Hello Kevin,

A "highly confident prediction of climate change research"? I cannot find in any of your links, or links from those links, what these confidence levels are. In any case predictions, which I assume you mean forecasts, can only be verified by calculating some error upon realisation of actual values. Without such rigour, the sea-level rise phenomenon is merely an assertion. Have you knowledge of such studies, or do you accept it as fact and move on from this obvious methodological problem. In one of the links I have found to the journal Science, Willis and Church (2012) state:

"Credible projections of sea-level rise in the 21st century are essential for devising adaptation or mitigation measures. Yet, present estimates of future sea-level rise are too imprecise to inform such decisions." Does this not conflict with your assertion?

Willis and Church (2012) go on to say:

"discrepancies between observations and simulations remain. Large discrepancies between regional projections from different models suggest that the ocean's dynamic response to climate forcing is poorly understood"

So, I ask how you could even say "almost certain" when there is such a lack of understanding? How could you swiftly discount the possibility of the naive forecast of no change, or even of sea levels falling by 2100?

Looks like the projections are good for Eastern Macedonia. From the NOAA (sorry to cherry-pick):

"Kavalla, Greece - The mean sea level trend is -6.73 mm/year with a 95% confidence interval of +/- 2.55 mm/year based on monthly mean sea level data from 1969 to 2010 which is equivalent to a change of -2.21 feet in 100 years." I am not sure why a linear trend is used. I don't have the data but it is rare that natural phenomena like this follow a linear deterministic process. Maybe the NOAA would like to keep it simple and easy to understand and explain.

Spiro. Seems like you have a bit of work to do to understand the science. Perhaps start with the law of gravity.

Can I recommend this video of a lecture by Jerry Mitrovica, Professor of Geophysics at Harvard University.
Key points
"The current rate of sea level rise varies from place to place, however this is to be expected due to the location and presence of land-based ice sheets, and gravitational changes brought about by the disintegration of these present-day glaciers and ice sheets."

"The future sea level rise projections of the 2007 IPCC report were too low. Current sea level rates are already at the uppermost range of projections, which reinforces this view."
http://skepticalscience.com/Jerry-Mitrovica-Current-Sea-Level-Rise-is-Anomalous-Weve-Seen-Nothing-like-it-for-the-last-10000-Years.html

Or Figure 2 in this presentation by James Hansen which shows an acceleration in sea level rise.
http://www.columbia.edu/~jeh1/2012/20120917_GroverNorquist.pdf

Here are a couple of additional articles to help you along.
http://e360.yale.edu/feature/the_secret_of_sea_level_rise_it_will_vary_greatly_by_region/2255/
http://www.skepticalscience.com/Sea-Level-Isnt-Level-This-Elastic-Earth.html

I am really not interested in any of your comments unless you can explain why NOAA use a linear trend for sea-level data. Can you justify it?

Spiros - You keep quoting Willis and Church (2012) as your authoritative source. While I have no issue with the discussion raised by the learned gentlemen, it is in fact a series of interesting points, I do take issue with your apparent lack of understanding about what does and does not represent a reliable source. Their comment was published in the "Perspectives" section of Science. To the best of my knowledge this is a place to provide an opinion on matters, and to suggest concepts for further discussion rather than a section for the pulblication of peer-reviewed papers.

I am not sure it is valid to use their commentary as an authoritative source in the way you seem to be doing.

I used a link in this article. Is it now credible? I was interested in the source of the assertions.

Spiro -

Your posts tend to have a 'unconstructive' rating.

Those you criticise tend to have a 'insightful' rating.

So do your own research and stop trolling.

Personal abuse again.

I was asking a valid methodological question. I believe that I get unconstructive ratings since I give valid questions that are difficult to answer. Expertise is supposed to be held up to scrutiny. It is an academic tradition. This is not a fan site.

There is this amazing invention called the internet. If you genuinely wished to become informed about climate change then you could answer most of your questions by doing some research.

Your posts here are perceived by many, including me, as just trying to throw mud with the hope that some of it will stick.

Do you accept the scientific consensus on climate change? If not, lets talk big picture and not waste every bodies time on issues such as "why NOAA use a linear trend for sea-level data?"

So a big picture question - Do you accept the science of climate change as presented by the IPCC, Garnaut, etc? If not, please provide something to justify your denial.

