Sentences with phrase «change of ice sheet»

Our assumption that global temperature passed the Holocene mean a few decades ago is consistent with the rapid change of ice sheet mass balance in the past few decades [75].

That estimate was based in part on the fact that sea level is now rising 3.2 mm / yr (3.2 m / millennium)[57], an order of magnitude faster than the rate during the prior several thousand years, with rapid change of ice sheet mass balance over the past few decades [23] and Greenland and Antarctica now losing mass at accelerating rates [23]--[24].

Slow feedbacks, such as change of ice sheet area and climate - driven changes of greenhouse gases, are not included.

That estimate was based in part on the fact that sea level is now rising 3.2 mm / yr (3.2 m / millennium)[57], an order of magnitude faster than the rate during the prior several thousand years, with rapid change of ice sheet mass balance over the past few decades [23] and Greenland and Antarctica now losing mass at accelerating rates [23]--[24].

«This is probably the best method to look at mass changes of ice sheets if you want to get a number that you can trust,» Rignot says.

Model studies for climate change between the Holocene and the Pliocene, when Earth was about 3 °C warmer, find that slow feedbacks due to changes of ice sheets and vegetation cover amplified the fast feedback climate response by 30 — 50 % [216].

The results are very conservative because they exclude the possibility of rapid changes of the ice sheets as the numerical models do not yet know how to deal with those.

In addition there are slow climate feedbacks, such as changes of ice sheet size, that occur mainly over centuries and millennia.

Model studies for climate change between the Holocene and the Pliocene, when Earth was about 3 °C warmer, find that slow feedbacks due to changes of ice sheets and vegetation cover amplified the fast feedback climate response by 30 — 50 % [216].

Not exact matches

«If you're trying to detect change in something, you need long and continuous uninterrupted records of things like the sea ice or sea level rise or Greenland's ice sheet,» Shepherd said.

Throughout most of the current geological era North America was a sheet of ice, but the global climate changed; mostly due to solar activity.

Things I changed: - cut the sugar by about half, using mostly dark brown sugar for the molasses kick - scratched the nutmeg and allspice but added about 1/3 extra of all of the other spices and also added nearly a tsp of ground cardamon - replaced the veggie oil with melted leaf lard - scratched the raisins - baked it on a deep sheet for only ~ 20 minutes - just barely until firm to the touch - then cut that sheet into three layers - replaced the icing with my own 16 ounce cream cheese, 8 ounce butter, ~ 6 ounce heavy cream, ~ 5 ounce honey, 1 tsp vanilla combo - toasted the coconut before dressing the cake.

But, rapid change in the behavior of parts of the Antarctic ice sheet might cause much greater rise than is often included in coastal planning.

This magma plume isn't an alternative possible cause of recent upticks in melting along the West Antarctic Ice Sheet attributed to human - generated climate change.

Understanding sea level change in relation to the mass balance of Greenland's and Antarctica's ice sheets is at the heart of the CReSIS mission.

Developing an understanding of how ice sheets are changing over time requires precise measurements of the thickness of the ice sheets and accurate mapping of the bedrock below.

Following the maxim of keeping everything as simple as possible, but not simpler, Will Steffen from the Australian National University and I drew up an Anthropocene equation by homing in on the rate of change of Earth's life support system: the atmosphere, oceans, forests and wetlands, waterways and ice sheets and fabulous diversity of life.

Stewart Jamieson from Durham University in England and his colleagues made the discovery by looking for subtle changes in the ice sheet's surface shapes, developed as a result of ice flowing over diverse topography.

This water pump can be put out of action or weakened by changes in the freshwater pressure, the ice sheet breaking up or shifting sea ice and this results in the increasing climatic variability.

Scientists may also become able to distinguish between different scenarios sooner by studying the physics of local ice - sheet changes and refining reconstructions of changes during warm periods in geological history.

The first of these pathways, marine ice sheet instability, has been studied for decades, but the second, marine ice cliff instability, has only recently been considered as an important contributor to future sea level change.

Studying surging glaciers could also offer insights into grander - scale ice flows with global consequences: the movements of the ice sheets in Antarctica and Greenland, which can change abruptly, altering the ice discharges that affect sea level.

Mote was one of 12 lead authors on a chapter of the fifth Intergovernmental Panel on Climate Change report looking at the cryosphere, which is comprised of snow, river and lake ice, sea ice, glaciers, ice sheets and frozen ground.

We may have already changed the ice sheets to a point that some parts of them may go, but we have the ability to stop changing it more and to adapt to what we have already done.

Estimated changes in the mass of Greenland's ice sheet suggest it is melting at a rate of about 239 cubic kilometres (57.3 cubic miles) per year.

The U.S. team is one of three international groups that sought to penetrate Antarctica's subglacial waters in the past month, seeking clues not only to glacial microbiology but also to ice sheet dynamics and the impact of climate change on the continent.

Antarctica's vulnerability to climate change has also become increasingly clear, said Robin Bell of Columbia University's Lamont - Doherty Earth Observatory, who studies how ice sheets change.

