Wednesday, July 30, 2008 at 12:03am
IPCC external reviewer Dr Madhav Khandekar says the UN body has exaggerated the costs of global warming:
Using unpublished work to bolster claims of escalating economic costs while ignoring peer reviewed studies which document otherwise is an unacceptable and unscientific practice…
The exaggerated claim of GW impacts by the IPCC has led to a distortion of the reality of climate change and its future impact. The earth’s climate has changed and is changing continuously, a fact accepted by most climate scientists on both sides of the present debate. Is the present climate change deleterious to human societies? Are there beneficial aspects of climate change that have been overlooked? Do adverse impacts outweigh beneficial impacts? We do not have all the answers yet. There is a definite need to carefully analyze climate change impact on world-wide human societies. The IPCC assessment is far from objective and needs to be critically re-assessed.
The full paper, kindly sent to me by Dr Khandekar, a former research scientist with Environment Canada who holds a PhD in meteorology and has worked in the fields of climatology, is below:
MULTI-SCIENCE PUBLISHING CO. LTD.
5 Wates Way, Brentwood, Essex CM15 9TB, United Kingdom
VOLUME 19 No. 5 2008
HAS THE IPCC EXAGGERATED ADVERSE IMPACT
OF GLOBAL WARMING ON HUMAN SOCIETIES?
Madhav L Khandekar
HAS THE IPCC EXAGGERATED ADVERSE IMPACT
OF GLOBAL WARMING ON HUMAN SOCIETIES?
Madhav L Khandekar1
Environmental Consultant Unionville Ontario CANADA 1. INTRODUCTION
Has the IPCC exaggerated adverse impact of Global Warming on human societies?
Yes, Certainly! Let me explain: While reviewing the IPCC WGII (Working Group
II) Chapter “Assessment of observed changes and responses in natural and managed
systems” (Chpt.1, WGII IPCC, 2007) as an external reviewer, I felt time and time
again that there were areas where the chapter authors highlighted adverse impact of
GW (Global Warming) on human societies, while downplaying possible beneficial
impacts. The IPCC authors referred to several publications which projected adverse
impacts while ignoring many excellent studies which have questioned these
projections. Throughout the text of this important chapter of WGII, there were many
instances where adverse impact was highlighted or exaggerated, while possible
beneficial impacts were totally ignored. Further, IPCC authors while assessing
observed changes in natural systems chose to highlight only those changes which
support the GW hypothesis while completely ignoring other observed changes which
did not conform to the human-induced GW hypothesis and change. Such cherrypicking
of observed climate change to bolster claims of human-caused GW and
climate change is disingenuous and does not help understand the real cause of how and
why the earth’s climate has changed in historical and geological times.
A detailed reading of the Chapter left me with an impression that the deleterious
impact of GW on human societies was so imminent and overwhelming that unless
something is done right away (to curb the warming), human societies world over are
about to perish!
The following section provides selected examples (from Ch 1 WGII) of
exaggerated claims made by the IPCC authors:
1Dr Madhav L Khandekar is a former Research Scientist from Environment Canada and is presently on the
editorial board of the Journal Natural Hazards ( Kluwer, Netherlands). Khandekar has been in the fields of
weather & climate for over fifty years and has published over 120 papers, reports, book reviews etc. While
at Environment Canada, Khandekar wrote a monograph on ocean surface wave analysis and modeling which
has been published by Springer-Verlag in 1989. Khandekar is an External Reviewer for the IPCC 2007
Climate Change Documents.
Address for correspondence: 52 Montrose Crescent, Unionville, Ontario, Canada, L3R 7Z5: email@example.com
714 Energy & Environment · Vol. 19, No. 5, 2008 2. SELECTED EXAMPLES
1. Executive Summary: Here the GW impacts are listed under several
categories, in each a deleterious impact is prominently spelled out. Examples:
increasing droughts and flash floods, widespread coastal erosion, cryospheric
changes and resulting glacial floods, increased run-off in snow & glacial
basins, lower crop yields due to warming with an example for the Sahel region
(Africa) due to reduction in decadal scale precipitation, impact on human
health (cholera etc) related to El Nino-Southern Oscillation incidences,
increased vector-borne diseases and some water-borne diseases, increasing
global catastrophes and significant increases in the values of exposure at risk.
2. Observed Changes in systems & Sectors: Here examples given are:
cryospheric reduction world-wide and rapid glacier melts in South America,
escalating sea-level rise, the European heat wave of summer 2003, increase in
world-wide drought areas and possibly in flood areas as well, changes in
coastal processes due to escalating sea-level rise.
