Introduction to environmental science

 Growth of available resources is linear while population growth is often non-linear exponential... growth Resource growth Deficit  The consequence of these two principles is that ev

Introduction to Environmental Science

Environmental Concepts

The environmental system

 The natural environment, commonly referred

to simply as the environment, is a term that encompasses all living and non-living things occurring naturally on Earth or some region thereof.

The environmental system

 The concept of the natural environment can be broken

down into a few key components:

 Complete ecological units that function as natural

systems without massive human intervention,

including all vegetation, animals, microorganisms, soil, rocks, atmosphere and natural phenomena that occur within their boundaries

 Universal natural resources and physical phenomena that lack clear-cut boundaries, such as air, water, and climate, as well as energy, radiation, electric charge, and magnetism, not originating from human activity

The environmental system

 The environmental system may be understood

in an ecological sense as the set of

interactions between the elements of the

biosphere, which includes the atmosphere, the hydrosphere, the lithosphere and the

ecosphere.

The environmental system

 The atmosphere is a mixture of nitrogen (78%),

oxygen (21%), and traces (remaining 1%) of carbon dioxide, argon, water vapor and other components.

 The atmosphere is approximately 1,100 km high, the stratosphere (10 to 50 km) and the troposphere (less than 10 km) are the main atmospheric interactors of the biosphere

 The atmosphere is a prime mean for the spatial

diffusion of pollutants and a temporary mean of

their accumulation

 The hydrosphere is the accumulation of water in all its states (solid, liquid and gas) and the elements dissolved

it in (sodium, magnesium, calcium, chloride and

sulphate)

 97% of the water forms the oceans, 2% is ice (north

and south poles) and 1% forms rivers, lakes, ground water and atmospheric vapor

 It covers around 71% of the earth's surface and is an important accumulator of pollutants and a significant vector of diffusion

The environmental system

 The lithosphere is the thin crust between the mantle and the atmosphere Although the lithosphere is around 100 km

thick, only 1 km of it can be considered in interaction with the biosphere

 Main constituents are oxygen (47%), silicon (28%),

aluminum (8%), iron (5%), calcium (4%), sodium (3%),

potassium (3%) and magnesium (2%) in a crystalline state

 The lithosphere is the main source of pollutants and a

permanent accumulator Some are naturally released

through sources like volcanic eruptions, while others like fossil fuels are the result of artificial extraction and

combustion

The environmental system

 The ecosphere is the set of all living organisms,

including animals and plants

 They are temporary accumulators (like lead) and sources for pollutants (natural forest burning) in a very complex set of relationships with the

atmosphere, hydrosphere and lithosphere

The environmental system

The Environmental System

 What is an environment?

 What is Environmental Science?

The Environment

 Environment: Circumstances and conditions that

surround an organism or group of organisms Social and cultural conditions that affect an individual or community

 Environment: all the external conditions, both

abiotic and biotic, that affect an organism or group

of organisms.

 Organisms also exert effects on their

environment

Environment: the total of our

• Continents, oceans, clouds, soil, rocks

• Our built environment

• Buildings, human-created living centers

• Social relationships and institutions

Humans and the world around us

 Humans change the environment… in ways not fully

understood

 We depend completely on the environment for survival

 Increased wealth, health, mobility, leisure

time

 But…natural systems have been degraded

 i.e., pollution, erosion and species extinction

 Environmental changes threaten long-term

health and survival

(i.e., id est; (e.g., exempli gratia)

Environmental science - Definition

 Environmental science is the science of the

interactions between the physical, chemical, and

biological components of the environment, including their effects on all types of organisms

 Environmental Science: Systematic study of our

environment and our place in it.

 Environmental science includes specific areas of

study, such as: biology, ecology, and environmental engineering

 Environmental science is the study of:

 How the natural world works

 How the environment affects humans and vice versa

HISTRORY OF ENVIRONMENTAL SCIENCE

Malthus’ Theory

 Context

 Thomas Malthus (1766-1834) in his book

“Essays on the Principle of Population” (1798).

 Relationships between population and food resources (area under cultivation).

 Growth of available resources is linear while population growth is often non-linear

(exponential).

 Written during a period of weak harvests.

 Over a century’s time, population would rise

by a factor of 16 while food rose by a factor of 4.

