On the recovery from the Little Ice Age

daisypusher wrote: I like how this paper takes into account the context of Earth's warming trend. It seems more reasonable than the "hockey stick" approach. It also seems very testable in the short term. I hope other "Climatologists" take this model into consideration.

This "model" is all about natural variation, which absolutely has been taken into consideration and is incorporated into all current climate models. The effects of natural variation have been tested and do not account for the warming that is being seen right now.
[youtube:2pn8x7pm][/youtube:2pn8x7pm]

"More reasonable than the hockey stick approach" - this statement makes no sense. The hockey stick graph is not a model, nor an approach; it is a compilation of temperatures from various sources that has been replicated more than once. http://www.realclimate.org/index.php/ar ... ey-ya-mal/

This paper contains glaring errors, for example:
1.

Although a drastic decrease in 2007 (not shown here) was widely reported, it is found that winds and many other factors were responsible for it (Zhang et al. 28,29); in fact, the ice has shown a steady recovery since then (Muskett 30).

Citation #30 is [30]Muskett, R. (2008) Personal communication.
Apparently, even though this paper was published in Sept 2010, the author chose to base his analysis on a personal communication from 2008, rather than the data from 2010.
http://nsidc.org/arcticseaicenews/

Arctic sea ice extent averaged over November 2010 was 9.89 million square kilometers (3.82 million square miles). This is the second-lowest November ice extent recorded over the period of satellite observations from 1979 to 2010, 50,000 square kilometers (19,300 square miles) above the previous record low of 9.84 million square kilometers (3.80 million square miles) set in 2006.

November 2010 compared to past years
November 2010 had the second-lowest ice extent for the month since the beginning of satellite records. The linear rate of decline for the month is –4.7 % per decade.

The study also showed that multiyear ice loss increased in the last few years. From 2005 to 2008, the Beaufort Sea lost 490,000 square kilometers (189,000 square miles) of multiyear ice, 32% of the total loss of multiyear ice in the Arctic Ocean during that time period.

http://www.arctic.noaa.gov/reportcard/seaice.html

On September 19, 2010 sea ice extent reached a minimum for the year of 4.6 million km2. The 2010 minimum is the third-lowest recorded since 1979, surpassed only by 2008 and the record low in 2007. Overall, the 2010 minimum was 31% (2.1 million km2) lower than the 1979-2000 average. The last four summers have experienced the four lowest minimums in the satellite record, and eight of the ten lowest minimums have occurred during the last decade. Surface air temperatures through the 2010 summer were warmer than normal throughout the Arctic, though less extreme than in 2007. A strong atmospheric circulation pattern set up during June helped push the ice edge away from the coast. However, the pattern did not persist through the summer as it did in 2007 (see the Atmosphere Section for more details).

The March 2010 ice extent was 15.1 million km2, about 4% less that the 1979–2000 average of 15.8 million km2. Winter 2010 was characterized by a very strong atmospheric circulation pattern that led to warmer than normal temperatures.

The time series of the anomalies in sea ice extent in March and September for the period 1979–2010 are plotted in Figure I2. The anomalies are computed with respect to the average from 1979 to 2000. The large interannual variability in September ice extent is evident. Both winter and summer ice extent exhibit a negative trend, with values of -2.7 % per decade for March and -11.6% per decade for September over the period 1979-2010.

http://www2.ucar.edu/news/846/arctic-wa ... al-cooling
Arctic Warming Overtakes 2,000 Years of Natural Cooling
September 03, 2009

BOULDER—Arctic temperatures in the 1990s reached their warmest level of any decade in at least 2,000 years, new research indicates. The study, which incorporates geologic records and computer simulations, provides new evidence that the Arctic would be cooling if not for greenhouse gas emissions that are overpowering natural climate patterns.

The international study, led by Northern Arizona University and the National Center for Atmospheric Research (NCAR), will be published in the September 4 edition of Science. It was primarily funded by the National Science Foundation, NCAR's sponsor.

