due to excess CO 2 , it would not reduce ocean
acidification, and its cooling effects would be
regional due to the limited lifetime of CCN.
Surface Albedo Enhancement
Increasing the surface’s reflectivity toward solar
radiation is another method of albedo enhancement. One method is to use reflective materials to
cover roads and roofs. This has an immediate
local effect for the building or road and, with
widespread use, could cool a city and region.
There are several kinds of roofing technologies
conducive to this approach including membranes,
cool-surfaced modified asphalt systems, and
metal roofing panels [138]. The city of Los
Angeles found that streets painted with a white
sealant were 5–15
C cooler than similar asphalt
streets. Painting the roofs will not only reflect
50–70% solar radiation [138] but also reduce
energy consumption for air conditioning due to
the decreased cooling load after reflecting the
solar radiation.
Space Reflectors
Another way to reduce the absorption of solar
radiation at the surface would be to reflect parts
of incoming solar radiation before it enters Earth’s
atmosphere. This could be accomplished by placing reflectors in space, between the sun and Earth
[118]. In 1989 Walter Seifritz proposed [139]
placing mirrors in a Lagrange orbit [140]. The
Lagrangian point is the (moving) location where
the gravitational forces of the sun and Earth cancel
[140]. Placing mirrors in a Lagrange orbit is effective at deflecting sunlight for the entire planet, not
just for a certain region(s). Putting mirrors in a
Lagrange orbit is very costly. A cheaper option
would be to place reflectors in orbit around the
Earth [140]. However, mirrors in Earth orbit
reflect less solar radiation because the reflectors
might be in the Earth’s shadow part of the orbit.
Stratospheric Aerosol Injection
The third method or achieving solar radiation
management would be to inject sulfur into the
lower stratosphere. The stratosphere is known to
contain a layer of sulfuric acid aerosol, the
so-called Junge layer, with sulfur provided by
OCS from the troposphere and volcanic injection
[198]. Large volcanic eruptions such as the eruption of Mount Pinatubo in 1991 are known to cool
the global climate [141]. Paul Crutzen proposed
[199] that if elemental sulfur was injected into the
lower stratosphere using missiles, the dispersed
sulfur, after being oxidized in the atmosphere
yielding sulfate, would give a cooling effect with
a lifetime of 1–2 years. The amount of cooling
would thus be reversible and could be controlled
by the rate of injection. The sulfate aerosols
increase scattering of shortwave solar radiation
before it reaches the Earth’s surface [140] by
absorbing and emitting longwave radiation
[118]. There are several proposed techniques of
sulfate injection including the use of artillery
shells and putting the sulfur in aircraft fuels [140].
Compared with the space reflectors and sea
spray generation, stratospheric aerosol injection
is more technologically feasible and less costly.
However, there are unavoidable disadvantages
of stratospheric sulfate injection. First, it could
cause a small increase in ozone depletion by
increasing the number of aerosols. Second, the
aerosols will cause sky whitening [140]. Finally
this method would not solve the problem of ocean
acidification.
Ethics and Philosophy of Climate
Change
Scientific understanding of the issues surrounding
climate change is a vital foundation, and in addition, there are critical ethical implications which
should not be ignored. Environmental and climate
science addresses complex and interacting systems, thus involving “integrating knowledge and
expertise from several disciplines” [200,
201]. One such interdisciplinary intersection
occurs with the field of environmental ethics,
which is a “discipline in philosophy that studies
the moral relationship of human beings to, and
also the value and moral status of, the environment and its non-human contents” [202]. In fact,
many of the arguments made in environmental
ethics are often dependent on the findings of scientific research [200]. However, ethics and
308
Air Pollution and Climate Change: Sustainability, Restoration, and Ethical Implications
acidification, and its cooling effects would be
regional due to the limited lifetime of CCN.
Surface Albedo Enhancement
Increasing the surface’s reflectivity toward solar
radiation is another method of albedo enhancement. One method is to use reflective materials to
cover roads and roofs. This has an immediate
local effect for the building or road and, with
widespread use, could cool a city and region.
There are several kinds of roofing technologies
conducive to this approach including membranes,
cool-surfaced modified asphalt systems, and
metal roofing panels [138]. The city of Los
Angeles found that streets painted with a white
sealant were 5–15
C cooler than similar asphalt
streets. Painting the roofs will not only reflect
50–70% solar radiation [138] but also reduce
energy consumption for air conditioning due to
the decreased cooling load after reflecting the
solar radiation.
Space Reflectors
Another way to reduce the absorption of solar
radiation at the surface would be to reflect parts
of incoming solar radiation before it enters Earth’s
atmosphere. This could be accomplished by placing reflectors in space, between the sun and Earth
[118]. In 1989 Walter Seifritz proposed [139]
placing mirrors in a Lagrange orbit [140]. The
Lagrangian point is the (moving) location where
the gravitational forces of the sun and Earth cancel
[140]. Placing mirrors in a Lagrange orbit is effective at deflecting sunlight for the entire planet, not
just for a certain region(s). Putting mirrors in a
Lagrange orbit is very costly. A cheaper option
would be to place reflectors in orbit around the
Earth [140]. However, mirrors in Earth orbit
reflect less solar radiation because the reflectors
might be in the Earth’s shadow part of the orbit.
Stratospheric Aerosol Injection
The third method or achieving solar radiation
management would be to inject sulfur into the
lower stratosphere. The stratosphere is known to
contain a layer of sulfuric acid aerosol, the
so-called Junge layer, with sulfur provided by
OCS from the troposphere and volcanic injection
[198]. Large volcanic eruptions such as the eruption of Mount Pinatubo in 1991 are known to cool
the global climate [141]. Paul Crutzen proposed
[199] that if elemental sulfur was injected into the
lower stratosphere using missiles, the dispersed
sulfur, after being oxidized in the atmosphere
yielding sulfate, would give a cooling effect with
a lifetime of 1–2 years. The amount of cooling
would thus be reversible and could be controlled
by the rate of injection. The sulfate aerosols
increase scattering of shortwave solar radiation
before it reaches the Earth’s surface [140] by
absorbing and emitting longwave radiation
[118]. There are several proposed techniques of
sulfate injection including the use of artillery
shells and putting the sulfur in aircraft fuels [140].
Compared with the space reflectors and sea
spray generation, stratospheric aerosol injection
is more technologically feasible and less costly.
However, there are unavoidable disadvantages
of stratospheric sulfate injection. First, it could
cause a small increase in ozone depletion by
increasing the number of aerosols. Second, the
aerosols will cause sky whitening [140]. Finally
this method would not solve the problem of ocean
acidification.
Ethics and Philosophy of Climate
Change
Scientific understanding of the issues surrounding
climate change is a vital foundation, and in addition, there are critical ethical implications which
should not be ignored. Environmental and climate
science addresses complex and interacting systems, thus involving “integrating knowledge and
expertise from several disciplines” [200,
201]. One such interdisciplinary intersection
occurs with the field of environmental ethics,
which is a “discipline in philosophy that studies
the moral relationship of human beings to, and
also the value and moral status of, the environment and its non-human contents” [202]. In fact,
many of the arguments made in environmental
ethics are often dependent on the findings of scientific research [200]. However, ethics and
308
Air Pollution and Climate Change: Sustainability, Restoration, and Ethical Implications