by Andy May, June 9, 2017 in WUWT
In previous posts (here, here and here), we have shown reconstructions for the Antarctic, Southern Hemisphere mid-latitudes, the tropics, the Northern Hemisphere mid-latitudes, and the Arctic. Here we combine them into a simple global temperature reconstruction. The five regional reconstructions are shown in figure 1. The R code to map the proxy locations, the references and metadata for the proxies, and the global reconstruction spreadsheet can be downloaded here
by Andy May, June 8, 2017 in WUWT
As we did in the previous two posts, we will examine each proxy and reject any that have an average time step greater than 130 years or if it does not cover at least part of the Little Ice Age (LIA) and the Holocene Climatic Optimum (HCO). We are looking for coverage from 9000 BP to 500 BP or very close to these values. Only simple statistical techniques that are easy to explain will be used.
by Andy May, June 6, 2017, in WUWT
In the last post (see here) we introduced a new Holocene temperature reconstruction for Antarctica using some of the Marcott, et al. (2013) proxies. In this post, we will present two more reconstructions, one for the Southern Hemisphere mid-latitudes (60°S to 30°S) and another for the tropics (30°S to 30°N)
by Yair Rosenthal et al., January 1, 2017
Here we review proxy records of intermediate water temperatures from sediment cores in the equatorial Pacific and northeastern Atlantic Oceans, spanning 10,000 years beyond the instrumental record.
These records suggests that intermediate waters were 1.5–2 °C warmer during the Holocene Thermal Maximum than in the last century.
Intermediate water masses cooled by 0.9 °C from the Medieval Climate Anomaly to the Little Ice Age.
By Kenneth Richard , April 2017
According to a new paper, the Bølling Warming event 14,700 years ago raised the surface temperature for the entire Northern Hemisphere by 4 to 5°C within a few decades. This is a hemispheric warming rate of approximately 2.0°C per decade, which is 40 times faster than the 0.05 °C per decade global warming rate since 1850 (and 1998).
by JM Schaefer et al., Nature, December8, 2016
Here we show that Greenland was deglaciated for extended periods during the Pleistocene epoch (from 2.6 million years ago to 11,700 years ago), based on new measurements of cosmic-ray-produced beryllium and aluminium isotopes (10Be and 26Al) in a bedrock core from beneath an ice core near the GIS summit.
by Kenneth Richard, March 20, 2017
According to an estimate of global sea surface temperature (SST) changes during the last 2,000 years (“Robust global ocean cooling trend for the pre-industrial Common Era“), the addition of the last 2 centuries (1800 to 2000 C.E.) of relatively modest SST warming only changes the overall per-millennium global cooling trend (~0.4°C) by one tenth of one degree. In other words, using a long-term perspective, the Holocene cooling trend has continued largely uninterrupted during the last two centuries.
Analysis of tree rings reveals highly abnormal solar activity in the mid-Holocene
by Fusa Miyake et al., January 31, 2017
An international team led by researchers at Nagoya University, along with US and Swiss colleagues, has identified a new type of solar event and dated it to the year 5480 BC.