**AFFIDAVIT**

**U.S. Committee on Commerce, Science, and Tourism**

**6 May 2004**

**Carbon Dioxide and Climate Change:**

**Dual Threats to Public Health**

**Paul R. Epstein M.D., M.P.H.**

**Associate Director**

**Center for Health and the Global Environment**

**Harvard Medical School**

**Landmark Center**

**401 Park Drive**

**Boston, MA 02215**

**http://www.med.harvard.edu/chge**

**Summary**

**Rising levels of carbon dioxide (CO~2~) -- in addition to trapping
more infrared (heat) radiation leaving the earth \-- promote plant
pollen production, soil bacteria and fungi, and alter species
composition by favoring opportunistic weeds (like ragweed and poison
ivy). Other emissions from burning fossil fuels in cars, trucks and
buses -- nitrogen compounds (NO~x~s) and volatile organic compounds \--
form photochemical smog that causes and exacerbates asthma, while diesel
particulates help deliver pollen and molds deep into lung sacs. The
combination of air pollutants, aeroallergens, heatwaves and unhealthy
air masses -- increasingly associated with a changing climate -- causes
damage to the respiratory systems, particularly for growing children,
and these impacts disproportionately affect poor and minority groups in
the inner cities.**

**The estimated cost in the U.S. of treating asthma in those younger
than 18 years of age is \$3.2 billion per year. The health impacts
include asthma and other respiratory illnesses, infectious diseases,
heat stress, heart disease. Meanwhile the preventative strategies
include measures that could simultaneously improve air quality and
enhance the livability of urban communities.**

**Combustion of fossil fuels -- oil, coal and natural gas -- is
responsible for air pollution and climate change, and air quality is a
particular problem for urban centers worldwide. Traffic patterns and
automotive exhaust, power plants, airports and industrial emissions are
the primary sources, while wind patterns can bring in pollution and
unhealthy air masses originating in other regions. Allergens (molds and
pollen) originating in rural urban areas can reach high levels in highly
populated cities.**

**The impacts of air pollution can be compounded by extreme weather
events, whose intensity and frequency is increasing as climate changes.
These include more heatwaves, drought-driven fires, floods and the
impacts of warming are exacerbated by "the heat island effect" generated
in cement cities with inadequate green space.**

**Today, atmospheric concentrations of CO~2~ are 379 parts per million.
The earth has not experienced levels of CO~2~ above 280 ppm for at least
420,000 years. This report examines the direct impacts of CO~2~ combined
with the climate change the rise generates, focusing on urban centers;
examining synergies between air pollution and climate change and
connections between climate change and emerging infectious diseases --
in particular, West Nile virus, a disease carried by urban-dwelling
mosquitoes that presents new problems for public health and mosquito
control authorities.**

**[Key Points]{.underline}**

1.  **Ragweed** (in vacant lots and other disturbed areas) pollen and
    tree pollens (e.g., maples, birches, poplars) are stimulated by
    increased carbon dioxide (CO~2~), and by warmer winters and early
    arrival of spring.

2.  **Molds** are also stimulated by higher levels of CO~2~. In
    addition, humidity, heavy rain and floods associated with climate
    change foster fungal growth in houses.

3.  **Diesel** particles combine with aeroallergens (pollen and mold) to
    deliver them deep into lung sacs.

4.  Fungal growth inside houses can affect respiratory **health and
    insurance coverage**.

5.  Floods can drive **rodents** from their natural burrows into
    developed areas.

6.  **Photochemical smog** (ground-level ozone) is a product of
    reactions between tailpipe emissions -- oxides of nitrogen (NO~x~s)
    and volatile organic compounds (VOCs) \-- and the chemical reaction
    is accelerated during heatwaves -- intensified with climate change.

7.  **Heatwaves**, unhealthy air masses, high heat indices (a function
    of temperature and humidity), plus lack of nighttime relief all
    affect cardio-respiratory illness and mortality.

8.  Increased **humidity** and **nighttime temperatures** (daily
    minimums) are associated with a changing climate.

9.  The **Heat Island Effect** can raise ambient temperatures in urban
    centers as much as 7ºF over those in rural areas.

10. **Particulates**, carbon monoxide (**CO**), ground-level ozone and
    carcinogenic polycyclic aromatic hydrocarbons (**PAHs**) from
    drought-driven wildfires can affect populations living far from the
    fires.

11. **West Nile virus** in the U.S. is a new phenomenon \-- a
    mosquito-borne disease in urban areas; one not previously faced by
    public health and mosquito control agencies.

