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.»
Not exact matches
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.
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.
black
soot has also been found by a recent university of california study to be the direct cause of the
albedo warming effect
on the otherwise highly reflective and pristine white arctic ice & snow.
«
Soot snow / ice
albedo climate forcing is not included in Intergovernmental Panel
on Climate Change evaluations.
«Our estimate for the mean
soot effect
on spectrally integrated
albedos in the Arctic (1.5 %) and Northern Hemisphere land areas (3 %) yields a Northern Hemisphere forcing of 0.3 W m2 or an effective hemispheric forcing of 0.6 W m2.»
In Hansen Nazarenko 2004, Hansen wrote that «Our estimate for the mean
soot effect
on spectrally integrated
albedos in the Arctic... is about one quarter of observed global warming.»
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.
Judith - Apart from the general anthro vs. natural disussion of sea ice, I'm always wondering: has anyone seriously considered / studied the possible anthropogenic contribution from NON-CO2 sources (black carbon
soot / aerosol deposits
on the ice surface, increasing the
albedo, melting the ice faster in the sun)?
Ibid., pp. 393 — 96; Yun Qian et al., «Effects of
Soot - Induced Snow
Albedo Change
on Snowpack and Hydrological Cycle in Western United States Based
on Weather Research and Forecasting Chemistry and Regional Climate Simulations,» Journal of Geophysical Research, vol.
Black
soot on multiyear ice is a player in
albedo space because, unlike water, it's
albedo remains low regardless of sun low
on the horizon or not.
Algae responsible for large
albedo feedback
on Greenland's frozen surface, not only
soot and dust.
Twohy et al. (1989) concluded from measurements off the coast of California and from simple radiative calculations that the observed levels of
soot would not lead to a significant impact
on the cloud
albedo.
Read more: Stanford University Aerosols Also Implicated in Glacier Melting, Changing Weather Patterns Other research examining the effects of
soot on melting glaciers and changing weather pattens in South Asia has reached similar conclusions: Beyond increasing atmospheric warming, because the
soot coats the surface of the snow and ice it changes the
albedo of the surface, allowing it to absorb more sunlight and thereby accelerating melting.
I recall one post
on how Earth came out of a snowball, which explanation may be a possibility but then again there may be other explanations (eg., oceanic volcanos splitting in the ice and thereby releasing some water vapour,
soot deposits changing
albedo, even meteor collision — who knows given the lack of evidence).
Paper: Reference: Yun Qian, William I. Gustafson Jr., L. Ruby Leung, Steven J. Ghan, Effects of
soot - induced snow
albedo change
on snowpack and hydrological cycle in western U.S. based
on WRF chemistry and regional climate simulations, Journal of Geophysical Research - Atmospheres, 2009, doi: 10.1029 / 2008JD011039