Chapter 1: Introduction to Environment

BBR36803 Introduction to Environmental Science

Chapter Outlines

Upon completion of this chapter, student should be able to:-

Define the term environment and identify some important environmental concern

Describe matter, atoms, molecules

Define species, populations, biological communities and ecosystem and understand their systems

Explain the importance of material cycles such as carbon and nitrogen cycle in ecosystem

Environmental Science

Introduction

Environmental science is the systematic study of our environment and place in it. It integrates information from various discipline such as biology, chemistry, geography, agriculture and many more

The relationship between human and nature shall always keep in harmony. For instance; people affect environment, and the environment also affects people.

Environment: all the living and non-living things around us

– Animals, plants, forests, farms, etc. – Continents, oceans, clouds, ice caps– Structures, urban centers, living spaces– Social relationships and institutions

All living things have needs too. All organisms need:

Energy Air

Food and Water

Living Space

Acceptable Temperature

Needs of Living Things

Introduction

Image sources: icicp.blogspot.com; www.universetoday.com

Where we live?

Introduction

Natural world

Social Institution

Our beautiful

Earth

The Nature of Environmental Science

impacts

An interdisciplinary fieldNatural sciences:

examines the natural world

Environmental science programs

Social sciences: examines values and human behavior

Environmental studies programs

Environment Humans

Introduction

Humans depend on a healthy, functioning planet The fundamental insight of environmental science:

We are part of the natural world, but we can also change it

Our interactions with its other parts matter a great deal

We depend completely on the environment for survival Increased health, longer lives, wealth, mobility,

leisure But natural systems have been degraded by

pollution, soil erosion, species extinction, etc. Environmental changes threaten long-term health

and survival

Introduction

• All the things around us with which we interact:• Living things (biotic)

• animals, plants, forests, fungi, etc.

• Nonliving things (abiotic)• continents, oceans, clouds,

soil, rocks• Our built environment

• buildings, human-created living centers

Environment the total of our surroundings

Environmental science is the study of: How the natural world works How the environment affects humans and vice

versa We need to understand our interactions with the

environment To creatively solve environmental problems

Global conditions are rapidly changing We are also rapidly gaining knowledge The opportunity to solve problems is still

available

What is Environmental Science about

Introduction

Garrett Hardin, 1968:

In a “commons” open to all, unregulated use will deplete limited resources.

The tragedy of commons

How does the natural world work?

How does our environment affect us?

How do we affect our environment?

Applied goal: Developing solutions to environmental problems.

Why we learn Environmental Science

1.1 Matter, Energy and Life

What is Matter?

Matter, Energy and Life

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Everything that takes up space and has mass is matter.

Has three interchangeable physical forms or phases: gas, liquid and solid.

Matter is transformed and combined in different ways, but it doesn’t disappear. This condition known as the physical principle of conservation of matter.

What is Energy?

Matter, Energy and Life

Energy and matter are essential constituents of both the universe and living organism.

Matter is the material of which things are made, energy is the capacity to do work such as moving matter over a distance.

Image source: www.homes-energy-efficient.com 

Energy can take many different form. Heat, light, electricity, and chemical energy are common forms.

Kinetic energy is the energy that contained in moving objects. E.g. water flowing over a

dam, wind blowing through tree, rock rolling down the hill, or electrons speeding around the nucleus of an atom.

Matter, Energy and Life

Potential energy is stored energy that is latent but available to use. E.g. a rock poised at the top

of the hill contains potential energy, which is converted to kinetic energy when the rock starts rolling down the hill, gasoline, food and etc

Measured in units of heat (calories) or work (joules). 1 joule is the work done when one kg is accelerated 1 m per second per second (1J= 1 kg.m2/s2)

Matter, Energy and Life

Heat described the energy that can be transferred between object of different temperature.

When the substance absorbs heat, its internal energy increases, or it may change state; a solid may become liquid, or a liquid become gas. E.g. heat a water

Liquid change to vapor

Matter, Energy and Life

Most energy used in ecosystems originates as sunlight.

Green plant capture and convert some of this energy to chemical energy which can be used or stored.

Animal consume plants and convert some of the chemical energy o kinetic energy and heat.

Under thermodynamic law, energy is conserved; it is neither created or destroyed under normal conditions. It may be transferred or transformed but the total amount of energy remains the same.

Eventually, the energy dissipates and becomes no longer useful. It is degraded from higher quality to lower quality forms as it moves through living systems.

Matter, Energy and Life

Renewable resources like sunlight cannot be depleted. Nonrenewable resources like oil CAN be depleted.

Resources like timber and clean water are renewable

only if we do not overuse them.

Natural Resources

Matter, Energy and Life

Matter, Energy and Life

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1.2 Atoms, Molecules and Compounds

An Atom is the smallest particle that exhibits the characteristics of the element.