3. Terrestrial & Biological Systems: changes in phenology (seasonal activities
of animals and plants) and their northward migration in Europe.
4. Agriculture & Forestry: The overall discussion emphasizes reduction in
crops and yields due to warming with specific example of Sahel region;
increased risk of forest fire activity with increasing temperature.
5. Human Health: Here an increased possibility of outbreak of malaria with
examples from East Africa ( Kenya) and South Asia, water-borne disease like
cholera in South Asia and other ENSO (El Nino-Southern Oscillation) related
health impacts in Asia are highlighted.
6. Disasters & Hazards: A general theme here is “ increase in catastrophic
events like floods, droughts, heat waves etc and related economic losses
worldwide which are all directly related to warming of the earth’s surface
temperature’. As supporting evidence, a couple of unpublished documents are
cited, while several published studies refuting such increases are ignored.
3. A REALITY CHECK WITH OBSERVATIONS
AND PEER-REVIEWED STUDIES
It is imperative to analyze various claims made above in the context of the reality of
climate as it continues to evolve in different regions of the earth. It is also important
to carefully assess all available literature and observed data to determine if the present
climate does indeed follow the “Global Warming” path as projected by the IPCC
scientists and the climate model projections.
The Executive Summary for Chapter 1 uses terms like “increase in floods, flash
floods etc” which are very general in nature and do not appear to have been thoroughly
analyzed to determine if there is indeed a ‘human influence’ in such events. Several
peer-reviewed studies published in recent literature document an increase in extreme
weather (EW) however, a close analysis reveals that such ‘increase’ is more a
perception than reality. In a report prepared for the Government of Alberta in western
Canada (Khandekar 2002), I have examined typical EW events like thunderstorms,
tornadoes, floods, droughts, heat waves for the Canadian Prairie provinces and
concluded that none of the EW events showed any increase in recent years. I have also
examined such EW events elsewhere (Khandekar et al, 2005) and the general
conclusion was that these events did not show any systematic increase/decrease in
recent years. As synthesized by Khandekar et al (2005) “the link between GW & EW
is more a perception than reality, this perception being fostered as a result of increased
awareness and media attention to such weather events”. Additional discussion on EW
will be presented in a later section.
A reality check for some of the items listed earlier is presented below:
1. Cryospheric Reduction: Glacier retreat and advances are part of natural
variability and not a direct consequence of GW as IPCC authors seem to imply
in their assessment. The authors have avoided referring to many studies readily
available in peer-reviewed literature while emphasizing studies which
purportedly show ‘rapid’ shrinking of world-wide glaciers and associated sealevel
rise. One of the most talked about examples is the ‘vanishing ice cap on
Mt Kilimanjaro’ in equatorial Africa. This melting has been going on for well
over a hundred years now as documented in a paper by Kaser et al (2004). The
paper by Kaser et al discounts any GW impact and suggests a drastic drop in
atmospheric moisture at the end of the 19th century and the ensuing drier
climate as possible reasons for the declining ice cap. Ironically however, the
authors of Ch1 did not refer to this important paper as well as several other
papers on the glaciers in the Swiss Alps and elsewhere (e.g., Hormes et al
2001, 2006). A few other papers suggest glacier shrinking to solar variability
during the Holocene in particular. The issue of glacier retreat and advance is
much more complex than what IPCC authors have presented in their simplistic
treatment using the GW hypothesis.
2. The European summer 2003 heat wave: The heat wave in Europe during
June-July of 2003 was an exceptional event and received wide publicity
because of a large number of fatalities due to dehydration and heat stress
which affected several thousand elderly people in France and elsewhere in
Western Europe. Although an exceptional weather event, the 2003 European
heat wave was by no means unprecedented and was a result of a persistent
upper-level ridge of high pressure over the Continent (see AMS Bulletin,
June 2004). Linking the 2003 heat wave in Europe to human activity is
unconvincing and without any merit. Such heat waves have occurred in the
past in various parts of the earth and have been triggered by various
reasons, most commonly due to an anomalous but not uncommon
atmospheric flow pattern. What is of interest here is that just six months
earlier, the winter months of December 2002 and January 2003 were
unusually cold in many parts of North America, Europe and this unusually
cold winter was felt even in the tropical latitudes of Vietnam and
Bangladesh where several hundred people died of long exposure to
significantly below normal temperatures. The winter season of 2002/03 over
Northern Hemisphere was much more wide-spread globally than the
Has the IPCC Exaggerated Adverse Impact of Global Warming on Human Societies? 715
European heat wave of summer 2003. The IPCC authors highlighted the
European heat wave as an example of human activity induced EW event,
but completely ignored the unusually cold winter season of 2002/03. Also
the summer (June/July/August) of 2004 was one of the coldest over most of
North America. These and many other recent climate anomalies of cold as
well as warm season are most certainly due to natural climate variability
and are in no way associated with human activity.
