Welcome to Environmental Science

Objectives: Define environment Define and describe the field of environmental science What is exponential growth What are the important environmental issues Define a sustainable system What role do environmental indicators play

Environment: the total of our surroundings All the things around us with which we interact: Biotic  Living things Animals, plants, forests, fungi, etc. Abiotic  Nonliving things Continents, oceans, clouds, soil, rocks Our built environment Buildings, human-created living centers Social relationships and institutions Environment is everything that affects a living organism (any unique form of life).

What is Environmental Science? Its is an interdisciplinary science that uses concepts and information from natural sciences such as ecology, biology, chemistry, and geology and social sciences such as economics, politics, and ethics to help understand – How the earth works, How we are affecting the earth’s life-support systems (environment), and How to deal with the environmental problems we face

Environment  Impacts  Humans Environmental Science is especially broad because it encompasses: Natural sciences: disciplines that examine the natural world Environmental Science programs Social sciences: disciplines that address human interactions and institutions Environmental Studies programs

Environmental Science is NOT Environmentalism The pursuit of knowledge about the natural world Scientists try to remain objective Environmentalism A social movement dedicated to protecting the natural world

The cast of major characters : Ecologists, who are biological scientists studying relationships between living organisms and their environment. Environmental scientists, use information to understand how Earth works, learn how humans interact with Earth, and  develop solutions to environmental problems. Conservation biologists, created a multidisciplinary science in the 1970s to  investigate human impacts on the diversity of life found on Earth (biodiversity) and develop practical plans for preserving such biodiversity.

Environmentalists, are 1) concerned about the impact of people on environmental quality and 2) believe some human actions are degrading parts of Earth's life-support systems for humans and many other forms of life. Some of their beliefs and proposals for dealing with environmental problems are based on scientific information and concepts, and some are based on their social and ethical environmental beliefs (environmental worldviews). Environmentalists are a broad group of people from different economic groups and with different political persuasions. Preservationists, are concerned primarily with setting aside or protecting undisturbed natural areas from harmful human activities. Conservationists, are concerned with using natural areas and wildlife in ways that sustain them for current and future generations of humans and other forms of life.

What defines an Environmental Problem? The perception of what constitutes a problem varies between individuals and societies (place) and time. Ex. DDT, a pesticide In developing countries: its welcome because it kills malaria-carrying mosquitoes, lice and other insects In developed countries: not welcome, due to health risks (found to be a carcinogen a half century later)

What Is Exponential Growth? Fold a piece of paper in half to double its thickness. If you could do this 42 times, the stack would reach from Earth to Moon, 386,400 kilometers (240,000 miles) away. If you could double it 50 times, the folded paper would almost reach the sun, 149 million kilometers (93 million miles) away!

Important Environmental Issues population growth  increasing resource use loss of biodiversity destruction and degradation of wildlife habitats premature extinction of plants and animals,  poverty pollution  All are interconnected and growing exponentially

Populations Growth Human population growth: J-shaped curve The world’s population has increased sixfold in the past 200 years

Resources = Capital To economists, capital is wealth used to sustain a business and to generate more wealth. By analogy, we can think of  energy from the sun as solar capital and the planet's air, water, soil, wildlife, forests, rangelands, fisheries, minerals, and natural purification, recycling, and pest control processes as natural resources, or natural capital Solar energy includes direct sunlight and indirect forms of solar energy such as  (1) wind power,  (2) hydropower (energy from flowing water), and  (3) biomass (direct solar energy converted to chemical energy stored in biological sources of energy such as wood).

Types of Resources Perpetual Resources – Resources that are renewed continuously Renewable Resources – Resources that can be replenished fairly rapidly (hours to several decades) through natural processes as long as it is not used up faster than it is replaced Nonrenewable Resources – Resources that can be environmentally depleted to the point where it costs to much to obtain what is left. The sources can be degraded economically when the cost of extracting and using what is left exceeds its economic value.

