On the recovery from the Little Ice Age

lionshead2010 wrote: I had to go back at least 12 pages to find a thread on climate change here on 285 Bound. Then out of curiosity I started poking around the internet (not a terribly thorough search I will admit) to see what climatologists and others have to say about the record breaking winter we are having in the Northeast US and Europe.
Now I realize I haven't taken an ad nauseum approach to citing sources but common sense makes me question what's really going on with the weather and our climate. How can places like Hartford, CT and many European cities be setting records on snowfall totals if the earth is warming? Does a "warming" climate mean more snowfall in the temperate latitudes?

Here's a couple of quick links for you on the difference between predicting weather and predicting climate and why the latter can't do the former very well.
http://www.realclimate.org/index.php/ar ... l-climate/
Why global climate models do not give a realistic description of the local climate
— rasmus @ 27 May 2007

http://www.realclimate.org/index.php/ar ... predicted/
Short and simple arguments for why climate can be predicted
— rasmus @ 12 August 2006

http://www.realclimate.org/index.php/ar ... ojections/
Regional Climate Projections
— rasmus @ 27 August 2007

lionshead2010 wrote: SC, with a degree in Geology, I'm confident I can think "big" and "long term". It may only be a bachelor's degree but it's enough for me to have gotten an appreciation for the scale of things. It's too bad we didn't have anyone around to record the previous glacial and interglacial periods. I'm really curious just how erratic the climate (and weather) was as the earth went through those previous cycles.

I also know that a couple of snowy winters in New England or Europe don't mean much at all...though it's strange to me that we are setting these records right now when we might, instead, be expecting record high temperatures, drought or other phenomenon. In the end I suspect the whole system is a whole lot more complicated than ANY model some climatologist has used to make predictions and may very well defy prediction with any reasonable accuracy. I wonder if the models used...though seemingly complex by man's account....simply don't come close to replicating nature.

I believe there are, indeed, other factors at work that haven't been considered or are simply not understood. Rock Doc's point about the sun's activity is a good example. I also know the earth has been warming and cooling in cycles for at least the last 20,000 years and likely much longer. With the earth being at least 4.5 billion years old...I'm having a hard time convincing myself that the current trend is anything new.

I wonder what the REAL implications of a warming climate are on the planet AND humans...and is it necessarily a bad thing, from the point of natural order, that the human race and other species are wiped out as a result of these natural climate changes? It's been happening for a very long time according to the fossil record and could happen again.

This is waaaaay more interesting than politics.

Yea! Another geologist - awesome! Well, the instrument records aren't there, but some pretty good proxies are. I'll post a list of my fave links at the end, but this is what I understand in a nutshell (and if I'm mistaken, I certainly want you guys to point it out - you're talking to a former geneticist/molecular biologist/neurobiologist who's been teaching herself climate science for the last year and a half. I am far from an expert, but I like to think that I've read enough to have gotten a pretty good handle on it, feel free to correct me if I'm wrong, and I'll try to analyze if your point has merit! I'd like this to be a learn-from-each-other exercise!).
1. There are reliable records of CO2 and temps going back 800,000 years, over glacial and interglacial periods, and the CO2 always tracks with the temps (and even further records looking at isotopes that go back 1.5 million years and 15 million years).
2. The radiative forcing CO2 has on atmospheric temps has been known since Arrhenius's paper in 1896 http://en.wikipedia.org/wiki/Svante_Arrhenius which built on work by Fourier and Tyndall. http://www.ossfoundation.us/projects/en ... ce-history
3. The carbon cycle isn't known in exact detail, but roughly enough to understand what happens when carbon that was buried millions of years ago gets dug up and burned (and pretty precise amounts that are consumed can be measured) that it will go to the atmosphere 1st, dissolve in the ocean 2nd as well as be re-absorbed by plant material and use that to accurately predict global temp changes over decades and centuries.
4. Changes in climate have always occurred, and before the arrival of a large number of us, completely naturally. But we are disrupting that balance, and the carbon isotopes can be tracked that lead back to fossil fuels, and the science behind the effects of CO2 in the atmosphere are clear-cut: it causes warming. What makes outspoken advocates sound like doomsayers is that they get frightened by the thought that the momentum in the climate cycle is lumbering and slow - the effects of the carbon we use today will not be felt for decades, and the effects will last for thousands of years. All we ever hear is the predictions to 2100, but climate change won't stop then: glaciers will continue to melt, creating less albedo and more positive feedback, oceans will absorb all the CO2 they can and begin releasing it back to the atmosphere, where even more warming will occur, and if the oceans get warm enough, large stores of frozen methane clathrates could be released in addition to the methane stored in the melting permafrost, also adding to AGW.
5. The radiative forcing of CO2 is much stronger than the effects of the Milankovitch cycle (which we are in the middle of anyway), and much stronger than the radiative forcing of the sun.
http://climateprogress.org/2009/10/18/s ... a-level-i/
http://www.realclimate.org/index.php/ar ... 0-kyr-ago/
http://www.realclimate.org/index.php/ar ... p-and-co2/
http://www.realclimate.org/index.php/ar ... nsitivity/

