Humans and Nature: An OverviewHumans and Nature: An Overview

““The environmental crisis is an outward manifestation of a The environmental crisis is an outward manifestation of a crisis of mind and spirit. There could be no greater crisis of mind and spirit. There could be no greater misconception of its meaning than to believe it is concerned misconception of its meaning than to believe it is concerned only with endangered wildlife, human-made ugliness, and only with endangered wildlife, human-made ugliness, and pollution. These are part of it, but more importantly, the pollution. These are part of it, but more importantly, the crisis is concerned with the kind of creatures we are and crisis is concerned with the kind of creatures we are and what we must become in order to survive.”what we must become in order to survive.”

~ Lynton K. ~ Lynton K. CaldwellCaldwell

A useful definition is simply …the study of Earth’s various environments including the biosphere, lithosphere, hydrosphere and atmosphere.

It should emphasize knowledge and awareness of:

•major environmental problems in the United States and the world;

•factors relating to human interaction with the environment;

•human-environmental interaction, global habitability and environmental change, and sustainable human societies.

What is environmental science?What is environmental science?

Environmental ScienceEnvironmental ScienceAnimal and vegetable life is too complicated a problem for human intelligence to solve, and we can never know how wide a circle of disturbance we produce in the harmonies of nature when we throw the smallest pebble into the ocean of organic life. ~ George Perkins Marsh

Define EnvironmentDefine Environment

Everything that Everything that surrounds a surrounds a particular organism.particular organism.

The term The term ‘‘environmental healthenvironmental health’ ’ is used to describe is used to describe problems that arise in problems that arise in the relationship of the the relationship of the environment and health environment and health of populations within of populations within the environment. the environment.

Diagram makes it clear that environmental science is multidisciplinary and interdisciplinary.

That is, “it takes all kinds” of observations and inputs to “do” environmental science.

If you really got a hold of anything in the Universe, you find out that it’s hitched to everything else.—John Muir, Founder, Sierra Club

Biosphere (Ecosphere)Biosphere (Ecosphere)

All the parts of Earth that All the parts of Earth that support and contain life.support and contain life.

Reaches from the floor of Reaches from the floor of the ocean to the tops of the ocean to the tops of the mountains.the mountains.

Approximately 20 km Approximately 20 km (12.4 mi) thick.(12.4 mi) thick.

If the earth were an apple, the If the earth were an apple, the ecosphere would be no thicker ecosphere would be no thicker than the apple’s skin!than the apple’s skin!

Ecological InteractionsEcological Interactions

Identify the roles of Identify the roles of producers, consumers producers, consumers and decomposersand decomposers

You should remember You should remember most of this from most of this from Living Environment Living Environment (Biology)(Biology)

EcosystemsEcosystems3:07

Change in the BiosphereChange in the BiosphereThe changing environmentThe changing environment

Changes in the Lithosphere

•Leads to local and global health issues

•Competition for resources

•Destruction of habitats and upheaval of human populous

Changes in the AtmosphereChanges in the Atmosphere

Increased global Increased global temperatures – temperatures – greenhouse effect? greenhouse effect? Normal or enhanced?Normal or enhanced?

Loss of ozone due to Loss of ozone due to chlorfluorocarbons chlorfluorocarbons (CFCs)(CFCs)

Increase of natural Increase of natural gases (Sulfur and gases (Sulfur and COCO22) due to volcanic ) due to volcanic eruptionseruptions

The Great American HypocriteThe Great American Hypocrite

What characteristics of Earth make life possible?What characteristics of Earth make life possible?

WaterWater AirAir (nitrogen, oxygen, (nitrogen, oxygen,

carbon dioxide and carbon dioxide and water vapor)water vapor)

SunSun – driving force – driving force behind all life behind all life processes.processes.

Increased agricultural production has benefits and Increased agricultural production has benefits and costs (trade-offs implied)costs (trade-offs implied)

Pollution comes in many forms—resources out of placePollution comes in many forms—resources out of place

Aquatic and marine resources—long-neglected, over-Aquatic and marine resources—long-neglected, over-exploited, directly and indirectly* impacted.exploited, directly and indirectly* impacted.

*remember, water flows downhill—The 1st Law of Ecology

What characteristics of life allow it to influence the What characteristics of life allow it to influence the

environment on the global scale?environment on the global scale?

1.1. Life spreads exponentiallyLife spreads exponentially

rate of population growth depends on number of individuals

What characteristics of life allow it to influence the What characteristics of life allow it to influence the

environment on the global scale?environment on the global scale?

