I think the other point is that summer sea ice extent is important because of its
effect on albedo.
The most significant projected
impact on albedo is through future global warming.
In other words, don't let the perception or possibility of «moral hazard» stop you from doing the research
on albedo modification in the first place.
I've thought that clouds are the more significant factor due to their
effect on albedo.
There is just the effect of CO2 on radiative absorption, the effect of land use
changes on albedo, and perhaps waste heat itself if you value completeness.
«Because access to the Arctic is so difficult, there is not much reliable
data on albedo there,» explains Sebastian Gerland, who headed the AMORA project and is a research scientist at the Norwegian Polar Institute.
Referring to a 2004 paper examining the impact of
soot on albedo, Goddard fabricates a conclusion by Hansen: «In 2004, Dr Hansen... explained that most of Arctic warming and melting is due to dirty snow from soot, not CO2.»
First, the NAS released two distinct reports — one on CDR and the
other on Albedo Modification — with language explicitly stating that these two categories of «climate interventions» should not be analyzed together.
The impact of grain
size on albedo — the ratio between reflected and incoming solar radiation — is strong in the infrared range, where humans can't see, but satellite instruments can detect the change.
«As other nations have launched research
programs on albedo modification, the Committee recommends the Department review the findings of the NAS report... and leverage existing computational and modeling capabilities to explore potential impacts of albedo modification,» says a report that accompanies the Senate budget bill.
The study released yesterday in Nature Climate Change breaks new ground by putting definitive
numbers on the albedo effect, using satellite data.
The relationship between the effective radiation temperature and the strength of incoming radiation determines whether Earth is warming or not (the albedo must also be taken into account and the influence of the
temperature on the albedo is one of the problems in determining how strong the warming ultimately is).
The
report on albedo modification draws from Long and Scott's (2013) work on vested interests in geoengineering research, identifying «the four Fs», or factors that should be considered in research design and execution.
The retreat exposes soil, rock, and ocean surfaces, which absorb light and heat, causing further melting.10, 11 (See Jakobshavn Isbræ and Helheim glacier hotspots for more
information on albedo.)
A different
take on albedo is at the core of the CPOM (a.k.a. University of Reading) model.
But if we are ever driven into the desperate circumstances of needing to
rely on albedo hacking, surely it would be better to have some form of CDR deployable first, so as to provide an exit strategy that avoids the dangers of a millennial commitment.
They base this claim on Earthshine data (a measurement of the glow of the dark side of the moon that they use to deduce the earth's reflectance) and
on an albedo proxy derived from ISCCP parameters after they are regressed with two years of overlapping, but not global, earthshine observations.
Trees (and shrubs) also reduce the impact of snow
on albedo by standing taller than the snow cover.
The Berkeley Lab study found that global land surface temperature decreased by a modest amount — an average of roughly 0.01 degrees Celsius, based
on an albedo increase of.003 averaged over all global land surfaces.
Allen also led his own
project on the albedo of snow and ice on the icefield, engaging students to measure the brightness and reflectance of different snow and ice surfaces.
«The unmanned SRB buoy we built made it possible for the first time to generate continuous
data on albedo and other properties of sea ice over a long period,» says Dr Gerland.
I understand that their
affect on albedo is unfortunate, and their affects on transpiration / evaporation / cloud cover are ambiguous, but aren't these outweighed by their sequestration benefits, especially at low - latitude or even low - ish latitued (e.g., Israel)?
Since NASA's Fact Sheets provide no blackbody prediction for Titan, I extrapolated one myself,
based on its albedo and solar irradiance at Saturn's distance.
However, although this can have an effect
on the albedo (as can dust from the Sahara), most mountain glaciers are extremely «dirty» already and are only really bright when there is fresh snow fall.
During that process, upward LW radiation reaching the upper atmosphere will increase (depending
on albedo / solar heating feedbacks), which will change the equilibrium temperature of the upper atmopshere again.
All the other changes like
those on albedo are indirect.