysis and more prominent discussion of the nature, effectiveness, timing and costs of various adaptation strategies. But whatever the outcome in Paris, or of future discussions of emissions and the climate, the reality is that humans must continue to adapt, as they always have.

[PassedOut]

 Daniel1960, on 2015-November-04, 06:05, said:

Yes, and are we in agreement that sea level rise accelerated for the next 50 years, and that sea level rise has been fairly constant since?

No, you are wrong. Sea level rise decelerated significantly between 1910 and 1930. (That's why 1930 is a bogus starting point.)

[Incidentally, why would you even post such a statement, when you must know from your reading that it is wrong?]

The changes in sea level are strongly correlated with changes in global warming, not linearly with time. If the earth continues to warm, the long-term acceleration will continue. If the earth cools (for example, if Yellowstone blows), it will reverse.

[Zelandakh]

 Al_U_Card, on 2015-November-02, 22:41, said:

Despite their equivocation, the info from the actual measurements shows clearly that there is no clear link to CO2 rise and climate doom. At least from Antarctic meltdown... Too bad for all the alarmists, what with the Paris extravaganza on its way.

I asked for actual measurements and not for your own interpretation, which I would personally rank somewhere below your evaluation of climate models.

[Daniel1960]

 PassedOut, on 2015-November-04, 07:14, said:

No, you are wrong. Sea level rise decelerated significantly between 1910 and 1930. (That's why 1930 is a bogus starting point.)

[Incidentally, why would you even post such a statement, when you must know from your reading that it is wrong?]

The changes in sea level are strongly correlated with changes in global warming, not linearly with time. If the earth continues to warm, the long-term acceleration will continue. If the earth cools (for example, if Yellowstone blows), it will reverse.

Perhaps I should clarify, sea level rise accelerated from its earlier (19th century) rate to its current rate at or around 1930. Since 1930, the rate has been fairly constant. See the analysis by Rahmstorf, using the data from Church and White, 2006, and from Jevrejeva, 2014.

https://climatesanit...-sea-level.jpeg

http://d29qn7q9z0j1p...36/F4.large.jpg

As you can see, 1930 was the start of the current sea level rise. It is not a cherry-picked date, but a conclusion, based on the data. You may call it "bogus." However, that is when sea level started on its current trajectory. The rise does show quite some scatter, but has not shown any significant acceleration or deceleration since.

[PassedOut]

 Daniel1960, on 2015-November-04, 10:14, said:

As you can see, 1930 was the start of the current sea level rise. It is not a cherry-picked date, but a conclusion, based on the data. You may call it "bogus." However, that is when sea level started on its current trajectory. The rise does show quite some scatter, but has not shown any significant acceleration or deceleration since.

It's just bogus from the standpoint of disputing the long-term trend of acceleration since the industrial revolution.

Anyone can cherry-pick unrepresentative dates from an irregular graph for biased reasons, but the conclusions drawn from doing so are worthless for purposes of analyzing a long term trend. In fact, that was the point explained and emphasized in the refutation to the Houston and Dean paper we discussed a few posts back.

[kenberg]

I have a question.


Is there agreement on the data as data?

I find it useful to ask Do we agree on the reasonable accuracy of the data and then do we agree on what it means? Obviously their is not total agreement. But how about the published data? Is there general agreement that this can be accepted as reasonably accurate? I am thinking here of sea level data, but the same question applies to other data.


Global warming is one of many topics that I accept as important but that I have not, and probably never will, put in the effort to be confident in any discussion. The combatants do not agree on what day of the week it is. Yes, it may be Wednesday here, but you are cherry-picking the time zone.

So I ask: Putting aside the interpretation of the data, is there agreement on the accuracy of the data?Or, perhaps better, for which data is there general agreement as to its accuracy?

[Daniel1960]

 kenberg, on 2015-November-04, 11:39, said:

I have a question.


Is there agreement on the data as data?

I find it useful to ask Do we agree on the reasonable accuracy of the data and then do we agree on what it means? Obviously their is not total agreement. But how about the published data? Is there general agreement that this can be accepted as reasonably accurate? I am thinking here of sea level data, but the same question applies to other data.


Global warming is one of many topics that I accept as important but that I have not, and probably never will, put in the effort to be confident in any discussion. The combatants do not agree on what day of the week it is. Yes, it may be Wednesday here, but you are cherry-picking the time zone.

So I ask: Putting aside the interpretation of the data, is there agreement on the accuracy of the data?Or, perhaps better, for which data is there general agreement as to its accuracy?

Unfortunately, no. Here are a sampling of the changes in temperatures since 1980 (3-year smoothing). For surface thermometer data, we have HadCRU (+0.56), NCDC (+0.48), and GISS (+0.47). For atmospheric temperatures, we have UAH (+0.31) and RSS (+0.27). For sea surface temperature, we have UAH (+0.25), HadSST (+0.40), and NOAA (+0.35). The sea level satellite data shows a linear increase of 3.2 mm/yr since 1993. Church and White, using tide gauges calculated a linear increase of 2.8 mm/yr. Gehrels and Woodworth, also using tide gauges, calculated a rise of 2.4 mm/yr.

Obviously, the choice of data does make a difference. However, consistency can remove some of the uncertainty. Using the same data set over the entire time frame can yield much better results, than mixing the data. The satellite data is considered higher precision, but it has a limited time frame. I wish I had a better answer, such as use this data set. Unfortunately, that is not the case.

[Zelandakh]

 kenberg, on 2015-November-04, 11:39, said:

Is there agreement on the data as data?

This is actually a point of great contention within the whole debate Ken. The problem is that the raw data is not good enough to stand on its own. Measurement devices need to be replaced and different devices produce different results that require calibration. And that is just one of the factors. So adjustments need to be made and noone really contests that. The contention comes from the fact that these adjustments give the appearance of increasing the warming effect in many cases, with older measurements being reduced downwards and newer ones upwards. It raises the question of what the base data actually is and whether that is reliable.

And older data sets are even more contentious as they rely on proxies and putting them together uses techniques that are statistically questionable. Daniel's point of using the same data set has both pros and cons. Yes it improves the data in many ways but it also makes it much easier to cherry-pick and manipulate.

Then there is the ice data. How much ice is there in the Antarctic? or Greenland? Well you just measure the extent from space, right? Well no. That is done of course but a greater extent does not automatically mean more ice because the ice may well be thinner giving a lower volume. So finding any data for which there are no objections at all from either side is not as easy as you might think. That does not mean that there is not good data out there, it just means that you have to be careful not simply to accept graphs at face value.

[PassedOut]

 kenberg, on 2015-November-04, 11:39, said:

I find it useful to ask Do we agree on the reasonable accuracy of the data and then do we agree on what it means? Obviously their is not total agreement. But how about the published data? Is there general agreement that this can be accepted as reasonably accurate? I am thinking here of sea level data, but the same question applies to other data.

It reasonably accurate, given real life, and confidence levels are (generally) clearly displayed. There is a strong correlation between global temperature changes and global sea level changes (no surprise), but global warming is not linear.

[Al_U_Card]

Just read the assessment reports. As the model estimates diverge from reality, the SPMs INCREASE their declarations of certainty about the anthropogenic influence on climate catastrophy. They simply rely on "expert opinion" rather than actual analysis of data.... perhaps because they know that the converted don't really listen to the sermon in a faith-based environment.