Environmental Problems, Their Causes, and Sustainability Chapter 1 Environmental Problems, Their Causes, and Sustainability

Some Basic Introductory Terms Environment External conditions that affect living organisms Ecology Study of relationships between living organisms and their environment Environmental Science Interdisciplinary study of humanity’s relationship with other organisms and the environment.

CASE STUDY: North Carolina Neuse River * 1 billion+ fish died in 1991 over a few days. Cause: Pfiesertia; a free-swimming microscopic dinoflagellate. Concern: People using the river for recreation and fishing could be exposed to the toxins. Overloading of nutrients!

Environmentally Sustainable Society Meeting the present “needs” of people without depleting or degrading natural capital so that future generations can meet their needs.

Environmental Scientists Monitor Natural Systems for Signs of Stress Ecosystem services- environments provide life supporting services such as clean water, timber, fisheries, crops. Environmental indicators- describe the current state of the environment. Sustainability- living on the Earth in a way that allows us to use its resources without depriving future generations of those resources.

5 Global Environmental Indicators 1. Biological diversity 2 5 Global Environmental Indicators 1.Biological diversity 2.Food production 3.Average global temperature and [CO2] in the air 4. Human population 5. Resource depletion

Biological Diversity Biodiversity- the total number of different species in an area. Ex: genetic, species and ecosystem diversity.

Human Well-Being Depends on Sustainable Practices In order to live sustainably: Environmental systems must not be damaged beyond their ability to recover. Renewable resources must not be depleted faster than they can regenerate. Nonrenewable resources must be used sparingly.

Ecological Footprint Individual’s environmental impact (measure of how much a person consumes, expressed in area of land)) Amount of land (hectares) needed to produce the resources needed by an average person in a country. 1 hectare= 2.47 acres

The Scientific Method Observations and questions Hypothesis Collecting data Interpreting results Disseminating findings

Chapter 2 Environmental Systems

Case Study: MONO LAKE Located in California between deserts and Sierra Mountains. Lake is saltier than the ocean due salt picked up from flowing water that enters. 1913-1994: water that flowed into Mono lake was diverted to L.A. Resulted in lake degradation- low levels, high salt, lower biodiversity. 1994- water diversion stopped. By 2009 lake ecosystem is recovering.

Forms of Energy

First law of thermodynamics Energy is neither created or destroyed. You can’t get something from nothing.

Second law of thermodynamics When energy is transformed, the quantity of energy remains the same, but its ability to do work decreases. Figure 2.15

Second law of thermodynamics Energy Efficiency- the amount of useful work. Use less energy to provide the same service.

Open system- exchanges of matter or energy occur across system boundaries. Closed system- matter and energy exchanges across system boundaries do not occur. Does not occur naturally.

Steady state- in a system, when input equals output it is said to be in a steady state. steady states Ex: Oceans are in steady state- inflow of water EQUALS the rate of evaporation

Steady States FEEDBACKS/FEEDBACK LOOPS Negative feedback loops- system responds to change by returning to its original state. RESISTS CHANGES. Positive feedback loops- system responds to change by increasing the rate at which the change is occurring. AMPLIFIES CHANGES.