12. The avian-mosquito cycle of West Nile virus (WNV) is amplified by
    **warm winters, spring droughts and summer heatwaves**. Bird-biting,
    urban-dwelling mosquitoes (*Culex pipiens*) breed in shallow pools
    in city drains with organically-rich litter (e.g., leaves and
    pollen). The disease threatens humans, birds and other wildlife.

13. **Severe and erratic weather** -- early and late snowstorms, ice
    storms and dense fog -- present hazards for automotive drivers and
    pedestrians.

14. **Severe storms** in coastal cities (intensified by sea level rise)
    can damage infrastructure, such as water and sanitation systems,
    with wide-ranging implications for public health.

15. **Early warning systems** of conditions conducive to large outbreaks
    of WNV can facilitate environmentally-friendly public health
    interventions.

16. **Roof gardens, urban parks, tree--lined streets**, "smart growth,"
    and improved pedestrian, bicycle and public **transport** can reduce
    the "Heat Island Effect."

17. Developing **alternatives to fossil fuels** is fundamental for the
    protection of public health and for maintaining environmental and
    economic stability.

**Affidavit**

Global warming has entered our backyards.

I begin with findings from the home state of this committee's chair --
the honorable Senator John McCain. Just outside Tucson, Arizona
Biosphere II was erected to examine the way Earth functions. After
several years of humans and animals living with plants and small oceans,
carbon dioxide (CO~2~) levels rose. Weeds flourished and, when I visited
with a team of scientists, the ants were crawling everywhere.

Biosphere II is becoming our new reality. CO~2~ levels are today 379
parts per million \-- having risen 3 ppm last year, up from the average
1.8 ppm throughout the 1990s \-- 100 ppm above where they have been for
over 420,000 years, and, probably, for 2 million years when earth began
cycling between medium and large size ice caps. Today we are speeding
head-long into a third state -- with small polar caps. We are in truly
in uncharted, overheated waters.

Weedy species---ragweed, poison ivy and insects ---thrive on disturbance
and, for plants, CO~2~ provides new opportunities for the opportunists
to flourish. Weeds and pioneering trees, whose seeds and pollen line our
streets and enter our airways, increase with CO~2~ as do molds,
mosquitoes, bark beetles and aphids that threaten our nation's forests.

CO~2~, released in our breath attracts mosquitoes and we use CO~2~ in
mosquito traps to catch and sample them. Whether rising CO~2~ stimulates
mosquito activity, in general, requires further study.

Then we come to what we know from elemental chemistry: CO~2~ stimulates
plant growth through photosynthesis, combining with water to generate
carbohydrates and oxygen---plants being the primary producers of our
food and air. But some plants respond to higher levels of CO~2~ by
producing excessive amounts of pollen, enabling them to spread. And
those most stimulated are the weedy, opportunistic species. Ragweed, and
some pioneering trees that colonize field edges, seize upon increased
levels of CO~2~ to grow in new, often disturbed, territory. Poison ivy
also thrives in higher CO~2~ levels. Abandoned lots in urban centers are
ideal places for the spread of ragweed, as are old railway lines and
fields following fires.

***[What are the new concerns for public health?]{.underline}***

Let's look at urban centers first.

> 1\. Asthma and associated childhood mortality has increased 2½ - 3
> times since 1984. 7.5% of the U.S. population has asthma; 11-12% of
> children; and ¼ of the children in Harlem suffer from this sometimes
> frightening and life-threatening affliction.

Asthma affects patients and parents, causes school and work absences,
and costs the health care system \$18 billion per year.

> 2\. Pollen counts are rising exponentially. Levels of 100 to 150
> grains per cubic meter often generate alerts. In the past few springs
> levels of up to
>
> 6, 000 grains per M^3^ have been reported in many U.S. cities and we
> see it on ponds and roadways and feel it in our lungs.

Of note, mosquito larvae eat pollen. This is an added stimulus for the
carriers of West Nile virus, a mosquito-borne disease in cities. Public
health authorities know well how to control mosquitoes in rural areas;
but this new problem poses new challenges as to how safely to use
chemicals in the cities. Horses and birds are affected and the disease
is now spreading in the Americas.

