week 1 concepts in env science

7/31/2019 WEEK 1 Concepts in Env Science

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SKL/MSM 3204Environmental Science course

Lecturer for Semester 2007:

Prof. Dr. Noor Azhar Mohd ShaziliBSc Appl. Biology (1979 Wales, UK);PhD Aquatic Toxicology (1984 Wales, UK)

Fakulti Pengajian Maritim & Sains Marin

Pengarah, Institut Oseanografi


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Yourreference

text book


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What is Environmental Science?

Natural world we live in and the world ofsocial institutions that humans created arethe important parts of our environment

Environment means-the conditions and circumstances thatsurround organisms

- the social and cultural conditions that

affect an individual or community Environmental science : systematic study of

our environment and our place in it


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More definitions

Ecosystem: a region in which the organisms and thephysical environment form an interacting unit

Biodiversity: the variety of all forms of life, fromgenes to species, communities, through to the broadscale of ecosystems of the world

Sustainability: a relationship between dynamiccultural, economic and biophysical systems associatedacross the landscape such that quality of life for

humans continues. It is a relationship in which theeffects of human activities do not threaten theintegrity of the self-organising systems that providethe context of these activities


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Environmental science as adiscipline

Interdisciplinary:integrates biology,chem, geography,agriculture, statistics,

marine science etc.

To improve the waywe treat our world,these sciences and

knowledge on socialorganisation, politicsand humanities areincorporated


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Environmental issues

For many env issues, we have the technologicalsolutions; to make them successful, these solutionshave to be socially, economically and politicallyacceptable

- foresters can plant forests but how do villagersmanage them?

- engineers know how to control air pollution but howto convince factories to install them? It costs a lot forfactories to do it

- city planners can plan a green city but can poorpeople afford them?

- green cars (hybrid tech; biodiesel; electric car) butcan most people afford them?


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Are countries that regulate greenhousegases exposing their industries to unfaircompetition from those that do not?

IN AMERICA they call it the China question.In Europe they call it the America question.In every country that has contemplatedregulating greenhouse gases, it is seen as aproblem: how can policy ensure that legal

limits on emissions do not put local firms at adisadvantage to their foreign competitors?After all, if the cost of compliance putsfactories in countries with strict rules out ofbusiness, while those in grubbier placesflourish, a regulation is worse than useless.

The planet's emissions stay the same, orrise, while the country doing its bit for theenvironment loses investment and jobs.

FromEconomist.comJune 24, 2008


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Natural Science + Human Socialsystems

Solutions to environmental problemsfrequently requires involvement ofhuman social systems as well as thenatural science formulation ofenvironmental standards, laws andpolicies, pollution control .


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Current Global EnvironmentalConditions

Global Population

6 billion, increasingby 85 million every

year 8 10 b by year

2050

What is the impact

of 10b people onthe planetsresources?


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Water

Water may be the most critical resource in 21stcentury

Nations go to war because of conflicts on water

resources 1.2b people lack access to clean drinking water

Polluted water kills 5 m people every year (2.2m arechildren)

40% of world population are in countries where

demand for water exceeds supplies (UN says 75% byyear 2025if present conditions continues)


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Water

Humans now use half of planetsrenewable, fresh water. If agricultureproduction is doubled (with no

efficiency improvement), then 85% ofthe water supply would be used.

Dams and aqueducts are used insome parts of the world to divertwater for cities or agriculture somerivers dry up downstream as a result


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Global Food Production

In the last 100 years global food production

has exceeded demand even though worldpopulation has been growing rapidly. Howdo we achieve this?

Can humans maintain this pace?

Biotechnology and intensive farming mayhelp produce more food in the future. Canpoor countries afford this?


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Food production..

Food production has led to environmentaldegradation and degradation of agricultural

land Can we produce more food without

degrading the environment?

Is food being distributed equitably around

the world? The world produces excess foodbut 800 m people are undernourished; 20m have food shortages due to bad weatherand politics


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Energy

How we obtain and use ourenergy is important in thefuture

Fossil fuels (oil, natural gas,coal) now provides 80% ofenergy needs of industrialisednations.