Resources Perpetual Nonrenewable Winds, tides, flowing water Fossil fuels Metallic minerals Non- metallic minerals Direct solar energy (iron, copper, aluminum) (clay, sand, phosphates) Renewable Fresh air Fresh water Fertile soil Plants and animals (biodiversity)

Perpetual and Renewable Resources Solar energy is called a perpetual resource because on a human time scale it is renewed continuously. It is expected to last at least 6 billion years as the sun completes its life cycle. On a human time scale, a renewable resource can be replenished fairly rapidly (hours to several decades) through natural processes as long as it is not used up faster than it is replaced. Examples are: forests,  grasslands,  wild animals,  fresh water, fresh air, and fertile soil.

Increasing Renewable Resource Use Renewable resources can be depleted or degraded. The highest rate at which a renewable resource can be used indefinitely without reducing its available supply is called sustainable yield. If we exceed a renewable resource's natural replacement rate (sustainable yield), the available supply begins to shrink, a process known as environmental degradation.

Examples of such degradation include: urbanization of productive land, waterlogging and salt buildup in soil, excessive topsoil erosion,  deforestation, groundwater depletion,  overgrazing of grasslands by livestock,  reduction in Earth's forms of wildlife (biodiversity) by elimination of habitats and species, and  pollution

Nonrenewable Resources Nonrenewable resources exist in a fixed quantity or stock in Earth's crust. On a time scale of millions to billions of years, geological processes can renew such resources. However, on the much shorter human time scale of hundreds to thousands of years, these resources can be depleted much faster than they are formed. These exhaustible resources include  energy resources (such as coal, oil, and natural gas, which cannot be recycled),  metallic mineral resources (such as iron, copper, and aluminum, which can be recycled), and  nonmetallic mineral resources (such as salt, clay, sand, and phosphates, which usually are difficult or too costly to recycle).

Increased Nonrenewable Resource Use We never completely exhaust a nonrenewable mineral resource. However, such a resource becomes economically depleted when the costs of extracting and using what is left exceeds its economic value. At that point, we have six choices:  try to find more,  recycle or reuse existing supplies (except for nonrenewable energy resources, which cannot be recycled or reused),  waste less,  use less,  try to develop a substitute, or  wait millions of years for more to be produced. Some nonrenewable material resources, such as copper and aluminum, can be recycled or reused to extend supplies.

Loss of Biodiversity Biodiversity is the variety of earth's species, the genes they contain, the ecosystem in which they live, and the ecosystem processes of energy flow and nutrient cycling that sustain all life. It exists on three scales: Genetic diversity is a measure of the genetic variation among individuals Species diversity indicates the number of species in a region or in a particular type of habitat. Ecosystem diversity is a measure of the diversity of ecosystems or habitats that exist in a given region.

Environmental Effects of Poverty Daily life is a harsh struggle for the estimated one of every two people on Earth who try to survive on an income of $1-3 (U.S.) per day. Such acute poverty is related to environmental quality and people's quality of life because poor people often Deplete and degrade local forests, soil, grasslands, wildlife, and water supplies for short-term survival. They do not have the luxury of worrying about longterm supplies of natural resources when their daily life is focused on getting enough food and water too survive. Live in areas with high levels of air and water pollution and with the greatest risk of natural disasters such as floods, earthquakes, hurricanes, and volcanic eruptions. Spend an average of 4-6 hours  per day searching for and carrying fuelwood and  per week drawing and carrying water.

Environmental Effects of Poverty Have many children as a form of economic security. Must take jobs (if they can find them) that subject them to unhealthy and unsafe working conditions at very low pay. Die prematurely from preventable health problems. According to the World Health Organization (WHO), each year at least 10 million of the desperately poor die prematurely of malnutrition (lack of protein and other nutrients needed for good health), infectious diseases caused by drinking contaminated water, and  increased susceptibility to infectious diseases

Pollution Pollution is any addition to air, water, soil, or food that threatens the health, survival, or activities of humans or other living organisms. Pollutants can enter the environment  naturally (for example, from volcanic eruptions) or  through human (anthropogenic) activities (for example, from burning coal). Most pollution from human activities occurs in or near urban and industrial areas, where pollutants are concentrated. Industrialized agriculture also is a major source of pollution.

