Memorandum by Dr Indur M Goklany
Dependence of damage estimates upon assumptions
of economic growth and technological development
Greater economic growth could, by
increasing emissions, lead to greater damages from climate change.
On the other hand, by increasing wealth, and advancing technological
development and human capital, economic growth would also increase
a society's adaptive capacity and reduce those damages. But although
analyses of the impacts (or damages) of climate change generally
incorporate economic growth into the emissions and climate change
scenarios that they use as inputs, these analyses do not adequately
account for the increase in adaptive capacity resulting from that
very growth. Because of this inconsistency, these analyses generally
tend to overstate impacts.
For instance, the average GDP per
capita for developing countries in 2100 is projected to be $11,000
(in 1990 US$, at market exchange rates) under A2, the slowest
economic growth scenario, and $66,500 under A1, the scenario with
both the greatest economic growth and largest climate change.
By comparison, in 1990 the GDP per capita for Greece, for example,
was $8,300 while Switzerland, the country with the highest income
level at that time, had a GDP per capita of $34,000. Based on
historical experience, one should expect that at the high levels
of GDP per capita projected by the IPCC scenarios in 2100, wealth-driven
increases in adaptive capacity alone should virtually eliminate
damages from many climate-sensitive hazards, eg, malaria and hunger,
whether or not these damages are caused by climate change.
Current damage estimates are inflated
further because they usually do not adequately account for secular
(time-dependent) improvements in technology that, if history is
any guide, ought to occur in the future unrelated to economic
A compelling argument for reducing
greenhouse gases is that would help developing countries cope
with climate change. They need this help because, it is asserted,
their adaptive capacity is weak. Although often true today, this
assertion becomes increasingly invalid in the future if developing
countries become wealthier and more technologically advanced,
per the IPCC's scenarios. Damage assessments frequently overlook
Are scenario storylines internally consistent
in light of historical experience?
Regardless of whether the economic
growth assumptions used in the IPCC scenarios are justified, their
specifications regarding the relationship between wealth and technological
ability are, in general, inconsistent with the lessons of economic
history. They assume that the less wealthy societies depicted
by the B1 and B2 scenarios would have greater environmental protection
and employ cleaner and more efficient technologies than the wealthier
society characterized by the A1F1 scenario. This contradicts general
experience in the real world, where richer countries usually have
Under the IPCC scenarios, the richer
A1 world has the same population as the poorer B1 world, but total
fertility ratesa key determinant of population growth ratesare,
by and large, lower for richer nations and, over time, have dropped
for any given level of GDP per capita (Goklany 2001a).
Merits of reallocating expenditures from mitigation
to international development
Halting climate change at its 1990
level would annually cost substantially more than the $165 billion
estimated for the minimally-effective Kyoto Protocol. According
to DEFRA-sponsored studies, in 2085, which is at the limit of
the foreseeable future, such a halt would reduce the total global
population at risk (PAR) due to both climate change and non-climate-change-related
causes by 3 per cent for malaria, 21 per cent for hunger, and
86 per cent for coastal flooding, although the total PAR for water
shortage might well increase.
The benefits associated with halting
climate changeand morecan be obtained more economically
through "focused adaptation", ie, activities focused
on reducing vulnerabilities to the above noted climate-sensitive
hazards, or through broadly advancing sustainable development
in developing countries by meeting the Millennium Development
Goals (MDGs) by 2015. In fact, such efforts, which together could
annually cost donor countries $150 billion according to UN Millennium
Project and World Health Organization studies, should reduce global
malaria, hunger, poverty, and lack of access to safe water and
sanitation by 50 per cent (each); reduce child and maternal mortality
by at least 66 per cent; provide universal primary education;
and reverse growth in AIDS/HIV, and other major diseases.
These numbers also indicate that
no matter how important climate change might be in this century,
for the next several decades it would be far more beneficial for
human well-being, especially in developing countries, to deal
with non-climate change related factors.
Not only would either focused adaptation
or adherence to the MDGs provide greater benefits at lesser costs
through the foreseeable future than would any emission reduction
scheme, they would help solve today's urgent problems sooner and
more certainly. Equally important, they would also increase the
ability to deal with tomorrow's problems, whether they are caused
by climate change or other factors. None of these claims can be
reasonably made on behalf of any mitigation scheme today.
