Chapter 1 Studying the State of Our Earth Pfiesteria Cell Environmental Science.. Controversial and Related to Humans! Neuse River Fish Killer • 1991 in North Carolina 1 billion fish died. • Pfiesterisa, a free living aquatic organism identified as the cause. • Emits a toxin. • 24 different life stages…usually harmless. • Large influxes of nutrients to blame. • Not proven until 16yrs later! Our World and How We Influence It Environment: the sum of all the conditions surrounding us that influence life. Environmental Science: field that looks at interactions among human systems and those found in nature. System: any set of interacting components that influence one another. The study of environmental science uses knowledge from many disciplines. Humans Alter Natural Systems • Environmental Scientist study ecosystems including both the biotic and abiotic factors. Abiotic: Non-living. Biotic: Living. • Humans manipulate the environment more than any other species (2.5 myo). • We have had the biggest impact the last 10,00020,000 yrs. Los Angeles in 1880 with less than 6000 people. Los Angeles in 2009 with 3.8 million people. Monitoring Natural Systems Environmental Indicators: Used to describe the health and quality of natural systems. Help us analyze the health of the planet . Examples: human population, ecological footprint, extinction rate, water quality, habitat loss, etc. Sustainability: Living on Earth in a way that allows us to use its resources without depriving future generations of those resources. 5 Global Scale Environmental Indicators 1. Biodiversity a. Genetic Diversity b. Species Diversity c. Ecosystem Diversity • 2 million species identified. Speciation: making a new species(1-3 new/yr). Background Extinction Rate: average rate in which a species goes extinct (1 species per million/yr). • Scientists estimate that more than 10,000 species are currently going extinct each year. • Human intervention has saved some species. Species Diversity American Bison Peregrine Falcon Snow Leopard West Indian Manatee 2. Food Production • Ability to grow food and nourish the human population. • Has increased since the 1950s due to genetic engineering, fertilization, and expanded irrigation. • Worldwide production of grain per person, also called per capita has leveled off. • Grain production is not keeping up with population growth. Try This: calculate the approximate percent change in world grain production per person between 1950 and 2000. 3. Average Global Surface Temps and Carbon Dioxide Concentrations • The greenhouse gas (CO2) helps to maintain a constant temp on Earth. • Over the last 2 centuries the concentration of CO2 has increased. • Increase is anthropogenic- derived from human activities. 4. Human Population • Currently 7.2 billion and growing. • Places demands on the natural environment. • Over 1 million additional people every five days! Kolkata, India 5. Resource Depletion • Resources are becoming depleted. • Extracting resources negatively effect the environment. • Non-renewable resources include coal, oil, and uranium (finite). • Al and Cu are finite but can be recycled. • Consumption is directly related to development. • 20% of the global pop lives in developed nations but uses most of the worlds resources. Humans Need Sustainable Practices • Easter Island- lets learn from it!! In order to live sustainably : 1. Environmental systems must not be damaged beyond control. 2. Renewable resources must not be depleted faster than they can regenerate. 3. Nonrenewable resources must be used sparingly. Ecological Footprint Ecological footprint is a measure of how much that a person consumes, expressed in area of land. The total amount of land required to support a person’s lifestyle. Science as a Process Scientific Method (controlled & natural experiments) 1. 2. 3. 4. 5. Observations and Questions Forming Hypothesis Collecting Data Interpreting Results Disseminate Findings a. Theory: repeatedly tested and accepted. b. Natural Law: no known exceptions, withstood rigorous testing. Natural Experiment: Mount St. Helens preeruption forest area. The same location post-eruption in 1982. The same location in 2009 showing forest re-growth. Environmental Science and Unique Challenges • Lack of Baseline Data: no “control planet”. • Subjectivity: Our choices involve personal opinions and value judgments. • Interactions: Results of one system may not work for another. • Human Well Being: When basic needs are not being met, natural environment is less of a concern.