Yes, the internet?

I was asking the author. He gave me somewhat of a response. I showed him quotes from the links in his article that contradict his assertions. I explained that statements of forecasts 88 years out cannot possibly not include the probability of no change. These are serious methodological issues. Issues that those with particular expertise in climate science would not want to risk their remuneration with. I have no issue since in Economics we employ much more scrutiny.

I am really not interested in your crass personal abuse.

So, no answer as to whether or not you accept the majority view on climate change.

And if, as seems very likely, you do disagree, then you are unable to give a big picture view of why the science is wrong.

If you are unwilling to state your position and justify it then you are just a troll.

More personal abuse.

I am asking valid methodological questions. There are many to be answered. Can you answer any?

Willis and Church (2012):

"discrepancies between observations and simulations remain. Large discrepancies between regional projections from different models suggest that the ocean's dynamic response to climate forcing is poorly understood"

How is it personal abuse to ask whether or not you support the mainstream science on climate change?

How is it personal abuse in an academic themed forum to ask for you to provide some evidence to support your views?

And if you fail to do both of these, why is it wrong to conclude that you are just a troll?

Spiro - as I stated, I think the questions posed by Willis and Church are valid and interesting, but you used their article to contradict Kevin Walsh's assertion.

a) I don't think their work contradicts his assertion at all
b) best go to the peer reviewed literature in any case to start a discussion on the reliability on estimates

More personal abuse!

Michael, Seriously. I am not interested in your simple views.

I am not attempting to contradicting Kevin, but merely to state that a finite forecast interval for 88 years ahead suffers from obvious methodological flaws in its construction. In any case the value of zero change should be included in these intervals. The NOAA use a linear trend on past data. Kevin, in this article offers a projection for the year 2100, and goes on to state that a sea-level increase has a "highly confident prediction" and is "almost certain". I would take Willis and Church as a little more nuanced, which is less likely to attract the charge of being hysterical or alarmist. A future projection is a probabilistic event, and this should be made clear.

And let the reader decide which one of us is a fool and a troll.

Spiro. You say
Willis and Church (2012) go on to say:
"discrepancies between observations and simulations remain. Large discrepancies between regional projections from different models suggest that the ocean's dynamic response to climate forcing is poorly understood"

This is the actual quote.
"Large discrepancies between regional projections from different models suggest that the ocean’s dynamic response to climate forcing is poorly understood (1). Local geological influences in important urban settings like New Orleans (7) could result in tens of centimeters of additional rise by 2100 C.E."

Why did you drop the second sentence?

You are doing an Ian Plimer - claiming a reference supports you views when it says the opposite.
Even the subheading would give you a clue "More accurate projections of regional sea levels are needed to inform adaptation and mitigation planning."

Here is the article.
http://sciences.blogs.liberation.fr/files/niveau-marin-nw-science.pdf

You pompously claim "...in Economics we employ much more scrutiny." I hope that is true and your economics colleagues check the veracity of your cites.

Hang in there Spiro. You're well and truly in front. And you're not likely to come second against someone whose best shots are crass and meaningless platitudes about "the scientific consensus on climate change" and "justify your denial".

BTW Spiro if you want some comic relief, there's an "amateur climate science" blog with some interesting insights into the peer reviewed Gergis et al debacle ... er paper.

(Thankyou big oil for your financial support in allowing me and other conspirators to comment on this article)

Grant - I assume that you also don't accept the science on climate change. Is this so?

If you don't accept the science, as Spiro is unable to provide a link to a well argued case against the scientific consensus, it would be great if you could do so.

And to Grant and Spiro, if 95% of climate scientists are wrong, how has this happened? Are they ALL incompetent? Or is this a big conspiracy? And if it is a conspiracy, how have is been able to happen in EVERY country for over 20 years?

And for either scientific incompetence or conspiracy, how come noted economists such as Stern and Garnaut have been taken in?

And why are some right wing governments in Europe reducing their emissions? And why is China devoting so much money to energy efficiency and green energy?

MWH, please get your percentages correct! It was 97% of the entire world's climate scientists and not 95%. I'm on an iphone so can't give the link, but I'm sure you can. However, as I recall, this was the seminal paper in the expanding and crucial research area of climate science denial. Please send a link to it.