2. Life 2. Life needs needs energyenergy – –

Sun – primary Sun – primary sourcesource

COCO22 cycle cycle

CH3COOH -->CH4+CO2

                                                          

CO2 + H2O --> CH2O + O2

                                               

CH2O + O2 --> CO2 + H2O

       

3. Life “pollutes”

This job STINKS!!!

DecomposersDecomposers

Bacteria and fungi Bacteria and fungi that consume the that consume the bodies of dead bodies of dead organisms and other organisms and other organic wastes.organic wastes.

Decomposers Decomposers complete the cycle of complete the cycle of matter in the matter in the ecosystem.ecosystem.

4. Life is versatile4. Life is versatile

Evolution and AdaptationEvolution and Adaptation

Ecosystems change Ecosystems change over time (this is over time (this is natural and natural and sometimes a good sometimes a good thing) and changes in thing) and changes in the environment the environment affect the evolution of affect the evolution of populations.populations.

What will we study this semester?What will we study this semester?

Several themes—recurring and inter-connected Several themes—recurring and inter-connected Human population x demand for resources = root Human population x demand for resources = root

problem. problem. (Problem for each other as individuals, communities, (Problem for each other as individuals, communities,

nations; for the rest of the ecosphere.)nations; for the rest of the ecosphere.) The impact of environment on human healthThe impact of environment on human health

Carrying CapacityCarrying Capacity

The number of individuals of a species The number of individuals of a species that can be supported by an ecosystem.that can be supported by an ecosystem.

As population grows, it takes more from its As population grows, it takes more from its habitat.habitat.

Resources such as food and living space Resources such as food and living space become scarce.become scarce.

As resources become scarce, individuals As resources become scarce, individuals begin to compete.begin to compete.

Which leads to global Which leads to global environmental problems like….environmental problems like….

Overpopulation (Exponential growth)Overpopulation (Exponential growth) ResourcesResources PollutionPollution Risk, Toxicology and Human HealthRisk, Toxicology and Human Health Climate, Global Warming and Ozone Climate, Global Warming and Ozone

DepletionDepletion Water resources and water qualityWater resources and water quality Solid and hazardous wasteSolid and hazardous waste

Human Population on the 50th Earth DayHuman Population on the 50th Earth Day

The following is from an insert to a solicitation The following is from an insert to a solicitation letter from the group letter from the group Zero Population GrowthZero Population Growth. .

In the seconds it takes you to read this sentence, 24 people will be added to the Earth’s population.

 Before you’ve finished this letter, that number will reach 1,000. Within an hour ... 11,000. By day’s end ... 260,000.

 Before you go to bed two nights from now, the net growth in human numbers will be enough to fill a city the size of San Francisco.

 It took four million years for humanity to reach the 2 billion mark. Only 30 years to add a third billion. And now we’re increasing by 95 million every single year.

 No wonder they call it the human race.

That was 1999, it’s 6.46 billion now

Living in an exponential ageLiving in an exponential age

The environmental problems we face – population growth, wasteful use of resources, destruction and degradation of wildlife habitats, extinction of plants and animals, poverty, and pollution – are interconnected and are growing exponentially.

ActivityActivity: Global & Local Issues: Global & Local Issues

As future decision-makers, you may have As future decision-makers, you may have to deal with many local and global to deal with many local and global problems. Learning about and problems. Learning about and understanding public sentiment regarding understanding public sentiment regarding such issues can help put your own values such issues can help put your own values into perspective.into perspective.

Complete the survey “Global and Local Complete the survey “Global and Local Issues” by yourself.Issues” by yourself.

Take the other copy home and survey an Take the other copy home and survey an adult. Both survey’s should be brought to adult. Both survey’s should be brought to class on Thursday 2/11!class on Thursday 2/11!

The survey can be found on the wiki!The survey can be found on the wiki!

Environmental Human HealthEnvironmental Human Health

Should be of importance to all of you.Should be of importance to all of you.

‘…‘….[All] that which is external to individual .[All] that which is external to individual human host.human host.

[It] can be divided into physical, biological, [It] can be divided into physical, biological, social cultural any or all of which…social cultural any or all of which…

Can influence health status in Can influence health status in populations.’populations.’

• WHO, 1995WHO, 1995

Our Job……Our Job……

Determine the source and nature of Determine the source and nature of hazardshazards

Determine the exposure pathwayDetermine the exposure pathway Measure the effectsMeasure the effects Apply Controls…if, and however possible.Apply Controls…if, and however possible.