Accordingly, over the next few decades
the focus of climate policy should be to: (a) broadly advance
sustainable development, particularly in developing countries
since that would generally enhance their adaptive capacity to
cope with the many urgent problems they currently face, including
many that are climate-sensitive, (b) specifically reduce vulnerabilities
to climate-sensitive problems that are urgent today and might
be exacerbated by future climate change, and (c) implement "no-regret"
emission reduction measures, while (d) concurrently striving to
expand the universe of no-regret options through research and
development to increase the variety and cost-effectiveness of
available mitigation options.
Ancillary benefits associated with greenhouse
gas (GHG) reductions
Some GHG emission control options might provide
substantial co-benefits by concurrently reducing problems not
directly caused by climate change (eg air pollution or lack of
sustained economic growth, especially in developing countries).
However, in both these instances, the same, or greater, level
of co-benefits can be obtained more economically by directly attacking
the specific (non-climate change related) problems rather than
indirectly through greenhouse gas control. For example, a direct
assault on the numerous climate-sensitive hurdles to sustainable
development (eg hunger, malaria, and many natural disasters) would,
as indicated, provide greater benefits more cost-effectively than
would efforts to mitigate climate change.
1. Introduction. I am an energy
and environmental policy analyst with over 30 years experience
in the United States working for state and federal governments,
think tanks, consulting enterprises, and the private sector. I
have participated in the IPCC's activities and deliberations off
and on since its founding in 1988 to the present. I was the rapporteur
for the Resource Use and Management Subgroup of IPCC's Work Group
III for the First Assessment Report, and helped develop the program
leading to the Second Assessment Report.
2. I have written extensively on climate
change, adaptation, biodiversity, sustainable development, human
well-being, technological change, bioengineered crops, and the
precautionary principle. Attachment A provides a selected list
of relevant publications. I also have a PhD in Electrical Engineering
from Michigan State University.
3. I am currently Assistant Director, Science
and Technology Policy, Office of Policy Analysis, at the US Department
of the Interior, which manages 20 per cent of US surface area,
all its Outer Continental Shelf, and their biological, water and
mineral resources. This evidence, however, is submitted in an
individual capacity. I do not represent any agency, group or institution.
4. I am grateful for the opportunity to
submit evidence to the Select Committee.
5. Scope of Evidence. My evidence
is limited to the following issues: (a) Dependence of estimates
of climate change damages on assumptions about future economic
growth and technology development. (b) Whether the basic specifications
for the IPCC's scenarios, ie their "storylines", regarding
economic growth and technological development are internally consistent
in light of historical experience. (c) The relative costs and
benefits of allocating resources to climate change control rather
than to greater international development assistance. (d) What
other associated benefits might there be from reducing greenhouse
6. My evidence draws upon a set of impacts
analyses funded by DEFRA (and its predecessor, DETR). These studies
(Parry and Livermore 1999, Parry et al 2001, Arnell et
al 2002) apparently form the basis of claims by several advocates
of stronger greenhouse gas (GHG) controls, eg Sir David King (2004),
that, unless curbed, climate change would place additional millions
at risk of diseases such as malaria, hunger, water shortage and
coastal flooding. I will also touch on recent updates to these
studies (Parry 2004). Along with the authors of these studies,
I will: (a) assumeoptimistically, I believethat
socio-economic scenarios are not credible beyond 2085 and, therefore,
2085 is at the limit of the foreseeable future, and (b) restrict
myself to the impacts of "gradual", as opposed to abrupt,
7. For brevity's sake, my evidence concentrates
on damage estimates for the four above-mentioned climate-sensitive
hazards to human health and safety, namely, malaria, hunger, water
shortage and coastal flooding. However, analyses of the impacts
of climate change on "natural" systemsto the
extent that natural systems still exist anywhereare provided
in two papers that I am submitting to supplement my comments.