The scientists reconstructed summer temperatures across the Arctic over the last 2,000 years by decade, extending a view of climate far beyond the 400 years of Arctic-wide records previously available at that level of detail. They found that thousands of years of gradual Arctic cooling, related to natural changes in Earth's orbit, would continue today if not for emissions of carbon dioxide and other greenhouse gases.

http://climateprogress.org/2009/09/03/s ... l-cooling/

2.

5) The negative trend after the peak in 1940 and 2000 overwhelmed the linear trend of the recovery, causing the cooling or halting of warming.

Not so at all - 2000-2010 contained 3 of the hottest years on record since 1998. That little dot the author put on his graph indicating 2008 temps is misleadingly placed - it should be higher up than it is.
http://data.giss.nasa.gov/gistemp/graphs/
http://www.ncdc.noaa.gov/sotc/global/2010/11
http://climateprogress.org/2010/11/11/n ... rd-so-far/

This paper completely ignores the fact that CO2 is rising at unprecedented rates, and what effect it has in increasing concentrations. Yes, the warming would look like a nice multi-decadal oscillation, if CO2 wasn't rising and their conclusion that it will continue to rise that way ignores the physics behind the greenhouse gas effects.
3.

The meaning of the linearity of the recovery from 1800-1850 is crucial in considering the cause of the warming in the last century (the amount of CO2 in 2000 was at least 14 times greater than that in 1900 and was even greater than in 1850), so it is difficult to associate the linear warming only with CO2. The temperature rise from 1800-1850 to the present is fairly steady. Therefore, it is not unreasonable to assume the rise after 1900 is a continuation of the same process, namely the recovery from the LIA. Assuming that the recovery from the LIA and the multi-decadal oscillation would continue during the next 100 years or so, the future trend until 2100 is predicted in Figure 9.

Ah, but see, warming due to CO2 isn't linear, and the effects aren't immediately seen in temp records as a major chunk of CO2 put into the atmosphere is absorbed by the ocean (at the moment anyway, it will reach saturation at some point and stop absorbing so much CO2). It is unreasonable to assume that warming will continue in a linear fashion based on the fact that CO2 continues to be pumped into the atmosphere at unnatural rates.
http://www.realclimate.org/index.php/ar ... asy-steps/
http://www.realclimate.org/index.php/ar ... cosub2sub/
http://www.realclimate.org/index.php/ar ... nsitivity/
http://www.realclimate.org/index.php/ar ... se-effect/

Finally, what credible primary research paper cites published books as sources of data? Or a news piece in Science cherry picking the graph only because it shows a flattened warming trend and none of the text which refutes the conclusion of this paper (and not citing the original research paper from which that graph came - tsk tsk)? Check out Reference #56 http://www.sciencemag.org/content/326/5949/28.1.full
Science 2 October 2009:
Vol. 326 no. 5949 pp. 28-29
DOI: 10.1126/science.326_28a
* News of the Week
What Happened to Global Warming? Scientists Say Just Wait a Bit
Richard A. Kerr

So contrarian bloggers are right: There's been no increase in greenhouse warming lately. That result came as no surprise to Knight and his colleagues or, for that matter, to most climate scientists. But the Hadley Centre group took the next step, using climate modeling to try to quantify how unusual a 10-year warming pause might be. In 10 modeling runs of 21st century climate totaling 700 years worth of simulation, long-term warming proceeded about as expected: 2.0°C by the end of the century. But along the way in the 700 years of simulation, about 17 separate 10-year intervals had temperature trends resembling that of the past decade—that is, more or less flat.

From this result, the group concludes that the model can reproduce natural jostlings of the climate system—perhaps a shift in heat-carrying ocean currents—that can cool the world and hold off greenhouse warming for a decade.

