Visualizing Environmental Science The Environmental Challenges We Face Chapter 1 Copyright
A World in Crisis: Humans are the Most Significant Agent of Environmental Change Increasing populations are overwhelming the Earth s ability to regenerate Humans transform the landscape Destroying or altering habitats leads to species extinction Profound affect on processes such as nutrient cycles and climate In 2009, a total of 5566 species were classified as endangered worldwide
Human Impacts on the Environment: Human population exceeded 7 billion in 2011 Several billion more projected in 21 st Century Overpopulation
Human Impacts on the Environment: The Gap Between Rich and Poor Globally, A condition in which people are unable to meet their basic needs, earning less than $2/ day 3.3 billion people live in poverty Poverty associated Fertility rates vary: 1.7 in highly developed countries compared to 4.5 in least developed countries Highly developed countries have complex industrialized bases, low population growth rate and high per person incomes
Population, Resources, and the Environment People in highly developed countries consume more resources per person than people in developing countries Nonrenewable resources Fossil fuels Finite supply that took millions of years to form Renewable resources Trees, soil, water Potentially replaced by natural processes
Population, Resources, and the Environment As a rule, developing countries export their natural resources to highly developed countries Developed countries already exploited their own resources A larger population consumes more resources and causes more environmental damage than a smaller population
Population, Resources, and the Environment Highly developed nations represent 20% of the world s population yet generate 75% of world s pollution and waste, and consume > half of the world s resources 86% of the aluminum used 76% of timber harvested 61% of meat eaten 42% fresh water consumed
Environmental Impact: Ecological Footprint Ecological footprint: amount of land and water needed to provide energy, housing, transportation per person Allotted global footprint 4.3 acres Average global footprint 6.7 acres overshoot! How many Earths do we need to support current consumption?
Environmental Impact : IPAT Although developing nations have lower individual footprints, because of their large populations, their overall footprint is high Mathematical IPAT model to assess human impact on the environment Impact = # people X affluence or resources consumed X technology used to obtain and consume resources (I=P x A x T) Goal: sustainable consumption
Sustainability and the Environment Sustainability is the ability to meet current needs without compromising the ability of future generations to meet their needs Based on several ideas Effects of our actions on the environment Earth s resources are finite Understanding impacts of consumption Shared responsibility for environmental sustainability
Environmental Science Interdisciplinary study of humanity s relationship with other organisms and the physical environment Combines information from many fields biology, geology, geography, chemistry, economics, agriculture, law, politics, ethics, etc.
Science is a body of knowledge AND a systematic process Science involves data collection and interpretation The scientific method is used to understand the principles that govern the operation of the natural world Science as Process
The Scientific Method The way a scientist approaches a problem, by formulating a hypothesis and then testing it
The Importance of Prediction Hypotheses based on what is believed to be true and based on prior scientific work Try to test one variable at a time and hold other constant Experimental group vs. control group May lead to a theory, a well-supported explanation
Science is Constantly Evolving As new evidence comes to light, conclusions may change Scientific goal is to explain events in nature
Handling Environmental Problems The ideal approach to systematically addressing environmental problems - Scientific assessment - Risk analysis - Public engagement - Political considerations - Long-term environmental management
Handling Environmental Problems