Sentences with phrase «year glacial climate»

In Possible solar origin of the 1,470 - year glacial climate cycle demonstrated in a coupled model, Holger Braun, Marcus Christl, Stefan Rahmstorf, Andrey Ganopolski, Augusto Mangini, Claudia Kubatzki, Kurt Roth & Bernd Kromer postulated that the combination of the 210 year DeVries — Suess and the 87 year Gleissberg cycle could tip nonlinear fresh water influxes and subsequent changes in Thermohaline Circulation triggering Dansgaard - Oeschger events.

Not exact matches

For millions of years global climate change has altered the structure and internal movement of mountain ranges, but the resulting glacial development and erosion can in turn change a mountain's local climate.

The sediment cores used in this study cover a period when the planet went through many climate cycles driven by variations in Earth's orbit, from extreme glacial periods such as the Last Glacial Maximum about 20,000 years ago, when massive ice sheets covered the northern parts of Europe and North America, to relatively warm interglacial periods with climates more like tglacial periods such as the Last Glacial Maximum about 20,000 years ago, when massive ice sheets covered the northern parts of Europe and North America, to relatively warm interglacial periods with climates more like tGlacial Maximum about 20,000 years ago, when massive ice sheets covered the northern parts of Europe and North America, to relatively warm interglacial periods with climates more like today's.

According to climate records stretching back a century, southern Greenland has warmed three degrees Celsius in just the past 20 years, driving melting that may help lubricate glacial flow along the bedrock, the two speculate.

«We see processes that operate in the climate system that either don't operate in glacial times we've seen in the last 2 million years, or they operate very differently,» she said, citing the behavior of ice sheets as an example.

The research team also assessed whether climate sensitivity was different in warmer times, like the Pliocene, than in colder times, like the glacial cycles of the last 800,000 years.

-- On the multi-million year time scale, passages through the spiral arms of the milky way correlate with climate on earth (e.g., this discussion), and on longer time scale, glacial activity correlates with star formation in the milky way.

There is a new paper on Science Express that examines the constraints on climate sensitivity from looking at the last glacial maximum (LGM), around 21,000 years ago (Schmittner et al, 2011)(SEA).

The archaeological record suggested that very roughly 150,000 individuals spanned Europe and Asia, living in small groups of 15 to 25 — and that their total numbers fluctuated greatly during the several climate cycles (which included harsh glacial periods) that occurred during the half a million years they inhabited Earth, before going extinct 40,000 years ago.

Samples of gas trapped in ice cores taken from the Greenland and Antarctic ice sheets have enabled scientists to determine that the level of CO2 in the atmosphere has fluctuated between approximately 180 ppm (glacial advance and colder climate in the higher latitudes) and 280 ppm (glacial retreat and warmer climate in the higher latitudes), over the past 400,000 or more years.

There is a new paper on Science Express that examines the constraints on climate sensitivity from looking at the last glacial maximum (LGM), around 21,000 years ago (Schmittner et al, 2011)(SEA).

Without our use of fossil fuels, we should be descending into another glacial maximum — albeit slowly, over tens of thousands of years (the pace of natural global climate change in the Pleistocene).

Walt, if you've ever studied Pleistocene geology and the million year history of glacial advances and interglacial warming cycles you would know human - induced global warming and climate changes are the dominant cause of current and future catastrophic consequences.

Aren't the neo-glacial readvances and other signs of a cooling climate during the past 3,000 years evidence of a gradual return to glacial conditions (prior to the anthropogenic influence brought on by the industrial revolution)?

There were two CLIMAP experiments to reconstruct past climates, one at the Last Glacial Maximum (LGM) 18,000 years ago when sea level was about 120 meters lower than today, and one at the Last Interglacial Maximum (LIM) 125,000 years ago when sea level was about 6 meters higher than today.

Only this past year I've come to understand we are at a climate high point, a sort of plateau, in the glacial - interglacial cycle.

Cochelin et al used a model of intermediate complexity to show that the orbital variations over the next 100,000 years are weak enough that even a little human CO2 remaining in the atmosphere is enough to keep the earth out of an ice age («Simulation of long - term future climate changes with the green McGill paleoclimate model: The next glacial inception»).

Alarmed at the pace of change to our Earth caused by human - induced climate change, including accelerating melting and loss of ice from Greenland, the Himalayas and Antarctica, acidification of the world's oceans due to rising CO2 concentrations, increasingly intense tropical cyclones, more damaging and intense drought and floods, including glacial lakes outburst loods, in many regions and higher levels of sea - level rise than estimated just a few years ago, risks changing the face of the planet and threatening coastal cities, low lying areas, mountainous regions and vulnerable countries the world over,

Should it be attained, this state would be more «symmetric» than the present climate, with comparable areas of ice / sea - ice cover in each hemisphere, and would represent the culmination of 50 million years of evolution from bipolar nonglacial climates to bipolar glacial climates.

A new research paper by Friedrich et al. looks at glacial - interglacial climate variability during the last 784,000 years to estimate Earth's climate variability.

The process involves years of analyzing tens of thousands of scientific journal articles on topics ranging from sea level rise and glacial melt to past climate shifts.

In the natural cycle regarding long term natural climate change caused by Milankovitch cycles, at least for the past million years or so, the sensitivity response to changes is indicated to alter the global temperature by 6º Celsius between warm periods and glacial periods.

Rather, the ice core record shows clearly that changes in temperature precede changes in carbon dioxide throughout the glacial - interglacial cycle (Mudelsee, 2001), and that for the last half million years the climate system has oscillated in a self - limiting way between glacials and interglacials by about 6 deg.

