FLAW
Page 159 top: ". . in essence have started at almost 50 % poor 30 years
later in 1980". Flaw: As explained below
concerning the right graph of Figure 48, this is not so. The level was
about 40 % poor in 1981.
(COMMENT)
Page 159 and note 850: ". . current opinion considers the
population component of SRES A2 ´out of the range´." Comment: This is true. Also Stern agrees with
that in his review.
ERROR
Page 159 and note 851: " . . but it can only be considered an absolute
worst-case scenario."
Error: This
is not so. There have been constructed a number of scenarios of global
GDP growth other than those of the SRES (IPCC Special Report on
Emissions Scenarios). When the four SRES scenarios A1, A2, B1 and B2
are compared to what other scenarios have been published, all four lie
within the range covered by the scenario literature. A1 is very high
though, and lies for some part of the 21st century at the absolute
upper boundary of the range. B1 is close to the average, and A2 and B2
are somewhat below average, but far from the absolute bottom of the
range. Source: Nakicenovic
et al. 2003.
In addition, the quote from Fischer et al. (2005) is wrong. What they
say is that their own projections of crop growth based on the A2
scenario are representative of a worst case scenario, not that A2
itself is so. Furthermore, Fischer et al. (2005, page 2072) point
out that the other three SRES scenarios have been criticized for
economic growth rates that are probably too strong, wherefore they have
also simulated lower economic growth scenarios. Lomborg´s
formulation, using the words "only", "absolute" and "worst-case", is so
categorical that it is downright wrong.
FLAW
Page 159, Figure 48, left graph: " The proportion of poor in the world,
1950-2015." Flaw: The data from Berry et
al. 1983 and 1991 (the two sources have identical data) give the number
of people with less than $200 (presumably per year). This amount is
given in 1970 U.S.$. To compare it with later Worldbank estimates, it
should be adjusted to 1993 as the base year (defined as lying 8 % above
the previous base year 1985), which means multiplying by
a factor of 2.77 x 1.08
using the consumer price index, or 2.53 x 1.08, using the GDP deflator.
This
means that the poverty line of Berry et al. corresponds to
approximately $1.5 - 1.6 per day, not $ 1 per day. However, the data
from the Worldbank
on number of poor below $1 per day, covering later years, do not fit
together with Berry´s data, being much higher, not lower as
expected. The reason for the discrepancy might
be explained by the statement in Berry et al. 1983: "In developing
countries, lack of adequate data is a major problem".
Methodologically uniform data exist for the period 1981 onwards
(Worldbank working papers by Chen
& Ravallion 2004 and Chen
& Ravallion 2008). They imply that the curve that Lomborg
attempts to draw should have been steeper in the first part (40 % below
$1 per day in 1981). What Lomborg has done, is to splice two data
sets that do not fit together. A person teaching statistics should not
do that.
FLAW
Page 159, Figure 48, right graph: " The proportion of poor . . . for
south Asia and Sub-Saharan Africa, 1981-2100." Flaw:
Lomborg´s curve starts at 1981, but the references given by him
do not have data from 1981. However, data from 1981 onwards exist
elsewhere (Worldbank working paper by Chen
& Ravallion 2004 and more recently Chen
& Ravallion 2008). The figures from 1990 onwards differ from
those used by Lomborg. In the recent data, the number of persons living
below $1 per day goes from 42 % in 1981 to 32 % in 2002. Thus, the
actual curve has a much flatter slope than the one given by Lomborg.
The number of poor in these regions does not drop as fast as he
indicates.
These are percentage figures. The absolute number of people living with
less than $1 per day has decreased only slightly in south Asia from
1981 to 2002, and in Subsaharan Africa, the number has nearly doubled
during this period (from 169 million to 310 million). Only after 2002
is there probably a small decline in the African figures. It is
conceivable that the absolute number of poor will decline faster in the
future in south Asia and eventually go towards zero. It is less
conceivable that the same will happen in Africa. Lomborg´s graph
would fit with a situation where the absolute number of poor in south
Asia and Subsaharan Africa has dropped to just above one fourth of the
number in 2002. This is a rather optimistic
scenario, considering that this drop has hardly started yet.
