Sentences with phrase «albedo changes from»

Water vapor again enters the atmosphere, ocean albedo changes from 90 % to 1 %, and the melt accelerates in one big hurry.

Many of the feedbacks are believed to be the same whether the cause of warming is greenhouse gases, solar or albedo changes from melting ice.

Internal variability doesn't imply an absence of radiative forcing but includes albedo changes from clouds, dust, snow and ice, vegetation and volcanoes.

So they say CO2 will rise at a certain rate, albedo changes from deliberate land - use changes including urban growth may or may not be specified, but given their assumptions, that is the projected change.

Isostatic rebound in response to glacier retreat (unloading), increase in local salinity (i.e., δ18Osw), have been attributed to increased volcanic activity at the onset of Bølling — Allerød, are associated with the interval of intense volcanic activity, hinting at a interaction between climate and volcanism - enhanced short - term melting of glaciers, possibly via albedo changes from particle fallout on glacier surfaces.

Albedo changes from about 0.5 in a snowball earth to 0.25 in a blue green planet with lots of forest.

This was a relatively stable climate (for several thousand years, 20,000 years ago), and a period where we have reasonable estimates of the radiative forcing (albedo changes from ice sheets and vegetation changes, greenhouse gas concentrations (derived from ice cores) and an increase in the atmospheric dust load) and temperature changes.

I've been told by a friend that James Hansen once said that albedo changes from melting the arctic sea ice would capture as much additional heat as doubling CO2.

As for irreversible, if an ice sheet starts flowing, or if an albedo change from sea ice gets locked in, I could imagine a climate change being essentially irreversible even if CO2 was brought back down, but it's just speculation, nothing more.

And then you have to accept that the climate models do a very poor job of predicting CO2 - AGW because the equation introduced by Lacis and Hansen in 1974 to predict cloud albedo change from pollution is useless even though Sagan derived it.

Really the big question for me, once aware of all in http://s24.postimg.org/rbbws9o85/overview.gif and much else, is whether or not coming cooling in the 21st century will end with a somewhat brief LIA - like event, or, via amplification of cooling through further albedo change from snow cover rise then, continue far longer into a non-little Ice Age afterwards..

It's albedo change from increased autumnal snow cover at high northern latitudes.

Not exact matches

Their analysis reveals that the conversion of broadleaved forests to coniferous forests caused significant changes in evapotranspiration, the evaporation of water through leaves, and albedo, the amount of solar energy reflected from the Earth back into space.

The study used satellite data to compare summertime changes in Greenland's albedo from 1981 to 2012.

Also about the ice - albedo feedback within 1K temperature oscillation the albedo will change of, let us say, 10 %, so for an increase of 1K the albedo will decrease from A = 0.3 to A = 0.27.

For one thing, the fit neglects lags in the system (such as those resulting from ocean heat uptake) and it also neglects changes in albedo and other radiative factors.

Lynn, the increase of temperatures in the Arctic, is mainly the result of an inflow of warmer air from lower latitudes (with the current AO) and the change in albedo (mainly in summer).

That's pretty alarming, especially when considered in the context of other positive feedbacks including changes in albedo from melting icecaps and release of carbon and methane from thawing permafrost.

He then uses what information is available to quantify (in Watts per square meter) what radiative terms drive that temperature change (for the LGM this is primarily increased surface albedo from more ice / snow cover, and also changes in greenhouse gases... the former is treated as a forcing, not a feedback; also, the orbital variations which technically drive the process are rather small in the global mean).

Forcing from orbital changes, albedo changes and greenhouse gas changes are discussed per Hansen et al..

I was interested not so much in the forcing effect of clouds themselves so much as the change in albedo which might result from a change in the overall extent of global cloud cover.

eg how big is the «expected» impact on the climate / temps etc from that kind of change / feedback in ASI albedo

Other factors would include: — albedo shifts (both from ice > water, and from increased biological activity, and from edge melt revealing more land, and from more old dust coming to the surface...); — direct effect of CO2 on ice (the former weakens the latter); — increasing, and increasingly warm, rain fall on ice; — «stuck» weather systems bringing more and more warm tropical air ever further toward the poles; — melting of sea ice shelf increasing mobility of glaciers; — sea water getting under parts of the ice sheets where the base is below sea level; — melt water lubricating the ice sheet base; — changes in ocean currents -LRB-?)

All it demonstrates is that there is more than one causal factor, as is well known, with aerosols (from fossil fuels and volcanoes), land - use changes (through affecting CH$ and CO2 levels and albedo) and solar irradiance all playing a role.

From the point of view of climate modelling the all - gone moment isn't as important as the magnitude of the change in albedo — particularly in the spring, summer and autumn.

, (3) changes in surface albedo of snow & ice due to changes in temperature and deposition of mineral and black carbon particulates, and last, but arguably most significantly (4) the intensity of the positive feedback that comes from the inevitable -LRB-?)

It's the same series of an initial forcing (change in insolation due to Milankovitch orbital cycles) being amplified by reinforcing feedbacks (change in albedo, change in temperature and partial pressure regulating both CO2 and H2O), but in reverse from an exit from a glacial period.

http://www.springerlink.com/content/lm0024kv72t3841w/ «The simulated magnitude of hydrological changes over land are much larger when compared to changes over oceans in the recent marine cloud albedo enhancement study since the radiative forcing over land needed (− 8.2 W m − 2) to counter global mean radiative forcing from a doubling of CO2 (3.3 W m − 2) is approximately twice the forcing needed over the oceans (− 4.2 W m − 2).