Atom are tiny units of matter composed of positively charged protons, negative charged electron and electrically neutral neutrons.

Protons and neutrons approximately have the same mass. Electrons which are tiny move at high speed around nucleus. Atom have equal numbers of electrons and protons are neutral.

Atoms, Molecules and Compounds

Charged atoms are called ions. Positive – anion; has a negative charge Negative – cation; has a positive charge

Identify atom by their atomic number (number of protons in their nuclei). E.g. hydrogen (H) atom has 1 protons, while carbon (c) has 6.

Atoms have some tendency to lose or gain electrons, most are not electrically stable as individuals. Gain stability by joining to from molecules.

Molecules is a group of atoms, such as O2, N2, H2

etc… A molecule containing different kinds of atoms is

called a compounds. E.g. water H2O

Atoms, Molecules and Compounds

Atoms, Molecules and Compounds

Chemical Reactions

Occurred when bonds are broken and re-formed among atoms and compounds.

Some reactions such as breakdown of sugar molecules can be very complex, but all reactions follow basic principle of physic. E.g. light a gas stove

The reaction shows how atoms are rearranged into new compounds when methane was burned.

Atoms, Molecules and Compounds

CH4 + 2O2 CO2 + H2O

1.3 Biochemical Cycles and Life Processes

Living systems are maintained by the use and recycling of energy and matter. Conceptually, we organize living systems in terms of species, populations, biological communities, and ecosystems.

A species is most often defined as all organism that are genetically similar enough to breed and produce live.

A population consists of all members of a species that live in the same area at the same time.

Food Chain, Food Web and Trophic Level

A biological community consists of all the populations living and interacting in an area

A biological community make up an ecological system or ecosystem

Organism identified by the kinds of food they eat. Herbivores- eat plant Carnivores – eat flesh Omnivores – eat both plant and animal matter

Scavengers such as crows, jackals and vultures clean up the dead carcasses of large animal.

Detritivores such as ant and beetles consume detritus while decomposer organism such as fungi and bacteria complete the final break down and return nutrients to the soil

Biochemical Cycles

The elements and compounds that sustain us are cycled endlessly through living things and the environment.

This movement referred as biochemical cycles Human activities alter flow rates in the natural

cycle, overwhelming the environment ability to process them, can become pollutants.

Water, Sulfur, nitrogen, and phosphorus are some of the serious example of this.

The continuous movement of water on, above and below the surface of the earth.

Hydrologic Cycles

The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, runoff , and subsurface flow. In so doing, the water goes through different phases: liquid, solid (ice), and gas (vapor).

Carbon Cycles

Carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, and atmosphere.

Carbon passes into ecosystems through photosynthesis and is captured in the bodies and products of living organism.

Weathering, respiration, and combustion release carbon to the atmosphere. Carbon may be locked up for long periods in both organic(coal, oil, gas) and inorganic (limestone, dolomite) geological formations, called carbon sinks.

Carbon Cycles

Nitrogen Cycles

The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms. This transformation can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification and denitrification.  

The nitrogen cycle is of particular interest to ecologist because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition.

Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitrogen cycle.

The blue boxes represent stores of nitrogen, the green writing is for processes that occur to move the nitrogen from one place to another and the red writing are all the bacteria involved.

Phosphorus Cycles

Minerals become available to organism after they are released from rocks.

Two minerals particular significant to organism are phosphorus and sulfur.

The amount of phosphorus in an environment can dramatically affect productivity. Abundant of phosphorus stimulates lush plant and algal growth, making phosphorus a major contribution to water pollution.

Phosphorus cycle begins when phosphorous leach from rocks and minerals over a long period of time.

Humans have greatly influenced the P cycle by mining P, converting it to fertilizer, and by shipping fertilizer and products around the globe.

Transporting P in food from farms to cities has made a major change in the global P cycle. However, excessive amounts of nutrients, particularly phosphorus and nitrogen, are detrimental to aquatic ecosystems.

Sulfur Cycles

The sulfur cycle is the collection of processes by which sulfur moves to and from minerals (including the waterways) and living systems. Biogeochemical cycles are important for life because sulfur is an essential element, being a constituent of many proteins and co-factors

Steps of the sulfur cycle are: Mineralization of organic sulfur into inorganic forms,

such as hydrogen sulfide (H2S), elemental sulfur, as well as sulfide minerals.

Oxidation of hydrogen sulfide, sulfide, and elemental sulfur (S) to sulfate (SO4

2–). Reduction of sulfate to sulfide.

Incorporation sulfide into organic compounds (including metal-containing derivatives).

1.4 Changes in Environment

Ecosystems are always changing. Sometimes those changes are quite fast, like in the case of a natural disaster.