FLAW
Page 160 top: " . . . the World Bank explicitly says that $2 -a-day
reflects "poverty lines more commonly used in lower-middle-income
countries."" Flaw: The quoted
sentence could not be found in Lomborg´s source. Instead, World
Bank experts Chen & Ravallion state in a later
publication (2008) that "a $2.00 line is the median poverty line
found amongst developing countries as a whole."
FLAW
Page 160 top: " Finally, Stern chose to assume that the world will warm
extra much . . " Flaw: This is a
misleading formulation. Stern operated with two versions, one
being the A2 baseline scenario, and the other being the same, with
extra heating due to possible feedback effects. Lomborg´s text
should have read: "Finally, Stern chose to include an additional
version in which the world will warm extra much." Without such a
formulation, the text is misleading.
(COMMENT)
Page 160: "After that it still only slowly starts declining . ." Comment: Lomborg´s graph for the
so-called worst-case world does not seem to fit with the parameter
values on which it is based. See the comment below to Figure 49.
(COMMENT)
Page 160: " With a high degree of warming, it is likely that . . . ". Comment: It seems that Lomborg mixes up
things here. It is not clear if his graph originating from the A2
scenario includes the negative effects of climate change on the
economy. What Anderson (2006) has done, is to project the development
first with the A2 scenario, and then with the same scenario but now
including the effect of climate on the GDP growth rate. He does that
with two versions, one with a 3.9° C temperature rise by
2100, and one with extra warming, i. a 4.3° C temperature rise by
2100. But Lomborg´s presentation does not tell whether the grey
graph labelled "worst-case world" includes any climate effect or not.
He only tells that extra warming (from 3.9° to 4.3° C) shifts
the graph from the black curve to the white curve.
ERROR
Page 160. "By 2100, global warming will cause the world to have 51
million more people below $2-a-day." Error:
At this point in the text, Lomborg has finally mixed up things
completely. The figure of 51 million seems to have been computed by
Lomborg (not by Anderson), and the reader will understand that it is
the difference between the grey curve and the white curve in 2100. The
text on the graph says "with high warming" for the white graph, but the
main text says that the difference is due to "global warming". In any
case, the figures computed by Anderson (2006), citing the mean values,
are that global warming will cause an extra 12 million poor (3.9°
warming) og 17 million poor (4.3° warming). Thus the difference
between the two extents of warming is just 5 million, and the
difference between no climate change and expected climate change is 12
- 17 million poor. None of these mean estimates fit with
Lomborg´s graphs, irrespectively of how these graphs are
interpreted.
(COMMENT)
Page 160: "If Stern . . also tweaks the risk of things going very
wrong. . ." Comment: To say that
Stern tweaks the risk is an unkind way of describing his text.
The issue is described in Chapter 4 of the Stern review, on page
109-110, and here Stern presents the mean values and the 95th %
percentile values for two climate models. He does not present the 5th %
percentile values. The graphs that he presents give the mean values.
The text is better than what Lomborg usually presents, because Lomborg
usually gives just one figure, with no indication whatsoever about the
uncertainty range around the figure, even when the uncertainty is
extremely large. Presenting the mean and
the upper range (95th
percentile) is at least somewhat better, because it gives an idea of
the size of the uncertainty. However, Stern´s text is not
quite neutral
when the 5th percentile is not also given. And Stern does put rather
much emphasis in his text on the unlikely 95th percentile values. The
reason for this is, of course, that society should be prepared for the
worst, not just for the mean, but it brings the text closer to
scaremongering.
ERROR
Page 160, Figure 49. "Millions of poor in south Asia and Sub-Saharan
Africa, 2002-2100, with Stern´s worst-case scenario. . ." Error:
Although the figure is based on Lomborg´s own calculations and
the graphs are therefore not easily checked, a sort of check is
possible. With the parameters given in Anderson (2006), the
income-per-capita doubles in Africa and south Asia from 2002 to 2050.