Doubling CO2 produces a radiative forcing of about 4 Watts per square meter. The effects of other well-mixed greenhouse gases can be accurately translated into radiative forcings. Forcing caused by changes in the Sun’s brightness, by dust in the atmosphere, or by volcanic aerosols can also be translated into radiative forcing. The equivalence is not so precise in this case, since the geographic and temporal pattern of the forcing is not the same as that for greenhouse gases, but numerous simulations indicate that there is enough equivalence for the translation to be useful.

The Last Glacial Maximum (i.e. the most recent "ice age", abbreviated LGM) probably provides the best opportunity for using the past to constrain climate sensitivity. The climate changes are large and reasonably well constrained by observations. Moreover, the forcing mechanisms are quite well known, and one of them is precisely the same as will cause future climate changes.

Now, how about the Holocene – including the Little Ice Age and Medieval Warm Period that seem to figure so prominently in many skeptics’ tracts ? This is a far harder row to hoe, because the changes in both forcing and response are small and subject to large uncertainties (as we have discussed in connection with the "Hockey Stick" here).

http://data.giss.nasa.gov/modelforce/efficacy_fig28.gif

http://www.realclimate.org/index.php/ar ... certainty/
http://www.realclimate.org/index.php/ar ... ming-last/
http://climateprogress.org/2010/02/17/a ... e-science/
An illustrated guide to the latest climate science
February 17, 2010

Rockdoc wrote: Tell me, how many papers have considered sun spot activity, a major influence on polar temperatures?

Here's some quick references for you, complete with explanations and links to the papers themselves. There's more, if you go to the index page you'll see solar as a subtopic, I just picked out and posted here what was helpful for me previously.
http://www.realclimate.org/index.php/ar ... #more-3007
More on sun-climate relations
— rasmus @ 9 March 2010
http://www.realclimate.org/index.php/ar ... or-a-spin/
Taking Cosmic Rays for a spin
— gavin @ 16 October 2006
http://www.realclimate.org/index.php/ar ... -sunspots/
The trouble with sunspots
— group @ 13 September 2006
http://www.realclimate.org/index.php/ar ... r-forcing/
The lure of solar forcing
— gavin @ 15 July 2005

Okay, it's late and my brain's starting to malfunction. There's a lot here so I don't expect a quick answer! I'll try to get to page 2 comments hopefully soon...

Rockdoc Franz wrote:

Science Chic wrote:
Real quick to answer you Rockdoc - it's an error to quote a personal communication when there's more recent published data to cite. Especially when there's more than one paper that's more recent, but those published papers contradict the claim that this author is trying to make so he's cherry-picking and making his data fit his conclusions instead of the other way around.

I can not disagree with you more on this. I've certainly not had that type of issue in refereed papers I've published and cited personal communications to give credit to someone who actually made the point I'm trying to make. Just because there are recent papers that disagree with a point of view does not negate the validity of a personal communication or the need to give credit where credit is due. Not all experts publish their thoughts on a matter for a variety of reasons. An author who fails to cite and discuss alternative views is not in error either. There is no error, but it may be correct to discuss "cherry picking" as bad vs good science. Unfortunately, it happens all the time and I've seen some of the worst science being conducted by politically motivated "scientists".

The bad vs good science was what I was trying to get at, obviously very badly worded on my part. Absolutely one should cite personal communication to give credit where it is due, but to make a flat-out statement like "in fact, the ice has shown a steady recovery since then (Muskett 30)" while completely ignoring the contradictory side of the argument, not providing any evidence to refute what other, more recently, published papers are measuring is to me suspect.