The first, "Relative Contributions of Global Warming to Various
Climate Sensitive Risks, and Their Implications for Adaptation
and Mitigation", was published in Energy & Environment
in 2003. The second, "Reducing Climate-Sensitive Risks in
the Medium Term: Stabilisation or Adaptation?" is an extended
abstract of a poster presented at the UK-government sponsored
Symposium on Avoiding Dangerous Climate Change, in Exeter,
February 1 to 3, 2005. These papers are identified in the following
as Goklany (2003) and Goklany (2005a), respectively.
8. Dependence of damage estimates on
future assumptions of economic growth and technological development.
Greater economic growth leads to greater emissions and, therefore,
increased impacts from climate change. But it also leads to greater
wealth, which allows societies to better afford the development
and use of new and improved technologies to combat adversity in
general, and climate change (and its impacts), in particular.
Cross country studies also show that greater levels of economic
development (measured as per capita income or GDP per capita)
are associated with higher agricultural yields, lower hunger and
malnutrition, better health, higher levels of education, and increased
resources for research and developmentall factors that
directly or indirectly increase human capital and technological
prowess (Goklany 2001a, 2002). Thus, economic development spurs
technological change and human capital. In turn, technological
change and human capital reinforce economic growth. Hence, wealthier
societies have greater "adaptive capacity" and resilience.
9. Adaptive capacity is a key determinant
of impacts, or damages, due to climate change. This is because
the greater a society's adaptive capacity, the greater its ability
to: (a) forestall or reduce some impacts through a combination
of "spontaneous" (or "autonomous") adaptations
and proactive adaptations, and (b) cope with any residual impacts
through reactive adaptations.
10. Although the DEFRA-sponsored impacts
analyses use climate (and emissions) scenarios that are driven
in large part by assumptions regarding economic growth, they fail
to adequately account for increases in adaptive capacity due to
that very growth. Because of this inconsistency, these studies
generally overstate impacts.
11. Cross country analyses also show that
for any given level of economic development, various indicators
of human developmentagricultural yields, food supplies
per capita, malnutrition, infant mortality, life expectancy, access
to safe water and sanitation, educational levelsimprove
with time (Goklany 2001a, 2002). That is, for each of these indicators
there is a secular (time-dependant) rate of technological progress
unrelated to economic development, which also increases a society's
capacity to cope with adversity. But this increase in future adaptive
capacity is either ignored or inadequately addressed in current
impact estimates, further reinforcing the tendency to overestimate
the future impacts of climate change.
12. Consider, for example, estimates of
the impacts of climate change on malaria (Arnell et al
2002, Lieshout et al 2004), which is both a problem in
its own right and a good surrogate for other climate-sensitive
diseases. These studies provide damage estimates in terms of the
future global population at risk (PAR), implicitly assuming that
incidences and deaths due to malaria would be proportional to
PAR. But these studies estimate changes in PAR on the basis of
changes in climatic factors and population. They assume no change
in adaptive capacity of these populations in the future, ie they
ignore the improvements in prevention and cure of malaria that
should occur over the next several decades,
and the fact that, with economic growth, societies should be better
able to combat all climate-sensitive diseases, including malaria.
But with current technology, malaria is functionally eliminated
in societies with annual per capita income of $3,100 (Tol and
Dowlatabadi 2001) and, since incomes are expected to grow under
every SRES scenario, few, if any, countries will be below this
$3,100 threshold by the end of this century. In fact, according
to the A2 scenariothe scenario with the lowest economic
growththe average income in developing countries will be
$11,000 in 2100 (in 1990 US$, at market exchange rates or MXR;
Arnell et al 2004), while under the A1 scenariothe
scenario with both the greatest economic growth and climate changetheir
average income would be $66,500, which is greater than any individual
country's heretofore. Thus, even ignoring secular trends in technological
ability, malaria should be restricted to a much smaller area,
if not totally eliminated. Clearly, the DEFRA-funded studies overestimate
the impacts of climate change on malaria in a richer and more
technologically advanced world.
