Sentences with phrase «glacial cycles over»

a) a glacial cycle over 100,000 years with warm interglacial periods in red and the long glacial period in between.

Not exact matches

Ice core records are rich archives of the climate history during glacial - interglacial cycles over timescales of up to ~ 800 kyr before the current age.

The Tropical Pacific climate response to the changing forcing over the last glacial cycle William Roberts, Paul Valdes

Ecological niche models supported inference of drastic changes in the extent of its breeding range over the last glacial — interglacial cycle.

We recently extended this record to approximately 120,000 years BP in order to track vegetation change over a full glacial cycle at millennial to orbital timescales.

Ice core records show that atmospheric CO2 varied in the range of 180 to 300 ppm over the glacial - interglacial cycles of the last 650 kyr (Figure 6.3; Petit et al., 1999; Siegenthaler et al., 2005a).

Changes in the mode of Southern Ocean circulation over the last glacial cycle revealed by foraminiferal stale isotopic variability.

Re # 8, any changes in climate over glacial - interglacial timescales have to take into account an additional component: the biogeochemical cycling of atmospheric gases.

The structure of residual anomalies over the glacial − interglacial climate cycles after subtraction of dust effects provides constraints for the strength and timing of other processes governing these cycles.»

The conclusion that they survived over at least two glacial cycles, where the amplitude of environmental change in the Arctic is quite large, suggests they have under natural conditions the ability to adapt / survive such changes.

[Response: To pre-empt some mutual incomprehension, note that industrial CO2 rises are certainly an anthropgenic forcing and not a response (see here and here), but clearly CO2 changes over glacial - interglacial cycles is both a response (to Milankovitch - driven changes) and a forcing (since the additional radiative forcing from CO2 is about a third of that needed to keep the ice ages as cold as they are — see here).

What this model shows is that if orbital variations in insolation impact ice sheets directly in any significant way (which evidence suggests they do Roe (2006)-RRB-, then the regression between CO2 and temperature over the glacial - interglacial cycles (which was used in Snyder (2016)-RRB- is a very biased (over) estimate of ESS.

Re glacial cycle CO2 and temp correlation, it is useful to remember that the timescale of that record is 100's of thousands of years, where as the CO2 rise today has occurred over ~ 100.

Reality: Whilst there are many areas of interesting research with respect to the glacial - interglacial cycles of the Quaternary, we have a good understanding of the primary drivers i.e. orbital variations occurring over cycles of tens of thousands of years.

The glacial cycles have been a lot bigger over the last million years, than they were prior to that.

Glacial cycles (ice ages) are set in motion by (1) periodic wobbles in the tilt of the Earth's rotation, (2) changes in the tilt of its axis, and (3) the shape of its orbit occurring over tens of thousands of years.

Figure 2 shows our data together with earlier results from the Dome C (650 — 390 kyr bp4 and 22 — 0 kyr bp5), Vostok1, 2,3 (440 — 0 kyr bp) and Taylor Dome6 (60 — 20 kyr bp) ice cores resulting in a composite CO2 record over eight glacial cycles.

However, there's less match between the amplitude changes in the most recent million years or so, yet another indicator that the response of glacial changes to astronomical cycles is itself changing over time.

The evidence for glacial cycles of about 100,000 years over the last half million years seems to be very compelling.

«The lags of CO2 with respect to the Antarctic temperature over glacial terminations V to VII are 800, 1600, and 2800 years, respectively, which are consistent with earlier observations during the last four glacial cycles.»

By over more than 20 times the amount (see Milankovitch cycles — recently improved in Wiki) starts the climate relevance: see glacial times...... To the point: I do not talk about ELLIPTICITY CHANGES, they stay constant on millenium scale.

Over the past 450,000 years there have been several major glacial / interglacial (ice age / current climate) cycles.

Over the course of a full glacial cycling, CO2 typically only goes through a similar change, 1/2 a doubling.

Obviously the change over the glacial cycle is much greater for the same change in CO2 forcing.

I think that the same signature over the last 4 glacial - interglacial cycles is ample evidence that a «strong CO2 model» can not be true.

We carried out a number of DCESS model simulations over the last three glacial cycles using the dust radiative and / or iron fertilization forcings shown in Fig. 4 and Fig.

The glacial - interglacial cycles are an example of tight coupling between climate and the carbon cycle over long time scales, but there is also clear evidence of the carbon cycle responding to short - term climatic anomalies such as the El Niño - Southern Oscillation (ENSO) and Arctic Oscillation (Rayner et al., 1999; Bousquet et al., 2000; C. Jones et al., 2001; Lintner, 2002; Russell and Wallace, 2004) and the climate perturbation arising from the Mt. Pinatubo volcanic eruption (Jones and Cox, 2001a; Lucht et al., 2002; Angert et al., 2004).

Variations over 420,000 years of CO2, methane (CH4), and temperature, from the Vostok ice core after it reached bedrock (1999): four complete glacial cycles.

We also made combined radiative and iron fertilization forcing simulations over the last three glacial cycles (Figs.

Weathering may depend on properties like temperature, pCO2, land ice abrasion, and sea level change but has been suggested to be stable over glacial − interglacial cycles (54).

Somewhat overshadowing the actual temperature reconstruction that Snyder presented was her calculation of an earth system sensitivity (ESS) based on a correlation between temperature and CO2 over the past few glacial cycles.

Residual GMT and pCO2 anomalies after subtraction of dust effects (red lines in Fig. 5) invite further interpretation of the strengths and timings of other mechanisms acting over glacial − interglacial cycles.

Comparison with data and data - based reconstructions over the last glacial cycle of a model simulation for combined dust radiative and iron fertilization forcing.

You have correctly stated that we are in a Coldhouse phase (only the third in the past 550 million years) and with that we get glacial - interglacial cycles and rapid climate changes (over years and decades).

• • Because the planet Earth wobbles on its long axis over a 23,000 year cycle, its inhabitants must endure glacial and glacial melt cycles.

Because all 2013 Intergovernmental Panel on Climate Change scenarios — except Representative Concentration Pathway 2.6 (RCP2.6), which leads to the total radiative forcing of greenhouse gases of 2.6 W m − 2 in 2100 — imply that cumulative carbon emission will exceed 1,000 Gt in the twenty - first century, our results suggest that anthropogenic interference will make the initiation of the next ice age impossible over a time period comparable to the duration of previous glacial cycles.»

The northern polar ice - cap has oscillated in size over the last 2 million years (the glacial - interglacial cycles of the Pleistocene Epoch).

Such as another fascinating paper by Don J. Easterbrook, Professor Emeritus in the Deptment of Geology at Western Washington University: «Solar Influence on Recurring Global, Decadal, Climate Cycles Recorded by Glacial Fluctuations, Ice Cores, Sea Surface Temperatures, and Historic Measurements Over the Past Millennium» — Hat tip to Anthony Watt's Watts Up with That.

Actually, by the time you approach 200ppmv for CO2, you have already reached the break point in the curve, beyond which additional CO2 has much less impact on the RF — and this is close to the glacial value — suggesting that CO2 changes do not drive the glacial cycles (CO2 changes are supposed to amplify T rise during deglaciation, but there is scant evidence for this and the assumption that it did also underlay the IPCC belief — and a great many references in academic papers give a T degrees C per ppmv CO2 without stating over which range of concentrations this is meant to apply.