Related Content
Search Google Scholar for:
More Information
Related Jobs from ScienceCareers
|
|
Science 23 January 1998: Vol. 279. no. 5350, pp. 491 - 497 DOI: 10.1126/science.279.5350.491
|
|
Association Affairs
Entering the Century of the Environment: A New Social Contract for Science
Jane Lubchenco
As the magnitude of human impacts on the ecological systems of the
planet becomes apparent, there is increased realization of the intimate
connections between these systems and human health, the economy, social
justice, and national security. The concept of what constitutes "the
environment" is changing rapidly. Urgent and unprecedented
environmental and social changes challenge scientists to define a new
social contract. This contract represents a commitment on the part of
all scientists to devote their energies and talents to the most
pressing problems of the day, in proportion to their importance, in
exchange for public funding. The new and unmet needs of society include
more comprehensive information, understanding, and technologies for
society to move toward a more sustainable biosphere--one which is ecologically sound,
economically feasible, and socially just. New fundamental research,
faster and more effective transmission of new and existing knowledge to
policy- and decision-makers, and better communication of this knowledge
to the public will all be required to meet this challenge.
The text is modified from her Presidential Address at the
Annual Meeting of the American Association of the Advancement of
Science, 15 February 1997. The author is in the Department of Zoology,
Oregon State University, Corvallis, OR 97331-2914, USA. E-mail:
lubchenj{at}bcc.orst.edu .
Scientists today are privileged to be able to indulge their
passions for science and simultaneously to provide something useful to
society. With these privileges, of course, comes serious
responsibility. The close of a century and a millennium provides an
occasion for reflection on the nature of these responsibilities and an
evaluation of the extent to which we are fulfilling
them.
The scientific enterprise has provided phenomenal understanding
of our bodies, our minds, our world, and our universe. The advances
that have emerged from space, defense, and medical research, among many
other areas--all of which have depended on basic research across all
disciplines--have been astounding. Space exploration, for
example, has given us not only new understanding of the cosmos, and
wonderful products and technologies, but also a new sense of our world
and ourselves: a sense captured forever by that first photograph of the
whole Earth taken against the black background of space. Scientific
research is advancing explosively on all fronts. The benefits include a
dizzying array of new knowledge, economic opportunities, and
products--ranging from laser surgery to genetic testing, from global
positioning systems to prediction of El Niño events, from the
discovery of new drugs derived from natural products to new information
systems.
In the United States, much of the investment that produced this
wealth was a result of strong bipartisan political support and popular
enthusiasm for science that began during World War II and increased
substantially in the 1960s. This support was predicated in part upon an
(unwritten) social contract between science and society, specifically
the expectation that a substantial investment in research would result
in winning the war (initially World War II and later the Cold War),
winning the space race, and conquering diseases (bacterial infections,
polio, and cancer). The scale of the U.S. investment in science changed
dramatically during this period. Investment in science in most other
developed nations is predicated upon a similar expectation of a return
of knowledge and technology to society. The scientific enterprise that
has produced this wealth is widely admired and envied. The question I
pose is whether the enterprise that has met these past challenges is
prepared for the equally crucial and daunting challenges that lie in
our immediate future. The answer that I must give is "no." I assert
that the immediate and real challenges facing us have not been fully
appreciated nor properly acknowledged by the community of scientists
whose responsibility it is, and will be, to meet them.
Part of our collective responsibility to society must include a
scientific community-wide periodic reexamination of our goals and
alteration of our course, if appropriate. The fact that the scientific
community has responded to societal needs several times in the past
century--although generally in wartime--provides encouragement that it
is possible to mobilize and change course rapidly in the face of a
crisis. As the geologist Marshal Kay was fond of saying, "What does
happen, can happen."
Despite the plethora of reports examining the future of the scientific
enterprise (1, 2), I see the need for a different perspective on how the sciences can and should advance and also return
benefit to society. This different perspective is firmly embedded in
the knowledge of specific, identifiable changes occurring in the
natural and social worlds around us. These changes are so vast, so
pervasive, and so important that they require our immediate attention.
Scientific knowledge is urgently needed to provide the understanding
for individuals and institutions to make informed policy and management
decisions and to provide the basis for new technologies.
This paper is organized around four key questions: How is our world
changing? What are the implications of these changes for society? What
is the role of science in meeting the challenges created by the
changing world? and How should scientists respond to these challenges?
My goal in communicating these thoughts is to stimulate a dialogue
within the scientific community on these topics. I hope that the result
will be a thoughtful reexamination of our individual and collective
priorities and actions.
The Board of Directors of AAAS has initiated an electronic discussion
of the relationship between science and society. A paper summarizing
its deliberations along with comments from a number of scientists are
posted to invite an exchange of ideas on the questions posed above. On
behalf of the Board, I invite your participation (3).
Global Changes and Their Causes
How is our world changing? One major way is that we now live
on a human-dominated planet. The growth of the human population and the
growth in amount of resources used are altering Earth in unprecedented
ways. Through the activities of agriculture, fisheries, industry,
recreation, and international commerce, humans cause three general
classes of change. Human enterprises (i) transform the land and
sea--through land clearing, forestry, grazing, urbanization, mining,
trawling, dredging, and so on; (ii) alter the major biogeochemical cycles--of carbon, nitrogen, water, synthetic chemicals, and so on; and
(iii) add or remove species and genetically distinct populations--via habitat alteration or loss, hunting, fishing, and introductions and
invasions of species (4-6).
The resulting changes are relatively well documented but not
generally appreciated in their totality, magnitude, or implications. Vitousek and colleagues have provided a succinct and dramatic summary
of the extent of human domination of Earth in the following six
conclusions (4): (i) between one-third and one-half of the
land surface has been transformed by human action (7); (ii)
the carbon dioxide concentration in the atmosphere has increased by
nearly 30% since the beginning of the Industrial Revolution (8); (iii) more atmospheric nitrogen is fixed by humanity
than by all natural terrestrial sources combined (9); (iv)
more than half of all accessible surface fresh water is put to use by
humanity (10); (v) about one-quarter of the bird species on
Earth have been driven to extinction (11); and (vi)
approximately two-thirds of major marine fisheries are fully exploited,
overexploited, or depleted (12).
The rates and spatial scales of most of these changes are increasing.