Assuming that the relative income distribution is constant (which is
reasonable), one may therefore assume that the proportion (32 %) living
with less than $1 per day in 2002 is the same as the proportion living
with less than $2 in 2050. As we have also figures for the population
increase (+ 86 % from 2002 to 2050), we can calculate the total number
of people living with less than $2 in 2050. The result is about 1270
millions. Similar calculations based on the proportion today living
below $1.25 per day tell that there will be about 1470 millions living
below $2 in 2033. These figures are for a scenario without economic
growth reduction caused by climate change. If the mean estimates in
Anderson (2006) of the number of poor extra because of climate change
are added, then that means adding about 1 million extra in 2033 and 2
million extra in 2050, i.e. the graph is essentially not changed in
this part of the time period. Thus the figures are much lower than in
Lomborg´s curve for the "worst-case world", and we may therefore
assume that Lomborg has dramatized the course of the graph.
FLAW
Page 161: " Perhaps even more important is to look at the other, more
likely, policy option, namely going down a different - and more likely
- development path, the A1" Flaw:
Lomborg misunderstands or misrepresents what the socio-economic
scenarios - A1 and A2 - are. They are not policy options; they are not
predictions; and there is no likelihood associated with
them. IPCC explicitly states that they are equally valid. They are just
scenarios to be used for testing the vulnerability to climate change in
different versions of the future world. A1 is constructed to show a
world where the gap between rich and poor countries closes, whereas A2
shows a world where the Third World countries do not manage fully to
catch up with the rest of the world. Many would consider the latter
more likely. Furthermore, A1 presupposes that it will be possible in
the future to sustain high economic growth rates continuously to obtain
ever larger income levels, not only in the Western World and Russia,
but also the Third World countries will obtain such high income levels.
It is doubtful if there are resources enough on the globe to make
this possible.
(COMMENT)
Page 160: "The World Bank´s expectation for poverty in
south Asia and Sub-Saharan Africa is spot on A1 . . " Comment: Yes, of course. The World Bank´s
projection for 2015 is based on the following premises (World Bank
2004, p. 21): "Developing country economic performance has been strong
since 2002, and this is projected to continue over the next two years
and beyond." So IF economic performance remains strong, then we will
get the same result as in A1, which is built on the assumption that
there will be a strong economic growth. No surprise - that is a
tautology. But nobody knows IF economic growth will remain strong. When
Lomborg wrote his text, nobody knew that a global financial crisis was
waiting just around the corner.
FLAW
Page 161: " . . . again indicating that Stern has picked the
wrong scenario. " Flaw: There is no
such thing as a wrong scenario. All scenarios are equally valid, as
explained above.
The reason that Stern gives why he chose to run his PAGE model on the
basis of the
A2 scenario, is that this produces a likely mean estimate of the global
temperature increase in the year 2100 - the increase is 3.9° C,
which compares well with the mean of the temperature projection in the
IPCC Third Assessment Report which is 4.1° C (Stern report chapter
6, page 154).
FLAW
Page 161: " . . . this future is also much more robust toward
climate change - you virtually can´t see the different climate
line in Figure 49 . . . " Flaw:
The "different climate line" (presumably?) gives the difference between
3.9° warming and 4.3° warming. It does not (?) give the
difference between climate change and no climate change.
(COMMENT)
Page 161: "Again, we are at a point where we have to realize that
we have several opportunities . . " Comment:
This is a misunderstanding. The scenarios are not opportunities. We do
not choose ourselves if we want a global financial crisis or not, or a
severe drought that sets back economic growth in Africa, or if we want
a per capita growth of income in Africa of 2 % or 4 %. These things
just happen, and the scenarios present some possibilities for what
might happen. If we indeed had opportunities and could choose, who
would choose 2 % growth rather than 4 % growth?
FLAW
Page 161 bottom: " . . . yet choosing A1 instead will drop that
number to 320 million . . . " Flaw:
As stated repeatedly in the comments above, the scenarios are not
something that you can choose.
FLAW
Page 162 top: " If we manage to move from A2 to A1, we will on average
reduce the number of poor people by a billion. . . " Flaw: As stated above, the graphs (at
least the upper graph) in Figure 49 are probably not right, and so the
conclusion that the average difference between the graphs is one
billion people is dubious.
