Sentences with phrase «holocene warming»

The authors then acknowledge that this suggests that there was «no significant contribution of CO2 forcing to climatically caused heat flux and thus to the temperature increase during the Pleistocene - Holocene warming».

Schmittner et al use a spatially more complete data set than Snyder and finds LGM - Holocene warming = 2.3 C. Snyder finds LGM - Holocene warming = 6.2 C.

The Holocene warming was related to the over-hunting and extinction of the mega-fauna.

Irrigation was one of the earliest technologies developed 9000 years ago to offset droughts in the Fertile Crescent, triggered by onset of Holocene warming.

Remarkably, the range of recent estimates of LGM — Holocene warming, from approximately 3 °C [94] to approximately 6 °C [95], is about the same as at the time of the CLIMAP [96] project.

Accurate data defining LGM — Holocene warming would aid empirical evaluation of fast - feedback climate sensitivity.

Pleistocene climate oscillations yield a fast - feedback climate sensitivity of 3 ± 1 °C for a 4 W m − 2 CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective because of poorly defined LGM global temperature and possible human influences in the Holocene.

The ice cores show the same Holocene warming pulse 16,000 years ago.

More information: Jonathan L. Baker et al, Holocene warming in western continental Eurasia driven by glacial retreat and greenhouse forcing, Nature Geoscience (2017).

Second, the abstract admits that, «Pleistocene climate oscillations yield a fast - feedback climate sensitivity of 3 ± 1 °C for a 4 W m − 2 CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective» and also «Ice sheet response time is poorly defined».

The global mean temperature at that time is thought to have reached about 1 °C warmer than the Holocene warming.

They also mention something about open Nw passage during the holocene warm period.

Leonid Polyak of the Byrd Polar Research Center at Ohio State University notes that the general climatic and ice situation in the Arctic now appears very different than what prevailed in earlier Holocene warm periods: «Overall, the early - Holocene situation in the Arctic seems to be very different from the modern one.

That trend is based on only 3 decades of data, not centuries and does not define the true Holocene warm period trend.

«It is getting warmer, but it is not warmer than it was in the Middle Ages, or in the Roman period, or in the Minoan warm period, or in the Holocene warm period, 8,500 years ago,» he said.

Not exact matches

Instead, the fossil record indicates they vanished during the Earth's glacial - interglacial transition, which occurred about 12,000 years ago and led to much warmer conditions and the start of the current Holocene period.

But some researchers have argued that the transition from the frigid climatic period known as the Last Glacial Maximum (LGM)-- about 20,000 to 25,000 years ago — to the current warm Holocene Epoch brought habitat changes that killed off the mammoths with little or no help from humans.

Another devastating cycle of cooling and warming followed: a sudden, brutal cold snap called the Younger Dryas around 13,000 years ago, followed by rising temperatures in the current Holocene Epoch.

The Holocene Climate Optimum was a period of global climate warming that occurred between six to nine thousand years ago.

Then, as the world warmed early in the Holocene epoch, about 10,000 to 12,000 years ago, the pine gave way to a dense woodland of oak, maple, and birch inhabited by smaller prey like deer and wild boar.

Long - term warming, not cooling, defined the Holocene Epoch, which began 12,000 to 11,500 years ago at the close of the Pleistocene Ice Age.

Since Vaks's present is the «preindustrial late Holocene,» that means the planet is already more than halfway there, having experienced 0.8 degree C warming to date.

Glaciers retreated and the world warmed, and by 11,500 years ago, the planet had entered the constant summer of today's Holocene Epoch.

Since then, there have been small - scale climate shifts — notably the «Little Ice Age» between about 1200 and 1700 A.D. — but in general, the Holocene has been a relatively warm period in between ice ages.

The current era (at least under present definitions), known as the Holocene, began about 11,700 years ago, and was marked by warming and large sea level rise coming out of a major cool period, the Younger Dryas.

Let us just concentrate on the warming from LGM (20 kya) to the Holocene Thermal Optimum (10 kya).

It seems that more northerly ice shelves around the northern Antarctic Peninsula (Prince Gustav, Larsen A) and on the western peninsula (George VI Ice Shelf), may have disintegrated previously during warm phases in the Holocene.