In addition, some of the changes are new. Novel chemical compounds--ranging from chlorofluorocarbons to persistent organic compounds such as DDT and PCBs--are being synthesized and released. Only a few of the thousand or so new chemicals released each year (13) are monitored; the biological effects of most are
unknown, especially synergistic interactions of different compounds
(14), and interference with developmental and hormonal
systems (15).
Many of these physical, chemical, and biological changes entrain
further alterations to the functioning of the Earth system, most
notably causing: (i) disruptions to the global climate (16), (ii) depletion of stratospheric ozone (17), (iii)
irreversible losses of biological diversity (18,
19), and (iv) changes in the structure and functioning of
ecosystems around the world (6, 20).
The conclusions from this overview are inescapable: during the
last few decades, humans have emerged as a new force of nature. We are
modifying physical, chemical, and biological systems in new ways, at
faster rates, and over larger spatial scales than ever recorded on
Earth. Humans have unwittingly embarked upon a grand experiment with
our planet. The outcome of this experiment is unknown, but has profound
implications for all of life on Earth. An assessment from the
Ecological Society of America entitled the Sustainable Biosphere
Initiative states that "environmental problems resulting from human
activities have begun to threaten the sustainability of Earth's life
support systems... . Among the most critical challenges facing
humanity are the conservation, restoration and wise management of the
Earth's resources" (21).
The world is changing in myriad other important ways as well.
Inequity within and among all nations has increased; new infectious diseases have emerged; there are dramatically more democratic governments; technology, communication, and information systems have
undergone revolutionary changes; markets have become global; the biotic
and cultural worlds have been homogenized; the rate of transport of
people, goods, drugs, and organisms has increased around the globe;
multinational corporations have emerged; and nongovernmental
organizations have increased. (22). Most of these changes
have profound implications for our future. Integration of the human
dimensions of these global changes with the
physical-chemical-biological dimensions is clearly needed.
The individual and collective changes described above are so different
in magnitude, scale, and kind from past changes that even our best
records and models offer little guidance concerning the scale or even
the character of likely responses to these challenges. The future is
quite likely to involve increasing rates of change; greater variance in
system parameters; greater uncertainty about responses of complex
biological, ecological, social, and political systems; and more
surprises. The world at the close of the 20th century is a
fundamentally different world from the one in which the current
scientific enterprise has developed. The challenges for society are
formidable and will require substantial information, knowledge, wisdom,
and energy from the scientific community. Business as usual will not
suffice.
Changes for Ecosystem Services and Humanity
Many of the environmental changes have serious consequences for
humanity. Climatic disruption, increased ultraviolet (UV)-B radiation,
or insufficient drinking water provide examples of undesirable
outcomes. Many of the most serious consequences are less obvious and
mediated through the functioning of ecological systems. Humans and our
social and economic systems are intimately dependent upon the
ecological systems now undergoing rapid changes (21,
23).
Ecological systems--from wetlands, forests, coral reefs, and tundra, to
grasslands, kelp beds, estuaries, and the open ocean--provide a broad
range of essential goods and services to humanity. They are the
life-support systems for all of life on Earth. Ecological goods and
services provide a key link to understanding how changes in
biodiversity, climate, land transformation, stratospheric ozone, water,
nitrogen, and so forth have immediate and long-term implications for
humanity. The key is simply that human well-being and prosperity depend
upon diverse, functioning ecological systems in ways we are only
beginning to appreciate.
Most people are well aware that humans extract goods from nature:
seafood, game animals, fodder, fuelwood, timber, pharmaceutical products, and genes, for example. We buy, sell, and trade these goods.
Until recently, little attention has been paid to another benefit
provided by natural ecological systems, the fundamental life-support
services without which human civilization would cease to thrive
(24, 25). These "ecosystem services" include the purification of air and water; mitigation of floods and droughts; detoxification and decomposition of wastes; generation and renewal of
soil and soil fertility; pollination of crops and natural vegetation; control of the vast majority of potential agricultural pests; dispersal
of seeds and translocation of nutrients; maintenance of biodiversity,
from which humanity has derived key elements of its agricultural,
medicinal, and industrial enterprise; protection from the sun's
harmful UV rays; partial stabilization of climate; moderation of
temperature extremes and the force of winds and waves; support of
diverse human cultures; and provision of aesthetic beauty and
intellectual stimulation that lift the human spirit (24).
Although these services are essential to human societies,
their continued existence has been taken for granted. Never before have
human actions so threatened their provision. Because these services
are not traded in economic markets, society has no feedback mechanisms
to signal changes in their supply or in the deterioration of
underlying ecological systems that generate them. Various attempts have
been made to calculate the worth of global ecosystem services; all
estimate the value to be in the trillions of U.S. dollars (24-27).
As land is transformed globally, as biogeochemical cycles are modified
on a grand scale, and as genetic, population, species, and ecosystem
diversity are lost, the functioning of ecological systems is disrupted
and the continued provision of ecosystem services is threatened
(4, 6, 20, 21,
24). Primary threats to ecosystem services include
habitat degradation or loss, changes in biodiversity, and synergistic
interactions between these factors and rapid climate change, release of
toxic substances, and stratospheric ozone depletion.
A recent synthesis of information about ecosystem services from the
Ecological Society of America (28) concluded that:
Based on available scientific evidence, we are certain that:
Ecosystem services are essential to
civilization. Ecosystem services operate on such a grand
scale and in such intricate and little-explored ways that most could
not replaced by technology. Human activities are already
impairing the flow of ecosystem services on a large scale. If current trends continue, humanity will dramatically alter virtually all of Earth's remaining natural ecosystems within a
few decades. In addition, based on current scientific
evidence, we are confident that: Many of the human activities
that modify or destroy natural ecosystems may cause deterioration of
ecological services whose value, in the long term, dwarfs the
short-term economic benefits society gains from those
activities. Considered globally, very large numbers of
species and populations are required to sustain ecosystem
services. The functioning of many ecosystems could be
restored if appropriate actions were taken in time. We believe that land use and development policies should strive to achieve
a balance between sustaining vital ecosystem services and pursuing
the worthy short-term goals of economic development.
Redefining the Environment
Recognizing the significance of the global environmental changes
summarized above, E. O. Wilson suggested that humanity is on the
verge of "Entering the Century of the Environment." Based on
emerging information about ecosystem services and other
environmental issues, I wish to take his phrase a step further and
broaden the dialogue about what constitutes an "environmental
issue." As we begin to appreciate the intimate fashion in which
humans depend on the ecological systems of the planet, it is becoming
increasingly obvious that numerous issues that we have previously
thought of as independent of the environment are intimately connected
to it. Human health, the economy, social justice, and national security all have important environmental aspects whose magnitude is not generally appreciated.