The cooling (that results from the change in albedo) necessarily reduces the amount of H2O in the atmosphere, which is a positive feedback that further cools the planet.

The changes in total insolation resulting from spreading ice (and the accompanying change in albedo) by themselves are no where near enough to drop temperatures by the amount needed.

[Response: The albedo change, going from last glacial maximum to present (pre-industrial time) was about 3.5 + / -1 W / m ^ 2, whereas CO2 change (including other greenhouse gases) was about 2.6 + / - 0.5), and aerosols about 0.5 + / -1.

Re 9 wili — I know of a paper suggesting, as I recall, that enhanced «backradiation» (downward radiation reaching the surface emitted by the air / clouds) contributed more to Arctic amplification specifically in the cold part of the year (just to be clear, backradiation should generally increase with any warming (aside from greenhouse feedbacks) and more so with a warming due to an increase in the greenhouse effect (including feedbacks like water vapor and, if positive, clouds, though regional changes in water vapor and clouds can go against the global trend); otherwise it was always my understanding that the albedo feedback was key (while sea ice decreases so far have been more a summer phenomenon (when it would be warmer to begin with), the heat capacity of the sea prevents much temperature response, but there is a greater build up of heat from the albedo feedback, and this is released in the cold part of the year when ice forms later or would have formed or would have been thicker; the seasonal effect of reduced winter snow cover decreasing at those latitudes which still recieve sunlight in the winter would not be so delayed).

The rise of CO2 from 270ppm to now over 400ppm, the extent of equatorial and sub tropical deforestation, the soot deposits on the polar ice caps, the increase in atmospheric water vapour due to a corresponding increase in ocean temps and changes in ocean currents, the extreme ice albedo currently happening in the arctic etc, etc are all conspiring in tandem to alter the climate as we know it.

Note that part of the uncertainy in all this is the time uncertainty — from the ice core records, we can pick a rather precise time and look at a rather precise number for greenhouse gas concentrations, but pinning down the magnitude albedo change at exactly the same time (since albedo is not globally uniform, obviously) is impossible.

I also believe that soot and all the other aerosols that combine and rain out has contributed to significant albedo changes and is food for localized warming from biochemical activity in the boreal north that has significantly contributed to the melting of land and sea ice.

Since aerosols, clouds, and the ground surface have very different polarization spectral signatures, it is possible to sort out the aerosol radiative properties from changes in surface albedo and cloud contamination.

Ok Monty: glacial interglacial transitions result from earth orbit changes combined with ice albedo feedbacks.

Forcing from surface albedo changes due to land use change is expected to be negative globally (Sections 2.5.3, 7.3.3 and 9.3.3.3) although tropical deforestation could increase evaporation and warm the climate (Section 2.5.5), counteracting cooling from albedo change.

Earth system and carbon - cycle feedbacks such as the release of carbon from thawing permafrost or vegetation changes affecting terrestrial carbon storage or albedo may further extend and possibly amplify warming (6).

From the figures I took an average value of 0.45 — but, hey, if you prefer to assume 0.35, that's OK, because it will not change the conclusion that the observed Arctic sea ice melt has not appreciably changed our planet's total albedo, and that a very small change in cloud cover would have a far greater effect.

The albedo change resulting from the snowline retreat on land is similarly large as the retreat of sea ice, so the combined impact could be well over 2 W / sq m. To put this in context, albedo changes in the Arctic alone could more than double the net radiative forcing resulting from the emissions caused by all people of the world, estimated by the IPCC to be 1.6 W / sq m in 2007 and 2.29 W / sq m in 2013.»

Based on evidence from Earth's history, we suggest here that the relevant form of climate sensitivity in the Anthropocene (e.g. from which to base future greenhouse gas (GHG) stabilization targets) is the Earth system sensitivity including fast feedbacks from changes in water vapour, natural aerosols, clouds and sea ice, slower surface albedo feedbacks from changes in continental ice sheets and vegetation, and climate — GHG feedbacks from changes in natural (land and ocean) carbon sinks.

From last glacial max the the albedo change was some 25W / m2.

E.g., human - caused albedo variations from desertification, and to some extent tropical deforestation, were connected with past global climate changes by Sagan et al. (1979); a pioneering model confirming «the long - held idea that the surface vegetation... is an important factor in the Earth's climate» was Shukla and Mintz (1982); Amazon Basin: Salati and Vose (1984); more recently, see Kutzbach et al. (1996).

From the last glacial max — CO2 forcing had about a 2W / m2 increase and ice sheet albedo change amounted to some 25W / m2 less reflected SW..

For example, I show in «The Tropical Thunderstorm Hypothesis» that the change from clear to cumulus conditions increases the albedo by about 60 w / m2, a large effect.

My interpretation from the news article is that he concludes that low clouds can exhibit a lower albedo than sometimes modeled, but then an important question is how low cloud cover is changing over recent decades of warming.

One of the main feedbacks is from changes in the Earth's albedo.

It's an approximation, but we should just have a new spherical system with an albedo a bit different from the first one, and it seems to me implausible that a few CO2 ppm added could change the albedo of this entire new system.

This explanation is plausible when the external forcing is something other than CO2, for instance an increase in SWR from the sun or a change in Earth's albedo.