Supplies are diminishing;mining them is polluting theenvironment

Need clean technologies for

the future: renewable energyresources (solar, wind,geothermal, biomass). Alsoneed conservation of energy


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Global Warming

CO2 emission from fossil fuelburning, forest cutting,agriculture, making cement,many human activities

CO2 concentration increased 30%in last 200 years. Mean globaltemp will increase by 1.5 and6C

Global climate change is alreadyaffecting many biological species;and severe weather events(floods and droughts)

Global warming will cause sealevel rise and flooding of low-lying islands and coastal areas


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Air Pollution

Toxic haze of ash, acids, aerosols, dust, photochemicalproducts over continents (India)

3m people die each year due to air pollution

2 b metric tons of air pollutants released every year in theworld

Air pollution is transboundary (transported by air currentsover long distances) problem nowadays and not local(pollutants from south Europe pollute the Scandinaviancountries and arctic ecosystem); China major problem

nowadays Mercury, polychlorinated biphenyls (PCB), DDT allpersistent chemicals- accumulate in snow and wildlife andnative people in the Arctic


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Habitat Destruction

Habitat destruction, overexploitation, pollution,introduction of exotic organisms are eliminating

species at rates that caused extinction of dinosaurs UN Environment Program says 800 species have

disappeared over the last century and 10,000 speciesnow threatened (Half of all primates and fish;10% ofall plant species; top predators big cats).

More than 75% of global fisheries are overfished Forests are being cleared very rapidly in Brazil, Asia


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Human dimensions of Env SciPoverty

Major proportion of earths population livein poverty

Policymakers understand that eliminatingpoverty and protecting our environment isclosely interlinked. Why?

The worlds poorest people are both the

victims and the agent of environmentaldegradation. They are forced to meetshort-term survival needs at the cost oflong-term sustainability


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Human dimensions of EnvSciPoverty

Poverty also leads tomalnourishmentand sickness. Thisleads to educational, psychological

and developmental deficits.and thecycle of poverty is perpetuated

These poor people have no choice butto over-harvest resources.in doingso they diminish their own resourcesand for future generations


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Rich countries vs Poor countries

Indicator Poor country Rich country Malaysia

GDP/capita $230 US $27,460 US $9,120 US

Total fertility

(average no ofchildren per woman

6.3 1.5 2.90

Life expectancy 49.3 years 77.8 years 70.8 years

Infant mortality (per

1000 live births)

100 5 8.0

Safe drinking water 44% 99% 39%

Adult literacy 38% 99% 92%

Annual population

growth

2.6% 0.3% 0.4%


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Solutions?

Food production may be enough for thehuman population of the future withadvances in fertilisers, pesticides, high-yield crops through genetic engineering,

biotechnology If everybody consumes oil like Americans,

oil reserves will run out in 10 years. Atcurrent rates, reserves will not be enoughfor this century. Cheaper ways to find oil

and extract it; alternative energy (fuel cell,H2 powered battery etc.) use may helpsustain human needs


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Solutions? Global environmentalethics

Environmental ethics: moral relationship of human beingsto the environment and its nonhuman contents

The planet can be saved if humans learn to share itsresources, use it wisely and think of other humans

elsewhere on the planet when using the planets resources.Is this possible do you think?- industrialised countries (USA, India, China, Europe)contain 20% of worlds population yet control 80% ofworlds goods (esp. oil, minerals) and create most of itspollution- individual people are now more aware of global andresponding to the issues by altering their values, beliefs andactions. Are you aware and responding to these issues bychanging your environmental ethical values?


