Download NATS 1510 Lecture 10

NATS 1510 Lecture 10 – Technological Fixes
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Agricultural revolution, steady state conditions, population size and wealth
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Agricultural revolution, population and food supply increase, accumulation of wealth
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Solar energy, industrial revolution, coal, natural gas, uranium, machines to convert energy into
work, increases in population and wealth
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GDP, Gross Domestic Product, total market value of all goods and services produced in a country
in a given year, increased consistently since late 1800s
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Economists and economic growth, improved conditions, harm to the environment
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Continued growth may not be sustainable in long run
Sustainability
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Business and government: sustainability = economic growth plus environmental protection
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Environmental protection = eco-efficiency, increasing growth while using minimum resources
and producing minimum pollution
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Eco-efficiency a technological fix, new technologies, efficiency, less resources, producing less
waste
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Question: will technology either reduce our use of resources or reduce our pollution significantly
enough to avoid economic and or environmental collapse?
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Limits to technology’s contribution to sustainability:
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Energy conversion efficiencies
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Minimum material inputs to sustain levels of production, limiting ability to
‘dematerialize” economy
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There is no such thing as an industrial process with a zero environmental impact
Efficiency gains rarely outpace growth, significant environmental impact
Why are Industrial Societies Unsustainable?
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For a number of reasons, industrialized economies are unsustainable:
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85% of energy used is derived from non-renewable fossil fuels and nuclear
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Many raw materials in industrialized economies are non-renewable
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Industrial processes produce waste at a rate greater than the environment can
assimilate
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Industrialization, scaling up, sustainability
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Agriculture: before industrialization smaller scale and energy efficient, after industrialization,
food transportation, fossil fuel powered machines, energy inefficient
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Modern agriculture dependent on non-renewable fossil fuels, unsustainable
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Industrialized farming depletes renewable resources at a rate higher than the environment can
restore them
Conditions of Sustainabilty
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What would allow us to have sustainable economies?
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Sustainable Energy Generation Condition: all energy should be produced from
renewable sources at a rate that does not lead to damage to the environment. If the
source of energy is biomass, consumption cannot exceed regenerative capacity of the
ecosystem that produced it (sustainable yield criteria)
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Sustainable Materials Use Condition
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All raw materials must be supplied from renewable sources at rates that allow
for regeneration and do not cause harm to the environment
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We must use recycling and substitute renewables for our non-renewable
resources
Sustainable Waste Discharge Condition
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Waste can only be discharged at a rate that can be absorbed by the
environment without undue damage
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Much less waste, raw inputs from biomass and renewable sources, waste more biodegradable
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Processed materials that cannot be biodegraded (e.g. plastics) prohibited
Environmental Challenges of Sustainable Systems
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Challenge 1 – Environmental Impacts of Large Scale Energy Generation
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Renewable energy sources (e.g. solar, wind, biomass, hydroelectric) and costs
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Costs decreasing, subsidies and improvements
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Assumed that renewable energy sources have no environmental impacts
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Scale up a process and even smallest impact is scaled up
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Possible impacts of wide use solar power
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Solar energy is used by the environment to create ordered structures in natural
objects (plants, animals), if that energy was diverted there would be less to
create ordered structures in nature
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Solar energy is part of other important processes, all of which would be
disrupted by excessive rediversion to solar power
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Heating of land and oceans, water cycle
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Wind which transports heat, water, pollen, seeds
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Rivers which transport nutrients and organisms
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Photosynthesis which allows plant growth, that further creates biomass
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What alternatives exist in renewables, and what are their costs?
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Biomass
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2/5 of land for food, energy and goods production, biomass use as fuel will tax
environment
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Unused biomass needed to maintain ecosystem functions and biodiversity
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Current energy demand in biomass would require use of 10% of the Earth’s surface
(about what we use for agriculture now)
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Biomass land intensive, competition with agriculture for land use (fact: the corn used to
produce fuel to fill one gas tank could feed a person for one year)
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Biomass for fuel competes with biomass for food, increased prices, poor
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Scaling up biomass, demand for water, fertilizers and pesticides
Hydro Electric
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Good sites taken, environmental consequences to large scale hydroelectric
Solar
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Wind
Land intensive, more dispersed approach (many smaller solar panels), waste generated and
energy consumed
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Land intensive, public resistance
Challenge 2: Replacing Non-renewables with Renewables
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Current rates of consumption, exceeding regenerative capacity of environment
Challenge 3: Recycling Non-Renewables
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Never completely efficient
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Some materials cannot be practically recycled (pesticides, propellants, detergents)
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Dissipation of waste, natural materials are recycled by environment, artificial materials
and natural recycling process
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Economic growth incompatible with protecting environment
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Currently exceeding our environmental limits
Conditions for Environmental and Social Collapse
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Rapid growth in resource use and pollution
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Limited resource availability and waste absorption capacity
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Delayed political responses to limits when they are encountered
Technological fixes are limited, sustainable changes and political and ideological factors
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