Environmental problems, their causes, and sustainability | Bài giảng chương 1 học phần Environmental Science | Trường Đại học Quốc tế, Đại học Quốc gia Thành phố Hồ Chí Minh
Sustainable yield is the highest rate at which a renewable and non-renewable resource can be used indefinitely without reducing its available supply. Humans depend on resources to meet our needs. A perpetual resource is continuously renewed and expected to last (e.g. solar energy). A renewable resource is replenished in days to several hundred years through natural processes. Tài liệu giúp bạn tham khảo, ôn tập và đạt kết quả cao. Mời bạn đón xem.
Trường: Trường Đại học Quốc tế, Đại học Quốc gia Thành phố Hồ Chí Minh
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Environmental science is a study of connections in nature
• Environment includes all living and nonliving things with which an organism interacts.
• Environmental science studies how the earth works, our
interaction with the earth, and ways to deal with
environment problems and live more sustainably.
• Ecology studies relationships between living organisms,
and their interaction with the environment.
• Environmentalism is a social movement dedicated to
protecting life support systems for all species.
Nature’s survival strategies follow three principles of sustainability
Sustainability has certain key components
• Life depends on natural capital (natural resources and natural services).
• Many human activities can degrade natural capital.
• Solutions are being found and implemented.
• Sustainability begins at personal and local levels. Nutrient cycling Fig. 1-4, p. 10
Some resources are renewable, and some are not
• Humans depend on resources to meet our needs.
• A perpetual resource is continuously renewed and
expected to last (e.g. solar energy).
• A renewable resource is replenished in days to several
hundred years through natural processes.
• Sustainable yield is the highest rate at which a renewable
and non-renewable resource can be used indefinitely
without reducing its available supply.
Some resources are renewable and some are not
• Some resources are not renewable.
– Nonrenewable resources exist in fixed quantities.
– Exhaustible energy (e.g. coal and oil).
– Metallic minerals (e.g. copper and aluminum).–
Nonmetallic minerals (e.g. salt and sand).
• Sustainable solutions: reduce, reuse, recycle.3Rs 5Rs 8Rs We are living unsustainably
Total and per capita ecological
footprint of selected countries Natural Capital Degradation
Degradation of Normally Renewable Natural Resources Fig. 1-5, p. 11 Ecological footprints: our environmental impacts
• Ecological footprint: amount of biologically
productive land and water needed to supply a
person or country with renewable resources
and to recycle the waste and pollution produced by such resource use.
• Per capita ecological footprint is the average
ecological footprint of an individual in a given country or area. Ecological footprints: our environmental impacts
• Ecological deficit means the ecological footprint is
larger than the biological capacity to replenish
resources and absorb wastes and pollution.
• Footprints can also be expressed as number of
Earths it would take to support consumption.
IPAT is another environmental impact model
• In the early 1970s, scientists Paul Ehrlich and John
Holdren developed the IPAT model.
• I (environmental impact) = P (population size) x A (affluence/person) x
T (technology’s beneficial and harmful effects). I = P x A x T
Experts have identified four basic causes of environmental problems
The human population is growing exponentially at a rapid rate
• Human population is increasing at a fixed
percentage so that we are experiencing doubling
of larger and larger populations.
• Human population in 2009 was about 6.8 billion.
• Based on the current increase rate there will be 9.6 billion people by 2050.
• We can slow population growth?!?!?!