3. Changes in phenology: Most studies cited in this area are almost
exclusively for Europe where considerable research efforts have documented
changes in bird and vegetation migration in the last few years. However a
significant lack of such studies from other regions of the world makes it
difficult to draw any conclusion about climate change link to this
‘northward’ migration. The IPCC authors do not provide any explanation for
lack of studies in other regions while concluding climate change impact on
4. Impact on Agriculture: The IPCC authors imply a deleterious impact of GW
warming on agriculture by providing an example of Sahel region where
recurring droughts have reduced peanut crop yield in recent years. The IPCC
authors completely ignore increased agriculture yields in other grain
producing regions (India, Canada, USA, Australia) where the mean
temperature has warmed by about 1C in the last fifty years, however grain
yields have not declined at all. In India, improved farming and irrigation
technology has resulted in four to five fold increases in rice and wheat yield
since 1950 (see Selvaraju 2003). Similar increase in grain yield has been
recorded in other grain producing countries which IPCC authors have
completely ignored. The IPCC authors also ignore the beneficial impacts of
increasing concentrations of carbon dioxide on world-wide forestry. Recent
satellite data show convincingly that the world forests have been enriched due
to increasing concentration of carbon dioxide and this has helped increase the
“greening” of the earth’s surface.
5. Disasters & Hazards: The IPCC continues with its theme of “increased
catastrophes world-wide leading to increased economic losses”. The evidence
for increased economic losses is presented using an obscure unpublished study
(Miller et al 2006) while several peer-reviewed studies, notably by the highly
respected US climatologist Stanley Changnon are completely ignored.
Changnon and his associates have amply documented that the Shifting
Economic Impacts from Weather Extremes is a Result of Societal Change, Not
Global Warming (Chagnon 2003, Chagnon et al 2001). Using unpublished
work to bolster claims of escalating economic costs while ignoring peerreviewed
studies which document otherwise is an unacceptable and
6. Human Health: The IPCC raises the specter of malaria becoming more
prevalent in a warmer future climate. The IPCC also refers to possible increase
in cholera and other ENSO related health impacts in south Asia, in particular.
Several studies by Dr Paul Reiter, an expert epidemiologist at the Pasteur
Institute in Paris (e.g., Reiter 2001) demonstrate that the mosquito-borne
716 Energy & Environment · Vol. 19, No. 5, 2008
diseases like malaria and dengue fever were prevalent in Europe and elsewhere
even during the Little Ice Age. Reiter further demonstrates that the control of
malaria and dengue is determined by human activity, ecology and vector
biology and there is no simple relationship to changing climate or to GW. The
IPCC reference to cholera and other ENSO related health impacts in south
Asia is a normal occurrence during the Asian Monsoon season and has no
relation to GW or climate change. 4. EXTREME WEATHER, SEA-LEVEL RISE AND OTHER ISSUES
Extreme Weather (EW) and Sea-level Rise (SLR) are two of the most contentious
issues in the present debate on GW impact. The IPCC Documents and climate
models project increasing EW events and an escalating SLR as the earth’s mean
temperature rises in future. As mentioned earlier, the EW/GW link is more a
perception than reality, primarily due to increased media attention. Many EW events
of the past have remained unnoticed and unreported due to lack of observing
technology and/or due to lack of interest in these events at the time. The recent
media hype about EW events has provided a new spin to these events as the
harbinger of future climate! Ironically, some of the winter season EW events are
also being linked with GW impact which neither the IPCC nor the climate models
project as possible GW impact. The recent statement on EW put out by the WMO
(World Meteorological Organization, Geneva) includes some winter weather
extremes of the Southern Hemisphere (SH). Two noteworthy winter weather
extremes from the SH this year are: 1. several centimeters of snow in Buenos Aires
(Argentina) on July 7, 2007, followed by a shivering temperature of –22C! The last
time it snowed in Buenos Aires was in 1918! 2. On 27 June 2007, a cold front moved
across South Africa bringing the country’s first significant snowfall since 1981 (25
cm in parts of the country). Many other winter weather extremes have been reported
in recent years (see Khandekar 2003, 2004). Interestingly, none of the climate
models offer any explanation for the increasing frequency of winter weather
extremes in recent years.
