Paleoclimate reconstructions refer to the process of studying and understanding the Earth's past climate conditions by examining various natural indicators, such as tree rings, ice cores, and sediment cores. Scientists use these indicators to gather information about temperature, precipitation patterns, and other climate variables from a time before we had direct measurements. By reconstructing the past climate, they can gain insights into how the Earth's climate has changed over long periods and better predict future climate changes.
Full definition
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As paleoclimate reconstructions are usually only measured against global instrumental temperature records commencing 1880 they do not find any of the «hockey stick» effects that can be seen in the older instrumental temperature records.
* When instrumental records are not available, the historic observed record of the past millennium is likely to be a valuable aid to the development of
paleoclimate reconstructions using proxies.
«Our study has found evidence to the contrary, suggesting that in fact, the future long - term trend based
on paleoclimate reconstructions is likely towards diminishing precipitation, with no relief in the form of increased Mediterranean storms, the primary source of annual precipitation to the region, in the foreseeable future.»
It's ironic to see McIntyre and the rest castigating Mann et al for being skeptical of Briffa's tree - ring
based paleoclimate reconstructions which they've put so much energy into supposedly proving «trees aren't thermometers».
I've also analyzed data (not conclusions, but raw data) relating to
paleoclimate reconstructions such as tree rings, ice cores, and (my personal favorite) borehole temperature profiles.
More recently two of the authors published Viau et al (2012) which surely supports the contention of this SkS OP as it kicks off its conclusions stating «The pollen - based
paleoclimate reconstructions show that warmer conditions during the MWP and cooler in the LIA were all nevertheless cooler than the 1961 — 1990 base period, and this result emerges even without comparing the results to the instrumental record.»
LGM simulations with relatively little Antarctic sea ice, instead, typically reveal stratification and circulation changes opposite to those suggested by
most paleoclimate reconstructions.
Mann, the author of a well
known paleoclimate reconstruction that has been subject to skeptics» attacks, declined to comment on whether scientists were justified in resisting FOI requests from skeptics.
# 72 Yes, I realize the history of Western Civilization doesn't necessarily match the world, however, I don't believe «my take» is contradictory to
paleoclimate reconstructions per se; I just don't have to take all the uncertainties into consideration, a benefit of not being a climatologist.
Most often the «climates have always changed» gets used to refute ridiculous graphs that join low frequency,
averaged paleoclimate reconstructions with modern high frequency instrument records.
In November 2005, Sen. Boehlert formally commissioned the U.S. National Academy of Sciences to review the science
behind paleoclimate reconstructions and the final NAS report fully vindicated Mann.
The Summary for Policymakers also incorporates, for the first time, information on, inter alia,
paleoclimate reconstruction studies, geoengineering, and an emissions - based perspective on drivers of climate change.
However, most
previous paleoclimate reconstructions of Southern Ocean sea ice have focused on the Last Glacial Maximum timeslice (CLIMAP, MARGO projects) or the Holocene and last interglacial periods (PAGES working group Sea Ice Proxies (SIP)-RRB-.
The predictors can be instrumental data if the reconstruction is used to infill missing data or proxy data if it is an indirect measure used to
develop paleoclimate reconstructions.
Actual paleoclimate reconstructions aren't exercises in mathematical interpolation but are the results of models based on principles of physics — and thus extrapolate beyond the evidence, and if they are good models that incorporate enough of the physics, they do so skillfully.
I doubt that climate models used today account for the substantial differences in vegetation for the predicted period, versus vegetation for the past warm climate episodes used
for paleoclimate reconstruction.
As changes in temperature and light can be excluded as reasons for the decline in magnesium concentrations, the researchers interpret it as a clear reaction to ocean acidification — with implications for
paleoclimate reconstructions.