Sentences with phrase «abrupt climate changes»

Why couldn't it have been caused by interactions of one or more the very large number of factors that cause the abrupt climate changes that happen periodically and also irregularly?

ABSTRACT: Greenland ice - core records provide an exceptionally clear picture of many aspects of abrupt climate changes, and particularly of those associated with the Younger Dryas event, as reviewed here.

Abrupt climate changes are those that exceed our expectations, preparedness, and ability to adapt.

The AMOC has a considerable influence over European climate from the northward heat transport by the Gulf Stream and a slowdown or halt of the AMOC could have a large impact on climate and even induce abrupt climate changes (Alley et al, 2002; Alley, 2007).

«The abrupt climate changes did not take place at the extreme low sea levels, corresponding to the time of maximum glaciations 20,000 years ago, or at high sea levels such as those prevailing today.

The view was supported by data gathered independently at the University of Wisconsin - Madison, where Reid Bryson was already interested in abrupt climate changes.

A variety of other evidence for very abrupt climate changes was accumulating, and some began to entertain the notion of such change on a global scale.

Now the climate scientists, other than the Team of course, can pursuit identifying the precursors of and eventually be able to predicts future abrupt climate changes.

Societies have faced both gradual and abrupt climate changes for millennia and have learned to adapt through various mechanisms, such as moving indoors, developing irrigation for crops, and migrating away from inhospitable regions.

Did the abrupt climate changes give our ancestors some opportunities that great apes didn't get?

The evolution of anatomical adaptations in the hominids could not have kept pace with these abrupt climate changes, which would have occurred within the lifetime of single individuals.

Abrupt climate changes can be seen working through the El Niño Southern Oscillation, the Pacific Decadal Oscillation, the North Atlantic Oscillation, the Southern Annular Mode, the Artic Oscillation, the Indian Ocean Dipole and other measures of ocean and atmospheric states.

Richard B. Alley, «Ice - core evidence of abrupt climate changes,» Proceedings of the National Academy of Sciences 97 (4): 1331 - 1334 (15 February 2000) at http://www.pnas.org/cgi/content/full/97/4/1331.

«Our study supports the view that changes in ocean circulation were at least in part responsible for causing abrupt climate changes.

Axel Timmermann, a professor of oceanography at the University of Hawaii who studies abrupt climate changes and was not involved in this study, called it a «breakthrough analysis.»

Gradual, insolation - driven millennial - scale temperature trends in the study area were punctuated by several abrupt climate changes, including a major transient event recorded in all five lakes between 4.3 and 3.2 ka, which overlaps in timing with abrupt climate changes previously documented around the North Atlantic region and farther afield at w4.2 ka.

The new study explores what happened to ocean circulation when the Earth went through a series of abrupt climate changes in the past, during a time when ice covered part of North America and temperatures were colder than today.

Those abrupt climate changes wreaked havoc on ecosystems, but their cause has been something of a mystery.

The scientists stress that more work is needed to determine whether changes in ocean circulation initiated the abrupt climate changes or were an intermediary effect initially triggered by something else.

This indicates that CO2 variability is not a detectable factor in abrupt climate changes.

More recent work is identifying abrupt climate changes working through the El Niño Southern Oscillation, the Pacific Decadal Oscillation, the North Atlantic Oscillation, the Southern Annular Mode, the Arctic Oscillation, the Indian Ocean Dipole and other measures of ocean and atmospheric states.

An international team of scientists, including Peter Schultz of Brown University, suggests that a comet or meteorite exploded over the planet roughly 12,900 years ago, causing the abrupt climate changes that led to the extinction of the wooly mammoth and other giant prehistoric beasts.

Recent work is identifying abrupt climate changes working through the El Niño Southern Oscillation, the Pacific Decadal Oscillation, the North Atlantic Oscillation, the Southern Annular Mode, the Artic Oscillation, the Indian Ocean Dipole and other measures of ocean and atmospheric states.

