by Renee Hannon, August 4, 2017 in WUWT
Detailed pattern correlation of Earth’s temperature changes during the past 450 kyrs reveals observations about several cyclic climate patterns. The past four glacial cycles are increasing in duration from 89 kyrs to 119 kyrs. Within these glacial cycles, two warm periods occur about 200 kyrs apart and have strikingly similar temperature characteristics.
During the last 450 kyrs, the five major warm onsets with rapidly increasing temperatures are triggered by increases in the eccentricity, obliquity, and precession of Earth’s orbit. The nearly concurrent increase in these three astronomical forces appears a necessary component for a major warm onset. Obliquity is the dominate control for ending these major warm periods and entering a cooling phase.
by Wim Röst, August 1, 2017 in WUWT
Today ‘warm’ is strongly connected with ‘climate change’, if not with ‘dangerous climate change’. In the minds of people ‘cold’ should be more stable. But, paleo data show that it is‘cold’ that is unstable. While ‘warm’ always shows a high stability in climatic conditions.
by Rice University, July 31, 2017 in ScienceDaily
Weathering of Earth by glaciers may have warmed the planet over eons by aiding the release of carbon dioxide into the atmosphere. A new study shows the cumulative effect may have created negative feedback that prevented runaway glaciation.
See also here
by M. Allan et al., July 11, 2017, in Climate of the Past
We present a decadal-centennial scale Holocene climate record based on trace elements contents from a 65 cm stalagmite (“Père Noël”) from Belgian Père Noël cave. Père Noël (PN) stalagmite covers the last 12.7 ka according to U/Th dating. High spatial resolution measurements of trace elements (Sr, Ba, Mg and Al) were done by Laser- Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Trace elements profiles were interpreted as environmental and climate changes in the Han-sur-Lesse region.
See also here
by David Middleton, July 17, 2017 in WUWT
The Tethys Sea couldn’t have been a better place for petroleum source rock deposition even if it had been designed for such a purpose. The “Tethyan realm” encompassed much of the Jurassic and Cretaceous periods…
See also here and also here
by Javier, July 11, 2017 in ClimatEtc.
In our attempt to better understand the nature of our planet’s abrupt climate changes I have already reviewed the glacial-interglacial cycle, and the Dansgaard-Oeschger cycle’s that take place during glacial periods. I now start reviewing the millennial climate cycles that abruptly impact the slowly changing Holocene climate. The most significant and regular one is the ~ 2400-year Bray cycle.
by James Edward Kamis, January 19, 2017 in ClimateChangeDispatch
Progressive bottom melting and break-up of West Antarctica’s seafloor hugging Larsen Ice Shelf is fueled by heat and heated fluid flow from numerous very active geological features, and not climate change.
See here, also here, also here
by Ed Hoskins, June1, 2015
When considering the scale of temperature changes that alarmists anticipate because of Man-made Global Warming and their view of the disastrous effects of additional Man-made Carbon Dioxide emissions in this century, it is useful to look at climate change from a longer term, century by century and even on a millennial perspective.
(i) See also here
(ii) See also here
by Kenneth Richard, July 11, in ClimateChangeDispatch
It’s official. According to a new paper published in the journal Scientific Reports, Greenland has been cooling slightly since 2005.
This trend development may be a harbinger of what may be in store for the coming years. Shifts in North Atlantic temperatures typically lead changes in the Arctic by a few years. And throughout the North Atlantic, rapid cooling has been underway since 2005, plunging below the levels reached in the 1950s
by James Kamis, July 4, 2017 in ClimateChangeDispatch
Geological heat flow is fueling bottom melting and associated cracks across West Antarctica’s Larsen Ice Shelf, having little to do with man-made global warming. Significant amounts of high-quality data and relevant geological observations support this revelation, given historical and current geological mapping efforts done in Antarctica.
see here, image credit NASA
See also here (in French)
by Dennis T. Avery, June 30, 2017 in WUWT
Carbon dioxide truly is “the gas of life.” The plants that feed us and wildlife can’t live without inhaling CO2, and then they exhale the oxygen that lets humans and animals keep breathing.
Our crop plants evolved about 400 million years ago, when CO2 in the atmosphere was about 5000 parts per million! Our evergreen trees and shrubs evolved about 360 million years ago, with CO2 levels at about 4,000 ppm. When our deciduous trees evolved about 160 million years ago, the CO2 level was about 2,200 ppm – still five times the current level.
See also here (in French)
by Maja Sojtaric, June 27, 2017
The Eurasian ice sheet was an enormous conveyor of ice that covered most of northern Europe some 23,000 years ago. Its extent was such that one could have skied 4,500 km continuously across it – from the far southwestern isles in Britain to Franz Josef Land in the Siberian Arctic. Suffice to say its existence had a massive and extremely hostile impact on Europe at the time.
This ice sheet alone lowered global sea-level by over 20 meters. As it melted and collapsed, it caused severe flooding across the continent, led to dramatic sea-level rise, and diverted mega-rivers that raged on the continent. A new model, investigating the retreat of this ice sheet and its many impacts has just been published in Quaternary Science Reviews.
by Andy May, June 19, 2017 i
Last week, I posted a global temperature reconstruction based mostly on Marcott, et al. 2013 proxies. The post can be found here. In the comments on the Wattsupwiththat post there was considerable discussion about the difference between my Northern Hemisphere mid-latitude (30°N to 60°N) and the GISP2 Richard Alley central Greenland temperature reconstruction (see here for the reference and data). See the comments by Dr. Don Easterbrook and Joachim Seifert (weltklima) here and here, as well as their earlier comments.
by Peter Brannen, June 14, 2017
“It is absolutely critical to recognize that I am NOT claiming that humans haven’t done great damage to marine and terrestrial [ecosystems], nor that many extinctions have not occurred and more will certainly occur in the near future. But I do think that as scientists we have a responsibility to be accurate about such comparisons.”
Many popular science articles take this as a given, and indeed, there’s something emotionally satisfying about the idea that humans’ hubris and shortsightedness are so profound that we’re bringing down the whole planet with us.
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