Testimony of Dr. John Christy
Greenhouse
http://www.co2science.org/edit/editor.htm
The 13 May 2003 Testimony of Dr. John Christy Before the
U.S. House of Representatives' Committee on Resources
Volume 6, Number 22: 28 May 2003
--------------------------------------------------------
In view of the intense controversy that currently swirls about the subject
of satellite-derived tropospheric temperatures [see our Editorial of 7 May
2003 for some of our thoughts on the subject], we here, for the benefit of
the public and with the blessing of Dr. Christy, reprint the written
testimony he presented to the Committee on Resources of the U.S. House of
Representatives on the topic.
*****
I am John Christy, Professor of Atmospheric Science and Director of the
Earth System Science Center at the University of Alabama in Huntsville or
UAH. I am also Alabama's State Climatologist and recently served as a Lead
Author of the U.N.'s Intergovernmental Panel on Climate Change.
CARBON DIOXIDE
The concentration of carbon dioxide (CO2) is increasing in the atmosphere
due primarily to the combustion of fossil fuels. Fortunately (because we
produce so much of it) CO2 is not a pollutant. In simple terms, CO2 is the
lifeblood of the planet. The vegetation we see around us would disappear if
not for atmospheric CO2. This green world largely evolved during a period
when the atmospheric CO2 concentration was many times what it is today.
Indeed, numerous studies indicate the present biosphere is being invigorated
by the human-induced rise of CO2. In and of itself, therefore, the
increasing concentration of CO2 does not pose a toxic risk to the planet.
In other words, carbon dioxide means life itself. CO2 is not a pollutant.
As an aside, it is clear that other emissions may be called pollutants, e.g.
sulfur oxides, nitrogen oxides and mercury. Controlling these is a
completely separate issue from controlling emissions of CO2 and so will not
be discussed here.
It is the secondary impact of increasing CO2 that may present challenges to
human life in the future. It has been proposed that CO2 increases could
cause climate change of a magnitude beyond what naturally occurs in the
climate system so that costly adaptation or significant ecological stress
might occur. For example, enhanced sea level rise and/or reduced rainfall
would be two possible effects likely to be costly to those regions so
affected. Data from the past and projections from climate models are
employed to provide insight on these concerns.
CLIMATE MODELS
Will increases in CO2 affect the climate significantly? Are significant
changes occurring now? Climate models suggest the answer is yes, real data
suggest otherwise. Climate models attempt to describe the ocean/atmospheric
system with equations which approximate the processes of nature. No model
is perfect because the natural system is incredibly complex. One modest
goal of model simulations is to describe and predict the evolution of the
ocean/atmospheric system in a way that is useful to discover possible
environmental hazards which lie ahead. The goal is not to achieve a perfect
forecast for every type of weather in every unique geographic region, but to
provide information on changes in large-scale features. If in testing
models one finds conflict with even the observed large scale features, this
would suggest that at least some fundamental processes, for example heat
transfer, are not adequately described in the models.
A common feature of climate model projections with CO2 increases is a rise
in the global surface temperature as well as an even more rapid rise in the
layer up to 30,000 feet called the troposphere.
Over the past 24+ years various calculations of surface temperature indeed
show a rise of about 0.7 °F. This is roughly half of the total rise
observed since the 19th century. In the lower troposphere, however, various
estimates which include the satellite data Dr. Roy Spencer of UAH and I
produce, show much less warming, about 0.3 °F - an amount less than half
that observed at the surface. The real world shows less warming in the
atmosphere, not more as models predict. Are these data reliable?
A new version of the microwave satellite data has been produced, but not yet
published, by Remote Sensing Systems or RSS of California. Two weeks ago a
paper was published in Science magazine' electronic edition which used a
curious means of testing our UAH version against RSS.[1] The paper cited
climate model results which agreed more with RSS, because RSS data showed
about 0.4°F more warming than UAH's data for this same layer called the
mid-troposphere. UAH's total warming for this layer was about 0.05°F.
(This layer is higher in the atmosphere than the lower troposphere mentioned
earlier with its 0.3°F warming.) The strong implication of the paper was
that since RSS was more consistent with the model output, it was likely a
more accurate dataset than ours.