3.  CO~2~ also stimulates molds.

4.  Warm temperatures stimulate ragweed pollen (Wan *et al., 2000)* and
    humidity and floods foster fungal growth.

5.  Another surprise is that CO~2~ levels in cities have reached
    extraordinary levels.

Under CO~2~ domes -- paralleling the "heat island effect," inversions
and unhealthy air masses -- researchers (Idso *et al*., 1998, 2001;
Ziska *et al.*, 2000, 2003) have found levels in the four and five
hundreds in Phoenix, Baltimore, and a reading of 611 ppm in New York
City.

> 6\. Diesel particles --themselves damaging to the lungs \-- provide an
> excellent delivery system for pollen and molds. They attach to the
> particles, helping them penetrate deep into lung sacs and sensitizing
> immune (defense) cells to the allergens.
>
> 7\. Photochemical smog -- ground-level ozone (O~3~) -- also causes
> asthma. This was demonstrated in Los Angeles, and the heatwaves --
> like the spring heatwave that occurred last week accelerates the
> reaction of the tailpipe emissions that combine to form ozone.
>
> 8\. In another recent surprise, CO~2~ -- that traps heat and is
> swelling the inner atmosphere (out to six or eight miles) -- is
> contracting the outer atmosphere (stratosphere, mesosphere and
> thermosphere) out to hundreds of miles. This new finding -- that our
> activities are affecting the atmosphere so far out, in addition to
> slowing repair of the 'ozone hole'\-- could cause the numerous
> satellites we have up to change their trajectories.

The concoction of pollen, molds, particles, unhealthy air masses,
photochemical smog and more intense heatwaves is assaulting our lungs,
especially for our young ones, and all these factors are related to the
emissions from fossil fuels \-- indirectly, through their impact on
plants and directly via heatwaves and the trapping of heat by CO~2~ and
other greenhouse gases.

While we comfort ourselves that public health authorities can control
emerging threats to our health, the ones I describe can only be
prevented.

***[Forest health]{.underline}***

Meanwhile plants, themselves, are under attack from insects and fungi.
From New Mexico to Alaska -- and the states and Canadian Provinces in
between \-- bark beetles, emboldened by warming, are overwintering and
slipping in an extra generation each year, then climbing to new heights
and high latitudes -- to bore through the bark of vast stands of pines
weakened by drought, now in its fifth consecutive year in the west. (The
resin that drowns the beetles dries out in drought.) The trees die in a
year -- setting the stage for further wildfires, burns, respiratory
disease, property and timber losses.

United States' forests are unhealthy; but thinning them will not cure
them. Pest infestations, climate extremes and poor management are
together increasing vulnerability to fire, and a sustainable "Healthy
Forest Initiative" will require an integrated set of policies aimed at
nurturing forest defenses and stabilizing the climate.

In the past five years over 90% of Southern California's pines have been
killed by bark beetles, and denuded stands from Arizona to Alaska
contributed substantially to this summer's conflagrations. When weakened
by drought and wilted by heat, trees become susceptible to pests.
Drought dries the resin that drowns the invaders, while the galleries of
eggs left by penetrating beetles pave the way for tree death within one
year.

While droughts weaken the hosts (trees), warming emboldens the pests.
Since 1994, mild winters have cut winter mortality of the larvae in
Wyoming, for example, from 80% per annum to under 10%. In Alaska, spruce
bark beetles are sneaking in an extra generation a year due to warming
and have stripped four million acres in the Kenai Peninsula. In British
Columbia, nearly 22 million acres of lodgepole pine have become infested
-- enough timber to build 3.3 million homes or supply the entire U.S.
housing market for two years (*The Economist* 9 Aug).

The battle between insects and plants began several hundred million
years ago, when forests spread across the land. Trees fought back the
leaf-eaters and bark-borers with chemicals; then garnered support from
birds, spiders and ladybugs. Woodpeckers and nuthatches keep beetle
numbers in check. But with warmer winters, beetle populations outpace
their pursuers and their populations can quadruple in a year.

"This is another example of global climate change that has deadly
implications for my state," declared Senator Ted Stevens (U.S.
Congressional Record, 24 July 2002). (The tundra is also melting,
undermining pipelines, and thinning of North Polar ice in the past 20
years occurred at 8 times the rate it did in the previous 100.)

Warming is also expanding the range of beetles. Lodgepole pines are the
preferred target, but "...in the past four or five years, the bugs
\[are\] attacking whitebark pine stands \[that\] grow at about 8,000
feet elevation or higher" (M. Stark, *Billings Gazette*, 8 Aug 2003).

