Sentences with phrase «holocene period»

The mean of a range of studies put the current warm period higher than at any other time since the last glacial (the Holocene period), but of those studies there is wide variance, with some showing higher temperatures, and some showing much lower.

New evidence from clams and mussels with temperature - sensitive habitat requirements confirm that warmer temperatures and less sea ice than today existed during the early Holocene period about 10.2 — 9.2 thousand years ago and between 8.2 and 6.0 thousand years ago (based on radio carbon dates) around Svalbard.

Just look at a graph for the Holocene period, where you can actually resolve a variation that is thicker than the sea level curve.

The Earth spends 90 % of its time in frozen conditions, with the recent warm Holocene period (11,500 yrs) drawing to an end.

During the recent Holocene period, carbon loss has been evident in the Arctic.

Well drained and rocky substrate there creates a glade ecosystem where sloping ground can encourage the growth of prickly pear cacti and other desert and prairie species such as the collared lizard, Crotaphytus that last covered the whole area around 7,000 years ago in the Hypsithermal Interval, during the Holocene Period, when warming dried out much of the glacial Northern Hemisphere.

However, the relative variations of the Be concentrations and the Be fluxes are very similar during the climatically stable Holocene period.

The early Holocene period clearly displays 1,000 year periodicity as shown by a Gaussian filter applied on the series (green curve).

In the article in science A Reconstruction of Regional and Global Temperature for the Past 11,300 Years the authors took 73 proxy records of temperature, including isotope ratios and pollen records in order to construct a global temperature record for the entire Holocene period.

It is not completely clear whether humans have caused this tipping — though nothing like it has ever occurred during the 11,500 - year Holocene period before humans started interfering with the planet's energy balance.

This [Holocene Climatic Optimum] is a somewhat outdated term used to refer to a sub-interval of the Holocene period from 5000 - 7000 years ago during which it was once thought that the earth was warmer than today.

Ice cores drilled from a glacier in a cave in Transylvania offer new evidence of how Europe's winter weather and climate patterns fluctuated during the last 10,000 years, known as the Holocene period.

This is based on the ice core record, but there are other measures of CO2 that strongly disagree with the ice core record: for example, the leaf stomata record generated by Wagner et al shows significant variation in the Holocene period, indicating that rapid fluctuations do occur and that 370ppm is «high» but not outside typical variability.

-- Besides the MWP discussion: 80 - 90 % of the Holocene period (last 10 - 12.000 years) has been warmer than today.

The practical and profitable path is to build on this wonderful tool Marcott has developed, beat the flaws out of it, and use it to validate Holocene - spanning GCMs (now that we can contemplate such as technically feasible in the near future) by comparing their outputs — which modellers can make as granular as computers can handle, thereby answering such questions as how probable is it the current rise is the fastest in the Holocene period — through a filter that derives the probable curves of proxies.

So we can blame the sun for the Holocene period, but even though solar radiation has increased right along with the temperature in the 20th century, we are assuming that the warming is due to the minute increase of atmospheric CO2 from humans?

Figure 1 (below) plots ice core data, covering the past 11,700 years — an age known as the Holocene period — with present day included at the far right of the graph.

In many records, there is no apparent consistent pacing at specific centennial to millennial frequencies through the Holocene period, but rather shifts between different frequencies (Moros et al., 2006).

For example, lake Lobnor vanished in 1972, and lake Kukunor, since the beginning of Holocene period, has dwindled in area by one third and in depth by 100 m. 3 Finally, the depth of lake Ohlin, at the head of the Yellow River, has been dropping by over 2 cm annually.4

Other scientists are exploring the origin of economic strategies, such as fishing, hunting and gathering, in modern humans over the last few thousand years, and how the development of these strategies may have contributed significantly to human survival at the onset of huge climatic changes at the beginning of the Holocene period.