That same week, with much less fanfare, my latest paper appeared in the
Journal of Atmospheric and Oceanic Technology.[2] Unlike the paper in
Science magazine, I performed several rigorous tests to estimate the
potential error of our UAH satellite data. I used real observations from
balloon datasets created by independent organizations, some with data from
as many as 400 different balloon stations. Our UAH satellite data and the
balloon data corroborated each other with remarkable consistency, showing
only a slow warming of the bulk of the atmosphere. This evidence indicates
that the projected warming of the climate model had little consistency with
the real world. This is important because the quantity examined here, lower
tropospheric temperature, is not a minor aspect of the climate system. This
represents most of the bulk mass of the atmosphere, and hence the climate
system. The inability of climate models to achieve consistency on this
scale is a serious shortcoming and suggests projections from such models be
viewed with great skepticism.
Changes in surface temperature have also been a topic of controversy. The
conclusion in IPCC 2001 that human induced global warming was clearly
evident was partly based on a depiction of the Northern Hemisphere
temperature since 1000 A.D. This depiction showed little change until about
1850, then contains a sharp upward rise, suggesting that recent warming was
dramatic and linked to human effects.[3] Since IPCC 2001, two important
papers have shown something else.[4] Using a wider range of information
from new sources these studies now indicate large temperature swings have
been common in the past 1000 years and that temperatures warmer than today's
were common in 50-year periods about 1000 years ago. These studies suggest
that the climate we see today is not unusual at all.
WEATHER EXTREMES AND CLIMATE CHANGE
I want to encourage the committee to be suspicious of media reports in which
weather extremes are given as proof of human-induced climate change.
Weather extremes occur somewhere all the time. For example, in the year
2000 in the 48 conterminous states, the U.S. experienced the coldest
combined November and December in 106 years. We've just again witnessed a
colder than average winter in the Eastern US with some record snowfalls here
and there, while the California mountains had one of the coldest and
snowiest April's ever. However, looking at these events does not prove the
country is experiencing global cooling any more than a hot July represents
global warming.
Has hot weather occurred before in the US? In my region of Alabama, the 19
hottest summers of the past 108 years occurred prior to 1955. In the
midwest, of the 10 worst heatwaves, only two have occurred since 1970, and
they placed 7th and 8th. Hot weather has happened before and will happen
again. Such events do not prove climate change is occurring.
Similar findings appear from an examination of destructive weather events.
The intensity and frequency of hurricanes have not increased. The intensity
and frequency of tornadoes have not increased. The same is true for
thunderstorms and hail. (Let me quickly add that we now have more people
and much more wealth in the paths of these destructive events so that the
losses have certainly risen, but that is not due to climate change but to
progress.) Droughts and wet spells have not statistically increased or
decreased. In a paper published last year I demonstrated from a rigorously
constructed temperature dataset for North Alabama that summer temperatures
there have actually declined since the 19th century.[5] Similar results
have been found within states from California to Georgia.
One century is a relatively short time in terms of climate time scales.
When looking at proxy records of the last 2000 years for drought in the
Southwest, the record suggests the worst droughts occurred prior to 1600.
The dust bowl of the 1930's appears as a minor event on such a time scale.
This should be a warning that with or without any human influence on climate
we should be prepared for a significant, multi-year drought. (Low cost
energy would help mitigate the costs of transporting water to the stricken
areas.)
When considering information such as indicated above, one finds it difficult
to conclude that climate change is occurring in the US and that it is
exceedingly difficult to conclude that part of that change might have been
caused by human factors.
In the past 150 years, sea level has risen at a rate of 6 in. ± 4 in. (15 cm
± 10 cm) per century and is apparently not accelerating. Sea level also
rose in the 17th and 18th centuries, obviously due to natural causes, but
not as much. Sea level has been rising naturally for thousands of years
(about 2 in. per century in the past 6,000 years). If we look at ice
volumes of past interglacial periods and realize how slow ice responds to
climate, we know that in the current interglacial period (which began about
11,000 years ago) there is still more land ice available for melting,
implying continued sea level rise with or without climate change.
One of my duties in the office of the State Climatologist is to inform
developers and industries of the potential climate risks and rewards in
Alabama. I am very frank in pointing out the dangers of beach front
property along the Gulf Coast. A sea level rise of 6 in. over 100 years, or
even 50 years is minuscule compared with the storm surge of a powerful
hurricane like Fredrick or Camille. Coastal areas threatened today will be
threatened in the future. The sea level rise, which will continue, will be
very slow and thus give decades of opportunity for adaptation, if one is
able to survive the storms.
The main point I stress to state and local agencies as well as industries is
that they invest today in infrastructure that can withstand the severe
weather events that we know are going to continue. These investments
include extending flood way easements, improvements in storm water drainage
systems and avoiding hurricane-prone coastal development, among other
actions. There are ways to reduce our vulnerabilities (i.e. enhancing our
resilience) by increasing the investment today in the proper infrastructure
or by avoiding future disasters with common sense building regulations. Our
economy is affected much more by these extreme events which arrive every few
years or decades versus whatever slow changes may occur due to human-induced
climate change. The economic payoff would be tangible for such investments.