Human health. Human health is being increasingly
recognized as having strong environmental components. Obvious examples
include the importance to human health of good air quality, clean
drinking water, clean food, and minimal exposure to toxic chemicals and UV-B radiation. Less apparent examples include the impact of land-use practices, climatic change, and population density on emergence and
transmission of diseases (29-31). Recent changes in the
epidemiology of Lyme disease, hantavirus, malaria, trypanosomiasis,
schistosomiasis, cholera, and yellow fever are attributable to changing
land-use practices (29, 31). For example, the
construction of roads in Amazonia to access and transport timber,
coupled with higher human population densities, has increased the
incidence and spread of malaria (32). Roads and the
accompanying canals of stagnant water provide prime conditions for the
numerical increase and spatial expansion of populations of mosquito
vectors for the malarial parasites.
Global climatic change is predicted to have direct and indirect effects
on human health. Direct effects include increases in heat stress,
decreases in cold-related mortality, and increases in air
pollution-related pulmonary and allergic complications. Indirect
effects, some mediated through interactions with land-use practices,
include increases in the geographic distribution of a variety
of diseases including malaria, dengue fever, yellow fever, and
hantavirus (16, 33).
The full consequences to human health of large-scale alterations
in biogeochemical cycles are not yet known. Over the last century,
human activities have more than doubled the amount of nitrogen fixed
and therefore entering the global terrestrial nitrogen cycle.
Nonanthropogenic nitrogen-fixation--accomplished by algae, bacteria,
and lightning--totals approximately 140 Tg/year. Anthropogenic sources--the making of fertilizer, planting of legumes (over larger areas than would naturally occur), and burning of fossil fuels--now contribute more than an additional 140 Tg/year. As Vitousek and colleagues state, "Serious environmental consequences are already apparent. In the atmosphere concentrations of the greenhouse gas nitrous oxide and of the nitrogen-precursors of smog and acid rain are
increasing. Soils in many regions are being acidified and stripped of
nutrients essential for continued fertility. The waters of streams and
lakes in these regions are also being acidified, and excess nitrogen is
being transported by rivers into estuaries and coastal waters. It is
quite likely that this unaccustomed nitrogen loading has already caused
long-term declines in coastal fisheries and accelerated losses of plant
and animal diversity in both aquatic and land-based ecosystems"
(34).
Increased nutrients in coastal waters may also trigger population
explosions of certain taxa of phytoplankton that contribute to human
health problems. Increases in the frequency, spatial extent, and
duration of harmful algal blooms are reported from shores around the
world (35). Many (although not all) harmful algal blooms
that involve toxic dinoflagellates and diatoms are known to respond to
increases in nutrients. In one such case, outbreaks of the ambush
dinoflagellate Pfiesteria piscicida in estuarine waters of
the middle and southern Atlantic shores of the United States have
resulted in the death of billions of fish (36) and are
suspected of causing human health problems ranging from amnesia to
kidney and liver impairment. Nutrient pollution from upstream sources
is the suspected trigger. Prevention of further nutrient-triggered
disruption of terrestrial, freshwater, and marine ecosystems and
resulting health consequences will be a formidable challenge in view of
the expected global increases in population, sewage, livestock,
aquaculture, and use of fossil fuels.
The economy. The economy is more interlinked with the
environment than is often appreciated (23, 37).
The false assertion that society must choose between the economy and
the environment is often made. In reality, this "jobs versus the
environment" choice is a false dichotomy: the real choice is between
short-term gain and long-term, sustained prosperity (23,
37, 38). The insurance industry has been a leader
in private sector concern about climatic change (39), in
part because its business demands a long-term perspective. The economic
consequences of increases in the frequency and severity of extreme
weather events provide strong motivation to act to decrease the
probability of likely causes of these anomalies.
Economic development and prosperity hinge upon maintaining an adequate
flow of essential services provided by natural ecosystems. Human-engineered sources of well-being foster the widespread
misconception that affluence is independent of--or possibly even
hindered by--the preservation of natural ecosystems (40).
However, as humans fill in wetlands, clear-cut forests, degrade coral
reefs, drive natural populations and species to extinction, and
introduce alien species, we often disrupt the functioning of the
systems or lose the ecosystem entirely. When we do so, we begin to
incur unanticipated and occasionally staggering costs--having now to
manufacture, grow, or otherwise provide what we once got for free.
A compelling example is provided by Chichilnisky and Heal's
analyses of options for the provision of drinking water for New York
City (27). Historically, the watershed of the Catskill Mountains provided the ecosystem service of water filtration and purification. Over time, this watershed system became overwhelmed by
sewage and agricultural runoff to the point that the water quality was
impaired. Chichilnisky and Heal calculated and compared the costs of
purchasing and restoring the watershed so that it could continue to
provide the ecosystem services of water purification and filtration
($1 billion) versus the costs of building and maintaining a water
purification and filtration plant ($6 billion to $8 billion in capital
costs, plus annual operating costs of $300 million). This comparison
provides an estimate of the replacement costs for only a single
service supplied by the watershed. Other services include flood
control, air purification, generation of fertile soil, and production
of a range of goods from timber to mushrooms, as well as sites for
recreation, inspiration, education, and scientific inquiry. Even
acknowledging that not all ecosystem services can be replaced by a
human-made substitute, this analysis helps put some of the tradeoffs in
perspective.
Social justice. Social justice, too, has intimate
environmental components (37, 41). The
consequences of environmental degradation are often borne
disproportionately by racially and economically disadvantaged groups.
Wealthier individuals or countries can afford to buy bottled water,
move away from degraded and contaminated sites, access information
about alternative choices, influence the political process, cope with
environmental disasters, buy better food, and purchase quality medical
services and treatments.
For example, intensive shrimp farming in Southeast Asia, India, and
parts of South and Central America often brings economic benefit to a
few owners (large multinational or national corporations) in the short
term but in the longer term destroys mangrove forests needed by
indigenous peoples to provide food, fiber, and ecosystem services
such as water purification, sediment trapping, and flood control.