Arctic climatic extremes include 25 °C hyperthermal periods during the Paleocene - Eocene (56 — 46 million years ago, Ma), Quaternary glacial periods when thick ice shelves and sea ice cover rendered the Arctic Ocean nearly uninhabitable, seasonally sea - ice - free interglacials and abrupt climate reversals.

About 14,500 years ago, the Earth's climate began to shift from a cold glacial world to a warmer interglacial state.

For my part, I have studied the oceanographic and biological consequences of abrupt climate warming in the very recent glacial and interglacial climates of the Late Pleistocene (from 20,000 years ago to the present).

Both panels are reconstructions of oxygen concentrations in the California Margin during a cold, glacial climate (left, 18,000 years ago) and a warm, interglacial climate (right, 14,000 years ago; Moffitt et al. 2015a).

So it can be said with fair confidence that the climate 4 - 5 thousand years ago was much warmer than it is now and had been warmer for long enough for trees to become established in what are now glacial valleys.

Dr. Soon: Earth's climate system dynamically oscillates between icehouse and hothouse conditions in geological time or, to a lesser degree, between the glacial and interglacial climates of the last 1 — 2 million years.

The vulnerable nations declared that they are, «Alarmed at the pace of change to our Earth caused by human - induced climate change, including accelerating melting and loss of ice from Greenland, the Himalayas and Antarctica, acidification of the world's oceans due to rising CO2 concentrations, increasingly intense tropical cyclones, more damaging and intense drought and floods, including Glacial Lakes Outburst Floods, in many regions and higher levels of sea - level rise than estimated just a few years ago, risks changing the face of the planet and threatening coastal cities, low lying areas, mountainous regions and vulnerable countries the world over...»

Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization.

In addition to running climate models, the researchers compared modern warming to similar temperature increases that happened approximately 120,000 years ago in a period known as the Eemian, when global sea level was 5 to 9 meters (between 16 and 30 feet) higher than it is today due to the release of glacial water.

Few people have read paleo - climatology text books, are aware of the glacial / interglacial cycle, are aware that the paleoclimatic record has unequivocal evidence of cyclic gradual changes and cyclic abrupt climate events, are aware that the abrupt climate change events such as the abrupt termination of the last 22 interglacial periods lacks an explanation, are aware that all of the past interglacial periods are short (roughly 12,000 years) and that they have ended abruptly, and so on.

However, he is also very interested in climate science, and developed an alternative theory to the Milankovitch theory for explaining the glacial - interglacial transitions between «ice ages» and non-ice ages every 100,000 years or so.

This case appears to be based on recent research taking two different approaches: looking at recent climate changes, and changes during the Last Glacial Maximum (LGM) about 20,000 years ago.

If, just over a year ago, had you proposed a film to Brian Cox, which took issue with the claims that climate change would massively reduce crop yields in Africa, or that the hundreds of millions of people living beneath the Himalayas face chronic water shortages as a result of glacial recession, you would, in his view, be a «maverick».

The climate history of the past few million years is characterized by repeated transitions between «cold» (glacial) and «warm» (interglacial) climates.

AMOC ¬ is implicated in the most fundamental and wide ranging changes of global climate — the plunge into and climb out of glacials over the past 2.58 million years.

Loss of glacial volume in Alaska and neighboring British Columbia, Canada, currently contributes 20 % to 30 % as much surplus freshwater to the oceans as does the Greenland Ice Sheet — about 40 to 70 gigatons per year, 66,78,63,57,64,58 comparable to 10 % of the annual discharge of the Mississippi River.79 Glaciers continue to respond to climate warming for years to decades after warming ceases, so ice loss is expected to continue, even if air temperatures were to remain at current levels.

For the past 2.5 m years climate has been usually unstable with a sucession of glacials and interglacials, that are otherwise uncommon in geological history.

However, sea - level fluctuations in response to changing climate have been reconstructed for the past 22,000 years from fossil data, a period that covers the transition from the Last Glacial Maximum to the warm Holocene interglacial period.

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

To better understand these discrepancies, a recent study published in Geophysical Research Letters investigates the drivers of changes in deep ocean circulation across a range of modern and Last Glacial Maximum (LGM, ~ 21000 years ago) climate simulations from the latest Paleoclimate Modelling Intercomparison Project (PMIP).

A climate cycle, glacial + interglacial period, is what, 100 - 150K years long.

Since the onset of the Northern Hemisphere glaciation (~ 2.7 million years ago), Earth's climate has undergone large transitions between cold «glacial» and warm «interglacial» (e.g., present - day) stages.

Quoting from a paper that was accepted: «Many palaeoclimate records from the North Atlantic region show a pattern of rapid climate oscillations, the so - called Dansgaard — Oeschger events, with a quasi-periodicity of ∼ 1,470 years for the late glacial period» http://www.nature.com/articles/nature04121

Knowing that abrupt and frequent climate changes attend the end extreme interglacials, and accepting your premise that CO2 can either cause warming by whatever process you propose, or ameliorate the drop to the glacial state, applying the Precautionary Principle absolutely requires that we avoid any possibility of climate back - sliding over the next, at least, 4,000 years:

The climate history of the past few million years is characterised by repeated transitions between «cold» (glacial) and «warm» (interglacial) climates.

Using climate records culled from tree rings, glacial - ice layers and coral - growth layers, the three professors — whose research was funded in part by the federal government — determined in 1998 that temperatures have skyrocketed in the past century compared with the 500 years preceding it.

Tags: earth system sensitivity, glacial, ice age, interglacial, Paleoclimate, Snyder, temperature reconstruction, two million years Posted in Climate science, English, Scenarios 4 Comments»