Topic 14: The Principles Of Earths Ecological Support Systems Flashcards
Natural systems and human processes
Natural systems are sustainable
Natural processes have been ignored in the development of human processes
By by understanding natural principles it may increase the sustainability of human activities
Give 2 examples of how the climate is regulated by natural negative feedback mechanisms?
Increased temp,increases could cover,increased albedo, causes decreased temperatures
Increased CO2,increases photosynthesis, increases carbon sequestration
How is the hydrological cycle regulated by natural feedback mechanisms?
Increased evaporation will lead to more precipitation
Do human activities utilise natural negative feedback mechanisms?
They are ignored if they restrict human activities
Humans find a new way to carry out the activity
Use agriculture as an example of how human activities that ignore natural negative feedback mechanisms are unsustainable
Agriculture causes soil degradation,reduces water,reduces natural predators.
Negative feedback would reduce crop yield as a result
Human response is fertilisers,irrigation and pesticides
These actions redice the natural systems that support food production so it becomes even more unsustainable
Why has climate control been dominated by negative feedback mechanisms rather than positive?
There are few natural positive feedback mechanisms
The negative feedback mechanisms that dominate the climate provide relatively stable conditions
What is the human impact on positive feedback mechanisms?
They have increased them
Give an example of a positvie feedback mechanisms that humans have increased
Global climate change has increased temperatures, which increases the rate of features in positive feedback mechanisms
Hat features of positive feedback mechanisms do humans increase?
Melting of permafrost
Ocean acidification
Decline of albedo
Methane hydrate releases
Why do natural systems rarely reach their tipping points
Because they are regulated by negative feedback mechanisms so they are restabilised
When can tipping points naturally be reached?
Whenever there have been large scale unusual events, that overwhelm the ability of natural mechanisms to re establish the equilibrium, so the equilibrium is recreated
Give an example of when tipping points have been reached naturally
The possible release of methane hydrate at the end of the Permian era that caused climate change and mass extinction
How do humans impact tipping points?
Global climate change
Causes an increase in the rate of natural processes so they become self sustaining because of human activities
We cause a lot of mechanism to reach their tipping point
Once that has happened we are unable to prevent those processes
What tipping points do humans impact?
Forest fires,release of methane hydrate,permafrost melting
Give 2 examples of naturally highly diverse systems
Tropical rainforests
Coral reefs
Why are diverse systems better?
They are more likely to be resistant to change
What impact do humans have on diverse systems?
They often produce less diverse systems
Why is the impact that humans have on diverse systems detrimental to humans?
Agroecosystems focus on the production of a limited range of food species and neglects to maintain other species that help maintain ecological stability and productivity
What types of organisms do agroecosystems neglect?
Pollinators
Detrivores
Natural pest predators
Describe the energy use of natural systems
Natural systems,tend to be driven by low energy-density,renewable energy resources,especially solar power
What drives natural processes?
All natural processes driven by solar energy are driven by low energy-density resources
Give examples of processes driven by solar energy that are driven by low energy density resources
Hydrological cycle
Nitrogen cycle
Carbon cycle
Atmospheric circulation
Thermohaline circulation
How do the human uses of energy prove using renewables is better?
Human activities powered by renewables have lower carbon footprints
What are not natural processes low temperature?
Enzymes reduce the activation energy of natural processes so high temperatures aren’t needed
Give examples of low temperature natural processes
Production of carbohydrates in photosynthesis
Decomposition
Nitrogen fixation
How are human processes different because of temperature?
Human activities tend to use higher temperatures, therefore more energy
Examples of high temperature human processes
Manufacturing processes
Haber process
Incineration of waste
Why are natural material cycles more sustainable systems than human systems?
Natural processes often link in sequences to produce cycles, where waste from one process is what needed in another
This means all processes can exist of small amounts of elements because they are reused= sustainable system
Are human material systems cyclical?
They are linear
It leads to resource depletion and waste generation
Why is fossil fuel use not sustainable?
Using non-renewables is not sustainable
There use when renewables are available accelerates depletion rates
Why is the human use of mineral resources unsustainable?
Human use causes them to be dispersed after use or they produce mixtures that are really difficult to seperate after use
What are the impacts of the human mineral use being unsustainable?
Recovery and reusing the materials is difficult
Less chance of sustainability exploitation and more chance of resource depletion
How does human mineral use compare to natural mineral use?
Waste from human use will build up,some of which is toxic
Natural waste products are either non-toxic or dont build up to the point where they are toxic
Why are natural processes sustainable and better for the environment?
Molecules produced in natural processes are biodegradable,non-toxic and can be broken down to the raw materials for other natural processes- this make s it sustainable
Low toxicity products reduce environmental impacts
Why do human activities cause damage ?
Toxic metals are used in consumer products e.g. electronics
They are difficult to extract from these products when disposed-cause damage
Persistent toxins with low degradability will bioaccumulate and biomagnify