13. By contrast, the recent analysis of
hunger (Parry et al 2004) does a better job of including
changes in adaptive capacity. It allows for some increases in
agricultural productivity over time, fertilizer-driven increases
in crop yield with economic growth (but not necessarily yield
increases due to other underused technologies that might become
more affordable at higher incomes), decreases in hunger due to
economic growth, and for some adaptive responses at the farm level
to boost agricultural productivity. However, as this study itself
acknowledges, these adaptive responses are based on currently
available technologies, not on technologies that would be available
in the future or any technologies developed to specifically cope
with the negative impacts of climate change (Parry et al
2004, p 57). The potential for future technologies to cope with
climate change is large, especially if one considers bioengineered
crops (Goklany 2001b, 2003).
14. With respect to water shortage, the
DEFRA-sponsored studies indicate that climate change might, in
fact, reduce the overall population under water stress
(defined as people living in areas where available water is less
than 1,000 m3 per capita per year) (Arnell 1999, 2004).
However, summaries of these studies which have advanced the notion
that additional millions are at risk of climate change (Parry
et al 2001, Arnell et al 2002) report the increase
in PAR without subtracting out the population for whom the risk
would be reduced (Goklany 2003).
15. Recent analysis of the impacts of climate
change on coastal flooding (Nicholls 2004) has, so far, done the
best job in incorporating improvements in adaptive capacity due
to increasing wealth. In particular, it assumes that the level
of protection against coastal flooding would rise step-wise as
a function of a country's GDP per capita. But, arguably, the relationship
should be more linear (or there should be more and shorter steps
from the lowest protection level to the highest). More important,
this study makes no adjustments for a country's expenditures on
coastal protection as the size of its coastal population increases
relative to its total population. It would be more reasonable
to assume that would lead to greater expenditures for coastal
protection on a per-GDP basis (through a push-and-pull effect).
16. Nicholls (2004) coastal flooding study
inadvertently points to the possibility that specifications
for various IPCC (SRES) scenarios are internally inconsistent
in light of historical experience regarding the relationship
between wealth, technological capabilities, and environmental
protection. Consider that the "storyline" for the A1
scenario is that it reflects a world with increased globalization,
materialism, less regard for the environment, and rapid technological
change (but, apparently, not with regard to environmental technologies),
while the B2 storyline reflects a more heterogeneous world, greater
priority for the environment, and clean and efficient technologies.
Economic growth is assumed to be faster, and substantially greater,
under A1 than B2. Consequently, in 2100, absolute GDP is projected
to be 2.2 times larger under A1 than under B2, while GDP per capita
is projected to be twice as large for industrialized countries
and 3.7 times as large for developing countries. Nevertheless,
Nicholls (2004) assumes that adaptive responses would be quicker,
and subsidence protection greater, under B2 than A1. Although
this assumption conforms with the SRES's manufactured storylines,
it is contrary to real world experience which indicates that richer
countries generally respond quicker to environmental problems,
spend more, and have greater environmental protection, than poorer
ones, especially at the high levels of development that are projected
to exist virtually everywhere later this century under the IPCC's
scenarios (Goklany 2002). Hence, one should expect that the richer
(A1) world would spend more on subsidence protection, and be better
protected, than would the B2 world. Moreover, if greater concern
for the environment is expressed as a larger fraction of GDP spent
on the environment then, despite spending a smaller fraction under
A1, that could still provide greater protection than what might
be obtained under B2, given the wide gaps in GDPs (and GDPs per
capita) between A1 and B2.
17. Under the IPCC scenarios, the richer
A1 world has the same population as the poorer B1 world, but total
fertility ratesa key determinant of population growth ratesare,
by and large, lower for richer nations and, over time, have dropped
for any given level of GDP per capita (Goklany 2001a).
18. Nicholls' (2004) damage estimates from
coastal flooding show lower damages in the B1 world than the A1F1
world. But for the reasons outlined in paragraphs 16 and 17, this
could be an artifact of the assumptions rather than a general
rule that the former is necessarily a more superior world to A1F1.
19. One of the most compelling arguments
advanced for reducing greenhouse gas emissions is that mitigation
would help developing countries because, it is asserted, they
lack the requisite economic resources and human capital to cope
with the impacts of climate change. Although many developing countries
indeed lack adequate adaptive capacity today, this assertion becomes
increasingly suspect if they become wealthier and technologically
more developed, per the IPCC's scenarios, especially if there
is no undue aversion to new or improved technologies (see footnote
1). [As noted in paragraph 12, the average GDP per capita for
developing countries is projected to be between $11,000 (under
A2) and $66,500 (under A1) in 2100.]
