Goddard post at WUWT

Posted: December 3, 2010 in Uncategorized

Very Busy this week, will get to posting more soon. Here’s a little tidbit to tide you all over. It’s from this thread in September. I.E. Goddard’s last post at WUWT.

This is why it can be frustrating to argue with Goddard, most people will concede a point when they’re clearly wrong, others won’t even when they are called out by their own readers… This is how “we scientists” do that indeed…

Anderson et al. 2008

Posted: November 29, 2010 in General Analysis, Uncategorized

I have decided that it’d be interesting to also begin to discuss some of my favourite peer-reviewed papers on here. I assure you that they won’t be the boring modelling type but the ones that have interesting applications of ideas and interesting results.

Today I will do the first of these posts. The paper that I have chosen is

Anderson et al. (2008). A millennial perspective on Arctic warming from 14C in quartz and plants emerging from beneath ice caps. Geophysical Research Letters.

This article by Anderson et al (2008) use exposure dating techniques on surfaces recently exposed by receding ice caps. In the case of Anderson et al (2008) the authors choose to conduct these measurements on thin cold-based ice caps on Baffin Island because ice caps are particularly sensitive to climatic changes because of their geometric shape. To clarify, the rounded shape of ice caps makes a small vertical change in the snowline cause a large change in the size of the ice loss area (denoted by red below). It is perhaps pertinent to note that the summer snowline generally is considered to be the point where above which ice tends to accumulate and below which ice tends to be lost.

The evidence of this climatic sensitivity is striking as these ice caps covered 150 km2 in the 1950s but have been recently measured (2005) as being only 67 km2 in area. The authors conclude that extending the linear melt rate already observed will result in most ice being gone by 2035 AD and all ice having disappeared by 2070 AD.


The primary goal established by Anderson et al (2008) is to construct a glacial history for these ice caps with a focus on specifically identifying whether current ice cap retreats are unique within the context of their postglacial history. The main method through which the authors aim to achieve this goal is through using in situ 14C cosmogenic radionuclide inventories in rock surfaces as well as 14C dates from recently exposed vegetation samples to help constrain the 14C results. Vegetation dates the last time the site was covered due to glacial advance but cannot recognize prior periods of ice cover. Cosmogenic 14C dating measures the reactions within rock surfaces when they are exposed to Galactic Cosmic Rays. In particular if a surface has been covered by thick ice it does not receive the rays and these reactions to not occur. For 14C the production of these reactions is reduced by 85% under 6 m of ice and is completely stopped under 35 m of ice.

Results

But really, who can summarize the results better than the authors?

“Fifty-year plateau-ice-margin retreat rates on northern Baffin Island show that the rapidly approaching ice-free state of the plateau will occur near the middle of the current century even without additional warming. Radiocarbondates on vegetation appearing beneath retreating ice caps indicate that some plateau ice caps have existed continuously since 350 AD, demonstrating that the current warming is unique in at least the past 1600 years. Lake cores and in situ 14C inventories in quartz document a trend toward more frequent ice cover in recent millennia, coincident with reduced summer insolation (Figure 2a), making the current ice-cap retreat even more unusual. Collectively, these data extend the timeframe in which 20th century warming is unprecedented in this part of the Arctic well beyond the past 400 years established by Overpeck et al (1997). Our chronologies also offer the first quantitative estimate for the onset of Neoglaciation in the eastern Canadian Arctic, suggesting an early onset consistent with sea-ice expansion documented in historical records from Iceland. Times of widespread ice-cap expansion coincide with the two most severe episodes of volcanic aerosol loading of the past millennium, offering tantalizing evidence for a volcanic trigger to Little Ice Age cooling coupled with strong positive feedbacks that reinforced the volcanic climate perturbation.”

I think the concluding paragraph says a lot about why I liked this paper. It’s not because it supports the AGW agenda or anything of the sort but rather it is a study which provides a lot of actual results and helps to illuminate a lot about what went on paleoclimatically in the eastern Canadian Arctic. I like any study that can demonstrate a new technique and then really open up a lot of ideas and move science forward.

Part Two: Response to Prof

Posted: November 28, 2010 in Rebuttals, Uncategorized

Yesterday I began a rebuttal of a few slides from a professor’s presentation to his students from last week (given to me from a friend of a friend). Today I will continue with the rebuttal and hopefully I will be able to convince you of why I found the presentation dishonest to the actual scientific basis for climate change. In fact, my feeling is that the “Prof” does a disservice to skeptics too who certainly don’t like it when people use easily debunked information because it takes away from their arguments too.

