Sentences with phrase «over ice age cycles»

That is not small, it is huge, and at a rate that is unprecedented (being over a period of 150 years not the 10s of thousands of years over the ice age cycles).

Furthermore, because the regression is being defined over ice age cycles where the biggest changes are related to the (now disappeared) North American and Fenno - Scandanavian ice sheets, the regression might well be much less for situations where only Greenland and West Antarctica are «in play».

See Gavin Schimidt, «Why correlations of CO2 and temperature over ice age cycles don't define climate sensitivity,» RealClimate.org, Sept. 24, 2016, online here.

Second, the relationship we are seeing in the ice cores is made up of two independent factors: the sensitivity of the CO2 to temperature over the ice age cycle — roughly ~ 100 ppmv / 4ºC or ~ 25 ppmv / ºC — and the sensitivity of the climate to CO2, which we'd like to know.

Not exact matches

Over hundreds of thousands of years, the Neandertal lineage developed successfully in western Eurasia and survived severe fluctuations between colder and warmer climactic cycles of the Ice Age.

Curiously, the decline in atmospheric oxygen over the past 800,000 years was not accompanied by any significant increase in the average amount of carbon dioxide in the atmosphere, though carbon dioxide concentrations do vary over individual ice age cycles.

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.

Re 92 and 105: First I just want to reitterate more generally what 105 said — Milankovitch cycles have had climate signals, in ice ages or otherwise, — well probably ever since the Moon formed, although the signal from times past will not always reach us, but I've read of evidence of Milankovitch precession cycle forcing of monsoons in lakes in Pangea (PS over geologic time the periods of some of the Milankovitch cycles have changed as the Moon recedes from the Earth due to tides).

Moreover, random interactions within the sun's magnetic field can flip the fluctuations from one cycle length to the other, matching the paleo - temperature record for ice ages on Earth for over the past 5.3 million years, when ice ages occurred occurred roughly every 41,000 years until about a million years ago when they switched to a roughly 100,000 - year cycle.

He's talking about the supposed ~ 60 year natural cycle over a benign recovery from the little ice age, as slightly influenced by mankind's emissions.

This gradual removal of CO2 from the atmosphere reduces the overall greenhouse effect and thus slowly draws the entire planet into an ice age, driving further ice sheet expansion over tens of thousands of years (a complete ice age cycle is around 100,000 years)

[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).

However, our fortune would last much longer than that: the Milankovitch cycles can be calculated over millions of years with astronomical precision (and incidentally be used to predict the beginning of all the past ice ages), and according to that, the next major climate change would arrive only in about 50,000 years.

A new analysis of the dramatic cycles of ice ages and warm intervals over the past million years, published in Nature, concludes that the climatic swings are the gyrations of a system poised to settle into a quasi-permanent colder state — with expanded ice sheets at both poles.

The combined effects of oceans and vegetation are known from ice cores: dCO2 / dT is about 8 ppmv / °C, pretty constant over 4 ice age — interglacial cycles in 420,000 years and surprisingly linear, despite that a number of players in this game are acting far from linear.

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.

Within this far more recent part of our planet's history the current disturbance of the radiative balance is unique at least over the last 20,000 years, stretching the entire Holocene up to the point where the Milankovitch cycles thought it fit to end the last ice age.

He also wants them to go over the history of climate change research, focusing on ice ages and previous cooling and warming cycles, among other topics.

In the 1970s, scientists showed that that Milankovitch cycles have driven repeated warming and cooling of the planet, and thus the waxing and waning of ice ages over the last few million years.

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

The concentration of CO2 varied between about 200 and 280 ppmv over the last several ice age cycles, and caused approximately 2 Wm 2 variations in surface longwave radiation forcing [e.g., Ramaswamy et al., 2001].

Due to the way in which these various cycles have been relative constant over the last 35 million years, the earth has settled into a relatively recent cycle of approximately 100,000 year long declining climates and ice ages, and brief 12,000 - 18,000 year long warm spells we call inter-glacial periods like our current Holocene.

While the earth does not exit an Ice Age every 41k years according to the obliquity cycle when it achieves it's maximum angle of > 24 degrees, over the 10 recorded Ice Age events, EVERY TIME WITHOUT FAIL as obliquity drops below 23.5 % an Ice Age STARTS.

There is also the geological record to take into account which documents the lockstep relationship between atmospheric CO2 and global temperature over multiple ice age / interglacial cycles.

Ice Age cycles once invoked, over ride the smaller influences of level 2 and 3.

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.»

Combined with carbon cycle feedbacks, it caused glaciers several kilometres thick to spread over most of North America and Eurasia during the last ice age.