I'm at the pub at the moment and have reached the darts final. I'll get back to you when I can. Trust me, I'm a doctor.

Damn, came second. Three shots at double 16 and missed! MWH, it might pay you to get out your Statistics 101 notes and look up hypothesis testing and HO in particular. And where H0 sits within climate science.

Sir Ronald must be turning in his grave.

I always love it when non scientists use information provided by scientists to show that the scientists do not know what they are talking about...

NOAA uses blah blah blah but what they dont realise is - why dont you go work for them and straighten out NASA, NOAA and all the other agencies, see how that works out for you

Michael, they may be scientists, but their forecasting is very ordinary. Read this article: "the sea is now rising" as evidenced by sources such as NOAA who imply a linear relationship and "this will continue" a linear projection "and indeed accelerate into the future." a non-linear projection. Very ordinary and amateur. Forecasting is a field that uses the same methods whatever you are forecasting. I would hope that policy decisions based on climate change forecasts require the same rigour that ASIC does when a company lodges a prospectus.

Thanks Grant. I keep on being reminded about the science when my argument is about forecasting or the lack of it. Evaluating their forecasts is the only way to confirm their "science" .

(I cant thank big oil yet but I am open to offers. This reminds me of the shock I put some of my Saudi Arabian students in when I forecast that oil prices would crash after the peak in 2007 and it began to come true, rather than continue to increase to $200 a barrel as many peak-oil alarmists were claiming. Lucky for them, it did not fall too far. They had no interest in sea levels. They did not want to go back to eating grasshoppers as did their grandparents.)

Grant, I think Michael is asking the Lenin (1920) question: "each man must choose between joining our side or the other side. Any attempt to avoid taking sides in this issue must end in fiasco."

That's not science.

Spiro - I'm still waiting for someone to post something that would convince a scientifically literate person that the big picture on climate change is wrong.

I've asked you and Grant for this, and neither of you have provided it.

My side is rationality and the scientific method. And I'll follow that where the evidence takes me.

the link to the actual article (not a reprint) is here:

http://www.sciencemag.org/content/336/6081/550.full#ref-13

The quote is correct.

My point is not that the projections are phony, but flawed. Anyone can make a projection that cannot be verified. Here Kevin is asking us to place belief in projections that cannot possibly be verified, at least not in our lifetimes, and on the basis of the "science". Again, I have lost count of how many times I have said this, but forecasts/projections can only be verified when compared with actual data. Otherwise, Kevin is asking us to believe that the forecasts are true because the models that they use to construct the forecasts are true. This is externally inconsistent.

The problem with approaching this as a random-walk sort of process, where a hypothesis of no sea level change might be meaningful, is that no change would break the law of conservation of energy. It's like asking why, when we drop a rock, we don't consider the "no change" hypothesis that the rock just stays there in midair, or the "negative" hypothesis that the rock will fall up into the sky. If we've dropped the rock in turbulent air, or in custard, or if it's a particularly aerodynamic rock, it might have a faster or slower rate of fall, but fall it will.

In this case the energy imbalance between energy absorbed and energy emitted by the earth (owing to the increasing levels of greenhouse gases) means that the system will get hotter. Water, when it gets hotter, expands. Ice, when it gets hotter, melts. There's nothing probabilistic about either of those facts. Together, they add up to sea level rise. The uncertainties are due to factors such as weather systems and geography affecting where the heat is distributed and consequently where the ice melt occurs, how the ice melt occurs in places like Antarctica and Greenland, the degree to which heat penetrates the deep oceans - that is, how is the thermal expansion distributed through the ocean? - together with other factor such as salinity and air pressure affecting the water's precise response, and the changes in continental plates (e.g. antarctica) as the weight of ice upon them changes.

Given that we know from simple conservation-of-energy that the water will rise, that thermal expansion of water occurs linearly with temperature, and that so far it appears to be doing so in a linear fashion, a linear projection seems the simplest and most assumption free. If it goes non-linear it is likely to be above rather than below trend, due to some nonlinear behaviour of the ice shelf (e.g. large bits of antarctica suddenly slide into the sea).

Not really. If I drop a rock, I don't need to worry about my probabilistic forecasting methodology to accurately predict that it's going to fall.