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Energy and Matter in theEnvironment

Living systems are maintained byprocesses that capture energy fromexternal sources and use it to carryout essential functions. Materials areused and recycled in these processes

Much of ecology is about

understanding how energy andmatter move through ecosystems


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Open ecosystems

Ecosystems are interconnected in thatanimals can move form one ecosystem toanother ecosystem. The boundary of an

ecosystem is permeable. Thus mostecosystems are open systems

Ecosystems are defined by their mostdominant components. Eg. A coral reef

ecosystem is defined in tems of the extentand composition of the community of coralpolyps


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Food chains, Food webs & Trophiclevels

Photosynthesis provides all the energy fornearly all ecosystems

One of the major properties of ecosystems

is productivity: the amount ofbiomass(biological material) produced in a givenarea during a given period of time

Primary producers photosynthesize whileconsumers get their nutrients by eatingother things

Net productivity is the amount of primaryproduction that accumulates in a system


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Biotic components of Ecosystems --producers

Biotic component ofEcosystems

1. Producers = Autotrophs

Photoautotrophs Chemoautotrophs

Producers are autotrophicphotosyntheticorganisms.

a. In terrestrialecosystems,producers arepredominantlygreen plants.

b. In freshwater andmarine

ecosystems,dominant


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1 and 2 productivity

Net primary productivity(NPP): therate at which energy is stored in thebody of producers by photosynthetic

activity.Gross primary productivity(GPP):the total production of organic matter(photosynthate) including the energy

used for cellular respiration (R). GPP = NPP + R


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Biotic components of Ecosystems --consumers

Consumers are heterotrophic organisms that eatpreformed food. a. Herbivores feed directly on green plants; are

primary consumers. b. Carnivores feed on other animals and are

secondary or tertiary consumers. c. Omnivores feed on both plants and animals; for

example, humans eat both leafy vegetables andbeef.

d. Decomposers are organisms of decay. i. Mostly are bacteria and fungi.

ii. Break down detritus, nonliving organic matter, intoinorganic matter.

iii. Small soil organisms are critical in helping bacteriaand fungi shred leaf litter and form rich soil.


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Basics ofenergy

exchange inan ecosystem

First Law of Thermodynamics:

Energy can be changed fromone form to another, but itcannot be created ordestroyed

The Second Law of

Thermodynamics states that"in all energy exchanges, if noenergy enters or leaves thesystem, the potential energyof the state will always be lessthan that of the initial state."
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Most consumers feed on multiple sources andlevels of the food web


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Energy flow in ecosystems

The Second Law of Thermodynamics is also commonlyreferred to as entropy. Examples:

- A car that has run out of gas will not run again untilyou walk 10 miles to a gas station and refuel the car.

- Once the potential energy locked in carbohydrates isconverted into kinetic energy (energy in use ormotion), the organism will get no more until energy isinput again.

- In the process of energy transfer, some energy willdissipate as heat.

- Entropy is a measure of disorder: cells are NOTdisordered and so have low entropy.

- The flow of energy maintains order and life.
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It takes 100kg of

clover to make10kg of rabbitand 10kg ofrabbit to make

1kg foxwhichmeans only 10%(less in mostsystems) of theenergy at each

stage istransferred tothe next. Thisprocess is notthat efficient..

ENERGY FLOW INECOSYSTEMS


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The biomass pyramidshows that theamount of biomass

decreases as you goup the trophic level ofthe food chain.Nutrients and energybecome less availableto successive

consumers

Biomass pyramid


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Biogeochemical cycles and Lifeprocesses

The elements and compounds thatsustain life are cycled endlesslythrough living things and through the

environment..biogeochemicalcycling

The flow rates or storage times in thenatural cycles can be altered by

human activity such that the naturalsystem can no longer process them


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Water cycle


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Issues on water

Human activity affecting naturalwater recycling processes

Less water available for humanactivities

Freshwater resources more polluted

Dwindling resource of cleanunpolluted fresh water


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CarbonCycle

Humans arealtering thebalances in

carbon cycle

Boxes in the figure refer topools of carbon, and arrowsrefer to the movement, orfluxes, of carbon from onepool to another


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Greenhouse effect


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90% certainty that humans toblame for global warming


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NitrogenCycle


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Phosphorous Cycle


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Issues related to P

Eutrophication (algal blooms) ofwaters by phosphate pollution due tooveruse of P in agriculture fertilizers,

detergents


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Sulphur Cycle


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week 1 concepts in env science

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