Basic Issues in Environmental Science

Transcription

1 Lecture -1: Basic Issues in Environmental Science ENV 107: Introduction to Environmental Science Dr. A.K.M. Saiful Islam

2 Case Study: Shrimp, Mangroves and Pickup Trucks: Local and Global Connections Reveal Major Environmental Concerns Activity: Maitri Visetak, a farmer, has small plot along the coast in Thailand. Wanted to improve life for his family. Began farming shrimp in two small ponds. In two years > purchase two pickups >> clear indication of financial success. consequence: But, by then, his ponds were contaminated with shrimp waste, fertilizer, pesticides etc. Pollutants escaping threatens survival of the area s mangrove trees. Conclusion: Consider abandoning these ponds and moving on to the others.

3 Shrimp farm & Mangrove Forest

4 Illustration from Maitri Visetak Story 1. Human population increase is a major contributor to environmental problem. 2. Industrial development and urbanization have serious environmental consequences. 3. Unsustainable use of resources must be replaced with sustainable practices. 4. Local changes can have global effects. 5. Environmental issues involve values and attitudes as well as scientific understanding

5 1.2 Human Population Growth Rapidly increasing human population underlies all environmental problems. Last part of the 20 th century we have seen the most dramatic increase in the history of the human population. In 35 years, human population of the world increase from 2.5 to 5.9 billion. The human population issue is the underlying issue of the environment, because most current environmental damage results from the very large number of the people on the earth!

6 Declination of human population The black death The epidemic diseases bubonic plague caused by the bacteria Yersinia pestis commonly known as black death spread throughout Europe during the fourteenth century ( ). Generally 1/8 to 2/3 population died. Consequences: The great reduction in the labor force led to an increase in wages and is believe to have been a contributing factor to a subsequence increase in the standard in living.

7 The Black Death

8 African Famine Drought and political unrest in Africa have led to major episodes of famine. In one year, as many as 22 African nations suffered catastrophic food shortage and 150 million Africans faced starvation. Four million tons of emergency food were needed. Five million refugees sought food and shelter. Which is more important, the survival of people alive today or the conservation of the environment, on which future food production and human life depend.

9 1.3 Sustainability and Carrying Capacity Sustainability must be achieved 1. A sustainable resource harvest The quantity of a resource can be taken in a particular period. 2. A sustainable ecosystem An ecosystem from which we are harvesting a resource that is still able to maintain its essential functions and properties. 3. A sustainable economy An economy that maintains its level of activity over time in spite of uses of environmental resources. 4. Sustainable development A society is able to continue to develop its economy and social institutions, and maintain its environment for a indefinite time

10 Carrying Capacity The maximum number of individuals of a species that can be sustained by an environment without decreasing the capacity of the environment to sustain that same amount in the future.

11 Difficulties in determining carrying capacity Graphs of annual catch of chinook salmon in the Columbia River of the Pacific Northwest. Catch increase rapidly from 1860 to Declined and fluctuated until 1920, when it decline again in a highly varying pattern.

12 1.4 Global Perspective Civilization can the change the environment at a global level is relatively recent. Emission of chemicals are changing the Ozone layer high in atmosphere. The burning of fossil fuels increases the concentration of greenhouse gases in the atmosphere, which may change the Earth s climate. The action of a group of people at many locations affect the environment of a global level.

13 1.5 An Urban World Situation: In developed countries about 75% of the population lives in urban areas. In developing countries 36% are city dwellers. By 2025, 62% of the population, 6.5 billion will live in cities. Tokyo, Japan in the world larges city. Bombay, India world s fastest growing city. In 2025, Asia will have 7 mega-cities (>10 million people). One of them is Dhaka. Concerns: In the future we must place more emphasis on urban environments and on the effects of urban environment on the rest of the planet.

14 1.6 Values and Knowledge Decision concerning solutions to environmental problems require both values and knowledge. 1. Utilitarian justification Sees some aspect of the environment as valuable because it provides individuals with economic benefit or it is directly necessary to their survival. Fishermen obtain their livelihood from the ocean and need a supply of fish so that they can continue to earn a living 2. Ecological Justification Is based on the value of some factor that is essential to larger life support functions., even though it may not benefit an individual directly. Burning coal and oil adds greenhouse to the atmosphere, which may lead to a change in climate that could affect the entire earth.

15 Placing a Value on the Environment 3. Aesthetic Argument Have to do with our appreciation of the beauty of nature. The state of Alaska acknowledges that sea otters have an important role related to recreation- people enjoy viewing them. 4. Moral justification Has to do with the belief that aspects of the environment have a right to exist and that it is our moral to allow them to continue or help them to persists. Nebraska, one of the few remaining prairie preserve, has a right to exists.

16 Five themes from today's lecture Human population growth is the fundamental environmental issue. Sustainability is the key to future availability of resources and environmental effects. The impact of people at a local level affects the environment globally. Our world is becoming increasingly urban, and urban areas have their own kinds of environmental effects, both inside the city and on the surrounding countryside. Any solution to environmental issues requires consideration of both knowledge and values.

17 What is more important? Human population: the quality of life of people alive today or the future life of human fetus? Sustainability: What is more important: abundant resources today as much as we want and can obtain or the persistence of these resources for future generations? Global Perspective: the quality of your local environment or the global environment. Urban World: Human creativity and innovation, including arts, humanities, and science, or the persistence of certain endangered species. Values and Knowledge: Does nature know the best or do we need to have knowledge so that we can make the best judgments given available information.