recapture it again, someday. It’s important to note
that CO 2 , once emitted, becomes very dilute in the
atmosphere and is therefore much harder to capture than when it is highly concentrated at a point
source of emissions. In addition, it is not sustainable to rely on the promise of a technology that is
not fully developed. To prevent a catastrophic
climate trajectory, it is important to reduce emissions now, by decreasing emissions of CO 2 and
pursuing negative emissions approaches [120].
Methane Control
As shown in Fig. 1, the radiative forcing of methane is quite large and has contributed over half
again as much radiative forcing as CO 2 . On a per
gram basis, methane is 86 times more warming
than CO 2 which means that reducing methane
could potentially be very cost-effective. Also,
since its atmospheric lifetime is short, about
10 years, reducing methane emissions would
have immediate benefits in contrast to CO 2 which
stays in the climate system for centuries [5]. Unfortunately, methane is very inert chemically. Its CH
bond is the least reactive of any hydrocarbon. It has
a very high vapor pressure and does not condense
or adsorb easily. Scientists discovered that zeolites
may hold promise for methane capture; the next
step is to test the zeolites and determine if the
theory works in practice [121]. Methane sources
include wetlands, methanogenic bacteria, garbage
dumps, cows, and termites [5]. The sources are
diffuse making them difficult to control.
McKinsey Marginal Abatement Cost Curve
Besides focusing on the mitigation target of keeping the temperature increase below 2
C relative to
pre-industrial [122], it is critical to consider the
effectiveness, cost, and scale of mitigation and
abatement actions when governments and organizations put the climate change mitigation strategies into wide practice.
The marginal abatement cost (MAC) is a measure of the cost of reducing an additional unit of
pollution. The MAC for many methods can be
summarized in a MAC curve which is defined as
“. . .a graph that indicates the cost, usually in $ or
another currency per ton of CO 2 , associated with the
last unit (the marginal cost) of emissions abatement
for varying amounts of emission reduction” [123].
A number of research organizations have
published MAC curves [2, 3, 123, 124]. The
global greenhouse gas abatement cost curve produced by the McKinsey & Company (Fig. 11) is a
typical and well-known example. It summarizes
the costs of different emissions reductions ordered
from lowest to highest and provides a discussion
about “what actions would be most effective in
reducing emissions” [2].
This figure shows vetted technologies for achieving a greenhouse gas abatement of 38 GtCO 2 e per
year [2]. Improving the energy efficiency of industries, buildings, and vehicles costs little and in many
cases saves money due to the decrease in energy
consumptions. In addition, many abatement
methods use low-carbon energy sources such as
wind, nuclear, solar, and hydro. There are also
approaches based on forestry and agriculture, such
as reforestation and land use change. Finally, emerging technologies such as CCS do not contribute
large abatements and are expensive; these prices
are expected to drop with further development and
implementation.
Besides McKinsey & Company, the Wuppertal
Institute for Climate, Environment and Energy
has produced MAC curves for Germany [124],
and the Bloomberg New Energy Finance has produced the curves for the United States [3].
Adaptation
Due to legacy emissions, past decisions, and
“political inertia,” humanity is already committed
to some dangerous climate change impacts, which
means that adaptation appears to be inevitable.
Adaptation has traditionally received less attention than mitigation mainly due to its limited
potential, uncertain benefits, and less straightforward measurements [127].
Examples of Adaptation Strategies
Adaptation in Europe
Countries across the globe are preparing and
implementing adaptation strategies. Though the
seriousness and speed of climate change impacts
are being debated, there is no doubt that it is
happening. Given the wide range of impacts, it is
Air Pollution and Climate Change: Sustainability, Restoration, and Ethical Implications
305
that CO 2 , once emitted, becomes very dilute in the
atmosphere and is therefore much harder to capture than when it is highly concentrated at a point
source of emissions. In addition, it is not sustainable to rely on the promise of a technology that is
not fully developed. To prevent a catastrophic
climate trajectory, it is important to reduce emissions now, by decreasing emissions of CO 2 and
pursuing negative emissions approaches [120].
Methane Control
As shown in Fig. 1, the radiative forcing of methane is quite large and has contributed over half
again as much radiative forcing as CO 2 . On a per
gram basis, methane is 86 times more warming
than CO 2 which means that reducing methane
could potentially be very cost-effective. Also,
since its atmospheric lifetime is short, about
10 years, reducing methane emissions would
have immediate benefits in contrast to CO 2 which
stays in the climate system for centuries [5]. Unfortunately, methane is very inert chemically. Its CH
bond is the least reactive of any hydrocarbon. It has
a very high vapor pressure and does not condense
or adsorb easily. Scientists discovered that zeolites
may hold promise for methane capture; the next
step is to test the zeolites and determine if the
theory works in practice [121]. Methane sources
include wetlands, methanogenic bacteria, garbage
dumps, cows, and termites [5]. The sources are
diffuse making them difficult to control.
McKinsey Marginal Abatement Cost Curve
Besides focusing on the mitigation target of keeping the temperature increase below 2
C relative to
pre-industrial [122], it is critical to consider the
effectiveness, cost, and scale of mitigation and
abatement actions when governments and organizations put the climate change mitigation strategies into wide practice.
The marginal abatement cost (MAC) is a measure of the cost of reducing an additional unit of
pollution. The MAC for many methods can be
summarized in a MAC curve which is defined as
“. . .a graph that indicates the cost, usually in $ or
another currency per ton of CO 2 , associated with the
last unit (the marginal cost) of emissions abatement
for varying amounts of emission reduction” [123].
A number of research organizations have
published MAC curves [2, 3, 123, 124]. The
global greenhouse gas abatement cost curve produced by the McKinsey & Company (Fig. 11) is a
typical and well-known example. It summarizes
the costs of different emissions reductions ordered
from lowest to highest and provides a discussion
about “what actions would be most effective in
reducing emissions” [2].
This figure shows vetted technologies for achieving a greenhouse gas abatement of 38 GtCO 2 e per
year [2]. Improving the energy efficiency of industries, buildings, and vehicles costs little and in many
cases saves money due to the decrease in energy
consumptions. In addition, many abatement
methods use low-carbon energy sources such as
wind, nuclear, solar, and hydro. There are also
approaches based on forestry and agriculture, such
as reforestation and land use change. Finally, emerging technologies such as CCS do not contribute
large abatements and are expensive; these prices
are expected to drop with further development and
implementation.
Besides McKinsey & Company, the Wuppertal
Institute for Climate, Environment and Energy
has produced MAC curves for Germany [124],
and the Bloomberg New Energy Finance has produced the curves for the United States [3].
Adaptation
Due to legacy emissions, past decisions, and
“political inertia,” humanity is already committed
to some dangerous climate change impacts, which
means that adaptation appears to be inevitable.
Adaptation has traditionally received less attention than mitigation mainly due to its limited
potential, uncertain benefits, and less straightforward measurements [127].
Examples of Adaptation Strategies
Adaptation in Europe
Countries across the globe are preparing and
implementing adaptation strategies. Though the
seriousness and speed of climate change impacts
are being debated, there is no doubt that it is
happening. Given the wide range of impacts, it is
Air Pollution and Climate Change: Sustainability, Restoration, and Ethical Implications
305