Abrupt climate changes have repeatedly affected the planet, including local changes of as much as a 10 °C in a decade and changes in hydrology by a factor of two.

The new ride is non-linear, chaotic Atmospheric / Ocean abrupt climate changes.

Strong evidence from ocean sediment data and from modelling links abrupt climate changes during the last glacial period and glacial - interglacial transition to changes in the Atlantic Ocean circulation.

As noted above, if the planet resists forcing changes (negative feedback) rather than amplifies forcing changes (positive feedback), then the explanation (only physical possible explanation) for cyclic abrupt climate changes is there is a very, very, powerful forcing mechanism.

It will also lower the risk of pushing our planet past a «threshold» that could lead to dramatic, abrupt climate changes with potentially catastrophic impacts for human societies and natural systems.

Enormous amounts of freshwater were released into the North Atlantic following deglaciation, and an influx of freshwater into the North Atlantic Deep Water formation zone can potentially trigger abrupt climate changes.

Can it be argued given the paleoclimate evidence for abrupt climate changes that there is likely no strong negative feedback over any meaningful time scale?

I also think that paleoclimate scientists tend to see more possibility of abrupt climate changes than climate modellers do.

You do seem not quite up to date with current thinking on abrupt climate changes (now I'm referring to your polemic question «Were all of these triggered by Lake Agassiz dam bursts?»

Many paleoclimate archives document climate changes that happened at rates considerably exceeding the average rate of change for longer - term averaging periods prior and after this change... A variety of mechanisms have been suggested to explain the emergence of such abrupt climate changes (see Section 12.5.5).

The bi-polar seesaw is usually associated with the higher - frequency abrupt climate changes (e.g., Dansgaard - Oeschger and Heinrich events) that are embedded within the longer, orbital timescale variations.

We propose that past abrupt climate changes were probably a result of rapid and extensive variations in sea - ice cover.

Alley, R.B., et al., 2002: Abrupt Climate Changes: Inevitable Surprises.

Such are the questions tackled here during a trip to hominid settings in Europe and Africa, followed by an over-the-pole flight that looks down on the probable origins of the abrupt climate changes: great whirlpools in the North Atlantic Ocean near Greenland.

The reason for this was growing evidence of abrupt climate changes in the history of the Earth due to instability of Atlantic currents.

You do seem not quite up to date with current thinking on abrupt climate changes (now I'm referring to your polemic question «Were all of these triggered by Lake Agassiz dam bursts?»

Climate scientists are interested in learning more about abrupt climate changes because they indicate that the climate system may have «tipping points.»

What happened in the years 1976/77 and 1998/99 in the Pacific was so unusual that scientists spoke of abrupt climate changes.

Abrupt climate changes may have predisposed big ice age mammals to extinction, argues new study

But within these long periods there have been abrupt climate changes, sometimes happening in the space of just a few decades, with variations of up to 10ºC in the average temperature in the polar regions caused by changes in the Atlantic ocean circulation.

That includes the potential for abrupt climate change and the factors amplifying warming in the Arctic, which is warming twice as fast as the global average.

But, says Axel Timmermann, a professor of oceanography at the University of Hawaii at Manoa, «None of these snapshots were able to capture abrupt climate change and transition,» thereby making them less useful for predicting coming sudden shifts.

The new study presents the most convincing evidence so far that abrupt climate change was instrumental in this development.

But theories about the cause of this abrupt climate change are numerous.

When comparing the history of hydrological changes in the region with artifacts from the Middle Stone Age, the researchers discovered a «striking correspondence between the archaeological record of South Africa and the timing of the abrupt climate change» as seen in the marine core, the study states.

Starting from the same kernel of scientific truth as did The Day After Tomorrow — that global warming could disrupt ocean currents in the North Atlantic — a study commissioned by the Pentagon, of all organizations, concluded that the «risk of abrupt climate change... should be elevated beyond a scientific debate to a U.S. national security concern.»

The last IPCC report also included a table debunking many worries about «tipping points» to abrupt climate change.