Warming of 1 °C relative to 1880 — 1920 keeps global temperature close to the Holocene range, but warming of 2 °C, to at least the Eemian level, could cause major dislocations for civiliWarming of 1 °C relative to 1880 — 1920 keeps global temperature close to the Holocene range, but warming of 2 °C, to at least the Eemian level, could cause major dislocations for civiliwarming of 2 °C, to at least the Eemian level, could cause major dislocations for civilization.

A previous warm period about 130,00 years ago, is the Eemian — sea level 5 - 9 meters higher than today, and enormous storms, not seen in the Holocene.

Short - term events within the Holocene interglacial period include the Medieval Warm Period (MWP), Roman Warm Period (RWP), Little Ice Age (LIA), and other cool events such as 4.2, 5.9, 7.2 and 8.2 kyr events.

Model studies for climate change between the Holocene and the Pliocene, when Earth was about 3 °C warmer, find that slow feedbacks due to changes of ice sheets and vegetation cover amplified the fast feedback climate response by 30 — 50 % [216].

Recent instrumental data spans 165 + years during the past 11,000 + years of the Holocene interglacial warm period as shown on figure 2.

That warming has brought global temperature close to if not slightly above the prior range of the Holocene.

A recent reconstruction from proxy temperature data [55] concluded that global temperature declined about 0.7 °C between the Holocene maximum and a pre-industrial minimum before recent warming brought temperature back near the Holocene maximum, which is consistent with our analysis.

The Holocene's warming onset started out like MIS 5e and 9 but was interrupted by the Younger Dryas (YD) cooling event.

Global warming of 2 °C would be well outside the Holocene range and far into the dangerous range.

This concatenation, which has global temperature 13.9 °C in the base period 1951 — 1980, has the first decade of the 21st century slightly (∼ 0.1 °C) warmer than the early Holocene maximum.

They observed a Holocene cooling trend in the Antarctic of -0.26 to -0.40 degrees C / millennium for the past 1900 years prior to present day warming of the most recent 200 years.

As the climate warmed during the Holocene, and suitable habitat expanded northward, gray fox population ranges shifted further north resulting in foxes with clade A haplotypes distributed as far north as Shasta County in northern California (Fig. 1).

Also, does everyone agree that it is now warmer than it was during the Holocene climate optimum (as has been recently widely reported; see RAG's link above or «oogle relevant phrases)?

I didn't keep the links but there is at least one d18O study from the Pacific Warm Pool which clearly indicates that first the deep ocean warmed there, followed later by the CO2 increase and then the shallow ocean warmed, leading to the LGM to Holocene transition.

The Wolcott paper was fascinating in the detail but not that surprising in the big picture; warming from the early Holocene to the inter-glacial optimum about 5000 years ago and then slow but steady cooling culminating in the LIA.

[Response: If this reservoir existed and was so poised to release methane as you speculate, then it would have done something during warmer conditions early in the Holocene, or in the last interglacial.

Sorry for lowering a bit the level of the discussion but 30 years into the most dramatic climate change that the Earth has experienced in the past millennium (perhaps since the beginning of the Holocene), I was wondering if this tremendous global warming should not have already become a bit more noticeable for the average person.

[Response: Sea ice is still not at levels seen during the Early Holocene, and since we are discussing sea floor sediments the main reason given to be concerned is that the change of summer sea ice will warm the bottom sea water, we are clearly not there yet.

You said: «If this reservoir existed and was so poised to release methane as you speculate, then it would have done something during warmer conditions early in the Holocene, or in the last interglacial.

I just meant that a thousand year period of stable temperature which happens to have a rapid warming trend at the end of the series is absolutely nothing out of the ordinary with regards to «other» thousand years periods in the Holocene.

[Aug. 9, 8:04 p.m. Updated Joe Romm has predictably assailed my view of Arctic sea ice trends and their implications, straying into discussions of melting permafrost (which is an entirely different issue laden with its own questions — one being why the last big retreat of permafrost, in the Holocene's warmest stretch, didn't have a greenhouse - gas impact) and my refusal to proclaim a magically safe level of carbon dioxide (which I discuss here).

During the so - called Holocene Climate Optimum, from approximately 8000 to 5000 years ago, when the temperatures were somewhat warmer than today, there was significantly less sea ice in the Arctic Ocean, probably less than 50 % of the summer 2007 coverage, which is absolutely lowest on record.

Here's another way to frame the question: Have we left the Holocene Epoch — the warm interval since the end of the last ice age some 10,000 years ago — and entered what is increasingly described as a geological epoch or age of our own making?