FLAW
Page 162, Figure 50: Flaw:
The source for the postulate that Kyoto will give just 1 million fewer
people is missing, and it is not stated if "Kyoto" just means the
present Kyoto agreement and nothing more. It is wrong to say that
there is a choice between A2 and A1 - scenarios are not opportunities
to choose or not choose. It is also wrong to say that the difference
between A2 and A1 is in essence a difference of economic policy; a main
difference is that whereas in A1 the world succeeds to reduce
population growth quite fast, in A2 population growth in The Third
World remains high for a long time. It is no wonder that if the world
population is higher (A2), then the number of poor people is also
higher. The figure of 984 million is much too precise,
given that the curves in Figure 49 are very uncertain and probably
wrong; indicating the figure with three digits implies a very false
degree of precision.
THE SRES
SCENARIOS
GENERAL COMMENTS:
The IPCC produced a Special Report on Emission Scenarios (Nakicenovic
et al. 2000), abbreviated SRES; it may be downloaded here.
The SRES report formulates 40 socio-economic scenarios for the world up
to the year 2100. They are divided into four main types, called A1, A2,
B1 and B2. Lomborg presents these four in his Figure 51. However, he
greatly misunderstands or misrepresents what the scenarios signify.
This is discussed in detail on this page.
(COMMENT)
Page 163, Figure 51: The size of the A1 pie is given as $3005T.
Comment:
It is stated in the SRES report that the size of the world econonomy in
the A1 world is $529 trillion per year in 2100. It may be calculated
that the total worth
of the income over the century would be around $12,000 trillion. Why
then does Lomborg tell that the total worth of income over the century
is estimated at $3,005 trillion? This is not evident to the reader, nor
clearly understandable from note 860. The explanation must be that the
future sums have been discounted back to present values. The rate of
discount used to do this is not given, but according to note 860,
Lomborg has used the same dynamic discounting as Nordhaus (2006), i.e.
presumably a discount rate that declines with time.
The
sizes of the slices marked
with black in the other pies depend on the rate of discount.
ERROR
Page 164 top: " Again, this should be seen in the light of a total cost
of global warming . . " Error: No
it should not. The black slices in the pies have nothing to do with
climate mitigation.
FLAW
Page 164 top: " Again, this should be seen in the light of a total cost
of global warming at about $14.5 trillion . . " Flaw: There is no source for this figure,
nor any indication of the uncertainty around the figure. Of course,
considering how difficult, if not impossible, it is to know what will
be the total costs all over the globe up to the year 2100 of global
warming, it is ridiculuous to postulate that one knows what the
cost will be with an accuracy of three significant digits and no
specification of
what scenario it
refers to. If the figure is meant to be of relevance when considering
the SRES scenarios, then it must have been obtained by calculations
that are relevant in relation to these scenarios. This seems not to be
the case.
FLAW
Page 164 top: " . . . or a cost of all the other environmental policies
. . . of about $60 trillion. . . " Flaw:
The black slices in the pies in Figure 51 might signify in part the
costs of following environmentally-friendly paths, and thus these black
slices are what should be compared to Lomborg´s alleged cost of
$60 trillion. Obviously the figures do not fit together, which proves
that the black slices actually do not represent the cost of any
environmental policy.
ERROR
Page 164 bottom: " . . . we can increase wealth by just $0.6 trillion .
. " Error:
Lomborg tries to tell us that the damages from climate change are a
thousand times smaller than the costs of fighting climate change. This
is very wrong. The figure of $0.6 trillion is not obtained in relation
to the SRES scenarios and is thus not comparable to costs calculated
from these. Actually the cost of mitigation by 2050 is in the size
order of 0.1 - 1.8 % of global GDP (see above), which will probably
keep the temperature increase at 2 - 3° C and prevent the most
serious damages from climate change in the years after that. The
prevented damages might very well be in the range of 1 % of GDP,
as an average of several estimates, wherefore it seems that cost and
benefits approximately are at a ratio of 1:1. This is very different
from Lomborg´s postulate of 1:1000, which illustrates how far out
Lomborg´s postulates in this chapter are.