20. Costs and benefits of using resources
for international development rather than emission control. The
studies cited by King (2004) to bolster the claim that climate
change could indeed place additional millions at risk also show
that, for the most part, many more millions would be at risk in
the absence of climate change (Goklany 2003, 2005a; Goklany and
21. For instance, Arnell et al (2002)
estimate that, without any additional climate change, the global
population at risk of malaria (PAR-M) would be 8,820 million in
2085. By contrast, unmitigated climate change would increase PAR-M
by another 300 million in 2085.
22. Hence, halting climate change at its
1990 levels would reduce total PAR-M in 2085 by 3% [= (100 x 300)/(300+8,820)],
at a cost of trillions of dollars (IPCC 2001).
23. Table 1, which despite the many reservations
noted above, is based on the results of DEFRA-sponsored studies.
It provides estimates of the percent reduction in total global
populations at risk (PAR) in the year 2085 for malaria, hunger,
water shortage and coastal flooding under four mitigation scenarios,
namely, the Kyoto Protocol (KP), stabilization of greenhouse gas
concentrations at 750 ppm in 2250, stabilization at 550 ppm in
2150, and "no climate change".
PER CENT REDUCTION IN THE TOTAL GLOBAL POPULATION
AT RISK (PAR) IN 2085 UNDER VARIOUS MITIGATION SCENARIOS
|% Reduction in total PAR in 2085
|due to the Kyoto Protocol (KP)
||Assuming stabilization at
|Assuming stabilization at|
if there is no
|Water shortage §|
-4.1% to 0.8%
-58.6% to 11.8%
*Total PAR = (PAR without climate change) + (PAR due to climate
change). § A negative sign indicates that emission reductions
will increase PAR. Method A calculates the net change in the global
population under greater water stress using Arnell (1999); Method
B provides an estimate of only the population experiencing greater
stress (Arnell et al, 2002).
Source: Goklany (2005a), based on Arnell (1999) and Arnell
et al (2002), with revisions.
24. This table assumes, charitably, that in 2085 the
Kyoto Protocol would reduce climate change by 7 per cent, which
would reduce the impacts of climate change on malaria, hunger
and water shortage by a like amount, and the impacts of coastal
flooding by thrice that (Goklany 2003).
25. The Protocol, whose annual cost is estimated at about
0.5 per cent of the GDP of Annex I nations in 2010 (equivalent
to about $165 billion in 2003 US$, MXR; Goklany 2005b), would
by 2085 reduce total PAR by 0.2 per cent for malaria, 1.5 per
cent for hunger, and 18.1 per cent for coastal flooding (see Table
1). On the other hand, there is no certainty that the Protocol
would not increase total PAR for water shortage.
26. But these benefitsand much morecould
be obtained by focusing on reducing vulnerabilities to these climate-sensitive
hazards today, and at substantially lesser cost:
Malaria's current global death toll of 1 million/yr
can be halved for less than $1.5 billion/year by improving treatment
and prevention of the disease (WHO 1999).
A $5 billion annual increase in agricultural R&D
should sufficiently raise productivity of agricultural land and
water to more than erase any climate-change-caused deficit in
agricultural production in 2085, especially if these additional
R&D resources are focused on solving developing countries'
agricultural problems that might be further exacerbated by warming
(Goklany 2005a, 2003).
Coastal protection against a sea level rise of
0.5 meters by 2100 can be effected at an annual cost of $1 billion
(IPCC 1996). Notably, the DEFRA-sponsored studies on which Table
1 is based project that global sea level will rise by 0.41 meters
27. Such measures, referred to as "focused adaptation"
because they focus on reducing damages from specific climate-sensitive
hazards, will not only help reduce present-day climate-sensitive
problems, they will also help reduce these problems in the future,
whether they are caused by climate change or another factor. On
the other hand, mitigation would mainly reduce damages only caused
by climate change (although they may be accompanied by some "co-benefits",
28. More important, reducing present-day vulnerabilities
will start to provide a steady stream of benefits in the very
near term, while the benefits of mitigation will not be significant
until decades have elapsed (because of the inertia of the climate
29. Moreover, as the case of water shortage illustrates
(see Table 1), mitigation would indiscriminately reduce all impacts
of climate change, whether they are positive or negative. But
adaptation can capture the positive aspects of climate change,
while reducing its negatives.