Two types of pollutant sources: Point sources, where pollutants come from single, identifiable sources. Examples are the smokestack of a coal-burning power plant, drainpipe of a factory, or  exhaust pipe of an automobile. Nonpoint sources, where pollutants come from dispersed (and often difficult to identify) sources. Examples are  runoff of fertilizers and pesticides (from farmlands, golf courses, and suburban lawns and gardens) into streams and lakes and  pesticides sprayed into the air or blown by the wind into the atmosphere. It is much easier and cheaper to identify and control pollution from point sources than from widely dispersed nonpoint sources.

Sustainability Sustainability – Living on Earth in a way that allows humans to use its resources without depriving future generations of those resources. Example – Imagine you inherit $1 million. Invest this capital at 10% interest per year, and you will have a sustainable annual income of $100,000 without depleting your capital. If you spend $200,000 a year, your $1 million will be gone early in the 7th year; even if you spend only $110,000 a year you will be bankrupt early in the 18th year. THE LESSON - Protect your capital!!! Deplete your capital, and you move from a sustainable to unsustainable lifestyle.

What is an Environmentally Sustainable Society? Living Sustainably means – living off the natural income replenished by soils, plants, air, and water, and not depleting the earth’s endowment of natural capital that supplies this income.

Four Scientific Principles of Sustainability: Copy Nature Reliance on Solar Energy Biodiversity Nutrient Recycling Population Control

Scientific Principles of Sustainability Reliance on solar energy- the sun warms the planet and supports photosynthesis used by plants to provide food for us and other animals. Biodiversity- a great variety of genes, species, ecosystems, and ecological processes have provided many ways to adapt to changing environmental conditions throughout 3.7 billion year history of life on earth. Population Control- competition for limited resources among species places a limit on how much any one population can grow. If a population grows beyond those limits, its size decrease from changes in birth rates and death rates. Nutrient Recycling- Natural processes recycle all chemicals or nutrients that plants and animals need to stay alive. In this recycling process, the wastes or dead bodies of all organisms become food or resources for other organisms.

Are We Living Sustainable? Environmentalists and many leading scientists believe we are living unsustainably by depleting and degrading Earth's natural capital at an accelerating rate as our population and demands on Earth's resources and life-sustaining processes increase exponentially. Other analysts do not believe we are living unsustainably. They contend that environmentalists have exaggerated the seriousness of population and environmental problems, and  any population, resource, and environmental problems we face can be overcome by human ingenuity and technological advances.

Environmental Indicators To describe the health and quality of natural systems, environmental scientists use environmental indicators. Environmental Indicators describe the current state of an environmental system. These indicators do not always tell us what is causing a change, but they do tell us when we might need to look more deeply into a particular issue. This information can be used to guide us toward sustainability, by which we mean living on Earth in a way that allows us to use its resources without depriving future generations of those resources.

Solutions Principles of Sustainability How Nature Works Lessons for Us Runs on renewable solar energy. Rely mostly on renewable solar energy. Recycles nutrients and wastes. There is little waste in nature. Prevent and reduce pollution and recycle and reuse resources. Preserve biodiversity by protecting ecosystem services and habitats and preventing premature extinction of species. Uses biodiversity to maintain itself and adapt to new environ- mental conditions. Controls a species’ population size and resource use by interactions with its environment and other species. Reduce human births and wasteful resource use to prevent environmental overload and depletion and degradation of resources.

Conclusion Environmental science helps us understand our relationship with the environment and informs our attempts to solve and prevent problems. Identifying a problem is the first step in solving it Solving environmental problems can move us towards health, longevity, peace and prosperity Environmental science can help us find balanced solutions to environmental problems for sustainable development