Malthus’ Theory of Population Growth

views on the effect of population on food

supply His theory has two basic principles:

2, 4, 16, 32, etc

rate i.e 1, 2, 3, 4, etc

1 Concept

growth

Resource growth

Deficit

 The consequence of these two principles is that

eventually, population will exceed the capacity

of agriculture to support the new population

numbers

 Population would rise until a limit to growth was reached

Malthus (cont.)

 Further growth would be limited when:

 preventive checks - postponement of marriage

(lowering of fertility rate), increased cost of food etc.

 positive checks - famine, war, disease , would increase the death rate

 Malthusian ideas are often supported by Western governments because it highlights the problem of too many mouths to feed, rather than the uneven distribution of resources;

Malthus (cont.)

Population grows geometrically….

Population exceeds carrying capacity…

Population is kept in

“check”– preventative and/or positive checks

“The Malthusian Trap”

New Technology

Low Income Income High

Subsistence Income

Births Deaths

Equilibrium (Births = Deaths)

Low Income Income High

Subsistence Income

2 The Malthusian Crisis

 The “Malthusian crisis”

 Available agricultural spaces are limited.

 Technical progresses (machinery, irrigation, fertilizers, and new types of crops) are slow to occur.

 Increasing incapability to support the

population.

 If this persists, the population will eventually surpass the available resources.

2 The Malthusian Crisis

 The outcomes are “Malthusian crises”:

 Food shortages.

 Famines.

 War and epidemics

 “Fix” the population in accordance with available resources.

 Necessity of a “moral restraint” on

reproduction.

The Malthusian Crisis

Population Resources

Malthusian Crisis

 The Malthusian Crisis has not occurred

 Malthus has been criticized on several

accounts during the last 200 years.

 Religious view (Protestantism), racist and elitist.

 Did not foresee the demographic transition:

 Changes in the economy that changed the role

of children in the industrializing societies

Malthusian Crisis

 The Malthusian Crisis has not occurred

 Failed to account for improvements in

technology:

 Enabled food production to increase at rates

greater than arithmetic, often at rates exceeding those of population growth

 Enabled to access larger amounts of resources

 Enabled forms of contraception

Malthus and his followers are mistaken on both the demand and the supply side:

On the demand side because population does not follow a geometric growth as Malthus predicted

On the supply side because the resources are not easily extinguished; rather, they are created and expanded by the people who are born, live and work

His followers have failed to produce sound projections They lacks sound data and sound logic

 Required housing space surpassed all that was

constructed since the beginning of mankind

Contemporary Issues

 The Malthusian crisis today

 Agricultural growth:

 Between 1960 and 1990, grain yields has increased

by 92% while cultivated surfaces have only increased by 8%

 Foresee a limit to growth in agricultural

production

 Consumption growth.

 Environmental degradation.

Contemporary Issues

 Relevance of the Malthusian theory

 Was Malthus right or the trend in

agricultural production will again increase

to surpass population growth?

 Are improvements in agricultural

techniques enough to answer demand?

 The next 25 years will be crucial and will

bring forward answers to these questions.

Contemporary Issues

 Relevance of the Malthusian theory

 The work of Malthus continues to be

important to demographers:

 Influence of many contemporary theorists

from various academic disciplines

 Built upon Malthus’s ideas and linked them to modern sciences

4 Neo-Malthusianism

 1 Neo-Malthusian Concepts

 How can the Malthusian theory be adapted

to the current situation?

 2 The Commons

 In which way common resources are used?

 3 Neo-Malthusianism and Human Reproduction

 Is reproduction a right or privilege?

Industrial output

Resources

Neo-Malthusian Concepts

 Limits to growth

 Blaming huge waste of resources by developed economies.

 Supporting a zero growth policy.

 Main arguments:

 Resources are in finite number.

 Demographic growth cannot occur indefinitely.

 Must stop at some point.

Population

Industrial output

Resources

 The human pop increases by 78 million each year

 increases demands on the environment

 Need more food, space, water, energy & resources and make more pollution, habitat destruction & loss

in biodiversity

 As affluence rises it is not spread evenly in the world

 The gap between wealthy & poor is increasing

 Wealthier countries also have an increasing bigger ecological footprint

 It is looking bad for our planet!!!!