Anyways the issue I came across which really ruffled my feathers so to speak was the following graph:
Not only was there no inclusion of where the data was received from, it wasn’t updated to the current data (a pet peeve of mine). Furthermore, I really have to ask why someone would plot the sunspot cycle length in years against temperature and call this “Solar Activity” but I digress…

To help out the poor busy prof who just probably hasn’t gotten around to updating his slides in years (poor guy..) I am going to do him a favor and plot the actual measure of solar activity (Total Solar Irradience) versus global temperatures and update it to present (aren’t I generous?).

**Notes for display purposes I standardized both measures using (x-mean/stdev). Also note that the TSI comes from Lean’s reconstruction spliced with PMOD (1976-present). In the 20 years they overlapped they matched very well (r2=0.98) so I feel confident in the reconstruction.

Notice that the agreement isn’t quite so good when you plot the actual measure of solar activity and have it updated to present. The prof continues on though and buries himself even more…

Some of you might question why someone doing a presentation in 2010 would put in UAH/RSS data only up until 2008 and then do a trendline from 2002-2008. Well I believe the point of these two slides were to show that in 2008 there were no sunspots and that 2008 was subsequently a cold year (thereby proving his solar thesis). The plotting of a trendline from 2002-2008 was just what I would call a kick to the groin of warmists trying to say “it’s not warming”. Once again, I think it is best if we understand his trendline selection very well. Consider the following graphic:

Now I am not usually one to call out individuals but putting a trendline from a moderate El Nino year (2002) and ending it in the 2nd deepest La Nina of the last 30 years (2008) is dishonest. In fact the insinuation that 2008 was a cold year because there were no sunspots is dishonest in itself. I think it is well-understood that 2008’s weather was dominated by the La Nina of that year but I digress…

Anyways I thought i’d help out the poor busy prof again and show him the updated UAH/RSS average with his trendline intact.

I have no problem with a professor being skeptical and trying to teach his students some of the reasons for his/her skepticism. But cherry-picking information to try and force students to retain his/her views is just plain wrong. I find it very interesting that all of the graphs he did not update were ones that if he did would refute his points… Nevertheless here are the final slides in the presentation…

Very suspicious
.

For today’s post I had originally thought of doing something different, I even had an article nearly ready to show. It was going to be a discussion of a research article that I really liked more or less, somewhat starting a common theme that would continue on in this blog. However sometimes things fall into your lap and there’s not much you can do but decide to respond.

A friend of a friend sent me a .pdf yesterday and it was interesting to say the least. It was from an undergraduate university class at a university that I will keep anonymous for now. Essentially it was just lecture slides from a long-term climate change sort of class. Although the discussion began with the normal long-term drivers of climate such as geological processes, milankovich cycles and so on, it soon became apparent that the professor was slanting his slides to try and put emphasis on CO2 not being a significant driver of the climate system. For example the 800 year lag between temperature and CO2 in ice core results was pointed out, but there was no mention of the feedback role that CO2 plays on these timescales (i.e. initial orbital perturbation amplified by CO2 warming/cooling effect as oceans absorb more/less CO2). Either way, those issues are relatively miniscule in comparison to what I found at the end.

More or less what was found at the end could be considered a diatribe. An anti-climate change diatribe which was not supported by the evidence which has merit (climate sensitivity …etc…) but rather it was supported by cherry-picking and easy to debunk arguments. So that is what I am going to do today. Debunk this prof.

One of the things that stuck out to me more or less (somewhat of a nitpick) was the following slide:


Now there is nothing wrong with indicating that radiatively, water vapor is the most dominant controller of the amplitude of the greenhouse effect, however to suggest that water vapor is the greenhouse effect’s origin is disingenuous at best.

Schmidt et al (2010) actually use the previous literature and a NASA radiation model to provide an overview of each absorber’s contribution to the present day Greenhouse Effect. They find that Water Vapor contributes 50%, Clouds contribute 25%, CO2 contributes 20% and a few others make up the remaining (5%). For me I think that if a slide is going to say the Greenhouse effect is essentially water vapor, then that is dishonest because it represents only half the effect.

Schmidt et al (2010) also use the model to predict the forcing for a doubled CO2 scenario and they find that the feedbacks are positive and that extra net absorption by CO2 amplifies the water vapor and cloud forcings.

I think those points (at least regarding water vapor) are pretty well understood but Lacis et al (2010) go further to point out that “Without the radiative forcing supplied by CO2 and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state” because “Water vapor and clouds are fast-acting feedback effects, and as such are controlled by the radiative forcings supplied by the noncondensing GHGs.”