Similarly, if the sea level didn't rise, it would violate conservation of energy, because energy is being pumped into the system and it will melt ice and thermally expand water. Nothing probabilistic about it. The uncertainties are all around how fast the ice will melt and how much the water will expand, not whether they will do so.

Very amateur.

The quote is dishonestly selective - you excised the sentence which contradicted you. Pointing to a paywalled version of the article does not make your behaviour honest.

The rest of your argument is hand waving. There are a number of papers which have compared the projections for sea level rise in the 2007 IPCC report against actual data and found that sea level rise is tracking at the upper range of model predictions.
http://www.skepticalscience.com/sea-level-rise-predictions.htm

Thanks for the reply Kevin.

FYI:

http://www.nytimes.com/2012/11/01/science/earth/scientists-unsure-if-climate-change-is-to-blame-for-hurricane-sandy.html?hp

Yes. Good article Spiro. Worth quoting.

"They do know, however, that the resulting storm surge along the Atlantic coast was almost certainly intensified by decades of sea-level rise linked to human emissions of greenhouse gases. And they emphasized that Hurricane Sandy, whatever its causes, should be seen as a foretaste of trouble to come as the seas rise faster, the risks of climate change accumulate and the political system fails to respond"

"Scientists note that a warmer atmosphere can hold more water vapor, which in principle supplies more energy for storms of all types. The statistics seem to show that certain types of weather extremes, notably heat waves and heavy downpours, are becoming more common."

The 'big picture' on climate change is it has been happening for eternity. The 'little picture' surrounds the times and lives of those who seek to spread lies about human induced climate change.

There is a reason why your posts get met with such resistence MWH and that is because like many, you fail to distinguish human induced climate fact from human induced climate fiction.

The several scientists that have written about our 'little' influence on 'Sandy' is a perfect example of this inability.

I'm still waiting for any of the deniers to post a link to a sensible case for why human induced climate change is wrong.

I've not yet made a post which has received a negative rating. And I've never noticed any of your posts having anything other than no rating or a negative. Spiro doesn't seem to be doing very well either.

Spread your wings outside of this forum and you may find yourself more alone than you realise.

I know the majority of the public laugh at this forum regarding the pro human induced climate change antagonists. I only come on here because I refuse to let the liars win.

As you can see, in a more academic and educated forum, reason prevails.

You give no justification for calling those who accept the science liars other than this upsets you greatly.

You are as useful and enlightening as a person who joins a discussion on Einstein's theories and says that they are all wrong because all the physicist are liars.

"As you can see, in a more academic and educated forum.........."

Ah, there's nothing like an early morning serve of pseudo-intellectual snobbery with your Weetbix.
However, it's always amusing to hear people rabbit on about Einsteins' theories, most of whom wouldn't recognise a Christoffel symbol if they tripped over one.

I'm still waiting for a reference which casts some real doubt on climate change ....

What are you on about? There is no doubt at all about climate change, real or imaginary.

You are not going all lawyerly on me Grant? The issue is climate science not climate change. Even Wade agrees the climate is changing - its the science he denies.

That sounds right. What would the scientists know!

Or perhaps, just maybe, the scientists have taken into account the increasing expansion of the oceans as the temperature warms, and how a warming climate will lead to increased melting of ice, etc.

Then there are trivialities, which are not included in reports such as the IPCC because of the uncertainty, of things like a greater than expected melting of the Greenland ice field (which once started might be impossible to stop) or some major melting of ice in the Antarctic.

Ask the scientists and I expect they will tell you that these things are perhaps more likely than having a major earthquake in an Italian town which has had a series of tremors.

Scientists make predictions based on short term trends because they know stuff all about the history of climate change on this planet outside of the major catastrophic events which are geographically evident.

Anyone can make a prediction for the future but it means stuff all. The wider planetary solar system dictates the future of this planet through ways man has simply little understanding.

That's right. We should just forget all this science stuff and accept that man can't understand anything. Race you to the cave.

Just don't light a fire to keep youself warm in that cave James...the carbon emmissions may just create another catastrophic hurricane!

Does Wade really not know that wood can be burnt without adding to emissions as long as the burnt wood does not exceed the amount of new wood grown.

At what point can we claim that Wade is deliberately disrupting the conversation?