Renaud
I can believe that some, even most, tropospheric aerosols are associated
with heart, lung and respiratory diseases. But the sub-micron salt we
would use for marine cloud brightening is beneficial especially for lung
problems. Asthmatic children in Poland get breathing exercises down
salt mines. Perhaps it is unfortunate that so little of it will reach
land from mid-ocean spray regions.
Stephen
Emeritus Professor of Engineering Design. School of Engineering.
University of Edinburgh. Mayfield Road. Edinburgh EH9 3JL. Scotland
[email protected] Tel +44 (0)131 650 5704 Cell 07795 203 195
WWW.see.ed.ac.uk/~shs YouTube Jamie Taylor Power for Change
On 02/08/2014 00:52, Michael Hayes wrote:
Renaud et.al.,
I'm 100% behind any effort to stop */any /*particulates from being
released. However, the current levels of BC/S seems to be keeping the
atmospheric moisture levels (i.e. global tempurature) artificially low
(up to 10% per S. Solomon <http://eaps-www.mit.edu/people/solos>)
through the BC/S wetting process. At this time, I can not find the
study in which she described this phenomena, yet I'm sure I can
eventually find it if you need.
Has the proposed particulate cleaning/trans-boundary injection method
considered the overall climate temperature implications of reducing
the BC/S wetting (i.e. moisture reduction/global temperature) factor?
Best regards,
Michael
On Friday, August 1, 2014 5:53:56 AM UTC-7, Renaud de_Richter wrote:
Currently, anthropogenic tropospheric aerosols present both Dr
Jekyll and Mr Hyde faces.
On the one hand, tropospheric aerosols play an important role on
climate, with a net cooling radiative forcing effect.
On the other hand, tropospheric aerosols affect terrestrial
ecosystems and human health and are associated with increased
heart, lung and respiratory diseases, which lead to disablement
and numerous premature human deaths (Shindell et al, 2012).
Consequently, reducing anthropogenic tropospheric aerosols
emissions, on the one hand will lead to a positive forcing
(warming) at local and regional scale, and on the other hand will
save numerous lives and significantly reduce health costs.
*What is proposed is to investigate means whereby the cooling
effect of current emissions is kept unchanged and their
deleterious effects are reduced,*using onlymodifications of
existing industrial aerosols emitters. Key advantages of such
investigations are that they avoid most of the roadblocks
associated with SRM.
So, what is proposed is a Win-Win research program that will at
the same time allow indirect geoengineering research, and reduce
tropospheric pollution.
/(Important remark: it is not proposed to perform CCS, or CDR).///
This is so, because the current anthropogenic tropospheric
sulphate aerosol emissions are estimated to be _almost two orders
of magnitude larger_ than requested by Stratospheric Particle
Injection geoengineering schemes to offset the effects of a
2 X CO_2 (carbon dioxide concentration doubling in the atmosphere).
Thus the strategy to reduce current sulphate _tropos_pheric
emissions and at the same time to keep their current cooling
effects will be like performing indirect climate engineering
without the need to artificially inject sulphates in the
_strato_sphere.
Now, the radiative forcing due to sulphate aerosols is estimated
to be ???0.4 W/m^2 with a range of ???0.2 to ???0.8 W/m^2 .
On a global average basis, the sum of direct and indirect
radiative forcing at the top of atmosphere by anthropogenic
aerosols is estimated to be ???1.2 W/m^2 [???2.4 to ???0.6 W/m^2 ]
(*cooling*) over the period of 1750 - 2000. This is significant
when compared to the positive (*warming*) forcing of +2.63 [??0.26]
W/m^2 by anthropogenic long-lived greenhouse gases over the same
period [Forster et al., 2007].
In heavily polluted regions, aerosol cooling overwhelms greenhouse
warming [Ramanathan et al., 2001; Li et al., 2010].
The tropospheric aerosol lifetimes are approximately 1 to 2 weeks,
which is quite shorter. Therefore, these current human made
aerosols have an uneven distribution, both horizontally and
vertically, and are more concentrated near their source regions
over continents and in the boundary layer.
*Emission reductions of aerosols in the troposphere will lead to a
positive forcing (warming), unless the sulphates lifetimes are
increased and their horizontal and vertical distribution are
improved. **Whilst the particulates are removed, some part of the
sulphates can be lofted higher to where they can act as a
solar-reflective shield to cool larger regions.***
To do so, what is proposed is to model the effects of a
theoretical fivefold aerosols emission reduction (80% removal of
sulphates, NOx, and > 95% removal of soot, black carbon, ash???) by
adding filters or electrostatic precipitators to the flue stack of
a majority of fossil fuel fired power plants, for adequate
particulate filtering and scrubbing, and *at the same time
increasing the height release of sulphates for a reduced number of
other power plant stacks in order to allow these (20% SOx)
emissions to over pass the boundary layer and stay longer in the
atmosphere*.
This can be__performed by the use of taller chimneys allowing the
flue gases to pass the boundary layer, so that the impact of a
regional emission reduction is not confined to the region itself,
by allows intercontinental transport (long-range transport) of
these sulphates _produced by existing anthropogenic aerosols_.
Several other possibilities exist to increase the height release
and dilution of gas emissions from flue stacks.
**
This strategy was proposed in page 818-819 of an _open access
article_
http://www.sciencedirect.com/science/article/pii/S1364032113008460
<http://www.sciencedirect.com/science/article/pii/S1364032113008460>
Fighting global warming by climate engineering.
//
/Two figures are attached to summarize this research proposal/
/
/
Public perception of SRM climate engineering is often presented as
Ulysses choices between the perils of Scylla and Charybdis,
despite the very good cooling potential to mitigate global
warming, and the high effectiveness and accessibility of
geoengineering schemes consisting of the stratospheric injection
of sulphate aerosols.
The Win-Win strategy proposed here may change this perception at
the same time as helping to advance CE research...
Renaud de_Richter, PhD
http://www.solar-tower.org.uk/
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