Chapter 1: An Introduction to Environmental Science

Our Island, Earth

Our environment is the sum total of our surroundings Environment: all the living and nonliving things around us with which we interact (i.e. continents, animals, plants,

landscapes)o More inclusive: includes built environment like structureso Even more inclusive: includes human relationships

Environmental science explores interactions between humans and the world around us Environmental science: the study of how the natural world works, how our environment affects us, and how we

affect our environmento Helps us solve our environmental issues

Natural Resources are vital to our survival Natural resources: the various substances and energy sources we need to survive Renewable natural resources: replenished over short periods of time (sunlight, wind, wave energy, water) Nonrenewable natural resources: resources in finite supply and form slower than we use them (mineral ore, crude

oil) Some renewable resources can turn nonrenewable if overused

Human population growth has shaped our resource use Current population: 6.7 billion Two phenomenas that triggered the increase

o Agricultural revolution: the transition from a hunter-gatherer lifestyle to an agricultural way of life (~10000 years ago) Nutritional needs are easier to meet People lived longer and produced more children

o Industrial revolution (mid-1700s): shift from rural life to an urban society powered by fossil fuels (nonrenewable energy sources, such as oil, coal, and natural gas) improvements in health and faster agricultural production

Thomas Malthus and the population growth At first, population growth was a good thing because there was more laborers and children can support parents Malthus thought unless population is controlled and limits on birth, people would outgrow the food supply until

war, starvation, or disease reduced the population

The Ehrlichs and the “population bomb” Wanted population control and thought population was growing faster than our ability to produce food The agricultural advances prevented this from fully occurring

Resources consumption exerts social and environmental impacts Industrial rev increased the consumption of natural resources

Garrett Hardin and the “tragedy of the commons” Disagreed with the idea that unfettered exercise of individual self-interest will serve public interest Garrett Hardin wrote an essay titled “The Tragedy of the Commons” that said resources that are open to

unregulated exploitation will be depleted In a public pasture that’s open to unregulated grazing, every person will try to increase the number of their animal in

the field. Since it’s unregulated and no one has the incentive to take care of it, everyone will take what they can until the field is completely depleted. (Pamphlet in 1833)

Prepared by Yiwen Wu. All Rights Reserved. The information may not be reproduced, distributed, modified or copied.

Chapter 1: An Introduction to Environmental Science This justifies government regulation of resources held in the common

Wackernagel and Rees and the ecological footprint Ecological footprint: the environmental impact of an individual or population in terms of the cumulative amount of

biologically productive land and water required to provide the raw materials the person or population consumes and to dispose of or recycle the waste the person or population produceso Measures the total area of Earth’s surface a person or population uses once all direct and indirect impacts are

totaled We use 30% more resources than sustainable (faster than replenished) Overshoot – excess use, surpassing earth’s capacity to support us

Environmental science can help us avoid mistakes made in the past Civilizations can crumble when pressures from population and consumption overwhelm resource availability (I.e.

Easter Island) Success of societies depend on their interaction with their environment

Easter Island One of the most remote spots on earth Filled with gigantic statues of carved stone. Scientists wonder how people carried these huge statues without wheels

or ropes Easter Island used to have a lot of trees and had a prosperous society, but the civilization overused its resources.

Now it stands as an example of what happens when a population consumes too much of the limited resources that support it

John Flenley excavated sediments from bottom of lakes and found pollen preserved there. By examining pollen, Flenley found that the island was covered with a species of palm tree related to the Chilean

wine palm (thick & tall tree) There were ancient palm nut casings and carbon lined channels in the soil that matched the Chilean wine palm.

