Environmental Science Intro

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

What is environmental science? 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.

Environmental Science Animal 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 Environment Everything that surrounds a particular organism. The term ‘ environmental health ’ is used to describe problems that arise in the relationship of the environment and health of populations within 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) All the parts of Earth that support and contain life. Reaches from the floor of the ocean to the tops of the mountains. Approximately 20 km (12.4 mi) thick. If the earth were an apple, the ecosphere would be no thicker than the apple’s skin!

Ecological Interactions Identify the roles of producers, consumers and decomposers You should remember most of this from Living Environment (Biology)

Change in the Biosphere The 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 Atmosphere Increased global temperatures – greenhouse effect? Normal or enhanced? Loss of ozone due to chlorfluorocarbons (CFCs) Increase of natural gases (Sulfur and CO 2 ) due to volcanic eruptions

What characteristics of Earth make life possible? Water Air (nitrogen, oxygen, carbon dioxide and water vapor) Sun – driving force behind all life processes.

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

Pollution comes in many forms—resources out of place

Aquatic and marine resources—long-neglected, over-exploited, directly and indirectly* impacted. *remember, water flows downhill—The 1 st Law of Ecology

What characteristics of life allow it to influence the environment on the global scale? Life spreads exponentially rate of population growth depends on number of individuals

What characteristics of life allow it to influence the environment on the global scale? 2. Life needs energy – Sun – primary source CO 2 cycle

3. Life “pollutes” CH 3 COOH -->CH 4 +CO 2 CO 2 + H 2 O --> CH 2 O + O 2 CH 2 O + O 2 --> CO 2 + H 2 O

Decomposers Bacteria and fungi that consume the bodies of dead organisms and other organic wastes. Decomposers complete the cycle of matter in the ecosystem.

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

What will we study this semester? Several themes—recurring and inter-connected Human population x demand for resources = root problem. (Problem for each other as individuals, communities, nations; for the rest of the ecosphere.) The impact of environment on human health

Carrying Capacity The number of individuals of a species that can be supported by an ecosystem. As population grows, it takes more from its habitat. Resources such as food and living space become scarce. As resources become scarce, individuals begin to compete.

Which leads to global environmental problems like…. Overpopulation (Exponential growth) Resources Pollution Risk, Toxicology and Human Health Climate, Global Warming and Ozone Depletion Water resources and water quality Solid and hazardous waste

Human Population on the 50th Earth Day The following is from an insert to a solicitation letter from the group Zero 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.

Living in an exponential age That was 1999, it’s 6.46 billion now 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.

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

Complete the survey “Global and Local Issues” by yourself. Take the other copy home and survey an adult. Both survey’s should be brought to class on Thursday 2/11! The survey can be found on the wiki!

Environmental Human Health Should be of importance to all of you. ‘….[All] that which is external to individual human host. [It] can be divided into physical, biological, social cultural any or all of which… Can influence health status in populations.’ WHO, 1995

Our Job…… Determine the source and nature of hazards Determine the exposure pathway Measure the effects Apply Controls…if, and however possible.

Epidemiology Environmental Health – The Role of Epidemiology What you need to know about epidemiology. What is a CLUSTER? [Activity]

How does the sun help sustain life on Earth? 28% of solar energy is reflected back into space by clouds, chemicals, dust and land and water. Remaining 72% warms air and land, evaporates water (weather), and generates winds.

Life as we know it? Most unreflected solar radiation becomes infrared (heat). How fast it flows through the atmosphere and back into space is affected by: Heat trapping gases (water vapor, CO 2 , methane, nitrous oxide and ozone) These gases provide a blanket for Earth produces a “natural greenhouse effect” Without it, Earth would be nearly as cold as Mars and life as we know it could not exist.

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

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

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

Human Health Hazards Cultural – lifestyle Chemical – Air, Water, Soil Contamination Physical – noise, fire, catastrophic events Biological – pathogens, allergens

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

Including the oft ignored…pathogens! Pathogens can: kill native species - humans spread new diseases and parasites to native species

Since our focus will be human health… 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:

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

Interdependence Bad health results from inaccessibility to sustainable resources or exposure to a hazard. Both exist in the environment. Therefore, quality of health depends on the environment.

Environmental Effects on Health Beneficial environmental effects are longevity and sustained functionality . Adverse environmental effects are: injury with decreased longevity or death

Community Action and the Environment What are the environmental problems that we face as communities, as states, as a country, and as part of the global community ? How many environmental problems are you aware of?

Environmental Science Intro

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Environmental Science Intro