This effect is particularly apparent in parts of the West Antarctic Ice Sheet (WAIS), long regarded as the more vulnerable part of the continent to climate change.

«Time and again, the models are conservative, and they're underestimating the magnitude of change,» says Robert DeConto, an ice sheet modeler at the University of Massachusetts Amherst.

Using NASA and European Space Agency satellites, the 2015 study had measured the changing height of the ice sheet and determined that East Antarctica was ballooning upward by roughly 1.59 centimeters a year (at least from 1992 to 2001 and from 2003 to 2008).

The digitized data extend the record of changes at the bottom of the ice sheet, such as the formation of channels as Antarctica's ice flows, by more than two decades.

The Arctic took another 3,000 - 4,000 years to warm this much, primarily because of the fact that the Northern Hemisphere had huge ice sheets to buffer warming, and the fact that changes in ocean currents and Earth's orbital configuration accelerated warming in the south.

Today, as warming waters caused by climate change flow underneath the floating ice shelves in Pine Island Bay, the Antarctic Ice Sheet is once again at risk of losing mass from rapidly retreating glacieice shelves in Pine Island Bay, the Antarctic Ice Sheet is once again at risk of losing mass from rapidly retreating glacieIce Sheet is once again at risk of losing mass from rapidly retreating glaciers.

«It is a very good paper which provides valuable new insights about the physical processes controlling the change in reflectivity of the Greenland ice sheet and specifically its darkening over time,» said Eric Rignot, a senior research scientist at NASA's Jet Propulsion Laboratory who studies ice sheets but was not involved with the new study.

A new study says that climate - induced feedback loops could lead to a change in ocean stratification and the more rapid melting of ice sheets.

Co-author Professor Jonathan Bamber, based at the University of Bristol, and President of the European Geoscience Union (EGU), added: «We are seeing changes in the large - scale circulation patterns, which leads to more frequent sunshine and higher amounts of solar energy reaching the surface of the ice sheet.

The two studies improve our understand of Greenland's deep past, while raising questions about both the past and future of its giant ice sheet in a changing climate.

Ice - sheet growth, coupled with favorable changes in Earth's orbit, pushed the planet past a climatic tipping point and led to both the rapid buildup of a permanent ice sheet in the Antarctic and much larger changes in global climate, says HrIce - sheet growth, coupled with favorable changes in Earth's orbit, pushed the planet past a climatic tipping point and led to both the rapid buildup of a permanent ice sheet in the Antarctic and much larger changes in global climate, says Hrice sheet in the Antarctic and much larger changes in global climate, says Hren.

New research indicates that climate change has triggered an unstoppable decay of the West Antarctic Ice Sheet, eventually leading to at least three meters of global sea level rise

«We argue that it was the establishment of the modern deep ocean circulation — the ocean conveyor — about 2.7 million years ago, and not a major change in carbon dioxide concentration in the atmosphere that triggered an expansion of the ice sheets in the northern hemisphere,» says Stella Woodard, lead author and a post-doctoral researcher in the Department of Marine and Coastal Sciences.

A report in the last issue of Nature finds that between April 2002 and April 2006, the rate at which southern Greenland's ice liquefied jumped by 250 percent — supporting the idea that the Greenland ice sheet responds quickly to slight changes in climate.

Massive reorganizations of the ocean - atmosphere system, the authors argue, are the key events that link cyclic changes in the earth's orbit to the advance and retreat of ice sheets

While some may see evidence of rapid glacier thinning in the past and again today as evidence that the West Antarctic Ice Sheet is nearing a collapse driven by human - caused climate change, Steig said at this point, scientists just don't know whether that is the case.

To better understand and anticipate changes in sea level rise, scientists have sought to quantify how much snow falls on the ice sheet in any given year, and where, since snow is the primary source of the ice sheet's mass.

Although CryoSat - 2 is designed to measure changes in the ice sheet elevation, these can be translated into horizontal motion at the grounding line using knowledge of the glacier and sea floor geometry and the Archimedes principle of buoyancy — which relates the thickness of floating ice to the height of its surface.

«So you see something in this one 4,000 - square - kilometer basin off the northeast coast of Venezuela, but you see similar changes in the Arabian Sea and in the tropical Pacific, and you can link it all back to changes seen in an ice sheet in Greenland.

Some climate scientists, including James E. Hansen, former head of the nasa Goddard Institute for Space Studies, say we must also consider slower feedbacks such as changes in the continental ice sheets.

Subglacial lakes are likely to influence the flow of the ice sheet, impacting global sea level change.

The biggest changes were seen in West Antarctica, where more than a fifth of the ice sheet has retreated across the sea floor faster than the pace of deglaciation.

«Polar regions have been changing very rapidly, providing data for our projections on sea ice, snow cover, ice sheets and sea level rise,» says David Vaughan of the British Antarctic Survey in Cambridge, UK, the lead author of the cryosphere chapter.