People’s script had the form of palm trees Orliac studied pollen and found 21 other species of plants (mostly trees) By 250 AD tree population declined and ferns and grass became more common. By 950 the trees were gone. By

1400, pollen levels plummeted, and there were very little vegetation First thought was because of climate change, but later found evidence that the people did it The stone statues were probably moved by the logs as rollers and a lot of rope (came from the hauhau tree) When trees were cone, soil eroded (there were sediments on the bottom of the lake) Faster runoff of rainwater would mean less freshwater for drinking Erosion degraded agricultural land, which leads to starvation and population decline Found bones of a lot of different types of birds and served as food source, but now there are almost none. Used to eat a lot of seafood too, but without trees, there were no boats to be built, so began eating very little of that As resources declined, they went into eating chicken. Chickens led to clan warfare

The Nature of the Environmental Science

Environmental science is an interdisciplinary pursuit Interdisciplinary – borrows techniques from numerous disciplines Encompasses both natural science (study the natural world) and social sciences (study human interactions and

institutions)

People vary in their perception of environmental problems A person’s age, gender, class, race, nationality, employment, and educational background affect what each person

considers a “problem”

Prepared by Yiwen Wu. All Rights Reserved. The information may not be reproduced, distributed, modified or copied.

Chapter 1: An Introduction to Environmental ScienceEnvironmental science is the not the same as environmentalism Environmental science pursues knowledge about the workings of the environment, environmentalism is the social

movement dedicated to protecting the natural world from undesirable changes brought about by human actions Environmental scientists try to remain objective and open to what the data shows

The Nature of Science Science: systematic process for learning about the world and testing our understanding of it

o Also the accumulated boy of knowledge that arises from this dynamic process of observation ,testing and discovery

Science is used to develop policy & management decisions and developing technology

Scientists test ideas by critically examining evidence Scientists designs tests to see if ideas can be supported Ideas can be refuted, but not proven. If a statement resists disproves then it is probably true. Incremental approach

to truth

The scientific method is the key element of science Scientific method: a technique for testing ideas with observations, with several assumptions and a series of

interrelated step (formalized version of common sense procedure to solve a question). Observation-based hypothesis testing approach

Doesn’t convey the true nature of science and different researchers can use different ways Relies on assumptions

o The universe functions in accordance with fixed natural laws that do not change from time to time or from place to place

o All events arise from some cause or causes and, in turn, cause other eventso We can use our sense and reasoning abilities to detect and describe natural laws that underlie the cause-and-

effect relationship we observe in nature

Make observation Observation of phenomenon to wish to explain Occurs throughout the process and starts it too

Ask questions I.e. what is causing excessive growth of algae in local ponds?

Develop a hypothesis Hypothesis – a statement that attempts to explain a phenomenon or answer a scientific question Attempt to answer questions by devising explanations that can be tested

Make predictions Use hypothesis to generate prediction (specific statements that can be directly and unequivocally tested

Test the predictions Test by gathering evidence that could refute the prediction/hypothesis Strongest form of evidence comes from experiments (an activity designed to test the validity of a prediction or a

hypothesis)o Involved manipulating variable (conditions that change)

Independent variable = variable that is manipulated Dependent variable = the variable that is affected as a result of the change in independent variable Controlled experiment: scientist controls for the effects of all variables except the one whose effect he or she is

testing

Prepared by Yiwen Wu. All Rights Reserved. The information may not be reproduced, distributed, modified or copied.

Chapter 1: An Introduction to Environmental Science Control: an manipulated point of comparison Treatment: variable manipulated It is best to replicate one’s experiment by staging multiple tests of the same comparison of control and treatment Correlation: statistical relationship among variables

o Weaker evidence than control but sometimes necessary

Analyze and interpret results Scientists record data (information) Quantitative data (numbers) are especially valued because numbers provide precision and are easy to compare

o Sometimes the results may not be clear-cut and the data need to be analyzed with statistical tests to determine the strength & reliability of patterns they find.