The payoff for restricting energy use and economic activity for an unknown
(and likely unknowable) future based on climate change scenarios is much
less profitable for all concerned.
KYOTO'S IMPACT ON CLIMATE AND ECONOMY
One week ago today, the BBC published a report noting that the European
Union has again exceeded their annual carbon dioxide targets under the Kyoto
agreement. So, in countries with apparently strong motivation for reducing
carbon dioxide the treaty is failing. But that really is not a problem.
(Under the Kyoto Treaty the U.S. was asked to reduced CO2 emissions 7% below
1990 levels.)
There have been many proposals to reduce CO2 emissions, some in this
country, both more and less harsh than the Kyoto Protocol. In one way or
another, each proposal seeks to limit energy usage through direct or
indirect increases of the cost over market prices. A fundamental fact that
our nation needs to understand is that any of these proposals if
implemented, will have an effect on the climate so small that we would not
be able to detect it. This is something I can speak to as my work focuses
on precise measures of climate quantities. The evidence convinces me that
none of these proposals would change to a noticeable degree whatever the
climate is going to do. Raising the cost of energy with no detectable
result generally falls into the category of a waste of American income.
I am decidedly an optimist about this situation. Our country is often
criticized for producing 25% of the world's anthropogenic CO2. However, we
are rarely recognized and applauded for producing, with that same CO2, 31%
of what the world wants and needs; it's food, technology, medical advances,
defense of freedom, and so on.[6] Today this is done primarily with the
burning of carbon, but in the future will come from other inexpensive and
efficient sources. For example, the US produces a unit of GDP using about
55% of the energy required to produce the same unit in 1970. The U.S. is
decarbonizing its economy and this will continue. Even though carbon
dioxide is not a pollutant, and energy from carbon allows people to live
better lives, we can look forward to new sources of energy as the genius of
America works on the next source of inexpensive energy.
I often mention that early in my career I served as a missionary in Africa.
I lived upcountry with people who did not have access to useful energy. Put
simply, access to energy means life, it means a longer and better life. I
watched as women walked in the early morning to the forest edge, often
several miles away, to chop wet green wood for fuel. They became beasts of
burden as they carried the wood on their backs on the return trip home. Woo
d and dung are terrible sources of energy, with low useful output while
creating high pollution levels. Burning wood and dung inside the homes for
cooking and heat created a dangerously polluted indoor atmosphere for the
family. I always thought that if each home could be fitted with an electric
light bulb and a microwave oven electrified by a coal-fired power plant,
several good things would happen. The women would be freed to work on other
more productive pursuits, the indoor air would be much cleaner so health
would improve, food could be prepared more safely, there would be light for
reading and advancement, information through television or radio would be
received, and the forest with its beautiful ecosystem could be saved.
Access to inexpensive, efficient energy would enhance the lives of the
Africans while at the same time enhance the environment.
There are parallels in this country. Any of the proposals to reduce energy
consumption by mandate (promoted in the state legislatures and the Congress)
would do nothing measurable to reduce the climate impacts of CO2. However,
they would cause increases in energy costs (i.e. taxes). These additional
taxes would fall disproportionately on the poor, who buy gasoline and
home-heating at the same rate as everyone else. Their lives would be made
more precarious as a result.
In Hearings such as this we are often asked at the close, "If you were a
congressman for a day, what would you do on this issue?" My answer is two
fold. First, I would do no harm, I would not force energy prices up and
thereby hurt the U.S. economy in general and the poor in particular.[7]
Second, I would help America do what the innovative people of this nation do
the best, help scientists and engineers discover the next source of low
carbon energy, while building up our resilience to weather events, like
floods, droughts, tornadoes, hurricanes that we know are going to continue,
climate change or not.
References
[1] Santer, B., et al., 2003. Influence of Satellite Data Uncertainties on
the Detection of Externally-Forced Climate Change. ScienceExpress
10.1126/science.1082393
[2] Christy, J.R. et al., 2003. Error estimates of Version 5.0 of MSU-AMSU
bulk atmospheric temperatures. Journal of Atmospheric and Oceanic
Technology 20: 613-629.
[3] Mann, M.E., R. S. Bradley, and M.K. Hughes, 1999. Northern Hemisphere
temperatures during the past millennium: Inferences, uncertainties, and
limitations. Geophysical Research Letters 26: 759-762.