«We grew teosinte in the conditions that it encountered 10,000 years ago during the early Holocene period: temperatures 2 - 3 degrees Celsius cooler than today's with atmospheric carbon dioxide levels at around 260 parts per million,» said Dolores Piperno, senior scientist and curator of archaeobotany and South American archaeology at the Smithsonian's National Museum of Natural History and the Smithsonian Tropical Research Institute, who led the project.

Ice cores drilled from a glacier in a cave in Transylvania offer new evidence of how Europe's winter weather and climate patterns fluctuated during the last 10,000 years, known as the Holocene period.

Previous studies have used a variety of computer models and data from fossils and flood events to argue that ENSO has become more exaggerated over the past 11,000 years, known as the Holocene period.

The article reveals the influence of human activity on the environment due to the beginnings of metallurgy at the end of the Holocene period in southern Europe.

Layers determined to be from the Holocene period, formed during the past 11,700 years, are shown in green.

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.

In their research, Smith and her colleagues found that this decline follows the global expansion of hominins over the late - Quaternary, including the Pleistocene and Holocene Periods.

Empirical evidence, such as the Greenland ice cores, point to three specific Holocene periods of ancient historical warming: the Minoan, the Roman, and the Medieval eras.

Multi-proxy records are aligning on painting a clearer picture of these relatively recent Holocene periods.

Not exact matches

The March 12, 2015 issue of Nature magazine contains an essay — not an original thesis, rather a summation — by two English geographers entitled «Defining the Anthropocene,» the subject of which is whether (and starting when) human activity has so altered the global environment as to constitute a new geologic age: the Anthropocene Age, as successor to the 11,000 - year Holocene Epoch that is itself part of the larger 2.6 million year - old Quaternary Period (or Great Ice Age).

Their findings reveal that dung beetles were much more frequent in the previous interglacial period (from 132,000 to 110,000 years ago) compared with the early Holocene (the present interglacial period, before agriculture, from 10,000 to 5,000 years ago).

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.

Biologists call it the Sixth Great Extinction, or the Holocene extinction event, after our current geologic time period.

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

In 2005, they formed the Holocene Impact Working Group (referring to the geological period covering the last 11,000 years) to seek out the geological signatures of a megatsunami.

Until now it had been assumed that thermophilic reptiles survived the Ice Ages only on the southern peninsulas of Europe and spread northward once the temperatures rose again during the Holocene and the interglacial periods.

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 combined sea ice data suggest that the seasonal Arctic sea ice cover was strongly reduced during most of the early Holocene and there appear to have been periods of ice free summers in the central Arctic Ocean.

By spanning the past 7,000 years — part of a period known as the Holocene — the new study triples the amount of data available for scientists to analyse.

does fit the temperature trend to an acceptable level, if one should reduce the sensitivity for CO2 / aerosols far enough... Current models also can reproduce other transitions (LGM - Holocene) with a reasonable accuracy, but this is mainly in periods where there is a huge overlap between temperature (as initiator) and CO2 / CH4 levels (as feedback).

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.

Renssen, H., V. Brovkin, T. Fichefet, and H. Goosse, 2003: Holocene climate instability during the termination of the African Humid Period.

Current spatial coverage, temporal resolution and age control of available Holocene proxy data limit the ability to determine if there were multi-decadal periods of global warmth comparable to the last half of 20th century.

Continue reading «Invariance of the carbonate chemistry of the South China Sea from the glacial period to the Holocene and its implications to the Pacific Ocean carbonate system»

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 eperiod 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 ePeriod (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 ePeriod (RWP), Little Ice Age (LIA), and other cool events such as 4.2, 5.9, 7.2 and 8.2 kyr events.

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

We use measured global temperature and Earth's measured energy imbalance to determine the atmospheric CO2 level required to stabilize climate at today's global temperature, which is near the upper end of the global temperature range in the current interglacial period (the Holocene).

During periods when ice sheets have been relatively stable, such as the last several millennia (the late Holocene), sub-millennial sea - level variability arose primarily from changes in atmosphere / ocean dynamics.

We conclude that an appropriate target is to keep global temperature within or close to the temperature range in the Holocene, the interglacial period in which civilization developed.