National security. National security is being viewed
increasingly as an environmental issue, with multiple, complex
connections among population growth, environmental quality, and
security, including human migrations, war, disease, social
disruption, political fragmentation, competition for scarce
resources, and ecoterrorism (42). Environmental degradation
and scarcity of resources (water, fuelwood, fertile land, forests,
fisheries) have been identified as key contributors to economic
disruption, ethnic strife, civil war, migration, and insurgency
throughout the world, for example in Bangladesh, India, Mexico, Gaza,
Pakistan, Rwanda, Senegal-Mauritania, South Africa, El Salvador,
Honduras, Haiti, Peru, Philippines, the West Bank, and Somalia
(21, 43). So-called "fish wars" for scarce
cod and salmon present ongoing challenges for the state departments of
the United States and Canada.
During his tenure as U.S. Secretary of State, Warren Christopher
initiated a new perspective when he pledged to make environmental issues "part of the mainstream of American foreign policy." In framing a bold, new perspective on national security, Christopher declared that "[t]he environment has a profound impact on our national interest in two ways. First, environmental forces transcend borders and oceans to threaten directly the health, prosperity and jobs
of American citizens. Second, addressing natural resource issues is
frequently critical to achieving political and economic stability and
to pursuing our strategic goals around the world" (44). In
1997, U.S. Secretary of State Madeline K. Albright issued the State
Department's first annual report on environmental diplomacy, stating
that "environmental problems are often at the heart of the political
and economic challenges we face around the world... . We would not
be doing our jobs as peacemakers and as democracy-builders, if we were
not also good stewards of the global environment" (45).
In summary, national security, social justice, the economy, and human
health are appropriately considered to be environmental issues because
each is dependent to some degree on the structure, functioning, and
resiliency of ecological systems. Linkages among the social, political,
economic, physical, biological, chemical, and geological systems
present new challenges to scientists. What is the role of science in
meeting these challenges?
The Roles of Science
Science is the pursuit of knowledge about how the world works, a
pursuit with an established process for inquiry, logic, and validation.
Scientists engage in science because we are curious about why things
are the way they are, we relish the fun and challenges of
problem-solving, and we wish to contribute something useful to current
and future generations. Society supports science because doing so in
the past has brought benefits and doing so now is expected to provide
more. Traditional roles of science have been to discover, communicate,
apply knowledge, and to train the next generation of scientists.
Society currently expects two outcomes from its investment in
science. The first is the production of the best possible science regardless of area; the second is the production of something useful.
The first goal reflects "the expectation that scientists will search
... for the truth about how nature works ... producing reproducible, independently verifiable results, logically consistent theories and experiments that explain patterns in nature"
(46). An emphasis on investigator-initiated, peer-reviewed
science is designed to help meet this expectation.
The second part of the contract reflects the anticipation that
the investment by society will lead not only to improvements in our
understanding of the world but also the achievement of goals that
society has deemed important--winning wars, conquering diseases,
creating products, and improving the economy. This second component
often weighs heavily in decisions about the allocation of funds. As
President John F. Kennedy stated, "Scientists alone can establish the
objectives of their research, but society, in extending support to
science, must take account of its own needs" (47). Hence,
both the rationale for public investment in science as well as specific
decisions about the allocations of resources are tied to expected
outcomes that are beneficial to society.
The needs of society have changed over the years. Vannevar
Bush's 1945 landmark report to the President of the United States, Science--The Endless Frontier, emphasizes providing help in
the medical, defense, and economic arenas. Bush's very first paragraph in his Summary of the Report stated (1):
Progress in the war against disease depends upon a flow of new
scientific knowledge. New products, new industries and more jobs
require continuous additions to knowledge of laws of nature, and the
application of that knowledge to practical purposes. Similarly, our
defense against aggression demands new knowledge so that we can develop
new and improved weapons. This essential, new knowledge can be obtained
only though basic scientific research.
Forty-five years later, Erich Bloch, director of the
National Science Foundation (NSF) (established in response to Bush's report), acknowledged the changing political landscape and highlighted the economic benefits of fundamental research and the primacy of
knowledge as a critical resource (48):
The National Science Foundation was a product of the Cold War and
of a national policy decision that the contribution of research to
national strength was too valuable to be limited to the years of armed
conflict. In recent years, the rationale for supporting science and
engineering research and education has been changing. As political
conflict among the great powers diminishes, the major arena for world
competition is increasingly becoming economic, and in this new global
economy, which runs on ideas and innovation, knowledge is the critical
resource.
In more recent years, as funding for science has gotten
tighter and other needs for funds expanded, there has been an even greater emphasis on the need for new knowledge to generate new products
and processes, for example, to fuel technological advances, provide a
competitive edge in the global marketplace, or develop new medical
treatments (2, 49). In this sense, public funding of science is often argued to be an investment that brings monetary returns. A different application of scientific knowledge is emerging as
equally important in today's world: knowledge to inform
policy and management decisions (49-51).
The latter focus on the role of science in informing decisions is
emerging as one of the critical unmet needs of society at the end of
the millennium (21, 49, 50). A better
understanding of the likely consequences of different policy options
will allow more enlightened decisions. Many of the choices facing
society are moral and ethical ones, and scientific information can
inform them. Science does not provide the solutions, but it can help understand the consequences of different choices.
The plethora of biological, physical, chemical, social, and economic
changes summarized earlier point to the myriad ways in which society's
needs for scientific knowledge are changing. A wide range of studies
focusing on environmental challenges all point to (i) the urgent need
for improved understanding, monitoring, and evaluation to protect,
manage, and restore the environment; (ii) more effective communication
of existing knowledge to the public and policy arenas; (iii) the
desirability of developing new technologies (manufacturing and waste
reduction, for example) to minimize the ecological footprints of human
activities; and (iv) better guidance about decision-making in the face
of uncertainty (50, 51).
In summary, the roles of science--to discover, communicate, and
use knowledge and train the next generation of scientists--have not
changed, but the needs of society have been altered dramatically. The
current and growing extent of human dominance of the planet will
require new kinds of knowledge and applications from science--knowledge to reduce the rate at which we alter the Earth systems, knowledge to
understand Earth's ecosystems and how they interact with the numerous
components of human-caused global change, and knowledge to manage the
planet (4).
A New Social Contract for Science?
