Page 22 - Environment: The Science Behind the Stories

Our Island, Earth interact with our environment in order to devise solutions to
our most pressing challenges. It can be daunting to reflect on
Viewed from space, our home planet resembles a small blue the sheer magnitude of environmental dilemmas that confront
marble suspended in a vast inky-black void. Earth may seem us today, but these problems also bring countless opportuni-
enormous to us as we go about our lives on its surface, but the ties for creative solutions.
astronaut’s view reveals that our planet is finite and limited. Environmental scientists study the issues most centrally
With this perspective, it becomes clear that as our population, important to our world and its future. Right now, global condi-
technological power, and resource consumption all increase, tions are changing more quickly than ever. Right now, through
so does our capacity to alter our surroundings and damage the science, we are gaining knowledge more rapidly than ever.
very systems that keep us alive. Finding ways to live peace- And right now, the window of opportunity for acting to solve
fully, healthfully, and sustainably on our diverse and com- problems is still open. With such bountiful opportunities, this
plex planet is our society’s prime challenge today. Meeting particular moment in history is indeed an exciting time to be
this challenge will require a solid scientific understanding of alive—and to be studying environmental science.
natural and social systems alike. The field of environmental
science is crucial in this endeavor. We rely on natural resources

Our environment surrounds us An island by definition is finite and bounded, and its inhabit-
ants must cope with limitations in the materials they need.
A photograph of Earth offers a revealing perspective, but On our island—planet Earth—human beings, like all living
it cannot convey the complexity of our environment. Our things, ultimately face environmental constraints. Specifi-
environment consists of all the living and nonliving things cally, there are limits to many of our natural resources, the
around us. It includes the continents, oceans, clouds, and ice substances and energy sources that we take from our environ-
caps you can see in the photo of Earth from space, as well ment and that we need in order to survive.
as the animals, plants, forests, and farms that comprise the Natural resources that are replenished over short periods
landscapes surrounding us. In a more inclusive sense, it also are known as renewable natural resources. Some renewable
encompasses the structures, urban centers, and living spaces natural resources, such as sunlight, wind, and wave energy, are
that people have created. In its broadest sense, our environ- perpetually renewed and essentially inexhaustible. In contrast,
ment includes the complex webs of social relationships and nonrenewable natural resources, such as minerals and crude
institutions that shape our daily lives. oil, are in finite supply and are formed much more slowly than
People commonly use the term environment in the first, we use them. Once we deplete a nonrenewable resource, it is
most narrow sense—to mean a nonhuman or “natural” world no longer available.
apart from human society. This usage is unfortunate, because We can view the renewability of natural resources as a
it masks the vital fact that people exist within the environment continuum (FIGURE 1.1). Renewable resources such as timber,
and are part of nature. As one of many species on Earth, we water, and soil renew themselves over months, years, or dec-
share with others the same dependence on a healthy, function- ades, and can be depleted if we use them faster than they are
ing planet. The limitations of language make it all too easy replenished. For example, pumping groundwater faster than
to speak of “people and nature,” or “humans and the envi- it is restored can deplete underground aquifers and turn lush
ronment,” as though they were separate and did not interact. landscapes into deserts. Populations of animals and plants we
However, the fundamental insight of environmental science harvest from the wild may vanish if we overharvest them. CHAPTER 1 • SCIENCE AND SUSTAIN ABILITY : AN INTR ODUCTI ON T O ENVIR ONMENTAL SCIENCE
is that we are part of the “natural” world and that our interac-
tions with the rest of it matter a great deal.
We rely on ecosystem services
Environmental science explores our If we think of natural resources as “goods” produced by nature,
interactions with the world then it is also true that Earth’s natural systems provide “ser-
vices” on which we depend. Our planet’s ecological systems
Understanding our relationship with the world around us is purify air and water, cycle nutrients, regulate climate, polli-
vital because we depend utterly on our environment for air, nate plants, and receive and recycle our waste. Such essential
water, food, shelter, and everything else essential for living. services are commonly called ecosystem services. Ecosystem
Moreover, we modify our environment. Many of our actions services arise from the normal functioning of natural systems
have enriched our lives, bringing us better health, longer and are not meant for our benefit, yet we could not survive
life spans, and greater material wealth, mobility, and leisure without them. Later we will examine the countless and pro-
time—yet they have also often degraded the natural systems found ways that ecosystem services support our lives and civi-
that sustain us. Impacts such as air and water pollution, soil lization (pp. 134–135, 170, 308).
erosion, and species extinction compromise our well-being Just as we may deplete natural resources, we may
and jeopardize our ability to build a society that will survive degrade ecosystem services. This can occur when we deplete
and thrive in the long term. resources, destroy habitat, or generate pollution. In recent
Environmental science is the study of how the natu- years, our depletion of nature’s goods and our disruption of
ral world works, how our environment affects us, and how nature’s services have intensified, driven by rising affluence
we affect our environment. We need to understand how we and a human population that grows larger every day. 21

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