EpidemiologyEpidemiology

Environmental Health – The Role of EpideEnvironmental Health – The Role of Epidemiologymiology

What you need to know about epidemiology.

What is a CLUSTER? [Activity]

How does the sun help sustain life How does the sun help sustain life on Earth?on Earth?

28% of solar energy 28% of solar energy is reflected back into is reflected back into space by clouds, space by clouds, chemicals, dust and chemicals, dust and land and water.land and water.

Remaining 72% Remaining 72% warms air and land, warms air and land, evaporates water evaporates water (weather), and (weather), and generates winds.generates winds.

Life as we know it?Life as we know it?

Most unreflected solar radiation becomes Most unreflected solar radiation becomes infrared (heat).infrared (heat).

How fast it flows through the atmosphere and How fast it flows through the atmosphere and back into space is affected by:back into space is affected by: Heat trapping gases (water vapor, COHeat trapping gases (water vapor, CO22, methane, , methane,

nitrous oxide and ozone)nitrous oxide and ozone) These gases provide a blanket for Earth These gases provide a blanket for Earth

produces a “natural greenhouse effect”produces a “natural greenhouse effect” Without it, Earth would be nearly as cold as Without it, Earth would be nearly as cold as

Mars and life as we know it could not exist.Mars and life as we know it could not exist.

Changes in ClimateChanges in Climate

4:05

Certain health outcomes are known to be Certain health outcomes are known to be associated with weather and/or climate, including: associated with weather and/or climate, including: illnesses and deaths associated with temperature;illnesses and deaths associated with temperature; extreme precipitation events; extreme precipitation events; air pollution; water contamination; and diseases carried air pollution; water contamination; and diseases carried

by mosquitoes, ticks, and rodents. by mosquitoes, ticks, and rodents.

MalariaMalaria

Because human health is Because human health is intricately bound to weather and intricately bound to weather and the many complex natural the many complex natural systems it affects, it is possible systems it affects, it is possible that projected climate change will that projected climate change will have measurable impacts, both have measurable impacts, both beneficial and adverse, on health.beneficial and adverse, on health.

Environmental Impact on LifeEnvironmental Impact on Life

The term ‘The term ‘environmental healthenvironmental health’ is used to ’ is used to describe problems that arise in the describe problems that arise in the relationship of the relationship of the environment and health environment and health of populationsof populations within the environment. within the environment.

Human Health HazardsHuman Health Hazards

CulturalCultural – lifestyle – lifestyle ChemicalChemical – Air, Water, Soil Contamination – Air, Water, Soil Contamination PhysicalPhysical – noise, fire, catastrophic events – noise, fire, catastrophic events BiologicalBiological – pathogens, allergens – pathogens, allergens

““For the first time in the history of For the first time in the history of the world, every human being is the world, every human being is now being subjected to dangerous now being subjected to dangerous chemicals from the moment of chemicals from the moment of conception to death.”conception to death.”

~Rachel Carson

Including the oft ignored…pathogens!

Pathogens can:

kill native species- humans

spread new diseases and parasites to native species

Direct – STDs

Indirect – Touching contaminated surfaces

Droplet – Ears, nose or mouth

Airborne – Influenza or pneumonia

Fecal-oral – Digestive

Vector-borne – (Flies, Rats, Mosquitoes)

Pathogens invade new hosts in two ways.  Most are transported by humans or animals (either on purpose or accidentally), but some make their own way (e.g., blown by a storm).  Methods of transmission include:

Since our focus will be human health…Since our focus will be human health…

InterdependenceInterdependence

Health depends on Health depends on resources.resources.

Good health depends Good health depends on accessibility to on accessibility to sustainable sustainable resources.resources.

InterdependenceInterdependence

Bad health results Bad health results from inaccessibility to from inaccessibility to sustainable resources sustainable resources or exposure to a or exposure to a hazard.hazard.

Both exist in the Both exist in the environment.environment.

Therefore, quality of Therefore, quality of health depends on health depends on the environment.the environment.

Environmental Effects on HealthEnvironmental Effects on Health

Beneficial environmental effects are Beneficial environmental effects are longevity longevity and sustained functionalityand sustained functionality..

Adverse environmental effects are: Adverse environmental effects are: injury with injury with decreased longevity or deathdecreased longevity or death

Community Action and the Community Action and the EnvironmentEnvironment

What are the environmental problems that What are the environmental problems that we face as communities, as states, as a we face as communities, as states, as a country, and as part of the global country, and as part of the global communitycommunity? ?

How many environmental problems are How many environmental problems are you aware of? you aware of?