Recognizing that the world is changing in new and different
ways, at faster rates and over larger scales than ever before recorded, and recognizing the urgent need for knowledge to
understand and manage the biosphere, I propose that the scientific
community formulate a new Social Contract for science. This contract
would more adequately address the problems of the coming century than does our current scientific enterprise. The Contract should be predicated upon the assumptions that scientists will (i) address the
most urgent needs of society, in proportion to their importance; (ii) communicate their knowledge and understanding widely in order to
inform decisions of individuals and institutions; and (iii) exercise
good judgment, wisdom, and humility. The Contract should recognize the
extent of human domination of the planet. It should express a
commitment to harness the full power of the scientific enterprise in
discovering new knowledge, in communicating existing and new
understanding to the public and to policy-makers, and in helping
society move toward a more sustainable biosphere.
Science alone does not hold the power to achieve the goal of
greater sustainability, but scientific knowledge and wisdom are needed
to help inform decisions that will enable society to move toward that
end. A sustainable biosphere is one that is ecologically sound,
economically feasible, and socially just. Scientific understanding can
help frame the questions to be posed, provide assessments about current
conditions, evaluate the likely consequences of different policy or
management options, provide knowledge about the world, and develop new
technologies. The Contract would reflect the commitment of individuals
and groups of scientists to focus their own efforts to be maximally
helpful. Each individual, each panel, each agency, each congressional
committee, each nation makes choices; these choices should reflect a
greater focus on the most critical issues of our day.
Fundamental research is more relevant and needed than ever before. The
Contract is absolutely not a call to abandon fundamental research; on
the contrary, it should be a call to invest in fundamental research in
a broad spectrum of areas where new knowledge is urgently needed. Just
as the Manhattan Project involved a major investment in fundamental
research, adequately addressing broadly defined environmental and
social needs will require substantial basic research (50,
51).
Because the environment is so broad a topic, research across all
disciplines is needed to provide the requisite knowledge base. Efforts
similar to those devoted to past societal wants and needs--for example
to space, medicine, and defense--are needed to focus more intensely on
the challenges we know lie ahead. These challenges encompass many of
the earlier ones, but expand them in new directions. The setting of
priorities about which science to fund cannot be done in a social
vacuum. The needs of society for scientific knowledge should be an
integral part of the decision-making process.
The Contract should also be a strong call for new research and
management approaches. For example, innovative mechanisms are needed to facilitate the investigation of complex,
interdisciplinary problems that span multiple spatial and temporal
scales; to encourage interagency and international cooperation on
societal problems; and to construct more effective bridges between
policy, management, and science, as well as between the public and
private sectors. A number of recent reports have recommended ways to
accomplish many of these goals (50, 51). The
Corson Committee of the National Research Council, for example,
evaluated the U.S. environmental research
establishment, found it lacking in numerous ways, and recommended a
number of steps to effect cultural and organizational changes in the
environmental research enterprise (51).
There is a concomitant requirement to train interdisciplinary
scientists and to provide the skills and savvy to work at the policy-science or management-science interface. Changes in university curricula and the reward system for professional scientists within and
outside universities would greatly facilitate achieving these goals.
The new Contract should extend well beyond research and training
activities. Some of the most pressing needs include communicating the
certainties and uncertainties and seriousness of different environmental or social problems, providing alternatives to address them, and educating citizens about the issues. In parallel to initiating new research, strong efforts should be launched to better
communicate scientific information already in hand. All too many
of our current environmental policies and much of the street lore about
the environment are based on the science of the 1950s, 1960s, and
1970s, not the science of the 1990s. Most of our efforts to address
economic and social problems are as yet mostly devoid of ecological
knowledge. Clearly, the interfaces between the environment, human
health, the economy, social justice, and national security are ripe for
developing and entraining into the policy arena. In view of the
overarching importance of environmental issues for the future of the
human race, all graduates from institutions of higher learning should
be environmentally literate.
Powerful tools in communicating knowledge to inform policy and
management decisions are scientific assessments from credible groups of
scientists. Assessments such as the Intergovernmental Panel on Climate
Change (16), the Ozone Assessment, and the Global
Biodiversity Assessment (19) have provided excellent guidance to policy-makers, especially when they summarize
certainties and uncertainties and specify the likely outcomes of
different options.
The whole system of science, society, and nature is evolving in
fundamental ways that cause us to rethink the way science is deployed
to help people cope with a changing world. Scientists should be leading
the dialogue on scientific priorities, new institutional arrangements,
and improved mechanisms to disseminate and utilize knowledge more
quickly.
All sciences are needed to meet the full range of challenges
ahead. It is time for the scientific community to take responsibility for the contributions required to address the environmental and social
problems before us, problems that, with the best intentions in the
world, we have nonetheless helped to create. It is time for a
reexamination of the agendas and definitions of the "grand problems" in various scientific disciplines.
We can no longer afford to have the environment be accorded
marginal status on our agendas. The environment is not a marginal issue, it is the issue of the future, and the future is here
now. On behalf of the Board of AAAS, I invite you to participate vigorously in exploring the relationship between science and society and in considering a new Social Contract for Science as we enter the
Century of the Environment.
Bill Watterson has summarized this challenge quite eloquently in the
following Calvin & Hobbes cartoon dialogue (52):
Calvin and Hobbes are riding along in their red wagon, careening
through the woods: Calvin: "It's true, Hobbes,
ignorance is bliss! Once you know things, you
start seeing problems everywhere ... ... and once
you see problems, you feel like you ought to try to fix them... ... and fixing problems always seems to require
personal change ... ... and change means doing things
that aren't fun! I say phooey to that!" Moving
downhill, they begin to pick up speed. Calvin
(looking back at Hobbes): "But if you're willfully stupid, you
don't know any better, so you can keep doing whatever you like! The secret to happiness is short-term, stupid self-
interest!" Hobbes (looking concerned): "We're
heading for that cliff!" Calvin (hands over his
eyes): "I don't want to know about it." They fly off the
cliff: "Waaaugghhh!" After crash
landing, Hobbes: "I'm not sure I can stand so
much bliss." Calvin: "Careful! We don't want
to learn anything from this."
REFERENCES AND NOTES
-
V. Bush, Science-The Endless
Frontier (40th Anniversary Edition, NSF, Washington, DC, 1990).