Other forest pests are challenging forest health. In California several
tree species have been attacked by an opportunistic fungus
(*Phytophthora*) akin to that of the Irish Potato Famine. On the East
Coast, aphid-like bugs -- the Wooly adelgid \-- threaten the dark green
hemlock pines that line rivers in Connecticut and Massachusetts, and
they are migrating towards Vermont with each warm winter.

Wildfires are hazardous for wildlife, property and people. They pose
immediate threats to courageous firefighters and homeowners, while
particles and chemicals from blazes and wind-carried hazes cause heart
and lung disease.

 

Not all forest fires should be suppressed; periodic fires can be
rejuvenating. But the drought- and beetle-driven wildfires today are not
self-limiting, and the underlying conditions need to be addressed.

Unfortunately, little can be done to directly control the pests.
Pesticides, which enter ground water, are minimally effective and must
be applied widely long before beetles awaken in spring.

Forest "thinning" has two meanings: the preferred method entails cutting
small trees (\<6" in diameter). But this approach is not profitable and
will not be employed without public financing. The extensive logging and
clear-cutting form of "thinning" under the resident's initiative is a
thinly disguised gift to the timber industry and these practices damage
soils, increase sedimentation, reduce water-holding capacity and dry up
rivers and streams -- all increasing vulnerability to pests and fires.

Even the best forest practices, however, will be insufficient to stem
the ravages of drought and the onslaught of beetles. The forests need
moisture. Climate-induced changes in Earth's water cycle pose threats to
the health of forests, crops and humans.

***[Climate instability]{.underline}***

In January, 2004, the Pentagon released one scenario based on the
growing signs of climate instability: an abrupt deep-freeze in northern
North America and Europe. "Global warming, rather than causing gradual,
centuries-spanning change, may be pushing the climate to a tipping
point,\" states an article in Fortune Magazine based on the Pentagon
document.\" The ocean-atmosphere system that controls the world\'s
climate can suddenly change its path.

The report 2002 report by the National Academy of Sciences, entitled
*Abrupt Climate Change: Inevitable Surprises*, reveals how an
accelerating pace of climate change and erratic weather patterns -- the
very changes we are experiencing today \-- can be precursors to abrupt
climate change.

Climate records show that warming trends can become quite variable and
can lead to "cold reversals" \-- affecting North America and Europe in
ways vastly different from the tropics. How might this work?

First, weather patterns have become more variable and extreme. Droughts
are drier and more prolonged while -- with increased water vapor -- more
precipitation falls in downpours. Last August -- while Europe was
suffering a sweltering heatwave \-- the World Meteorological
Organization reported that increased heat in the climate system
accounted for the severe and erratic weather patterns being observed
worldwide.

Such erratic weather is not good for our health and it certainly
confuses the birds. But it also tells us that our climate is not stable.

In the past 50 years the top two miles of the world's oceans have warmed
-- that's half way down -- and ocean warming is melting sea ice. In just
several decades the floating North Polar ice cap has shrunk from ten to
five feet thick during the summers and Greenland is losing 9% each
decade.

Fresh water from the melting ice and rain landing on the northern ocean
just layers out, instead of sinking. Cold, *salty* water sinks \-- the
deep water pump that pulls the warm Gulf Stream north and drives the
ocean conveyor belt that stabilizes climate over millennia.

The impacts of freshening are already apparent. The accompanying North
Atlantic "high" pressure system accelerates transatlantic winds and
pushes the Jet Stream south. And these changes may be driving frigid
fronts down the eastern US seaboard and across to Europe.

Ice core records demonstrate that the North Atlantic Ocean can freshen
to a point where the deep water pump fails and since the 1950s the deep
overflow between Iceland and Scotland has slowed by 20%.

Since cold reversals have occurred naturally, what is the contribution
of human activity today?

Cycles of the earth around the sun -- the tilts and orbits \-- change
over time. Recent calculations of these cycles indicate that our
hospitable climate was not likely to have ended any time soon. But due
to the buildup of carbon dioxide (CO~2~) \-- to levels greater than in
half a million years \-- the equations have changed, and we have entered
uncharted waters.

The Pentagon planners argue strongly that the climate system is
exhibiting greater turbulence and instability - as evidenced by the
hastening build-up of atmospheric carbon dioxide and heat, and wide
swings in weather, and the examination of surprise shifts by the
scientific community has generated a new sense of urgency.

The Pentagon report reclassifies climate change as a national security,
rather than an environmental, issue. The reason: the mounting extremes
and a sudden, abrupt change could well trigger conflicts globally for
shrinking resources.

