Sentences with phrase «for ice sheet response»

The millennial (500-2000 year) time scale of deep ocean ventilation affects the time scale for natural CO2 change and thus the time scale for paleo global climate, ice sheet, and sea level changes, but this paleo millennial time scale should not be misinterpreted as the time scale for ice sheet response to a rapid large human - made climate forcing.

What about the longer timeframe for ice sheet response and CO2 ouitgassing from the oceans etc?

What about the longer timeframe for ice sheet response and CO2 ouitgassing from the oceans etc?

Not exact matches

For this subsystem, many of the longer term feedbacks in the full climate system (such as ice sheets, vegetation response, the carbon cycle) and some of the shorter term bio-geophysical feedbacks (methane, dust and other aerosols) are explicitly excluded.

This sea level rise estimate is larger than that provided by the last IPCC report, but highlights the need for further research on ice sheet variablity and ice sheet response to climate change, both now and in the past.

An additional new feature is the increasingly visible fast dynamic response of ice shelves, for example, the dramatic breakup of the Larsen B Ice Shelf in 2002, and the acceleration of tributary glaciers and ice streams, with possible consequences for the adjacent part of the ice sheeice shelves, for example, the dramatic breakup of the Larsen B Ice Shelf in 2002, and the acceleration of tributary glaciers and ice streams, with possible consequences for the adjacent part of the ice sheeIce Shelf in 2002, and the acceleration of tributary glaciers and ice streams, with possible consequences for the adjacent part of the ice sheeice streams, with possible consequences for the adjacent part of the ice sheeice sheets.

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 potential for unstable ice sheet disintegration is controversial, with opinion varying from likely stability of even the (marine) West Antarctic ice sheet [94] to likely rapid non-linear response extending up to multi-meter sea level rise [97]--[98].

[Response: Here's a simple back - of - envelope consideration for the future: if the Greenland ice sheet melts completely over the next ~ 1,000 years (Jim Hansen argues in the current Climatic Change that the time scale could be centuries), this would contribute an average flux of ~ 0.1 Sv of freshwater to the surrounding ocean.

«This uncertainty is illustrated by Pollard et al. (2015), who found that addition of hydro - fracturing and cliff failure into their ice sheet model increased simulated sea level rise from 2 m to 17 m, in response to only 2 °C ocean warming and accelerated the time for substantial change from several centuries to several decades.»

For this subsystem, many of the longer term feedbacks in the full climate system (such as ice sheets, vegetation response, the carbon cycle) and some of the shorter term bio-geophysical feedbacks (methane, dust and other aerosols) are explicitly excluded.

Of course I can not prove that my choice of a ten - year doubling time for nonlinear response is accurate, but I am confident that it provides a far better estimate than a linear response for the ice sheet component of sea level rise under BAU forcing.

They offered a conclusion that the «coupling between surface melting and ice - sheet flow provides a mechanism for rapid, large - scale, dynamic responses of ice sheets to climate warming».

For weather predictions, accuracy disappears within a few weeks — but for ocean forecasts, accuracy seems to have decadal scale accuracy — and when you go to climate forcing effects, the timescale moves toward centuries, with the big uncertainties being ice sheet dynamics, changes in ocean circulation and the biosphere responFor weather predictions, accuracy disappears within a few weeks — but for ocean forecasts, accuracy seems to have decadal scale accuracy — and when you go to climate forcing effects, the timescale moves toward centuries, with the big uncertainties being ice sheet dynamics, changes in ocean circulation and the biosphere responfor ocean forecasts, accuracy seems to have decadal scale accuracy — and when you go to climate forcing effects, the timescale moves toward centuries, with the big uncertainties being ice sheet dynamics, changes in ocean circulation and the biosphere response.

Ian Joughin made some statements recently [context] that I thought were pretty solid about it being a few centuries before this kind of very rapid sea level rise can take place and that makes sense to me because there are some very important things that you have to do in order to turn on the rapid response of the Antarctic ice sheet — you have to get rid of a couple of big ice shelves for starters.

Another is lack of theory AND long - term data for other things that matter, like ice - sheet response to warming.

Pachauri outlined the potential for major changes to the climate system, which could overwhelm human response strategies - breakdown of the thermohaline circulation, disintegration of the West Antarctic Ice Sheet, a shift in mean climate towards an El Nino - like state, reduced carbon sink capacity, methane release from hydrates, and a rearrangement of biome distributions.

''... the world today is on the verge of a level of global warming for which the equilibrium surface air temperature response on the ice sheets will exceed the global mean temperature increase by much more than a factor of two.»

The most - optimal values for changes in bedrock elevation (GIA) in response to ice sheet mass changes have to be used

To quote «Proof is obtained by considering the contrary: ice sheet forcing approximately 3W / m ^ 2 and a 5 kyr timing gap between forcing and response, as appears to be the case at Termination IV (figure 2c), is 15,000 W yr / m ^ 2, enough to warm the upper kilometre of the ocean by approximately 160 C» (pdf page 7) This is his justification for modifying the data - not my «characterization» of what he said.