Neo-Malthusian Concepts

 Population bomb

 Brought forward by Paul Ehrlich in the late

1960s.

 Fast population growth seen as a threat:

 The word “bomb” refer to the perceived lethal

character of the problem

 Most Third World countries were in the middle of their demographic transition at the time

Neo-Malthusian Concepts

 Population bomb

 Ehrlich and others continued the basic Malthusian numbers game in which population growth

outstrips food production.

 Moved Beyond Malthus in their consideration of many environmental issues.

 Predicted that the population of the United States would shrink to 22.5 million in 1999 due to resource shortages.

 Estimates turned out to be completely inaccurate.

Neo-Malthusian Concepts

 Carrying capacity

 Issue linked with the carrying capacity of land.

 Limits to absorb ever-greater numbers of people.

 Population growth has environmental impacts.

 Support of family planning, contraception and abortion.

 Population problems cannot be addressed

through technology beyond the short term.

Ecological Footprint

 How many Earths would it take to support a population of people like YOU??

 What are you going to do about it?

 Please discuss with a neighbor

 Please rate each other’s ideas

Thomas Malthus and human population

has disastrous effects

• Paul and Anne

Ehrlich, The

Population Bomb

(1968)

4 Creative Pressure vs

 “Necessity is the mother

of all inventions”.

 Population will adjust itself to the quantity of available resources.

History of Environmental Science

 What we think of as the

environmental movement didn’t start until the 1960’s…

Around this time other major events got people’s attention

& made them think & care more about the environment

 The Dust Bowl of the 1930’s improper farming led

to the ruining of farm land & much of the soil in the

US was ruined & eroded away.

 The London Smog of 1952Air pollution & weather conditions led to such terrible air quality in London that 1000’s of people died & there was no visibility

 Cuyahoga River in Cleveland, Ohio It was so

polluted with chemicals that it caught on fire

numerous times in the 1950’s & 60’s

 Earth Day 1970

 First Earth Day started in New York to rally against pollution & population growth

 It has continued to grow & grow each year

America in the 60’s & 70’s was the leader in the environmental movement & many politicians supported the movement, BUT…

In the 80’s, under Reagan & Bush, politicians & people felt the policies were hurting

businesses  weakening & rolled back of

many envir laws

1987 Brundtland Report “Our Common Future”

Introduction of the sustainable development

paradigm

1987 Brundtland Report

“Our Common Future”

“Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”

“Sustainable development requires meeting the basic

needs of all extending to all the opportunity to satisfy

their aspirations for a better life.”

The environment doesn’t pay attention to countries

borders Countries need to work together to manage

resources

 1987 Montreal Protocol, 160 nations work to reduce

emissions of airborne chemicals depleting the ozone layer

 1992 Earth Summit in Brazil, 179 nations work towards sustainable development

 1997 Kyoto Protocol, worked to reduce fossil fuel

emissions

1992 UN Conference on Environment and

Development/UNCED “Earth Summit”– Rio

1. Rio Declaration on Environment and Development

2. Agenda 21 (to be done in the 21st Century)

 Framework Convention on Climate Change/UNFCCC

 Convention on Biological Diversity/CBD

 UN-Convention to Combat Desertification/UNCCD

 Forest Principles

UN Conference on Environment and

development

UNCED or Earth Summit, an 11-day meeting held in June, 1992, in Rio de Janeiro, Brazil, to discuss the global conflict between economic development and environmental protection Representatives of more than 170 nations agreed to work toward the

sustainable development of the planet and the

“highway” to a better world, although most of the

agreements were not legally binding.

In Rio, sustainable development was declared a

guiding vision.

 The Rio Declaration defines principles for the

relationship of states among each other and the

relationship between states and their citizens in the field of environment and development Agenda 21 is the programme of action (21st century) for

sustainable development containing

recommendations for action in all areas of policy

1. Declaration on Sustainable Development

2. Johannesburg Plan of Implementation

History of Environmental Science

 What we think of as the environmental

movement didn’t start until the 1960’s…

but environmental ideas, attitudes &

practices started earlier.

Brief History of Environmentalism

 Utilitarian Conservation- resources should be used for the greatest good, for the greatest number of

people

 Biocentric Preservation- organisms should be

preserved because they have a fundamental right to exist