Sentences with phrase «increased albedo from»

Is it known to what extent GISS models still rely upon the original Hansen 1998 estimates for increased albedo from LU changes?

The increased albedo from melting arctic ice should not matter very much, but the newly exposed cold surface water might absorb extra carbon dioxide, acting as a negative feedback on the whole system.

Therefore, the effect of warming in the arctic is cooling at the lower latitudes, from increased albedo from clouds and snow, and transportation of colder air from the arctic.

Today because there is less energy coming from the sun through reduced incident solar energy and increased albedo from greater cloud formation the Earth is cooling and the OLR will change accordingly.

Even ice ages with their vastly increased albedo from extra snow and ice cover are eventually overcome and if ice ages don't reach a perrmanent tipping point then nothing humans can do will ever do so.

What is presumably meant is that if you increase the albedo from, say, 0.30 to 0.31, then this would produce about the same magnitude forcing (opposite in sign) as doubling CO2.

As for recent albedo trends, earthshine data shows increasing albedo from 1999 to 2003 but little to no trend from 2003.

Not exact matches

Critics argue that albedo modification and other «geoengineering» schemes are risky and would discourage nations from trying to reduce their emissions of carbon dioxide, the heat - trapping gas that comes from the burning of fossil fuels and that is causing global warming by absorbing increasing amounts of energy from sunlight.

The researchers found that, in most cases, the extra energy embodied in the cool material was far greater than the energy savings from increasing the albedo.

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.

They tend to believe that as the planet warms, low - level cloud cover will increase, thus increasing planetary albedo (overall reflectiveness of the Earth), offsetting the increased greenhouse effect and preventing a dangerous level of global warming from occurring.

The reduction of surface reflection due to biological activity, derived from our results, was used as a proxy for a reduction in albedo in the regional climate model Modèle Atmosphérique Régional (MAR; Fettweis et al., 2013) to project future microbially - mediated increases in GrIS melt (see Methodology, Supplementary Information).

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).

So it currently includes a [positive] contribution from the ice - albedo feedback, because our current climate possesses sea - ice that will be melted by a modest increase in temperatures.

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).

For starters, one simply can not equate the positive feedback effect of melting ice (both reduced albedo and increased water vapor) from that of leaving maximum ice to that of minimum ice where the climate is now (and is during every interglacial period).

Ice sheet albedo forcing is estimated to have caused a global mean forcing of about — 3.2 W m — 2 (based on a range of several LGM simulations) and radiative forcing from increased atmospheric aerosols (primarily dust and vegetation) is estimated to have been about — 1 W m — 2 each.

[1] CO2 absorbs IR, is the main GHG, human emissions are increasing its concentration in the atmosphere, raising temperatures globally; the second GHG, water vapor, exists in equilibrium with water / ice, would precipitate out if not for the CO2, so acts as a feedback; since the oceans cover so much of the planet, water is a large positive feedback; melting snow and ice as the atmosphere warms decreases albedo, another positive feedback, biased toward the poles, which gives larger polar warming than the global average; decreasing the temperature gradient from the equator to the poles is reducing the driving forces for the jetstream; the jetstream's meanders are increasing in amplitude and slowing, just like the lower Missippi River where its driving gradient decreases; the larger slower meanders increase the amplitude and duration of blocking highs, increasing drought and extreme temperatures — and 30,000 + Europeans and 5,000 plus Russians die, and the US corn crop, Russian wheat crop, and Aussie wildland fire protection fails — or extreme rainfall floods the US, France, Pakistan, Thailand (driving up prices for disk drives — hows that for unexpected adverse impacts from AGW?)

, smoke from burning, maybe other stuff I haven't thought of yet, and there might be enough temporary albedo increase to cause short term cooling.

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-?)

According to the skeptics, the solar irradiance isn't very important, it is the strength of the sun's magnetic field (that allows or stops cosmic rays from coming in which then causes more or less clouds, which increases or decreases the Earth's albedo, which then causes warming or cooling of the Earth's surface).

The fraction of the light that scatters back out to space is responsible for the increased albedo and the cooling effect from sulfate aerosols.

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.

You seem to hold to those arguments that all this heat increase in the total system since the late 1800s has come at least mostly from a never - ending increase of heat into the system via either a posited increased output from the sun or a posited decreased albedo.

Here's an interesting thought for the ice experts, maybe Andy could pick this up, since he's done a very decent job of following up on my question: I've read suggestions that increased sea emissivity from the Arctic waters would gain relative to the loss of albedo from increasingly ice - free seas.

The famous «255 K» value for no greenhouse effect on Earth is an example of this, although in reality if we got that cold you would expect a snowball - like Earth and a much higher albedo from the increased brightness of the surface... and thus the «no - greenhouse temperature» would be even colder than 255 K.