-
Committee on Science, Engineering, and Public Policy,
National Academy of Sciences, National Academy of Engineering, Institute of Medicine, Science, Technology, and the Federal
Government: National Goals for a New Era (National Academy Press,
Washington, DC, 1993); W. J. Clinton and A. Gore Jr.,
Science in the National Interest [Executive Office of the
President, Office of Science and Technology Policy (OSTP), Washington,
DC, 1994]; National Science and Technology Council, OSTP,
Technology for a Sustainable Future: A Framework for Action
[U.S. Government Printing Office (GPO), Washington, DC, 1994];
Committee on Criteria for Federal Support of Research and Development,
National Academy of Sciences, National Academy of Engineering,
Institute of Medicine, National Research Council, Allocating
Federal Funds for Science and Technology (National Academy Press,
Washington, DC, 1995); National Science and Technology Council (NSTC),
Committee on Environment and Natural Resources, Preparing for the
Future Through Science and Technology: An Agenda for Environmental and
Natural Resource Research (NSTC, Washington, DC, 1995); Council
on Competitiveness, Endless Frontier, Limited Resources: U.S. R&D
Policy for Competitiveness (Council on Competitiveness,
Washington, DC, 1996); National Science and Technology Council, OSTP,
Accomplishments of the National Science and Technology
Council (GPO, Washington, DC, 1996); Carnegie Commission on
Science, Technology, and Government (CCSTG), Federal
Environmental Research and Development: Status Report with
Recommendations (CCSTG, New York, 1997); Energy Research and
Development Panel (ERDP), President's Committee of Advisors on Science
and Technology, Federal Energy Research and Development for the
Challenges of the Twenty-first Century (ERDP, Washington, DC,
1997); Executive Office of the President, OSTP, Science and
Technology Shaping the Twenty-first Century (OSTP, Washington,
DC, 1997); J. H. Gibbons, This Gifted Age: Science and
Technology at the Millennium (Springer-Verlag, New York, 1997);
National Academy of Sciences, National Academy of Engineering,
Institute of Medicine, National Research Council, "Preparing for the
21st Century," Rep. Ser. Nos. 1-6 (National Academy
Press, Washington, DC, 1997); P. M. Smith and M. McGeary, Issues in Science and Technology, p. 33 (Spring 1997);
A. H. Teich, S. D. Nelson, C. McEnaney, Eds., AAAS
Science and Technology Policy Yearbook 1996-97 (American
Association for the Advancement of Science, Washington, DC, 1997).
-
S. Jasanoff,
et al.,
Science
278,
2066 (1997).
[Free Full Text] The URL for the AAAS Board-initiated
electronic conversation is www.sciencemag.org/feature/data/aaasforum.shl.
-
P. M. Vitousek,
H. A. Mooney,
J. Lubchenco,
J. M. Melillo,
ibid.
277,
494 (1997).
[Abstract/Free Full Text]
-
L. W. Botsford, J. C. Castilla, C. H. Peterson, ibid., p. 509; J. B. Hughes, G. C. Daily,
P. R. Ehrlich, ibid. 278, 689 (1997); P. A. Matson, W. J. Parton, A. G. Power, M. J. Swift, ibid. 277, 504 (1997).
-
F. S. Chapin III et al., ibid.
277, 500 (1997).
-
P. M. Vitousek,
P. R. Ehrlich,
A. H. Ehrlich,
P. A. Matson,
Bioscience
36,
368
(1986)
[CrossRef] [ISI]
; R. W. Kates, B. L. Turner, W. C. Clark, in The Earth as
Transformed by Human Action, B. L. Turner II et
al., Eds. (Cambridge Univ. Press, Cambridge, 1990), pp. 1-17;
G. C. Daily,
Science
269,
350
(1995)
[Abstract/Free Full Text]
.
-
D. S. Schimel et al., in Climate
Change 1994: Radiative Forcing of Climate Change, J. T. Houghton et al., Eds. (Cambridge Univ. Press, Cambridge,
1995), pp. 39-71.
-
P. M. Vitousek et al., Ecol. Appl.
7, 737 (1997);
J. N. Galloway,
W. H. Schlesinger,
H. Levy II,
A. Michaels,
J. L. Schnoor,
Global Biogeochem. Cycles
9,
235
(1995)
[CrossRef].
-
S. L. Postel,
G. C. Daily,
P. R. Ehrlich,
Science
271,
785
(1996)
[Abstract]
.
-
S. L. Olson, in Conservation for the Twenty-First
Century, D. Western and M. C. Pearl, Eds. (Oxford Univ.
Press, Oxford, 1989), p. 50;
D. W. Steadman,
Science
267,
1123
(1995)
[Abstract/Free Full Text]
.
-
Food and Agricultural Organization (FAO), FAO Fish.
Tech. Pap. 335 (1994).
-
S. Postel, Defusing the Toxics Threat: Controlling
Pesticides and Industrial Waste (Worldwatch Institute,
Washington, DC, 1987).
-
United Nations Environment Programme (UNEP), Saving Our
Planet--Challenges and Hopes (UNEP, Nairobi, Kenya, 1992).
-
R. S. White,
S. Jobling,
S. A. Hoare,
J. P. Sumpter,
M. G. Parker,
Endocrinology
185,
175
(1994)
;
W. R. Kelce,
et al.,
Nature
375,
581
(1995)
[CrossRef] [Medline]
;
J. A. McLachlan and
S. F. Arnold,
Am. Sci.
84,
452
(1996)
; J. Toppari et
al., Environ. Health Perspect. 104 (suppl. 4), 741 (1996); P. M. Vonier, D. A. Crain, J. A. McLachlan, L. J. Guillette Jr., S. F. Arnold,
ibid. (no. 12), p. 1318; F. vom Saal et al.,
Proc. Natl. Acad. Sci. U.S.A. 94, 2056 (1997).
-
Intergovernmental Panel on Climate Change, Climate
Change 1995 (Cambridge Univ. Press, Cambridge, 1996), pp. 9-49.
-
F. S. Rowland,
Am. Sci.
77,
36
(1989)
[ISI];
S. Solomon,
Nature
347,
347
(1990)
[CrossRef] [ISI]
.
-
J. H. Lawton and R. M. May, Eds., Extinction
Rates (Oxford Univ. Press, Oxford, 1995);
S. L. Pimm,
G. J. Russell,
J. L. Gittleman,
T. M. Brooks,
Science
269,
347
(1995)
[Abstract/Free Full Text]
.
-
UNEP, Global Biodiversity Assessment, V. H. Heywood, Ed. (Cambridge Univ. Press, Cambridge, 1995).
-
E.-D. Schulze and H. A. Mooney, Eds., Biodiversity
and Ecosystem Function (Springer, New York, 1994); H. A. Mooney, J. Lubchenco, R. Dirzo, O. E. Sala, Eds., section 5, in
(19), pp. 278-325; section 6, in (19), pp.