Some research (esp in social science) uses qualitative data (not expressible in numbers)o Still scientific because it can be interpreted systematically using other methods of analysis

If the experiment refuted the hypothesis, it will be rejected and develop a new hypothesis If experiment support, doesn’t mean hypothesis is true. Scientist need to test hypothesis in different ways (method

repeats itself) If multiple tests fails to reject the hypothesis, researcher would conclude the idea is well supported Might think of testing other potential explanations

We can test hypotheses in different ways Manipulative experiment: an experiment in which the researcher actively chooses and manipulates the independent variable

o Reveals causal relationships so strongest (usually physics and chemistry uses this)o Some fields are difficult to manipulate experimentally (i.e. too big) and focuses on areas other than the behavior of general

constant Natural experiments are for disciplines that don’t really fit the physics model of science

o Experiment is done naturally and scientist interprets the results (i.e. results of evolution) Ecology (the distribution and abundance of living things, the interactions between them, and the interactions between

organisms and their nonliving environment) is one of the disciplines most central to environmental scienceo Both are used

Social science uses more observation and interpretation of patterns in data than experimentation Descriptive observation studies and natural experiments show correlation, but not causation. Not all variables are controlled n a natural experiment, so a single result can have several interps Environmental science are usually addressed with correlative data and few studies have neat and clean results

The Scientific process does not stop with the scientific method Needs to be made accessible to the scientific community to have impact

Peer Review Peer Review = after a researcher’s work is done, he publishes the findings and scientists specializing in the topic read

it and provide comments and criticism and judge whether the work merits publication Safeguard against faulty science contaminating the scientific lit Could have biases

Conference presentation Present work at professional conferences and receive feedback from colleagues

Grants and funding Grant application goes through peer review to receive funding Reliance on funding can lead to conflicts of interest Know who funded the study before trusting it

Repeatability Test a hypothesis repeatedly in various ways before submitting the finding and after publication others may try to

repeat the resultsPrepared by Yiwen Wu. All Rights Reserved. The information may not be reproduced, distributed, modified or copied.

Chapter 1: An Introduction to Environmental ScienceTheories If the hypothesis survives repeat tests, it could be turned into a theory (a widely accepted, well-tested explanation

of one or more cause-and-effect relationships that has been extensively validated by a great amount of research)o Consolidates many related hypotheses that have been tested and not refuted

Science goes through “paradigm shifts” As data is accumulated, interpretations may change Thomas Kuhn wrote The structure of scientific revolutions (1962) that argued science goes through periodic

revolutions where one scientific paradigm (dominant view) is abandoned for anothero I.e. geocentric/heliocentric

Sustainability and the future of our world

Population and consumption drive environmental impact We add 78 million people to the planet each year and our consumption is rising as well. The affluence rose, but its unequally distributed. The ecological footprint of an underdeveloped nation is smaller

than that of a developed one.

We face challenges in agriculture, pollution, and biodiversity Increase in agriculture has severe costs on the planet The pollution from the farms, industries, households, and individual actions are harmful Fossil fuels and others are causing imminent global climate change Biodiversity (the cumulative number and diversity of living things) is declining dramatically Millennium Ecosystem Assessment (our degradation of the world’s environmental systems is having negative impacts on all of

us, but we can still turn that around)o Humans have altered ecosystem in growing demands for certain materials. These changes caused loss and damage in the

life on Eartho Gains in human well-being have costso Degradation could grow worse during the first half of this centuryo It can be reversed, but policies need to be modified

Our energy choices will influence our future immensely We are becoming increasingly dependent on fossil fuels but they are running out

Fortunately, sustainable solutions abound There are solutions to help restore the environment

Are things getting better or worse? Cornucopia “horn of plenty” people that think we will find ways to make Earth’s natural resources meet all of our

needs indefinitely Cassandras are the people who predict doom because of our impact upon it

Sustainability is a goal for the future Sustainability – a guiding principle of modern environmental science. Conserving Earth’s natural capital. Maintain

fully functioning ecosystems.

Sustainable development involves environmental protection, economic welfare, and social equity Sustainable development – the use of renewable and nonrenewable resources in a manner that satisfies our current

needs but does not compromise the future availability of resourceso UN defines it as “development that meets the needs of the present without sacrificing the ability of future

generations to meet their own needs”Prepared by Yiwen Wu. All Rights Reserved. The information may not be reproduced, distributed, modified or copied.

Chapter 1: An Introduction to Environmental Science Triple bottom line = environmental, economic, social goals

Prepared by Yiwen Wu. All Rights Reserved. The information may not be reproduced, distributed, modified or copied.