30. Curiously, Table 1 indicates that in 2085 the PAR
for malaria and hunger would be greater under the 550 ppm stabilization
pathway than the 750 ppm pathway.
31. Table 1 also indicates that no matter how important
climate change might be in this century, through the foreseeable
future other non-climate change related factors ought to be even
more critical for human well-being, particularly for developing
32. Focused adaptation is far more likely to deliver
benefits than is mitigation because of the greater uncertainties
related to warming and its impacts.
33. Not least, co-benefits (or ancillary benefits) of
focused adaptation, most of which would flow directly or indirectly
from reduced malaria and increased agricultural productivity,
include lower hunger, better health, increased economic growth,
and greater human capital (Goklany 2001a, 2002). In addition,
increased agricultural productivity per unit of land and water
would reduce the diversion of land and water to agricultural purposes,
thereby, helping address the greatest threats to terrestrial and
freshwater biodiversity. In other words, focused adaptation should
enhance sustainable development (Goklany 2005a).
34. Moreover, increased economic development and human
capital should further increase the capacity to adapt to or mitigate
climate change (Goklany 1995, 2005a).
35. Thus, even if the cost estimates (in paragraph 26)
for reducing present day vulnerabilities are overoptimistic by
an order of magnitude, the set of focused adaptations listed in
that paragraph will, through the foreseeable future, cost less
than the Kyoto Protocol while providing greater benefits than
would a complete halt in further climate changeeven ignoring
36. Yet another option for using resources that might
otherwise be expended on mitigation would be to advance sustainable
development more broadly. In fact, the Millennium Development
Goals (MDGs) were formulated to achieve just such an end.
37. Such an approach would subsume focused adaptation,
and provide the same qualitative advantages.
38. The additional annual cost to the richest countries
of attaining the Millennium Development Goals (MDGs) by 2015 is
pegged at about $143 billion (in 2003 US$) in 2010, according
to the UN Millennium Project (2005). That is somewhat below the
cost of the barely-effective Kyoto Protocol, and less than the
cost of stabilization at either 750 or 550 ppm.
39. However, through the foreseeable future, the benefits
of meeting the MDGs far outweigh the benefits of either the deepest
mitigation or focused adaptation (see Table 2). They include halving
global poverty, hunger, lack of access to safe water and sanitation;
reducing child and maternal mortality by 66 per cent or more;
universal primary education; and reversing growth in malaria,
AIDS/HIV, and other major diseases.
COMPARING BENEFITS AND COSTS ASSOCIATED WITH MILLENNIUM
DEVELOPMENT GOALS (MDGs), MITIGATION AND FOCUSED ADAPTATION
|Dependence of ||Reduction in Total PARa
|Risk factor||risk factor on climate change (CC)
||Due to Kyoto Protocol|
Due to a halt in CC (in 2085)
Due to MDGs (in 2015)
|Water shortage||Yes||-4 to +1%
||-59 to +12%||+||Not addressed|
|Maternal mortality rateb,c
|Lack of access to safe waterc
||No||No effect||No effect
|Lack of access to sanitationc
||No||No effect||No effect
|Lack of primary educationb,c
||No||No effect||Zero to small +e
|Annual costs||~$165 billion
|> cost of Kyoto|
|< cost of|
Notes: (a) + denotes a positive reduction in P, while ++
denotes a larger positive reduction. (b) Reductions in malaria
and/or hunger should directly or indirectly reduce risks associated
with each other, poverty, child and maternal mortality rates,
educability, AIDS and TB. (c) Risks associated with these categories
should decline with economic development. (d) Assumes same measures
to reduce hunger as used to meet MDGs. (e) Indirect improvements
because hunger/malaria would be reduced under focused adaptation.
(f) Assumes $1.5 billion per year spent to halve malaria mortality.