328-452; H. A. Mooney, J. H. Cushman, E. Medina, O. E. Sala, E.-D. Schulze, Eds., Functional Roles of Biodiversity: A
Global Perspective (Wiley, New York, 1996).
-
J. Lubchenco,
et al.,
Ecology
72,
371
(1991)
[CrossRef] [ISI].
-
P. Kennedy, Preparing for the Twenty-First Century
(Random House, New York, 1993); J. A. McNeely, Conservation
and the Future: Trends and Options Toward the Year 2025 (IUCN,
The World Conservation Union Biodiversity Policy Coordination Division, Gland, Switzerland, 1997).
-
K. Arrow,
et al.,
Science
268,
520
(1995)
[Free Full Text]
.
-
G. Daily, Ed., Nature's Services: Societal
Dependence on Natural Ecosystems (Island Press, Washington, DC,
1997).
-
N. Myers,
Proc. Natl. Acad. Sci. U.S.A.
93,
2764
(1996)
[Abstract/Free Full Text]
; Y. Baskin, The Work of Nature: How the Diversity of
Life Sustains Us (Island Press, Washington, DC, 1997).
-
R. Costanza,
et al.,
Nature
387,
253
(1997)
[CrossRef] [Medline]
.
-
G. Chichilnisky and G. Heal, ibid., in press.
-
G. C. Daily et al., Issues Ecol.
2 (1997).
-
J. Lederberg, R. E. Shope, S. C. Oaks Jr., Eds.,
Emerging Infections: Microbial Threats to Health in the United
States (National Academy Press, Washington, DC, 1992).
-
R. M. Anderson and R. M. May, Infectious
Diseases of Humans: Dynamics and Control (Oxford Univ. Press,
Oxford, 1991);
A. P. Dobson and
E. R. Carper,
Bioscience
46,
115
(1996)
[CrossRef] [ISI]
.
-
L. A. Real,
Bioscience
46,
88
(1996)
[CrossRef] [ISI]
.
-
A. Cruz-Marques,
Parasitol. Today
3,
166
(1987)
[CrossRef] [ISI] [Medline]; C. E. A. Coimbra, Human Organ. 47,
254 (1988); D. R. Sawyer, "Malaria and the Environment,"
Working Paper No. 13 (Institute Sociedade, Populacas, e
Natureza, Brasilia, 1992).
-
A. J. McMichael, A. Haines, R. Slooff, S. Kovats, Eds.,
Climate Change and Human Health (World Health
Organization, Geneva, 1996).
-
P. M. Vitousek et al., Issues Ecol. 1 (1997).
-
G. M. Hallegraeff, Phycologia 32, 79 (1993); "ECOHAB: The Ecology and Oceanography of Harmful Algal
Blooms: A National Research Agenda," Report from NSF- and National
Oceanic and Atmospheric Administration-sponsored workshop, D. M. Anderson, Chair (Woods Hole Oceanographic Institution, Woods
Hole, MA, 1995).
-
J. M. Burkholder,
E. J. Noga,
C. H. Hobbs,
H. B. Glasgow Jr.,
Nature
358,
407
(1992)
[CrossRef] [Medline]
;
J. M. Burkholder,
H. B. Glasgow Jr.,
C. H. Hobbs,
Mar. Ecol. Prog. Ser.
124,
43
(1995)
;
P. R. Epstein,
Am. J. Public Health
85,
168
(1995)
[Abstract/Free Full Text]
;
J. A. Patz,
P. R. Epstein,
T. A. Burke,
J. M. Balbus,
J. Am. Med. Assoc.
275,
217
(1996)
[Abstract]
.
-
President's Council on Sustainable Development,
Sustainable America: A New Consensus for Prosperity, Opportunity, and a Healthy Environment for the Future (GPO, Washington, DC, 1996).
-
S. Schmidheiny, with the Business Council for Sustainable
Development, Changing Course: A Global Business Perspective on
Development and the Environment (MIT Press, Cambridge, MA, 1992);
P. Hawken, The Ecology of Commerce: A Declaration of
Sustainability (Harper Business, New York, 1993); S. Schmidheiny
and F. J. L. Zorraquin, with the World Business Council for
Sustainable Development, Financing Change: The Financial
Community, Eco-Efficiency, and Sustainable Development (MIT
Press, Cambridge, MA, 1996).
-
UNEP, "UNEP statement of environmental commitment by the
insurance industry" (UNEP, Geneva, 1996); "UNEP insurance initiative position paper on climate change" (UNEP, Geneva, 9 July
1996).
-
G. Daily, personal communication.
-
World Commission on Environment and Development, Our
Common Future (Oxford Univ. Press, New York, 1987); "Earth
Summit Agenda 21: The United Nations Programme of Action from Rio,"
U.N. Conference on Environment and Development, 3 to 14 June 1992, Rio
de Janeiro, Brazil (United Nations, New York, 1992); Global Change and the Human Prospect: Issues in Population, Science, Technology and Equity (Sigma Xi, Research Triangle Park, NC,
1992).
-
J. T. Mathews, Foreign Affairs 68, 162 (1989); T. F. Homer-Dixon, Int. Security 16, 76 (1991); J. T. Mathews, "Nations and Nature: A New Look at
Global Security," Twenty-First J. Robert Oppenheimer Memorial
Lecture, Los Alamos, NM, 12 August 1991; N. Myers, Ultimate
Security: The Environmental Basis of Political Stability (Norton,
New York, 1993); T. F. Homer-Dixon, Int. Security
19, 5 (1994); R. D. Kaplan, Atlantic Monthly (Feb. 1994), p. 44; T. F. Homer-Dixon, Environmental
Change and Security Project Report 2, 45 (1996); P. J. Simmons, Environ. Change Security Proj. Rep. 3, 1 (1997).
-
T. Homer-Dixon and V. Percival, Environmental Scarcity
and Violent Conflict: Briefing Book (Project on Environmental Population and Security, AAAS, Washington, DC, 1996).
-
W. Christopher, "American Diplomacy and the Global
Environmental Challenges of the 21st Century," address at Stanford University, 9 April 1996, reprinted in Environ. Change Security Proj. Rep. 2, 81 (1996).
-
U.S. Department of State, "Environmental Diplomacy: The
Environment and U.S. Foreign Policy" (Department of State Pub. 10470, Washington, DC, 1997).