A natural disaster like a flood, fire, earthquake, mudslide, hurricane or volcanic eruption can instantly change an environment and kill the communities that live there.

If this happens, a new community will replace the old community over time. This is called succession.

An example of succession is when a field is left untouched for a long time, it may turn into a forest. If a volcano wipes out a forest, it will eventually grow back.

Changes in Environment

Activities that Harm Our Environment

Water Pollution

Any physical, biological or chemical changes in water quality that adversely affects living organisms or makes water unsuitable for desired uses can be considered pollution.

Polluted water can destroys life in the freshwater ecosystems and oceans.

Two sources of water pollution; (i) Natural (ii) Human

Air Pollution

We pollute our air with factory pollution and car exhaust. Organisms, including humans need clean air to survive

The air quality in Malaysia is reported as the Air Pollution Index (API). Four of the index's pollutant components (i.e., carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide) are reported in ppmv but PM10 particulate matter is reported in μg/m3.

Activities that Harm Our Environment

This scale below shows the health classifications used by the Malaysian government.

If the API exceeds 500, a state of emergency is declared in the reporting area. Usually, this means that non-essential government services are suspended, and all ports in the affected area are closed. There may also be a prohibition on private sector commercial and industrial activities in the reporting area excluding the food sector

Activities that Harm Our Environment

Soil Pollution

The soil pollution is defined as the presence of materials in the soil which are harmful to the living beings when they cross their threshold concentration levels.

We pollute our ground with chemicals, hazardous waste and garbage. These hazardous materials can get into our drinking water and harm us.

Activities that Harm Our Environment

Construction: Expanding the places where humans live harms the natural ecosystems. Life in those ecosystems must move elsewhere and some do not survive.

Waste: People produce so much waste! Humans should be encouraged to follow the three R’s: reduce, reuse, and recycle! Many materials like plastic, glass, metal and paper can be recycled and re-used without causing more harm to our environment.

Activities that Harm Our Environment

Spraying pesticides and insecticides. It kills the bugs we don’t want, but what does it do to the environment?

Deforestation is the cutting down of many trees and not replacing them. We use wood as a resource, but trees support plant and animal life. We must think about our future before cutting down acres of forests, without making plans to replace them!

Activities that Harm Our Environment

The greenhouse effect

There are gases in the Earths atmosphere that are known as greenhouse gasses. The gases let sunlight pass through and trap some of the sun’s heat so that the Earth stays warm. This is called the greenhouse effect.

This is great for plants and animals to live, but too much greenhouse effect is a bad thing.

Worldwide pollution caused by humans is creating more greenhouse gasses. Some scientists believe that this will increase the temperature of the planet, resulting in global warming.

Activities that Harm Our Environment

Global warming is caused by human activity such as pollution. Pollution from the burning of fossil fuels is causes too many greenhouse gases to enter our atmosphere.

A warmer Earth may lead to the polar ice caps melting which could cause flooding, extreme weather conditions like hurricanes and changes in rainfall patterns

Activities that Harm Our Environment

Ozone Depletion

The Earth is protected by the atmosphere. The atmosphere is the air that surrounds the Earth. It protects us from the sun’s bad rays.

Ozone, a gas, absorbs most of the UV rays. Ozone protects people when it is high in the atmosphere, but it can hurt people when it is near the ground.

Activities that Harm Our Environment

Smog, is a fog-like substance caused by pollution. It contains ozone that can harm people. Bad ozone formed on Earth, rises into the atmosphere and causes good ozone to break down.

This thinning of the good ozone layer weakens the part of the atmosphere that protects animals, plants and humans from the sun. Again, humans creating pollution is bad for our planet!

Ozone Depletion

Activities that Harm Our Environment

The environmental impact of a person or population Amount of biologically

productive land + water for raw materials and to

dispose/recycle waste Overshoot: humans have

surpassed the Earth’s capacity

We are using 30% more of the planet’s resources than are available on a sustainable basis!

The Ecological Footprint

Changes in Environment

Environmental science helps us understand our relationship with the environment

It 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 challenges

Conclusion

THANK YOU

QUIZ 1

1. Please complete the chemical reaction below;-

2Fe4 + 3O2 2 Fe4O3

12 H2O + 6CO2 + sunlight 6O2 + C6H12O6 + 6H2O

2. The term “environment” includes

a) Animals and plantsb) Oceans and riversc) Soil and atmosphered) All of the above are included in this term

QUIZ 1

3. Do you think the rest of the world can have an ecological footprint as large as the footprint of the United States?

a) Yes, because we will find new technologies and resources

b) Yes, because the footprint of the United States is not really that large

c) Definitely not; the world does not have that many resources

d) It does not matter; it’s not that important

QUIZ 1