Sentences with phrase «holocene levels»

Hansen and Sato (7) argue that the climate of the most recent few decades is probably warmer than prior Holocene levels, based on the fact that the major ice sheets in both hemispheres are presently losing mass rapidly (9) and global sea level is rising at a rate of more than 3 m / millennium (25), which is much greater than the slow rate of sea level change (less than 1 m / millennium) in the latter half of the Holocene (26).

New paper predicts solar activity will decline over 21st century to average Holocene levels — Published in Climate of the Past

Minor exceptions, such as the fact that Arctic sea ice may disappear with a relatively small increase of climate forcing above the Holocene level, might put a small wave in the fast - feedback curve.»

Not exact matches

The volume of ash deposited, and the estimated height of the eruption plume (43 kilometers above sea level) put the eruption's magnitude at a minimum of 7 on the volcanic explosivity index (which has a scale of 1 to 8)-- making it one of the largest known in the Holocene.

Mud cores pulled from marshes in the city show that the sea level is already rising faster there than at any time in the past 1,500 years, according to research published in the Holocene Journal in January.

We find that ENSO variance was close to the modern level in the early Holocene and severely damped ~ 4 - 5 ka.

Geology textbooks will tell you that we are now 12,000 years into the Holocene Epoch, a time marked by violent geologic upheavals due to retreating glaciers and surging sea levels.

«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.

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.

This is a reference level within recent strata somewhere in the world that will be proposed to most clearly and consistently characterise the changes as the Holocene, which represents the last 11,700 years of geological time on this planet, gave way into the Anthropocene about 65 years ago.

Abstract: Mid - to late - Holocene sea - level records from low - latitude regions serve as an important baseline of natural variability in sea level and global ice volume prior to the Anthropocene.

Assessing Antarctic Ice Sheet - Sea Level Dynamics During the Holocene: The «Meltwater Test.»

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 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.

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.

reconstructing sea - level and ice - sheet changes on timescales ranging from the 20th century, to the late Holocene, to the last 150 thousand years, through statistical and geophysical modeling of geological and observational records;

Prior to the Holocene era sea levels were considerably lower, such that the water width separating the mainland was much less.

Sea level models suggest that the islands were larger and closer to the mainland and each other during the terminal Pleistocene and early Holocene but, throughout the Quaternary, they were always separated from the mainland by a watergap of at least 7 km [23,24].

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.

In particular, CO2 levels started to rise from full glacial levels of about 180 parts per million (ppm), reaching 265 ppm 10,000 years ago (or ~ 2.1 W / m2 radiative forcing), and with another slow ~ 15 ppm rise during the Holocene.

CH4 levels in the ice cores and the gradients between Greenland and Antarctica point clearly to tropical sources dominating the (small) observed Holocene variability.

[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).

The Arctic shelf is currently undergoing dramatic thermal changes caused by the continued warming associated with Holocene sea level rise.

Glacial, interglacial... at a somewhat finer level the mid-Holocene is distinct from the late Holocene, or a stadial different from an interstadial glacial.

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).

Behind peak oil and impacts of climate change on habitation and food supply, sea level rise will be the final wet blanket that will sweep inexorably over the inhabitants of the old Holocene.

Burning all fossil fuels, if the CO2 is released into the air, would destroy creation, the planet with its animal and plant life as it has existed for the past several thousand years, the time of civilization, the Holocene, the period of relative climate stability, warm enough to keep ice sheets off North America and Eurasia, but cool enough to maintain Antarctic and Greenland ice, and thus a stable sea level.

In fact, the literature is pretty clear that the better analog for the Holocene is actually MIS11 (Droxler), around 400 kya, when orbital eccentricity was quite low as it is today, resulting in a longer interglacial (Berger) with sea levels higher than during the Eemian.

Joe Romm has predictably assailed my rejection of his «death spiral» depiction of Arctic sea ice trends, 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).

Why should warming during the current Holocene Interglacial be significantly different / less than during the previous Eemian Interglacial (MIS5e), when sea levels were, per the IPCC's own comments, above modern levels or for that matter above the purported mid-Holocene highstand?

Our current climate in much closer to the coolest level of the Holocene than the warmest (Holocene Optimim ~ 8,000 years ago).

There's also lots of research showing sea level rise is begining to approach the Early Holocene Sea level Rise.

«Comparison between Holocene and Marine Isotope Stage 11 Sea Level Histories.»

Check out the early Holocene sea level rise before you say things like that.

In other words, aim to get temperatures back under the Holocene maximum of 0.5 ºC, which implies a level of greenhouse gases below 320 parts per million (ppm) of atmospheric carbon dioxide (CO2), compared to the current level of 405 ppm.

The desire to avoid large ice sheet shrinkage and sea level rise implies a need to get global temperature back into or close to the Holocene range on the time scale of a century or less.

Civilization developed during the Holocene, the interglacial period of the past 10,000 years during which global temperature and sea level have been unusually stable.

Where did you get the idea that sea level rose 35 m during the warmer part of the Holocene.

This slow decline in the 10 kyr after the initial peak is in contrast to the slowly increasing CO2 levels in the Holocene and the even slower increase in MIS 11, despite the similar orbital configuration of these three periods.

They found that the lake was six times larger and water levels were 60 meters higher than present during the early and middle Holocene — the period beginning about 11,700 years ago, and encompassing the development of human civilization.

Global temperature, therefore, has risen from near the coldest to the warmest levels of the Holocene within the past century, reversing the long - term cooling trend that began ~ 5000 yr B.P.

Yes, Jimbo, people are aware of the WUWT site, and of the fact that people like you and Anthony take false comfort in the fact that during a significant chunk of the Holocene it was warmer than today, leading to a lot of ice melting, not just in the Arctic basin but on land, as well, causing sea levels to rise dramatically.

I think that you will find sea - level variations around or greater than 1 meter when we have a better understanding of holocene dynamics.

Eventually Holocene warmth raised sea level and reduced sea ice allowing walrus populations to once again flourish in the Arctic.

The 2015 Vasskog et al study of Greenland compared the previous Eemian IG to the Holocene and found much higher sea levels, temp etc during the Eemian.

Holocene hydrological changes in south - western Mediterranean as recorded by lake - level fluctuations at Lago Preola, a coastal lake in southern Sicily, Italy; Magny et al, 2011, see abstract here.

NASA scientists patiently answer TonyB's question: Milankovitch insolation amplified by the CO2 greenhouse effect caused the Holocene sea - level rise.