[4] Soon, W. and S. Baliunas, 2003. Proxy climatic and environmental
changes of the past 1000 years. Climate Research 23: 89-110.
Esper, J. E.R. Cook, F.H. Schweingruber, 2002. Low-frequency signals in
long tree-ring chronologies for reconstructing past temperature variability.
Science 295: 2250-2253.
[5] Christy, J.R., 2002. When was the hottest summer? A State Climatologist
struggles for an answer. Bulletin of the American Meteorological Society
83: 723-734.
[6] World Development Indicators, World Bank 2001 (for year 2000), US is
$9,388B, World is $31,337B.
[7] Energy Information Administration, Impacts of the Kyoto Protocol on U.S.
Energy and Economic Activity (Washington D.C.: U.S. Department of Energy),
http://www.eia.doe.gov/neic/press/press109.html. Costs estimated for a
reduction of CO2 by 3 % (not Kyoto's 7 %) below 1990 emissions are between
$125 and $280 billion per year of an economy of $9,425 billion, or about 1
to 3 %.
Steve Rosenberg
as I am one myself. But much simpler problems - or at least what appear to
be such - like understanding when there might be a recession currently
escape our abilities.
--
Steve
www.vintagedow.com
"Greenhouse" <Green...@greenhouse.org> wrote in message
news:UzWBa.116185$Vi5.3...@news1.calgary.shaw.ca...
Titan Point
> I love all these discussions on climate models. Not to beat up scientists -
> as I am one myself. But much simpler problems - or at least what appear to
> be such - like understanding when there might be a recession currently
> escape our abilities.
>
>
> --
> Steve
> www.vintagedow.com
>
Just so. But to listen to quite a few on this NG, you'd have thought that
climate models produced testable quality data, which of course, they
don't.
I always wondered: with scientific reporting for peer review, how do you
know whether the output of a climate model making a claim of something is
actually correct? I mean, other than checking for spelling mistakes, bad
punctuation, and decimal points in wrong place, exactly what does a peer
review of such a report do?
Eric Swanson
>
>On Sat, 31 May 2003 20:51:46 -0400, Steve Rosenberg wrote:
>
>> I love all these discussions on climate models. Not to beat up scientists -
>> as I am one myself. But much simpler problems - or at least what appear to
>> be such - like understanding when there might be a recession currently
>> escape our abilities.
>>
>Just so. But to listen to quite a few on this NG, you'd have thought that
>climate models produced testable quality data, which of course, they
>don't.
The climate models are tested against the real world.
They produce the major features of the climate, such as yearly cycles with
the temperature variations across the globe which result. They produce
precipitation where it occurs on Earth and in quantities similar to that
seen. They produce ocean temperature distributions similarly. Cloud cover
and the sea-ice cycle are also reproduced with reasonable accuracy.
While the models results are not exactly the same as seen on Earth, they are
not used that way. They are run as a base line case first, then compared
with other cases after some variable(s) are changes, such as CO2 content of
the atmosphere. This is a logical approach, as any errors in the model would
likely appear in both sets of runs, thus taking the difference between the
cases would cancel out any systematic changes.
>I always wondered: with scientific reporting for peer review, how do you
>know whether the output of a climate model making a claim of something is
>actually correct? I mean, other than checking for spelling mistakes, bad
>punctuation, and decimal points in wrong place, exactly what does a peer
>review of such a report do?
"Peer Review" implies that the reviewer understands the science, something
which you obviously don't, TP Guy. Remember your grossly incorrect diatribe
about the CO2 heating on Mars???
--
Eric Swanson --- E-mail address: e_sw...@skybest.com :-)
--------------------------------------------------------------
David Ball
>I love all these discussions on climate models. Not to beat up scientists -
>as I am one myself. But much simpler problems - or at least what appear to
>be such - like understanding when there might be a recession currently
>escape our abilities.
Hmmm...A is false so B must be too? When we actually have a
discussion on climate models it will be an interesting exercise.
Trouble is, people have tried to start them and the local trolls crawl
out from under their rocks and turn the thread into an exercise in
futility. Discussion of climate models for many here amounts to
nothing more than: models are bad unless they say something that I
want to hear.
David Ball
<titanpoi...@myrealbox.com> wrote:
>On Sat, 31 May 2003 20:51:46 -0400, Steve Rosenberg wrote:
>
>> I love all these discussions on climate models. Not to beat up scientists -
>> as I am one myself. But much simpler problems - or at least what appear to
>> be such - like understanding when there might be a recession currently
>> escape our abilities.