On a different note. We geologists can hypothesize causes for ice ages in the Ordovician, Permian, etc. mostly using astrophysical phenomena, but we can not explain for sure what triggered them or ended them. Heck, even the Pleistocene ice ages are problematic in that regard. If we have trouble explaining why they occurred, it seems somewhat absurd to me to place the whole onset of global warming on man's activity. This to me seems like a perfect analogy to ecologic actions taken (i.e. the introduction of Kudzu) by ecologist who knew what they were doing with their research. Well, nature taught them that thy had no idea of all the parameters that govern ecologic balance. Similarly, I doubt that Climitologists have a handle on all the parameters that govern global warming and cooling. If you do not have a handle on all the parameters, how can you possibly produce a viable test that identifies THE culprit for global warming trends? THe best you can do is suggest that it may be a variable and acknowledge that other causes are possible. But that is not what is happening today. Once again we charge forward in blissful scientific ignorance.

So I've got some paleoclimate stuff for you to peruse. It's not the primary papers, b/c there are too many to cite (IPCC reports good for finding them http://zvon.org/eco/ipcc/ar4/ is a new, interactive way to search, still in beta release), but websites that I've found useful in summing it all up. I can't find anything out there that really ties it all together well, and likely won't b/c as you said, there are are many unanswered questions as to what kicked the planet into each ice age and interglacial. Climatologists put the uncertainties in their papers, and are upfront in stating that they don't know the entire picture, but the media does not report that kind of thing because it complicates the story. However, this doesn't make the unprecedented increase in CO2, and its physical effects, any less uncertain. And it all comes back to CO2 because that is the primary driver of the current climate change - we are unburying it in enormous amounts, it will persist for the longest of all the GHGs in the ocean and atmosphere, and have the greatest, most widespread effects - effects which were elucidated long before global warming ever became a political problem. Business as usual, i.e. we continue to exhume and exhaust all carbon energy sources at current rates, gets us estimates anywhere from 700ppm to over 1,000ppm by 2100 - and the momentum in the climate will continue for millenia afterward.
http://www.lakepowell.net/sciencecenter ... limate.htm
http://www.ncdc.noaa.gov/paleo/globalwa ... hange.html
http://www.noe21.org/dvd2/Global%20Warm ... limate.htm
http://www.yaleclimatemediaforum.org/20 ... te-system/
http://www.earthgauge.net/wp-content/CF_Quaternary.pdf
http://jrscience.wcp.muohio.edu/html/globalchange.html A website of websites!

http://cdiac.ornl.gov/epubs/other/Sicilypaper.pdf
http://www.realclimate.org/index.php/ar ... ctivities/

Some great video lectures by David Archer: http://geoflop.uchicago.edu/forecast/docs/lectures.html
And the Dec 2010 AGU meeting: http://www.agu.org/meetings/fm10/lectures/videos.php

Finally, this just came out, and is available in hardcopy only (no electronic version, which David Archer books seem to always be this way and it's quite annoying) so I haven't gotten it yet, but it seems like it might be a great resource collection:
The Warming Papers by David Archer and Ray Pierrehumbert http://www.amazon.com/Warming-Papers-Da ... 998&sr=8-1

Global warming is arguably the defining scientific issue of modern times, but it is not widely appreciated that the foundations of our understanding were laid almost two centuries ago with the postulation of a greenhouse effect by Fourier in 1827. The sensitivity of climate to changes in atmospheric CO2 was first estimated about one century ago, and the rise in atmospheric CO2 concentration was discovered half a century ago. The fundamentals of the science underlying the forecast for human-induced climate change were being published and debated long before the issue rose to public prominence in the last few decades.

The Warming Papers is a compendium of the classic scientific papers that constitute the foundation of the global warming forecast. The paper trail ranges from Fourier and Arrhenius in the 19th Century to Manabe and Hansen in modern times. Archer and Pierrehumbert provide introductions and commentary which places the papers in their context and provide students with tools to develop and extend their understanding of the subject.

Sorry for the huge info lob, I'm still working on getting it more organized on my own blog. Any insight, rebuttals, other resources, etc that anyone has to share would be greatly appreciated!

lionshead2010 wrote: The result: the Arctic stays warm and mid-latitude regions become colder and receive more snow for much of the winter. Last December was the coldest south Florida has experienced in more than a century of record-keeping.

So maybe global climate change does mean colder winters in the mid latitudes. It's amazing how complex the whole system is. So global warming COULD mean colder winters in the mid-latitudes. Who would have thought that?