These are bold statements but that is where the current thinking on the radiative effect of CO2 stand. I have decided that this will be likely a 2(or maybe 3) part series as it has taken more space than I anticipated. Part Two will look at the prof’s categorization of the relationship between the sun and current warming.

Questions for C3 Headlines

Posted: November 26, 2010 in Rebuttals, Uncategorized

I came across this umm “interesting” post by C3 headlines about Antarctic Ice Cores.

I zoomed in on the graph and saw that that the author was claiming that the Medieval Warm Period and Minoan Warm Period were almost 1°C warmer than today and that the 1950s were warmer in Antarctica than present. Furthermore the author states that the previous interglacial had temperatures 4°C above present.

Obviously this peaked my interest so I decided to look into it a little more. I did something the authors apparently didn’t do and carefully read the paper… So I actually have quite a few “bones” to pick with the author. First of all he chose to put in a graph which makes it difficult to decipher the most recent period for the comparisons he makes. But luckily the authors actually provided one of these graphs in the very next figure.


First thing you might notice is that this is a graph of the Holocene. Second thing you might notice is that none of these graphs show up to present. Third thing you might notice is that even up to “the most present” there is not a 1°C temperature difference between his two warm periods. In fact, it’s not even close for the MWP, and for the minoan it seems to be between 0.6 and 0.8 but once again, this isn’t up to present…

If you look at the graph he provides, he makes the claim that his conclusion is supported by an ice core reconstruction of the last 200 years from another study because this study doesn’t go up to present… The issue I have with that is that the other study (the 200 year one) isn’t calibrated to the 1200 to 2000 years before present calibration period like the current study we’re looking at, so how can one make effective comparisons? Is the author an ice core expert who can take the results from one ice core study and splice them on to another and call them even? I very much doubt the processing for both studies make the same assumptions…

Anyways, to his other claims. He claims that the previous interglacial at periods 4°C warmer than present. The study however says this:

So this is essentially an example of what NOT to do when reading a paper. You don’t take its results, splice it with another papers results (both using different methods) and then interpret (by eye apparently) the changes for yourself. Let alone not having a similar baseline…

Finally the last claim the author makes is that it was warmer in the 1950s. They’ll have to tell Steig et al (2009) that.

This is just a lesson for the future really. If you want to play scientist, you have to follow the methods outlined by other scientists, you can’t just throw together whatever you like and think it makes sense because it gives you the answer you want…

Short Rebuttal of Goddard…

Posted: November 25, 2010 in Rebuttals, Uncategorized

At the following website listed here.

Steven Goddard makes a statement that I found a little perplexing. He says that a new study shows that the annual world average sea level rise is about 1 mm per year. This statement gives the impression that a new study shows that NOAA is wrong on their annual sea level rise estimates, which since the 1990s have shown a rise of around 3 mm per year.

The source of Goddard’s information is a news article which links to the study. I clicked the link and noticed the names of the authors and thought “I’ve already read this study, this isn’t what the authors said at all!”.

So now i’m going to do something that perhaps Goddard has never thought of doing, i’m going to go to the original source.

The paper “Sea-level fingerprint of continental water and ice mass change from GRACE” was published in Geophysical Research Letters (Vol. 37) and estimates the contribution to sea level rise from ice and water loss from the continents.

They say:

What Goddard ignores is that thermal expansion explains the majority of global sea level rise. This study only looks at contributions from ice and water on continents. It isn’t exactly hidden in the fine print either, it’s in the abstract.
-1 for Goddard
.

Update
Goddard Responded with this

According to him thermal expansion cannot be causing sea level rise to be greater than 1 mm per year because the paleo records show something else causing sea level rise. So the disintegration of past ice sheets prove that sea level rise right now is not caused by thermal expansion? Wow…


But I suppose those folks at the IPCC are in on the conspiracy too…
-2 for Goddard

Old Tamino Posts

Posted: November 25, 2010 in Uncategorized

You all may have become familiar with Tamino as being amongst my favorite climate bloggers. He provides in depth statistical analysis and cuts through a lot of the noise levels from both sides. However one challenge is that all of his posts were lost from prior to the spring of 2010 (it’s complicated!).

Anyways someone over at his website sent me the following link
http://web.archive.org/web/*/http://tamino.wordpress.com

Which has over 46 of his posts archived there. It’s a great resource and I suggest anyone interested in climate statistics and rebuttals should read some of the articles!