Sentences with phrase «albedo feedbacks from»

Positive albedo feedbacks from melting ice and reducing cloud cover would be important to consider if this data is trustworthy.

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.

The time constants of albedo feedback from melting N America snow cover are shorter than the albedo feedback from melting Arctic sea ice, and the sea ice is changing response as its average thickness decreases, and the ratios of 1, 2, 3, 4, 5 year ice area changes.

Not exact matches

«As warming continues, the feedback from declining albedo will add up,» Tedesco said.

Another positive feedback of global warming is the albedo effect: less white summer ice means more dark open water, which absorbs more heat from the sun.

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.

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.

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).

Plotting GHG forcing (7) from ice core data (27) against temperature shows that global climate sensitivity including the slow surface albedo feedback is 1.5 °C per W / m2 or 6 °C for doubled CO2 (Fig. 2), twice as large as the Charney fast - feedback sensitivity.»

[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?)

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

«By comparing the response of clouds and water vapor to ENSO forcing in nature with that in AMIP simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor feedbacks has revealed two common biases in the models: (1) an underestimate of the strength of the negative cloud albedo feedback and (2) an overestimate of the positive feedback from the greenhouse effect of water vapor.

This positive climate feedback is greater than expected from the additional forcing alone, due to amplification by reduced surface albedo through melting of continental snow and decreased sea - ice coverage, especially in the wintertime.

, (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-?)

Analysis of observed declines in sea ice and snow coverage from 1979 to 2008 suggests that the NH albedo feedback is between 0.3 and 1.1 W m — 2 °C — 1 (Flanner et al., 2011).

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.

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.

A typo in mine at # 25 is where 40,000 m3 should read 400,000 m3, and an addendum is the reference for the forcing from the Albedo Loss feedback shown in the satellite record: «Observational determination of albedo decrease caused by vanishing Arctic sea ice» See: http://eisenman.ucsd.edu/publications/Pistone-Eisenman-Ramanathan-20Albedo Loss feedback shown in the satellite record: «Observational determination of albedo decrease caused by vanishing Arctic sea ice» See: http://eisenman.ucsd.edu/publications/Pistone-Eisenman-Ramanathan-20albedo decrease caused by vanishing Arctic sea ice» See: http://eisenman.ucsd.edu/publications/Pistone-Eisenman-Ramanathan-2014.pdf

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).

You can substitute «CO2 from the oceans», «lower albedo», or any of the other positive feedbacks for water vapor.

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.

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

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.

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

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).

Cloud variations are obviously an important element on a global scale, but the effects of Arctic ice melting are important locally and also a non-trivial fraction of global albedo feedbacks, which are a contributor to total feedback that is smaller than those from water vapor and probably from cloud feedbacks, but not insignificant.

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.

For example, the absence from AR5 of last January's Ramanathan paper indicating a large and very significant Albedo Loss feedback forcing can not be rectified until about 2019 under the current system of periodic IPCC reports advising the UNFCCC as to the climate predicament.

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.

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

The forcing is really a net albedo forcing from the varying ice extent, and the albedo has a positive feedback effect both on itself and with CO2 / H2O as the earth cools into an Ice Age.

So the level of ice albedo feedback was radically different from the modern period during the MWP?

Albedo is REFLECTIVITY, it is ONE aspect of several feedbacks which result from more open water.

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..

To date, while various effects and feedbacks constrain the certainty placed on recent and projected climate change (EG, albedo change, the response of water vapour, various future emissions scenarios etc), it is virtually certain that CO2 increases from human industry have reversed and will continue to reverse the downward trend in global temperatures that should be expected in the current phase of the Milankovitch cycle.

1 Positive 1.1 Carbon cycle feedbacks 1.1.1 Arctic methane release 1.1.1.1 Methane release from melting permafrost peat bogs 1.1.1.2 Methane release from hydrates 1.1.2 Abrupt increases in atmospheric methane 1.1.3 Decomposition 1.1.4 Peat decomposition 1.1.5 Rainforest drying 1.1.6 Forest fires 1.1.7 Desertification 1.1.8 CO2 in the oceans 1.1.9 Modelling results 1.1.9.1 Implications for climate policy 1.2 Cloud feedback 1.3 Gas release 1.4 Ice - albedo feedback 1.5 Water vapor feedback 2 Negative 2.1 Carbon cycle 2.1.1 Le Chatelier's principle 2.1.2 Chemical weathering 2.1.3 Net Primary Productivity 2.2 Lapse rate 2.3 Blackbody radiation

BUT, other important / related parameters — BRDF (bidirectional reflectance distribution function)-- albedo i. /: 00 solar local time Neural network based on CYCLOPES and MODIS / wrong ALSO Need to make assumptions about carbon lost via respiration to go from GPP to / Cox et al. (2000) Acceleration of global warming due to carbon - cycle feedbacks in a coupled / / JRC / FastOpt: http://www.fastopt.com/topics/publications.htmlhttp://www.fastopt.com/topics/publications.html 50 0 = water; 1 /

They also warn that feedback patterns are starting to emerge in the shape of the ice albedo effect: ice reflects heat away from the surface, so as it decreases in extent so warming quickens.

While we are probably some distance from inducing a Venus event (though there are some biogeochemists who think this is possible) the evidence is still that with the «let the market rule» approach, CO2 will continue to accumulate in the and eventually set off even worse positive feedback cycles than this years Arctic ice melt — methane and CO2 release from the tundra soils, destabilisation of methane hydrates, increased albedo in both the Arctic and Antarctic.

The net effect is a greater (reflecting) albedo, less sunlight reaching the surface, and therefore a negative feedback that reduces the original warming from increasing CO2.

A slight change of ocean temperature (after a delay caused by the high specific heat of water, the annual mixing of thermocline waters with deeper waters in storms) ensures that rising CO2 reduces infrared absorbing H2O vapour while slightly increasing cloud cover (thus Earth's albedo), as evidenced by the fact that the NOAA data from 1948 - 2008 shows a fall in global humidity (not the positive feedback rise presumed by NASA's models!)

``... underestimating the negative feedback from cloud albedo and overestimating the positive feedback from the greenhouse effect of water vapor over the tropical Pacific during ENSO is a prevalent problem of climate models.

(Note, however, that to the extent that positive cloud feedbacks on GHG - mediated forcing mediate a reduction in cloud cover, the amplification will substitute some SW effects for LW effects due to the reduced cloud greenhouse warming and increased warming from a lower albedo).

A CO2 pulse in the atmosphere will take centuries to finally return to original levels, and that is completely ignoring any potential feedbacks from other parts of the system (ie temperatures raised for centuries could result in massve methane releases and loss of signficant low albedo ice sheets etc.) The experiments I am aware of that show improved plant growth in elevated CO2 levels require that all additional biological needs are amply provided for.

Even that, however, is misleading for a substantial part of the «forcing» from seasonal drift in insolation is part of the ice albedo feedback.

In all of these simple models, we assume the atmosphere to have a volume as fixed as a bathtub, we assume that the atmosphere / ocean system is a closed system, we assume that the incoming radiation from the Sun is constant, we assume no turbulence, we assume no viscosity, we assume radiative equilibrium with no feedback lag, we take no account of water vapor flux assuming it to be constant, no change in albedo from changes in land use, glacier lengthening and shortening, no volcanic eruptions, no feedbacks from vegetation.

There are, however, also slow feedbacks like the change in surface albedo from the reduction of snow cover that contribute to TCS / ECS.

there is powerful negative feedback to temperature through ice albedo from snow.