I haven't seen anything prior concerning temperature predictions in response to changes in the Arctic, but the increase in precipitation for northern latitudes had been predicted and was published in the last IPCC report (Chapter 11 of AR4, Working Group 1).

http://www.realclimate.org/index.php/ar ... ojections/
Regional Climate Projections
Regional Climate Projections in the IPCC AR4
— rasmus @ 27 August 2007

How does anthropogenic global warming (AGW) affect me? The answer to this question will perhaps be one of the most relevant concerns in the future, and is discussed in chapter 11 of the IPCC assessment report 4 (AR4) working group 1 (WG1) (the chapter also has some supplementary material). The problem of obtaining regional information from GCMs is not trivial, and has been discussed in a previous post http://www.realclimate.org/index.php/ar ... l-climate/ here at RC and the IPCC third assessment report (TAR) also provided a good background on this topic. http://grida.no/publications/other/ipcc ... g1/378.htm

One of the most challenging and uncertain aspects of present-day climate research is associated with the prediction of a regional response to a global forcing. Although the science of regional climate projections has progressed significantly since last IPCC report, slight displacement in circulation characteristics, systematic errors in energy/moisture transport, coarse representation of ocean currents/processes, crude parameterisation of sub-grid- and land surface processes, and overly simplified topography used in present-day climate models, make accurate and detailed analysis difficult.

I think that the authors of chapter 11 over-all have done a very thorough job, although there are a few points which I believe could be improved. Chapter 11 of the IPCC AR4 working group I (WGI) divides the world into different continents or types of regions (e.g. ‘Small islands’ and ‘Polar regions’), and then discusses these separately. It provides a nice overview of the key climate characteristics for each region. Each section also provides a short round up of the evaluations of the performance of the climate models, discussing their weaknesses in terms of reproducing regional and local climate characteristics.

North America.
The annual mean precipitation is, according to AR4, likely to increase in the north and decrease in southwest. The projections are associated with a number of uncertainties concerning dynamical features such as ENSO, the storm track system (the GCMs indicate a pole-ward shift, an increase in the number of strong cyclones and a reduction in the medium strength storms poleward of 70N & Canada), the polar vortex (the GCMs suggest an intensification), the Great Plains low-level jet, the North American Monsoon system, ocean circulation and the future evolution in the snow-extent and sea-ice. Some of these phenomena are not well-represented by the GCMs, as their spatial resolution is too coarse.

Furthermore, most RCM simulations have been made for time slices that are too short to provide a proper statistical sample for studying natural variability. There are no references to ESD (empirical-statistical downscaling) for North America in the AR4 chapter except for in the discussion on the projections for the snow.

http://www.nature.com/news/2010/100120/ ... 3284a.html
The real holes in climate science
Like any other field, research on climate change has some fundamental gaps, although not the ones typically claimed by sceptics. Quirin Schiermeier takes a hard look at some of the biggest problem areas.
Published online 20 January 2010 | Nature 463, 284-287 (2010) | doi:10.1038/463284a

Still, the incident [ClimateGate] provides a good opportunity to point out that — as in any active field of inquiry — there are some major gaps in the understanding of climate science. In its most recent report in 2007, the Intergovernmental Panel on Climate Change (IPCC) highlighted 54 'key uncertainties' that complicate climate science.

Such a declaration of unresolved problems could hardly be called 'hidden'. And some of these — such as uncertainties in measurements of past temperatures — have received considerable discussion in the media. But other gaps in the science are less well known beyond the field's circle of specialists. Such holes do not undermine the fundamental conclusion that humans are warming the climate, which is based on the extreme rate of the twentieth-century temperature changes and the inability of climate models to simulate such warming without including the role of greenhouse-gas pollution. The uncertainties do, however, hamper efforts to plan for the future. And unlike the myths regularly trotted out by climate-change denialists (see 'Enduring climate myths'), some of the outstanding problems may mean that future changes could be worse than currently projected.

Nature has singled out four areas — regional climate forecasts, precipitation forecasts, aerosols and palaeoclimate data — that some say deserve greater open discussion, both within scientific circles and in the public sphere.

Regional climate prediction
The sad truth of climate science is that the most crucial information is the least reliable. To plan for the future, people need to know how their local conditions will change, not how the average global temperature will climb. Yet researchers are still struggling to develop tools to accurately forecast climate changes for the twenty-first century at the local and regional level. All the problems, however, do not make regional simulations worthless, as long as their limitations are understood. Simulations remain an important tool for understanding processes, such as changes in river flow, that global models just cannot resolve, says Jonathan Overpeck, a climate researcher at the University of Arizona in Tucson.

Precipitation
Rising global temperatures over the next few decades are likely to increase evaporation and accelerate the global hydrological cycle — a change that will dry subtropical areas and increase precipitation at higher latitudes. These trends are already being observed and almost all climate models used to simulate global warming show a continuation of this general pattern.