The SLR and its estimate for the next one hundred years has been a subject of
several dozen studies in recent years. Many of these studies assume significant melting
of the Arctic and Antarctic ice shelves (principally Greenland and West Antarctic ice
sheets) during the next 50 to 100 years and this melt-down could produce an escalated
SLR with values as high as 1 to 2 meters (or more) over the next 100 years. There are
several uncertainties in these estimates and the possibility of significant melt-down of
Arctic & Antarctic Ice Sheets remains far from certain. Other recent papers now seem
to suggest that the SLR due to melting of mountain glaciers and ice caps (outside of
Arctic & Antarctic) will only be about 5 cm over next 100 years, just half the earlier
estimate. Another recent paper (Holgate 2007) documents that the SLR during the first
half of the 20th century was higher than the latter half of the century, thus discounting
any suggestion about ‘escalating SLR at present’.
For many countries in the higher latitudes of both the Hemispheres, the present
climate change (milder winters, reduced house-heating cost, longer agricultural
season) can be beneficial in general. The IPCC scientists have completely missed this
aspect of climate change.
Has the IPCC Exaggerated Adverse Impact of Global Warming on Human Societies? 717 5. CONCLUDING REMARKS
The exaggerated claim of GW impacts by the IPCC has led to a distortion of the reality
of climate change and its future impact. The earth’s climate has changed and is
changing continuously, a fact accepted by most climate scientists on both sides of the
present debate. Is the present climate change deleterious to human societies? Are there
beneficial aspects of climate change that have been overlooked? Do adverse impacts
outweigh beneficial impacts? We do not have all the answers yet.
There is a definite need to carefully analyze climate change impact on world-wide
human societies. The IPCC assessment is far from objective and needs to be critically
I wish to express my sincere appreciation to Benny Peiser for encouraging me to
prepare this article. REFERENCES
AMS Bulletin 2004: Annual Climate Review 2003, p. S1–S72, Bulletin American
Meteorological Society June 2003.
Changnon S A et al 2000: Trends in socio-economic impacts related to weather & climate
extremes in the USA. Bulletin, American Meteorological Society, 81, 437–442.
Changnon S A 2003: Shifting economic impacts from weather extremes in the United States: A
result of societal change, not global warming. Natural Hazards 29, June 2003, 273–290.
Holgate S J 2007: On the decadal rates of sea level change during the twentieth century.
Geophysical Research Letters, 34 L01602, doi:10.1029/2006GL028492.
Hormes A. et al 2001: The Alps with little ice: evidence for eight Holocene phases of reduced
glacier extent in the central Swiss Alps. The Holocene, 11, 255–265.
Holmes A. et al 2006: A geochronological approach to understanding the role of solar activity
on Holocene glacier length variability in the Swiss Alps. Geogra. Ann. 88A(4),
281–294(Swedish Society for Anthropology & Geography).
Khandekar M L 2002: Trends and changes in extreme weather events: An assessment with a
focus on Alberta and Canadian Prairies. Report prepared for Alberta Environment (Canada),
October 2002, ISBN 0-7785-2428-0, p.56.
Khandekar M L 2003: Comments on WMO statement on extreme weather events. EOS, V 84,
No. 41, 14 October 2003( FORUM).
Khandekar M L 2004: Are climate model projections reliable enough for climate policy? Energy
& Environment 15 521–525.
Khandekar M L et al 2005: The global warming debate: A review of the state of science. Pure
& Applied Geophysics 162 1557–1586.
Miller S et al 2006: Weather related catastrophe loss trends and the impact of climate change.
To be published ( to be circulated prior to publication) [comment: This is all the info available
on this study. I find it incredible that the IPCC authors would use this obscure unpublished study
718 Energy & Environment · Vol. 19, No. 5, 2008
to bolster claims of increased economic losses while ignoring other available studies which
refute such claim].
Reiter Paul 2001: Climate change and mosquito-borne disease. Environmental Health
Perspectives, 109, 141–161.
Selvaraju R 2003: Impact of El Nino-Southern Oscillation on Indian food-grain production. Int’l
J of Climatology 23 187–206.
Has the IPCC Exaggerated Adverse Impact of Global Warming on Human Societies? 719