Solar physicist Judith Lean of the Naval Research Laboratory in Washington, D.C., and climate modeler David Rind of GISS reached the same conclusion in a peer-reviewed 15 August paper in Geophysical Research Letters. They broke down recent temperature variation into components attributable to greenhouse gases, pollutant aerosols, volcanic aerosols, El Niño/La Niña, and solar variability. Combined, those influences explain all of the observed variability, by Lean and Rind's accounting.

Researchers may differ about exactly what's behind recent natural climate variability, but they agree that no sort of natural variability can hold off greenhouse warming much longer. “Our prediction is that if past is prologue, the solar component will turn around and lead to rapid warming in the next 5 years,” says Rind.

This paper is yet another example of climate deniers showing misleading data with erroneous conclusions and ignoring other data that doesn't fit their model - not good science at all.

Hey Guys! All good questions, I've been meaning to get back to this thread (and I saw the one yesterday that Outdoor posted as well that I want to address) and just let other topics distract me! (trying to get my fill of football before suffering withdrawal for the next few months!). I've got to run to PT in just a few minutes, but I promise I'll address everything, if not today then definitely by this weekend - hubby's taking the kids to get his mom and bring her back for a week visit so I've got the house and computer all to myself this weekend - research galore! :woo hoo: :woo hoo: :woo hoo: :woo hoo: :woo hoo: (But I don't want to sit on my @$$ all weekend either so pineinthegrass - do you guys still have painting to do? I'll volunteer to help! If not, I'll give TPP a holler - I hear he has firewood to haul and split).

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.

residenttroll wrote: Who measures the daily temperatures in 1/10th of degrees? Yet, the climate change catastrophicants use a graph to show us how the earth is "warming" in tenths of degrees.

No one. That's why it's called global average temps.

lionshead2010 wrote: I wonder why the media isn't discussing this more? Does anyone find this curious besides me?

www.desmogblog.com/media-loses-interest-climate-change
Media Loses Interest In Climate Change
14 January 11

World news coverage spiked in late 2009, corresponding with the intense interest among politicians, bureaucrats and activists in the Copenhagen conference of the United Nations Framework Convention on Climate Change.

This study, however, is quantitative rather than qualitative. Boykoff and Mansfield have scoured the electronic sources and found how many stories appear in prominent global newspapers. But this graph doesn't answer whether what was being published was stupid or wrong. And previous Boykoff studies - beginning with the landmark 2004 study that he conducted with his brother Jules - have demonstrated that a stunning amount of media coverage was presenting an imagined version of reality that was not reflected in actual climate science.

That tendency - for example, to report a controversy that does not exist among the overwhelming majority of climate scientists - may account for the dminishing media and public interest in 2010. One of the biggest stories that captured world media attention around the time of the spike was related not to climate science, but to the wholly overblown "Climategate" controversy. Reporters covered trump-up accusations that climate science was somehow corrupt, but when those accusations were comprehensively disproved, those same reporters were less enthusiastic about following up with the corrections. Now, apparently, they just don't want to talk about it.

So it boils down to the media want to report on controversies for dramatics so they can boost their readership. They don't really care about reporting boring facts...

Just for fun, bet ya hadn't heard this: http://www.desmogblog.com/canadian-hots ... ove-normal
Canadian Hotspot Hits 21°C (37.8°F) Above Normal
22 January 11

While world media have been distracted by cold temperatures in Europe (December averages in the U.K. were 5.2°C [9.4°F] below normal), a vast pocket over northeastern Canada has been hitting heights that were not just unprecedented but, until this year, unimaginable.

As Bob Henson reports at the NCAR & UCAR Currents, the Canadian low Arctic has been unseasonably, unreasonably balmy, with the largest anomaly rising to 21°C [37.8°F] above normal.

Just like record-breaking cold, or temps, in small regions, these can't be absolutely traced back to global warming - there are always seasonal variations and each region has different climatic variabilities. That's why it's called global warming - it's the whole planet, not just the NE in America, or snowfall in London, we have to think bigger and longer-term.