Sustainability (A2) (Complete) Flashcards
Principles of sustainable lifestyles; why does sustainability refer to?
-The ability to have a lifestyle that can be maintained indefinitely
-On a global scale it relates to the overall impacts of the entire human population
Principles of sustainable lifestyles; what definition of sustainability was produced by the Brundtland Commission in 1987?
“Sustainable development meets the needs of the present generation without compromising the ability of future generations to meet their own needs.”
Principles of sustainable lifestyles; what are the different approaches to sustainable lifestyles?
-Some are founded in the moral belief that it’s the right thing to do
-Other approaches are based on ‘enlightened self-interest’; protecting the environment causes fewer difficulties than not doing so
Principles of sustainable lifestyles; which two main factors does the overall environmental impact depend on?
-The total population
-The individual impacts of each person
Principles of sustainable lifestyles; what are examples of sustainable activities that can become unsustainable with a big population?
-Slash + burn agriculture
-Fishing
-The discharge of some pollutants eg sewage
Principles of sustainable lifestyles; how has affluence increased in society and what impact does this have on the environment?
-As global human population has grown, so has the average per capita impact which is closely related to affluence
-W/ increasing affluence, access to energy has become easier which has made many new activities possible, many of which have greatly increased environmental impacts due to the scale of activities & production of toxic wastes that couldn’t be decontaminated by natural processes
Principles of sustainable lifestyles; why is unsustainable exploitation carried out?
-Development of new activities has rarely been restricted by an awareness that the environmental impact is unsustainable
-This may be because the new opportunity is overwhelmingly attractive, due to a lack of knowledge understanding the impacts or because impacts occur elsewhere/much later
Principles of sustainable lifestyles; what are the attitudes to sustainable exploitation?
-Attitude of a society to the sustainable exploitation of environmental resources is often linked to location of resources + where & when the problems occur
-Many sedentary, rural communities have a cultural belief that resources should be exploited sustainably & that level of exploitation should be limited to satisfying needs
Principles of sustainable lifestyles; how can over-exploitation be observed and what are the impacts of it?
-The problems caused by over-exploitation become obvious quickly as supplies of resources dwindle
-Urban populations are usually supported by resources brought in from other areas
-If resources are depleted in one area then exploitation just moves to another area w/ problem being evident to urban consumers
-This has occurred w/ resources like supplies of timber, energy, metal minerals & fish
Principles of sustainable lifestyles; what do sustainable lifestyles involve?
A holistic overview of the ecological support systems of Earth & an understanding of how human activities can be developed to operate by the same principles
Principles of sustainable lifestyles; what can sustainable lifestyles involve and what is necessary for them?
-Many people are prepared to reduce their environmental impact by lifestyle changes like recycling more, conserving energy/switching to renewable energy
-Some of the lifestyle changes can be enacted by individuals but others need the cooperation & decision-making of groups of people/complete societies, or international cooperation + agreement so that changed lifestyles are genuinely sustainable, not just doing a little less damage
Principles of Earth’s ecological support systems; how have natural systems developed?
Over long time periods, based on physical resources, renewable energy & natural processes that combine to provide long-term conditions that provide relatively stable conditions suitable to sustain abundant, diverse life
Principles of Earth’s ecological support systems- dynamic equilibria; what are the negative feedback mechanisms in natural processes which resist change?
-Climate regulation; increased temperatures causing increased cloud cover + a higher albedo & increased carbon dioxide levels leading to greater photosynthesis + carbon sequestration
-Hydrological cycle; increased evaporation leading to increased precipitation
-Population regulation; homeostatic population regulation caused by density-dependent factors
Principles of Earth’s ecological support systems- dynamic equilibria; what are the negative feedback mechanisms in human activity which resist change?
-Natural negative feedback mechanisms that’d curtail a human activity are often ignored
-Human response may be to find new ways of maintaining the activity
-Agricultural systems often cause soil degradation, reduced water availability & loss of natural pest predators
-Negative feedback mechanisms would reduce crop yields
-The human response may be to use fertilisers, irrigation & pesticides which further reduce natural systems that’d support food production
Principles of Earth’s ecological support systems- dynamic equilibria; what are the positive feedback mechanisms in natural processes which increase change?
Throughout the time that humans evolved, climatic conditions on Earth have been dominated by negative feedback mechanisms, producing relatively stable conditions
Principles of Earth’s ecological support systems- dynamic equilibria; what are the positive feedback mechanisms in human activities which increase change?
Global Climate Change; increased temps may increase following features involved in positive feedback mechanisms-
-Melting of permafrost
-Forest & peat fires
-Ocean acidification
-Formation of cirrus clouds
-Decline of albedo
-Soil decomposition rates
-Methane hydrate releases
Principles of Earth’s ecological support systems- dynamic equilibria; what are equilibrium tipping points in natural processes which lead to new equilibria + example?
-Natural systems regulated by negative feedback mechanisms rarely reach tipping points as the response to changes re-establishes the previous state of equilibrium
-Large scale unusual events can cause changes that reach tipping points as they overwhelm the ability of negative feedback mechanisms to re-create equilibrium eg possible release of methane hydrate at the end of the Permian era that caused climate change + a mass extinction
Principles of Earth’s ecological support systems- dynamic equilibria; what are equilibrium tipping points in human activity which lead to new equilibria?
-Global Climate Change; an increase in the rate of natural processes may become self-sustaining due to human activities, eg forest fires, methane hydrate releases & permafrost melting
Principles of Earth’s ecological support systems- dynamic equilibria; what are high diversity natural systems more likely to be resistant to change?
-Tropical rainforests
-Coral reefs
Principles of Earth’s ecological support systems- dynamic equilibria; why do human activities often produce less diverse systems?
Many agroecosystems focus on the production of a limited range of food species w/ little attempt to maintain other species that help maintain ecological stability & productivity eg. detritivores, pollinators, natural pest predators
Principles of Earth’s ecological support systems- energy; what kind of energy resources are natural systems driven by?
Low energy-density, renewable energy resources like solar power
Principles of Earth’s ecological support systems- energy; why are the natural processes driven by low energy-density resources/solar power?
-Hydrological cycle
-Carbon cycle
-Atmospheric circulation
-Nitrogen cycle
-Thermohaline circulation
Principles of Earth’s ecological support systems- energy; what different energy resources are human activities powered by?
-Human activities are usually powered by non-renewable energy resources
-Human activities based on renewable energy resources have low carbon footprints
Principles of Earth’s ecological support systems- energy; what are examples of low temperature natural processes?
-Production of carbohydrates by photosynthesis
-Enzymes reduce activation energy of reactions so high temps aren’t needed
-Decomposition
-Nitrogen fixation