(g) Assumes $1 billion per year spent on protection (IPCC, 1996a).
Sources: For costs, IPCC (2001), WHO (1999), World Bank
(2005) and UN Millennium Project (2005); for reduction in risks,
Table 1 and World Bank (2002).
40. Adhering to the MDGs would directly or indirectly
advance human well-being in many more aspects than would focused
adaptation, because the former is much wider in scope (Goklany
2005a). It would also more broadly increase: (a) adaptive capacity
to cope with adversity in general, and warming in particular,
and (b) the capacity to mitigate greenhouse gas concentrations
in the atmosphere.
41. Assuming it takes 50 years to replace the energy
infrastructure, Tables 1 and 2 suggest that we have at least 30
years (=2085-50-2005) before deciding on targets and timetables
for emission cuts.
42. In the meantime, we should focus on increasing adaptive
capacity, whether through pursuit of MDGs or through adaptation
focused on climate-sensitive hazards that might be exacerbated
by climate change. This could raise the level at which GHG concentrations
might become "dangerous" and/or allow mitigation to
be postponed. Simultaneously, we should strive to improve the
cost-effectiveness of mitigation so that, if or when mitigation
becomes necessary, net costs would be lower even if emission reductions
have to be more drastic.
43. Pursuing either the MDGs or focused adaptation would
be entirely consistent with the UN Framework Convention on Climate
Change's objectives outlined in Article 2, namely, "to allow
ecosystems to adapt naturally to climate change, to ensure that
food production is not threatened, and to enable economic development
to proceed in a sustainable manner" (Goklany 2003).
44. Co-benefits or ancillary benefits of reducing
greenhouse gas emissions. Some options for GHG emissions control
might provide substantial co-benefits by reducing problems not
directly caused by climate change. For example, a reduction in
fossil fuel usage could, by lowering traditional air pollutants
(eg sulfur dioxide, nitrogen oxides and particulate matter), provide
significant public health and environmental co-benefits. Similarly,
a reduction in global warming could, arguably, contribute to sustainable
development"arguably", because one cannot be
confident that such reductions might not result in costs in excess
of benefits (Tol 2005; Goklany 2001b).
45. One procedure to evaluate control (or response) options
is to compare marginal costs versus marginal benefits (both appropriately
discounted). If the latter exceed the former, the option being
evaluated is frequently deemed to have passed the test of economic
46. This procedure, however, can lead to less-than-optimal
solutions for society if it reduces resources available for implementing
other actions with higher benefit-to-cost ratios, or if there
are other, more economic options of obtaining the same level of
47. For example, it is, under current conditions in the
US, cheaper to reduce traditional air pollutants through a direct
assault on these pollutants (via add-on controls) than indirectly
through measures designed to reduce GHG emissions. Thus, even
if the sum of climate change-related and air pollution-related
benefits of GHG reductions were to exceed the total cost of GHG
controls, that could still lead to a squandering of scarce resources.
Similarly, as shown in Table 2 (above), it is much more economic,
for the foreseeable future, to advance sustainable development
directly through adherence to the MDGs or focused adaptation than
through mitigation measures.
48. Where benefits and co-benefits relate only to climate
change and air pollution, for instance, the optimal set of response
options is that which entails the least total cost to society.
The optimal set can be identified by minimizing the sum of: (a)
the cumulative cost of the response actions taken to reduce damages
from climate change and/or air pollution, and (b) the cumulative
cost of residual damages following the imposition of the response
actions (which, in general, would include both mitigation and
adaptation actions to reduce damages from climate change and/or
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It is, however, possible that despite increased technological
prowess and economic development, these diseases could extract
a greater toll in the future because of maladaptation. Perhaps
the best example of maladaptation is the suspension of indoor
residual spraying with DDT to control malaria in many developing
countries, which then contributed to the disease's resurgence.
When such spraying was reinitiated, eg in South Africa, malaria
once again declined (Goklany 2001b, Tren and Bate 2004). This
maladaptation attests to the importance of being open to technology
to help cope with adversity, the perils of over-precaution, and
the need for risk-risk analysis to identify the lesser of two
evils (Goklany 2001b). Back