Sentences with phrase «so albedo changes»

So albedo change (owing to changes in orbital forcing, which is what melts the ice sheets) was comparable to, and probably larger than, the CO2 change.

The Arctic Ocean losing its ice is almost certainly involved in the initiation of northern thermohaline demise, so albedo change will compensate.

Not exact matches

They found that in regions where the amount of snowfall was low and any snow that did settle was sublimating away, enough dust would have accumulated to change the surface albedo sufficiently so that the Earth absorbed sunlight and thawed (Journal of Geophysical Research — Atmospheres, DOI: 10.1029 / 2009jd012007, in press).

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.

I guess I am surprised that with better understanding of the importance of water vapor feedback, sulfate aerosols, black carbon aerosols, more rapid than expected declines in sea ice and attendant decreases in albedo, effects of the deposition of soot and dust on snow and ice decreasing albedo, and a recognition of the importance of GHGs that were probably not considered 30 years ago, that the sensitivity has changed so little over time.

Slow insolation changes initiated the climate oscillations, but the mechanisms that caused the climate changes to be so large were two powerful amplifying feedbacks: the planet's surface albedo (its reflectivity, literally its whiteness) and atmospheric CO2 amount.

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.

I guess I am surprised that with better understanding of the importance of water vapor feedback, sulfate aerosols, black carbon aerosols, more rapid than expected declines in sea ice and attendant decreases in albedo, effects of the deposition of soot and dust on snow and ice decreasing albedo, and a recognition of the importance of GHGs that were probably not considered 30 years ago, that the sensitivity has changed so little over time.

In our own modelling, we have improved the calculations to reduce the amount of numerical diffusion (which helped a lot), and increased resolution (which also helped), but changes to the ocean model also have a big impact, as do Arctic cloud processes and surface albedo parameterisations, so it gets complicated fast.

In LGM simulations land albedo changes are prescribed (at least in regards to ice sheets and altered topography due to sea level; there are feedback land albedo changes) so are a forcing, whereas sea ice is determined interactively by the model climate, so is a feedback in this framework.

In fact, if the physics - based understanding of «equilibrium sensitivity» to any forcing is too low, then not only will CO2 have a greater effect, so too will all other forcings, such as: changes in the sun, in cloud cover, in albedo, etc..

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).

In their latest Science paper submittal Jim Hansen, et al. argue that we must reduce atmospheric CO2 to below 350 ppm because so - called «slow feedbacks» such as changes in ice sheet albedo are occurring much faster than expected.

But the climate is changing so rapidly that we already face volatile scenarios like the possibility of escalating international conflicts over potentially dangerous albedo hacking experiments.

Taken into account with increase in the amount of insolation by reducing particulates, albedo changes, and so on, a couple of K or so might be reasonable.

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.»

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.

By so doing, we are ignoring other low frequency forcings (such as long wavelength changes in TSI and albedo) which would have to be included to make any sense of the data.

So far our best theory concerning changes in the «radiative rate» is that it depends upon the amount of solar energy reaching earth, that is a function of solar activity and changes in albedo.

Urban heat island - The relative warmth of a city compared with surrounding rural areas, associated with changes in runoff, the concrete jungle effects on heat retention, changes in surface albedo, changes in pollution and aerosols, and so on.

Finally, while economics may be critical to your definition of «catastrophic» anthropogenic global warming, economics says nothing about the science underlying the projections of sea level rise, the physics of Arctic amplification, changes to albedo that lead to greater warming that may lead to significant releases of methane clathrate deposits, regional projections of reduce (or enhanced) precipitation, and so on.

So now there only remains for you to factor in the time lagged responses of isostatic adjustments, albedo feedback, ice melt and ocean heat accumulation to rapid forcing changes.

This is the limit imposed by albedo which can only change so much with the current arrangement of the continents.

Slow insolation changes initiated the climate oscillations, but the mechanisms that caused the climate changes to be so large were two powerful amplifying feedbacks: the planet's surface albedo (its reflectivity, literally its whiteness) and atmospheric CO2 amount.

Pielke seniors thing is that land use changes leadto albedo changes which lead to more heat absorbed, so actually the warming isn't much to do with CO2 and so there isn't much of a problem.

IPCC AR4 WG1 tells us that the all anthropogenic forcing components except CO2 (aerosols, other GHGs, land use changes, other changes in surface albedo, etc.) have essentially cancelled one another out, so we can use the estimated radiative forcing for CO2 (1.66 W / m ^ 2) to equate with total net anthropogenic forcing (1.6 W / m ^ 2).

