Similar warming and cooling trends occurred in the mid-nineteenth and eighteenth centuries
From AGU highlights:
A 308-year ice core record provides new data on climate variability in coastal West Antarctica and shows that a clear warming trend has occurred in recent decades. To study climate over the past 3 centuries, Thomas et al. analyzed stable isotopes in the ice core, which provide a record of past temperatures. They observe that climate variability in coastal West Antarctica is strongly driven by sea surface temperatures and atmospheric pressure in the tropical Pacific.
The authors report that their ice core record shows that the region warmed since the late 1950s at a rate similar to that observed in the Antarctic Peninsula and central West Antarctica.
However, the authors note that this recent warming trend is similar in magnitude to warming and cooling trends that occurred in the mid-nineteenth and eighteenth centuries in their record, indicating that in this coastal West Antarctic location the effects of human-induced climate change in recent years have not exceeded natural climate variability over the past 300 years.
Source: Geophysical Research Letters, doi:10.1002/2013GL057782, 2013 http://onlinelibrary.wiley.com/doi/10.1002/2013GL057782/abstract
Title: A 308 year record of climate variability in West Antarctica
Authors: Elizabeth R. Thomas, Thomas J. Bracegirdle and John Turner: British Antarctic Survey, Cambridge, UK; Eric W. Wolff: Department of Earth Sciences, University of Cambridge, Cambridge, UK.
Abstract:
We present a new stable isotope record from Ellsworth Land which provides a valuable 308 year record (1702–2009) of climate variability from coastal West Antarctica. Climate variability at this site is strongly forced by sea surface temperatures and atmospheric pressure in the tropical Pacific and related to local sea ice conditions. The record shows that this region has warmed since the late 1950s, at a similar magnitude to that observed in the Antarctic Peninsula and central West Antarctica; however, this warming trend is not unique. More dramatic isotopic warming (and cooling) trends occurred in the mid-nineteenth and eighteenth centuries, suggesting that at present, the effect of anthropogenic climate drivers at this location has not exceeded the natural range of climate variability in the context of the past ~300 years.
Pippen Kool,
This chart by über-warmist Phil Jones shows that previous natural warming episodes are exactly the same as the most recent global warming. Therefore, the rise in CO2 has no measurable effect on global temperature. It matters not whether CO2 was low or high, the planet naturally warms in steps, in its recovery from the LIA.
Forget your model nonsense, that is nothing but speculation based on preconceived beliefs programmed into the models. When you look at the empirical evidence, the Scientific Method and the Null Hypothesis, you will find that the CO2=AGW conjecture is effectively deconstructed.
It is a strange world when someone looks at real world evidence, and concludes exactly the opposite. That is how witch doctors got their money and status in the past, and how the IPCC and modelers get their money and status now. Folks like you make it easy for them.
Of course since this is dynamical warming… see Leroux.
Manfred says: “They artfully use the meaningless term ‘climate change’ not only in the abstract but in the title of their article”
Nope.
“when in fact they are concerned with detecting changes in temperature”
When did temperature averages become not part of climate? I must have missed this.
Sorry, but I do not buy it.
Ice core isotope ratios might indicate some present correlation with weather such as surface sea temperatures and tropical barometric pressures, but these were absolutely not measured in the 1700s. Therefore, no causative claim can be made about the influence of SST and pressures in the 1700s.
This paper simply demonstrates yet again, the wrong technique of jumping several degrees of separation between various causes and effects and hoping, in the absence of any available proof, that there is nothing lost in the jumps.
In classical science, you establish cause and effect without guessing. You do not publish about a cause and effect that cannot be demonstrated as acting in the time period being studied.
Further, the simple, lazy equations used to relate temperature to isotope ratios cannot be taken as a given here, because they belong in that part of the mechanism under study, not in the proven lookup file.
This is bad science, unless you have joined the sloppy club of climate scientists who are seemingly capable of establishing effects when they are not present in the data and cannot be reconstructed.
If you write a speculative paper, please be so kind as to label it as such in several prominent places including the Abstract. If authors do not do this, they run the risk of being labelled as fraudulent. There has been altogether too much of this sloppy type of climate ‘science’.
Pippen Kool . ‘Variability’ = ‘change’. Having trouble are we?
When did temperature averages become not part of climate?
When ‘global warming’ became truely inconvenient by failing to agree with those pesky models, around the late ’90’s I understand.
How do they decide that bit is “West” Antarctica? It’s clearly part of North Antarctica (as is the rest of the coast), but there is quite a lot of Antarctica West of Ellsworth Land. On the other hand, if you travel due East, you end up in Ellsworth land again. This proves that Ellsworth land is actually East Antarctica.