No of course it doesn't, But if the past tells us that ice sheets can break up quickly and sea levels rise quickly (for example) than this may give us insight into likely future system response.

Finally, it's slightly off - topic, because we are discussing Charney type sensitivities for climate responses that are discernible over the course of perhaps a few centuries at most, but Jim Hansen has argued that when longer term responses are included (e.g., disappearance of land - based ice sheets), a reasonable modal value is 6 C per doubling, and an upper limit is considerably higher.

The growth and decay of continental ice sheets represents a slow feedback operating over millennia; if one is concerned with the more rapid response of the climate to CO2, ice sheets have to be accounted for as a major forcing.

The potential for unstable ice sheet disintegration is controversial, with opinion varying from likely stability of even the (marine) West Antarctic ice sheet [94] to likely rapid non-linear response extending up to multi-meter sea level rise [97]--[98].

Rather, it both offers a tool for exploring the sea level implications of polar ice sheets» complex physical responses to global warming and highlights the deep uncertainty that characterizes sea level change in a high - emissions future.

Our atmosphere - ocean model shows that the freshwater spurs amplifying feedbacks that would accelerate ice shelf and ice sheet mass loss, thus providing support for our assumption of a nonlinear ice sheet response.

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].

A major consideration is the potential for a slowdown or stop of the AMOC in response to freshwater from the melting of the Greenland Ice Sheet, which lowers the density of the surface waters and puts the brakes on the thermohaline component of the AMOC.

Second, the abstract admits that, «Pleistocene climate oscillations yield a fast - feedback climate sensitivity of 3 ± 1 °C for a 4 W m − 2 CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective» and also «Ice sheet response time is poorly defined».

We also have to account for the very slow response of the ice sheets and the biosphere to higher temperatures, and this Earth System Sensitivity (ESS) can take quite a bit longer than getting to ECS — maybe up to centuries or longer.

A lowering of atmospheric carbon dioxide levels near the beginning of this time period occurred in response to the rise of land plants and likely cooled Earth, but the rapid growth of extensive Gondwanan ice sheets was delayed for tens of millions of years, until the Late Mississippian.»

For example, Overpeck et al. (2006), and Hansen (2007) suggest possibilities which could eventually lead to a nonlinear response from ice sheets — accelerating the current observed sea level rise.

The largest unknown for future sea level rise is caused by uncertainty in the predicted response of the Antarctic ice sheet to global warming.

The uncertainties lie in the precise figure for CS (which we will probably never know) and the impacts (ie ice sheet response, sea level rise, impact on flooding etc).

This millennial carbon cycle time scale should not be misinterpreted as the ice sheet time scale for response to a rapid human - made climate forcing.

Examples: Weertman (1976a)(Northwestern Univ., IL, and the U.S. Army Cold Regions Research and Engineering Laboratory, Hanover, NH); note also his pioneering calculation of ice sheet buildup and shrinkage times, Weertman (1964); Sergin (1979)(Laboratory for Mathematical Modeling of the Climate, Pacific Institute of Geography of Academy of Sciences, Vladivostok, but written while visiting NCAR, Boulder, CO); Budd and Smith (1981)(Meteorology Dept., U. Melbourne); as a perhaps more typical example, Young (1979)(Antarctic Division, Dept. of Science and Technology, Kingston, Tasmania) conservatively showed a response time of perhaps 20,000 years; an especially influential model involving ice sheet buildup delay was Imbrie and Imbrie (1980); a good review is Budd (1981).

For the ice sheets the answer is probably no (but experts on the subject might have a better idea), but for the overturning circulation or the ecosystem changes, the answer is probably yes — i.e. a slower rate of warming could lead to a different response (allowing time for ocean mixing to mitigate the effects, or adaptation of species to the new conditionFor the ice sheets the answer is probably no (but experts on the subject might have a better idea), but for the overturning circulation or the ecosystem changes, the answer is probably yes — i.e. a slower rate of warming could lead to a different response (allowing time for ocean mixing to mitigate the effects, or adaptation of species to the new conditionfor the overturning circulation or the ecosystem changes, the answer is probably yes — i.e. a slower rate of warming could lead to a different response (allowing time for ocean mixing to mitigate the effects, or adaptation of species to the new conditionfor ocean mixing to mitigate the effects, or adaptation of species to the new conditions).

However, recent observations of the rate and severity of physical and ecological responses to escalating radiative forcing — melting glaciers and ice sheets resulting in sea level rise and major changes in weather patterns, prolonged droughts, more frequent hurricanes and storms, and so on — are surprising even top climate experts, and raising awareness that, as a nation, we are dangerously unprepared for the inevitable consequences.

The Last Interglacial was also a period with higher global sea - level and a corresponding reduction in ice sheet area and volume, which are consistent with IPCC predictions for responses to future global warming.