-
J. Pastor, personal communication.
-
J. F. Kennedy, address at the Anniversary Convocation of
the National Academy of Sciences (22 October 1963).
-
E. Bloch, foreword in (1), pp. v-vi.
-
National Science Board, "Government Funding of Scientific
Research," Working Paper NSB-97-186 (1997).
-
Carnegie Commission on Science, Technology, and
Government, Environmental Research and Development: Strengthening the Federal Infrastructure (CCSTG, New York, 1992);
International Environmental Research and Assessment: Proposals
for Better Organization and Decision Making (CCSTG, New York,
1992); J. C. I. Dooge et al., Eds., An
Agenda of Science for Environment and Development into the 21st
Century (Cambridge Univ. Press, Cambridge, 1992); National
Commission on the Environment, Choosing a Sustainable Future (Island Press, Washington, DC, 1993);
H. W. Kendall et al., "Meeting the Challenges of
Population, Environment and Resources: The Costs of Inaction. A Report
of the Senior Scientists' Panels," Environmentally Sustainable
Development Proceedings Ser. 14 (World Bank, Washington,
DC, 1995); R. J. Naiman, J. J. Magnuson, D. M. McKnight,
J. A. Stanford, Eds., The Freshwater Imperative: A Research
Agenda (Island Press, Washington, DC, 1995).
-
Committee on Environmental Research, Commission on Life
Sciences, National Research Council, Research to Protect, Restore, and Manage the Environment (National Academy Press,
Washington, DC, 1993).
-
B. Watterson, Calvin and Hobbes, 17 May 1992, distributed by Universal Press Syndicate.
-
I thank B. Menge, M. Derr, the AAAS staff (especially R. Nicholson and G. Seiler), and the editors of Science for their assistance. I am grateful to S. Arnold, S. Carpenter, T. Chapin, G. Daily, J. Diamond, R. Dirzo, D. Epel, P. Farber, V. Plocq
Fichelet, J. Gibbons, B. Goldburg, M. Green, M. Hixon, T. Janetos, S. Jasanoff, B. Johannes, E. Kelley, H. Kendall, C. King, J. Lash, G. Likens, M. Linn, O. Loucks, M. Mangel, J. Maienscheim, T. Malone, B. McKay, B. Miller, H. Mooney, W. Murdoch, J. P. Myers, R. Naiman,
R. Naylor, R. Noss, G. Omenn, B. Paine, J. Pastor, A. Petsonk, S. Pimm,
S. Postel, W. Reid, P. Risser, C. Safina, E. Sanford, D. Simberloff, B. Singer, V. Spruill, K. Shine, C. Stimpson, D. Suzuki, D. Tilman, P. Vitousek, D. Wilcove, and D. Zare for constructive comments on early
drafts of this paper and to the Andrew W. Mellon Foundation, the John
D. and Catherine T. MacArthur Foundation, the Pew Charitable Trusts,
and NSF for funding support.
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
- Invasive Spartina and reduced sediments: Shanghai's dangerous silver bullet.
- J. Chen, B. Zhao, W. Ren, S. C. Saunders, Z. Ma, B. Li, Y. Luo, and J. Chen (2008)
J Plant Ecol
| Abstract »
| Full Text »
| PDF »
- PEP/IS: A New Model for Communicative Effectiveness of Science.
- H.-S. Kim (2007)
Science Communication
28, 287-313
| Abstract »
| PDF »
- Ecophysiology and conservation: The contribution of energetics--introduction to the symposium.
- R. D. Stevenson (2006)
Integr. Comp. Biol.
46, 1088-1092
| Abstract »
| Full Text »
| PDF »
- Collapse of Easter Island: Lessons for Sustainability of Small Islands.
- P. Nagarajan (2006)
Journal of Developing Societies
22, 287-301
| Abstract »
| PDF »
- Countering the Loading-Dock Approach to Linking Science and Decision Making: Comparative Analysis of El Nino/Southern Oscillation (ENSO) Forecasting Systems.
- D. W. Cash, J. C. Borck, and A. G. Patt (2006)
Science Technology Human Values
31, 465-494
| Abstract »
| PDF »
- Precaution as an Approach to Technology Development: The Case of Transgenic Crops.
- R. Welsh and D. E. Ervin (2006)
Science Technology Human Values
31, 153-172
| Abstract »
| PDF »
- New Civic Epistemologies of Quantification: Making Sense of Indicators of Local and Global Sustainability.
- C. A. Miller (2005)
Science Technology Human Values
30, 403-432
| Abstract »
| PDF »
- Risk Perception, Risk Communication, and Stakeholder Involvement for Biosolids Management and Research.
- N. Beecher, E. Harrison, N. Goldstein, M. McDaniel, P. Field, and L. Susskind (2005)
J. Environ. Qual.
34, 122-128
| Abstract »
| Full Text »
| PDF »
- New Visions for Addressing Sustainability.
- A. J. McMichael, C. D. Butler, and C. Folke (2003)
Science
302, 1919-1920
| Abstract »
| Full Text »
| PDF »
- How Should Society Approach the Real and Potential Risks Posed by New Technologies?.
- C. F. Cranor (2003)
Plant Physiology
133, 3-9
| Full Text »
| PDF »
- Science and Technology for Sustainable Development Special Feature: Knowledge systems for sustainable development.
- D. W. Cash, W. C. Clark, F. Alcock, N. M. Dickson, N. Eckley, D. H. Guston, J. Jager, and R. B. Mitchell (2003)
PNAS
100, 8086-8091
| Abstract »
| Full Text »
| PDF »
- Medical Activism and Environmental Health.
- M. McCALLY (2002)
The ANNALS of the American Academy of Political and Social Science
584, 145-158
| Abstract »
| PDF »
- European Perspectives on Therapeutic Cloning.
- K. Evers (2002)
N. Engl. J. Med.
346, 1579-1582
| Full Text »
| PDF »
- Environment and health: 8. Sustainable health care and emerging ethical responsibilities.
- A. Jameton and J. Pierce (2001)
Can. Med. Assoc. J.
164, 365-369
| Full Text »
| PDF »
- Ecosystem evasion and health.
- (2000)
Can. Med. Assoc. J.
163, 489
| Full Text »
| PDF »
- L'evasion de l'ecosysteme et la sante.
- (2000)
Can. Med. Assoc. J.
163, 491
| Full Text »
| PDF »
|
|