Ecological Concerns

Global Warming An increase in temperatures around the world Caused by adding CO2 and other gases such as methane to the air from burning fossil fuels; removal of trees keeps CO2 from being taken from the air As a result, heat can’t escape

It is predicted if global warming continues, polar ice caps will melt, causing flooding Storms and other weather disturbances will become more common Serious droughts will occur

Ozone Depletion Composed of O3 molecules Absorbs ultraviolet (UV) radiation from the sun Discovered as a hole in the ozone layer over Antarctica

A similar ozone hole has appeared over the Arctic, which has grown so large to expose the northern part of the U.S.

Caused by chlorofluorocarbons (CFCs) Used in aerosol cans, in the manufacture of plastics, and coolants in refrigerators and air conditioners

Most countries have banned the use of CFCs

Acid Rain Caused from burning fossil fuels Acidic gases are given off which contain nitrogen and sulfur; when they combine with water vapor, they form drops of nitric or sulfuric acid

When it rains (or sleets, snows, etc), the water has an acidic pH The acid builds up in the soil, causing damage to plants and runs off into rivers

Mount Mitchell, NC

NATURAL ENVIRONMENTAL PROCESSES INFLUENCE ECOSYSTEMS https://www.cnn.com/2018/05/09/us/hawaii-kilauea-volcano-acid-rain/index.html

Logistic vs Exponential Growth

carrying capacity is the maximum population size an ecosystem can support population sizes are dependent on limiting factors, such as space, food, sunlight, oxygen, carbon dioxide, nitrogen in soil, etc.

HUMAN POPULATION GROWTH Has grown exponentially

Increasing Populations Affect… Amount of clean water (lack of clean drinking water is the major cause of death world wide) Increase of waste Soil lost when it is cleared for agriculture Demand for land has led to deforestation, which contributes to global warming Pollution of the environment (can lead to bioaccumulation) Food shortages Spread of diseases

Bioaccumulation can lead to biological magnification (concentrations of chemical such as pesticides and fertilizers, increase from lower to higher levels of a food chain)

NC Example – Waste Lagoons on Hog Farms There are approximately 7 million hogs on industrial farms in NC, most in eastern NC which is a flood-prone coastal plain. Industrial farms raise thousands of animals in a small space, producing TONS of waste. The waste is stored in lagoons, but may run-off, leak or spill into surface water with rainfall. The sewage in the surface water leads to high levels of disease-causing bacteria such as E. coli, oxygen-depleting organic matter, and hormones/antibiotics used in feed Also, nitrogen run-off from the waste may contribute to outbreaks of Pfisteria, a single-celled alga that produces a deadly neurotoxin. Massive fish kills have resulted, along with health problems in fishermen and others exposed

HUMAN POPULATION GRAPHS – AGE STRUCTURES (OR POPULATION PYRAMIDS)

One of the tools that demographers use to understand population is the age structure diagram This diagram shows the distribution by ages of females and males within a certain population, along with percentages of people in different age categories Notice the percentage of children on the different graphs that can be used to determine rapid, slow, or no growth

QUESTIONS Countries showing rapid growth show the majority of the population in which age group(s)? For a country to have zero population growth, such as Italy, how many children would each couple have?

ANSWERS Countries showing rapid growth have high birth rates and low death rates, so the majority of people would be children. Each couple would have 2 children for zero population growth. One child to replace each parent when they die.

TECHNOLOGY Technology can help solve problems, but also contributes to pollution of air, soil, and water Sustainable agriculture aims to conserve soil so it can be reused Farm equipment consumes nonrenewable resources (oil, gas) and causes air pollution

Chemicals are added to soil for agriculture (fertilizer, pesticides, etc.) Man-made chemicals contribute to environmental problems, such as CFCs that deplete the ozone Outdated equipment (old computers, cell phones, etc.) have to disposed of Modern transportation causes an increase of use of gas and oil and creates air pollution

Transportation also causes acid precipitation Nuclear power doesn’t create pollution, but wastes have to be disposed of Some resources are renewable and can be replaced almost as quickly as they are used (trees used for paper), but some are nonrenewable and can not be replaced (metals, minerals, coal, oil)