>>
>>
>> --
>> Steve
>> www.vintagedow.com
>>
>Just so. But to listen to quite a few on this NG, you'd have thought that
>climate models produced testable quality data, which of course, they
>don't.
Speaking of the local trolls, here's Titan now. Titan, how
many times have you been told that model output are not data and that
they should never be confused with data? Oh, about a thousand, yet
here you are spreading the big lie again.
Titan Point
> In article <pan.2003.06.01....@myrealbox.com>, titanpoi...@myrealbox.com says...
>>
>>On Sat, 31 May 2003 20:51:46 -0400, Steve Rosenberg wrote:
>>
>>> I love all these discussions on climate models. Not to beat up scientists -
>>> as I am one myself. But much simpler problems - or at least what appear to
>>> be such - like understanding when there might be a recession currently
>>> escape our abilities.
>>>
>
>>Just so. But to listen to quite a few on this NG, you'd have thought that
>>climate models produced testable quality data, which of course, they
>>don't.
>
> The climate models are tested against the real world.
> They produce the major features of the climate, such as yearly cycles with
> the temperature variations across the globe which result. They produce
> precipitation where it occurs on Earth and in quantities similar to that
> seen. They produce ocean temperature distributions similarly. Cloud cover
> and the sea-ice cycle are also reproduced with reasonable accuracy.
No they're not. In fact they're hopeless.
>
> While the models results are not exactly the same as seen on Earth, they are
> not used that way. They are run as a base line case first, then compared
> with other cases after some variable(s) are changes, such as CO2 content of
> the atmosphere. This is a logical approach, as any errors in the model would
> likely appear in both sets of runs, thus taking the difference between the
> cases would cancel out any systematic changes.
But not water vapour. Shame that since water vapour is 97% of all the
greenhouse gases by volume...shame.
Eric Swanson
>
>On Sun, 01 Jun 2003 16:27:11 +0000, Eric Swanson wrote:
>
>> In article <pan.2003.06.01....@myrealbox.com>, titanpoi...@myrealbox.com
says...
>>>
>>>On Sat, 31 May 2003 20:51:46 -0400, Steve Rosenberg wrote:
>>>
>>>> I love all these discussions on climate models. Not to beat up scientists -
>>>> as I am one myself. But much simpler problems - or at least what appear to
>>>> be such - like understanding when there might be a recession currently
>>>> escape our abilities.
>>>>
>>
>>>Just so. But to listen to quite a few on this NG, you'd have thought that
>>>climate models produced testable quality data, which of course, they
>>>don't.
>>
>> The climate models are tested against the real world.
>> They produce the major features of the climate, such as yearly cycles with
>> the temperature variations across the globe which result. They produce
>> precipitation where it occurs on Earth and in quantities similar to that
>> seen. They produce ocean temperature distributions similarly. Cloud cover
>> and the sea-ice cycle are also reproduced with reasonable accuracy.
>
>No they're not. In fact they're hopeless.
Yes, the models are tested against reality.
Can't understand that?? Sorry, TP Guy.
>> While the models results are not exactly the same as seen on Earth, they are
>> not used that way. They are run as a base line case first, then compared
>> with other cases after some variable(s) are changes, such as CO2 content of
>> the atmosphere. This is a logical approach, as any errors in the model would
>> likely appear in both sets of runs, thus taking the difference between the
>> cases would cancel out any systematic changes.
>
>But not water vapour. Shame that since water vapour is 97% of all the
>greenhouse gases by volume...shame.
The models include water vapor. Are you denying this too?
Care to elaborate on your cryptic comment??
>>>I always wondered: with scientific reporting for peer review, how do you
>>>know whether the output of a climate model making a claim of something is
>>>actually correct? I mean, other than checking for spelling mistakes, bad
>>>punctuation, and decimal points in wrong place, exactly what does a peer
>>>review of such a report do?
>>
>> "Peer Review" implies that the reviewer understands the science, something
>> which you obviously don't, TP Guy. Remember your grossly incorrect diatribe
>> about the CO2 heating on Mars???
Still no reply from you about your gross misunderstanding of Mars.
Phil Hays
> But not water vapour. Shame that since water vapour is 97% of all the
> greenhouse gases by volume...shame.
So?
Mass or volume is fairly meaningless. More to the point would be how
much of the spectrum is blocked by water, and how much by CO2, CH4 and
other gases?
And do remember that there is very very little water high in the
atmosphere...
--
Phil Hays