Supposedly a doubling of CO2 is supposed to produce 3.71 watts / m ^ 2 (5.35 ln (2) = 3.71) and changing the albedo from 30 % to 29 % increases the incoming solar radiatyion by 3.42 watts / m ^ 2 so this could be and is most likely the cause of observed warming.

As it happens, the lake is freezing later by 8.3 days per century, and thawing earlier by 8.5 days per century, so the change in albedo for Autumn is nearly that for Spring.

The only thing that I would contend could be added would be long slow cumulative changes in solar output other than raw TSI namely changes in the mix of particles and wavelengths over longer periods of time such as MWP to LIA to date and which seem to have some effect on surface pressure distribution and global albedo so as to alter solar shortwave into the oceans and thus affecting the energy available to the ENSO process.

All that is needed is to add heat carried upwards past the denser atmosphere (and most CO2) by convection and the latent heat from water changing state (the majority of heat transport to the tropopause), the albedo effects of clouds, the inability of long wave «downwelling» (the blue balls) to warm water that makes up 2 / 3rds of the Earth's surface, and that due to huge differences in enthalpy dry air takes far less energy to warm than humid air so temperature is not a measure of atmospheric heat content.

Motivated by findings that major components of so - called cloud «feedbacks» are best understood as rapid responses to CO2 forcing (Gregory and Webb in J Clim 21:58 — 71, 2008), the top of atmosphere (TOA) radiative effects from forcing, and the subsequent responses to global surface temperature changes from all «atmospheric feedbacks» (water vapour, lapse rate, surface albedo, «surface temperature» and cloud) are examined in detail in a General Circulation Model.

Being an ocean, the Arctic ice is a much less stable system because it is subject to positive feedback from the albedo change, while the Antarctic albedo can stay quite fixed, so it is not going to have this positive feedback.

So a long term trend in horizontal heat transport can't change weather patterns or weather patterns don't affect albedo or albedo doesn't affect the energy budget?

Once the Arctic goes, the albedo change affects the whole earth, so everyone warms up.

Apologies if this has already been stated, but my view on decreased Arctic ice cover is: - 1, as Judith pointed out, when ice is at a minimum the sun is already so low in the sky that there is no noticeable change to albedo, 2 when there is ice cover warm water is kept at depth by differences in salinity, When there is open water, storms mix the haline layers bringing warm water to the surface where it can more readily radiate it's energy into outer space.

A 1 % change in albedo can lead to a degree in surface temperature, so if they assign an albedo to forests of 0.16 instead of 0.17, or some other seemingly minor choices, this would affect their overall temperature.

That's a pretty silly claim on Dr. Curry's part if you consider that in the months the arctic sea ice isn't diminished, there's never really so much sunlight as you'd count it against the average, so whatever albedo changes there are during the half of the year that matters, they're when the sun is at its highest angle.

«when ice is at a minimum the sun is already so low in the sky that there is no noticeable change to albedo» The problem is that it is not only the minimum that is trending down.

I think (without knowing so) that the other impacts of deforestation — like carbon cycle, water cycle and albedo changes — tend to make direct effects on winds virtually insignificant.

So how can we possibly start talking about anthropogenic forcings and surface temperature changes wrought by same when we don't even know to + -5 C what the average temperature of the earth should be due to our albedo measurements being so imprecise and having no bloody idea how, when, and why the earth's average albedo varieSo how can we possibly start talking about anthropogenic forcings and surface temperature changes wrought by same when we don't even know to + -5 C what the average temperature of the earth should be due to our albedo measurements being so imprecise and having no bloody idea how, when, and why the earth's average albedo varieso imprecise and having no bloody idea how, when, and why the earth's average albedo varies.

A mechanist will argue that albedo driven climate changes cause greenhouse gases to rise thus amplifying temperature, while arguing that greenhouse gases themselves can not do so.

This tells us that over this period all other anthropogenic forcing components (aerosols, other GHGs, land use changes, surface albedo changes, etc.) essentially cancelled one another out, so we can ignore your statement «we suspect that aerosols caused cooling», as this is already compensated for by other anthropogenic warming beside CO2.

The proposed explanation (see article: Evidence mounts that Maya did themselves in through deforestation) based on a slight change in albedo after deforestation and a corresponding decrease in solar energy available for convection does not make sense to us (although as we understand this work has not yet been published so we could not read it in detail).