Changes in the chemical composition of the atmosphere are changing the
heat balance in the air, land, oceans and ice. The inner atmosphere is
actually swelling from the heat and, as Earth's surfaces warm,
evaporation dries out soils and forests. Paradoxically, rising
evaporation from warming oceans and melting ice also generate more
tropical--like outbursts when it does rain.

While engineers are turning their attention to technologies to clean the
air and bury the carbon, we are faltering on prevention.

***[Heatwaves]{.underline}***

Returning to immediate threats -- heatwaves have already begun. The
heatwave in Los Angeles in the third week of April was unusually early
and ozone levels were high. During the Boston marathon on April 19 140
people were felled from heat exhaustion and dehydration. The August 14,
2003 blackout during Last summer's heatwave could easily be repeated and
the grid is still vulnerable. Temperatures in New Delhi have been over
107 for weeks and a heatwave in Greece during the Olympics -- like that
in Europe last summer that killed some 30,000 people in five countries,
and led to crop failure and wildfires \-- could be devastating.

Just as we underestimated the rate that the climate would change, we
have underestimated the responses of biological systems -- especially
the opportunistic weeds, microorganisms and insects \-- to the warming
and the wide swings in weather. The oceans are warming, ice is melting
and water vapor is rising, as are the costs from extreme weather events.

All these impacts come with costs. Homes in Texas are no longer insured
for floods and mold. Insurance companies are pulling costs back from
houses on Cape Cod. Costs have risen from \$4 billion per year in the
1980s a year to \$40 billion in the 1990s, were \$55 billion in 2002,
\$60 billion in 2003 and the United Nations Environment Programme
projects the losses to rise to \$150 billion a year -- and business
interruptions, plus restrictions on trade, travel and tourism \-- within
this decade if current trends continue. This has generated collaborative
work through our Center with the Swiss Reinsurance company and the UNDP
to project the health, ecological, and economic dimensions of possible
climate futures.

The costs of weather extremes and spreading diseases involving humans,
crops, trees, birds, chickens, cows, pigs, cats, rodents, bats and
marine life are affecting international trade, causing business
interruptions and restricting tourism. The diseases involving insects,
rodents, migrating birds and marine organisms all reflect warming and
climatic extremes. And as climate becomes more unstable, it is playing
an ever-expending role in the emergence, resurgence and spread of
infectious diseases.

The good news is that we may have vastly underestimated the benefits
from making the transition to clean energy. A properly financed clean
energy transition -- with incentives for greater efficiency, alternative
sources, "green buildings," smart technologies to secure the grid,
distributed generation, streamlined transport, more livable cities with
pedestrian and biking pathways, hybrid cars, solar panels and fuel cells
-- can provide the sorely needed engine of growth for the 21^st^
century.

Solving the "triple-E" equation -- energy, environment and the economy
-- is the job of all, and means determining the public role to enable
market mechanisms that can drive the transition in a way that stabilizes
the climate, while initiating a cleaner, healthier and more equitable
form of economic growth.

Former U.K. Prime Minister Margaret Thatcher was one of the first world
leaders to address global warming and William F. Buckley has warned of
the dangers. As the climate becomes more unstable maintaining this
global threat as a partisan issue based in vested interests, will not
meet the needs of this generation and the increasingly troubled
generations to come.

\--END\--

See **http://www.med.harvard.edu/chge/green.pdf**

for full report and references for material in this affidavit.

Additional references in affidavit

Idso, C.D., Idso, S.B., and Balling Jr., R.C. The urban CO~2~ dome of
Phoenix, Arizona. *Physical Geography* 19, 95, 1998.

Idso, C.D., Idso, S.B., and Balling Jr., R.C. An intensive two-week
study of an urban CO~2~ dome in Phoenix Arizona, USA. *Atmos Environ*
35, 995, 2001.

Wan S, Yuan T, Bowdish S, Wallace L, Russell SD, Luo Y. Response of an
allergenic species, Ambrosia Psilostachya (Asteraceae), to experimental
warming and clipping: Implications for public health. *American J of
Botany* 2000; 89:1843-1846.

Ziska LH, *et al*. A global perspective of ground level \"ambient\"
carbon dioxide for assessing the response of plants to atmospheric
CO~2~. *Global Change Biology* 2000; 7:789.\
\
Ziska LH, *et al.*  Cities as Harbingers of Climate Change:  Common
Ragweed, Urbanization, and Public Health. *J Allergy Clin Immunol*
2003:111;290-5.