Global climate models have successfully predicted the rise in temperature as greenhouse gases increased, the cooling of the stratosphere as the troposphere warmed, polar amplification due the ice - albedo effect and other effects, greater increase in nighttime than in daytime temperatures, and the magnitude and duration of the cooling from the eruption of Mount Pinatubo.

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).

If CO2 in the Anthropocene atmosphere contributes to re-vegetating currently arid areas as it did post-LGM, we should expect an even greater warming feedback from CO2 than is assumed from water vapor and albedo feedbacks, due to decreased global dust - induced albedo and increased water vapor from transpiration over increased vegetated area.

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.

Since we receive about 245 watts / m ^ 2 at the surface after allowing for geometry and albedo, and a doubling of CO2 from pre-industrial levels increases the energy rate by approx. 4.5 w / m ^ 2, what's needed is to to reduce the energy received by the Sun by that amount or more.

Albedo from medium / low level clouds warms or cools the ocean surface by increasing or decreasing over time across the global surface.

Clouds are a negative feedback that follow from the increasing positive albedo feedback.

This is of particular concern to scientists because of the albedo effect, where the replacement of highly reflective sea ice with darker open water greatly increases heat absorbed from sunlight.

«Arctic Amplification» form CO2 was not primarily from the (theorectical) loss - of - ice / increase in albedo meme so often used, but ratehr it began from the relative amounts of GHG's in the warmer, more water - vapor laden equatorial climates to the very dry Arctic regions.

The water vapor, lapse - rate and ice - albedo feedbacks in isolation enhance the global warming that would result from increasing CO2 concentrations alone to around +2.2 °C.

Our observational studies (Gray and Schwartz, 2010 and 2011) of the variations of outward radiation (IR + albedo) energy flux to space (ISCCP data) vs. tropical and global precipitation increase (from NCEP reanalysis data) indicates that there is not a reduction of global net radiation (IR + Albedo) to space which is associated with increased global or tropical - regional raialbedo) energy flux to space (ISCCP data) vs. tropical and global precipitation increase (from NCEP reanalysis data) indicates that there is not a reduction of global net radiation (IR + Albedo) to space which is associated with increased global or tropical - regional raiAlbedo) to space which is associated with increased global or tropical - regional rainfall.

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.

I strongly believe that the increased summer melts of Arctic ice are in part a result of black carbon from Asia coal burning landing on the ice and reducing its albedo (and greatly accelerating melt rates).

Ice ages come on slowly as the albedo from greater and greated snow coverage increases causing greater and greater cooling, but end rapidly as the melt back rapidly decreases the albedo.

18.4wm - 2 higher assuming the same albedo means a radiative forcing of 3.23wm - 2, which is almost the forcing you get from doubling of CO2 or increasing solar output by 2 %.

Again, I do not see much to get excited about here, particularly when considering that the albedo increase from a 1 % increase in cloud cover would more than offset this decrease.

A substantial reduction in water vapor (shown below, from Lacis et al (2010) as well as increase in the surface albedo are important feedbacks here, showing that removing the non-condensing greenhouse gases (mostly CO2) in the atmosphere can collapse nearly the entire terrestrial greenhouse effect.

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.

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.

However, I am not a «warmista» by any means — we do not know how to properly quantify the albedo of aerosols, including clouds, with their consequent negative feedback effects in any of the climate sensitivity models as yet — and all models in the ensemble used by the «warmistas» are indicating the sensitivities (to atmospheric CO2 increase) are too high, by factors ranging from 2 to 4: which could indicate that climate sensitivity to a doubling of current CO2 concentrations will be of the order of 1 degree C or less outside the equatorial regions (none or very little in the equatorial regions)- i.e. an outcome which will likely be beneficial to all of us.

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.

«Kopacz et al. used a global chemical transport model to identify the location from which the BC arriving at a variety of locations in the Himalayas and the Tibetan Plateau originates, after which they calculated its direct and snow - albedo radiative forcings... they say that observations of black carbon (BC) content in snow «show a rapidly increasing trend,»... «emissions from northern India and central China contribute the majority of BC to the Himalayas,» and that «the Tibetan Plateau receives most BC from western and central China, as well as from India, Nepal, the Middle East, Pakistan and other countries.»»

AGW climate scientists seem to ignore that while the earth's surface may be warming, our atmosphere above 10,000 ft. above MSL is a refrigerator that can take water vapor scavenged from the vast oceans on earth (which are also a formidable heat sink), lift it to cold zones in the atmosphere by convective physical processes, chill it (removing vast amounts of heat from the atmosphere) or freeze it, (removing even more vast amounts of heat from the atmosphere) drop it on land and oceans as rain, sleet or snow, moisturizing and cooling the soil, cooling the oceans and building polar ice caps and even more importantly, increasing the albedo of the earth, with a critical negative feedback determining how much of the sun's energy is reflected back into space, changing the moment of inertia of the earth by removing water mass from equatorial latitudes and transporting this water vapor mass to the poles, reducing the earth's spin axis moment of inertia and speeding up its spin rate, etc..