Human Impacts on the Environment

• Humans are the most powerful agent of environmental change
• Intellectual capacity has allowed humans to travel into space and see the importance of the world in the solar system
• Expanding population, transforming environments, and consuming resources can overpower the world
• Evidence shows human-induced climate change puts the natural world at risk

Human Impacts on the Environment

• Earth's central environmental problem is its large and growing population
• The human population passed 6.8 billion in 2009 and has grown rapidly
• Population in 1960 was 3 billion
• Population in 1975 was 4 billion
• Population in 1987 was 5 billion
• Humans consume vast quantities of food, water, energy, and raw materials, generating much waste
• About 1 in 4 people worldwide live in extreme poverty, lacking basic needs
• Ensuring global sustainability is a major task, including feeding the population without disrupting ecosystems
• Quality of life for future generations depends on sustainable agriculture

Rich and Poor Countries

• Countries are divided into rich ("haves") and poor ("have-nots")
• Rich countries, also known as highly developed countries, are complex, industrialized, and wealthy with low population growth
• Examples of rich countries are Norway, Switzerland, Qatar, USA, Canada, and Japan
• Poor countries, about 82% of the world’s population, are split into moderately and less developed categories
• Moderately developed countries have medium industrialization and lower incomes

Moderately Developed Countries Examples

• Turkey
• South Africa
• Thailand
• Mexico
• Moderately developed countries have fewer opportunities for income, education, and health care

Less Developed Countries

• Low levels of industrialization
• Very high rates of population growth
• Very high infant mortality rates
• Very low per-person incomes
• Examples are the Philippines, Bangladesh, Haiti, and Laos

Population, Resources and the Environment

• Highly developed countries use more resources per person and negatively impact the ecosystem
• Over-consumption has as much impact as population boom
• Rapid population growth overwhelms and depletes a country's resources
• Developed nations’ high resource demands exceed survival needs, degrading the environment with nonessential items
• Renewable resources are resources that are replaced by natural processes but can be overexploited
• Nonrenewable resources are finite and depletable include minerals and fossil fuels
• Rapid population growth can cause renewable resource overexploitation like farming on unsuitable land
• Population growth impacts are critical in developing countries

Developing Countries Dilemma

• Exploiting resources for short-term population needs vs. conserving for future generations
• Exploitation of natural resources and resources for export to highly developed countries
• Poverty is tied to population pressures on resources and the environment

Population Size and Resource Consumption

• Overpopulation occurs when a country’s resource demand damages the environment
• People overpopulation means too many people in an area
• Consumption overpopulation means each person consumes too many resources
• Highly developed nations consume over half of the world’s resources and generate 75% of pollution
• Each person’s ecological footprint is the amount of land/water needed to supply resources and handle waste: food, energy, water, housing, clothing, transportation, and waste disposal
• Use the IPAT equation to estimate human impact, I = P x A x T

The IPAT Equation: I = P x A x T

• P = number of people
• A = affluence (consumption per person)
• T = environmental effects of technologies used
• The three factors in the IPAT equation are always changing in relation to each other
• Consumption of a particular resource may increase, but technological advances may decrease the environmental impact of the increased consumption

Sustainability and the Environment

• Sustainability ensures the ecosystem can work indefinitely without the burden human activities put on natural systems.