ES110 Midterm

Energy

• Capacity to do work, move things, or cause changes of state:

1. Kinetic- matter is moving

2. Potential- energy not in use at this moment but could be released

3. Electromagnetic- waves of energy that are emitted and passed through space

4. Nuclear change- a spontaneous change in the nucleus of an isotope, releases energy

Impacts of fossil fuels

• Climate change

• Air pollution

• Acid rain

• Water and land pollution

Environmental Impacts from Extraction and Transportation

· Depend on where it happened

· Spills from offshore oil rigs and other tanker ships are harmful to wildlife, contaminate freshwater

· Onshore rigs, leaky pipelines can contaminate soil and rivers

Alberta tar sands

· Some is mined from open pits, some it pumped out of the ground

· Steam is used separate tar from sand

· Chemicals are added to dilute the tar so that it flows like liquid

· Creates a low-quality product that at refinery is mixed with higher quality oil

· Producers call it "heavy oil"

· Very inefficient because it is very energy-intensive to separate the oil from the sand

· Contaminates large amount of water, generates large amount of greenhouse gas

Fracking

· A process whereby pressurized water, chemicals and sand are injected into the rock containing oil or natural gas

· Creates cracks in rock, makes it easier for the oil and gas to flow

· Increases the percent of oil and gad that can be extracted from a given formation

· Generates large amount of toxic waste above and below ground and mini earthquakes

Remediation

Remove toxins form site, cap and seal pipes and revegetate

Lack of remediation

Companies will typically try to avoid cleaning up abandoned mines and wells

Impacts from consumption of natural gas and oil

Greenhouse gases and air pollutants.

Wind turbines

· Transform kinetic energy to a more usable form

· Can perform mechanical work directly or generate electricity

· An old and simple effective technology still used

Electrical Turbine

· Conductive wire is coiled around the turbine shaft

· A magnet is placed adjacent to the shaft

· As shaft begins to turn, electrical current is generated in the coiled wire

Hydro-electric Generator

Hydroelectric moving water turns the shaft

Thermal,-powered electrical Generator

A pressurized tank of water is boiled to create steam that turns to the shaft

Nuclear-powered Turbine

Nuclear reaction inside chamber generates heat that boils water inside a pressurized tanks to create steam that turns to the shaft

Impacts of uranium mining

· Uranium is most common nuclear fuel

· Rock containing uranium is excavated, ground, chemicals applied to separate uranium from other material

· Damages surface land cover (forests, soil)

· Mine tailings (wastewater) are toxic and not easily disposed of

Alternative Energy Sources

• Wind

• Solar

• Hydroelectric

• Biomass

• Geothermal

• Fuel cells

Storage of Electricity for Later Use

· Battery technologies lag way being generation technologies

· Current batteries require large amounts of metals, elements that have environmental problems of their own

· If we cant solve the storage problem, we need to adapt the grid model to better accommodate renewables

· The baseload requirement of the grid model is too great for renewables to meet alone

· We need more local, small scale tie-ins to the grid

· We also need to reduce baseload requirements

Electric cars

· Charging network still being difficult

· Very expensive

· Recharging can take time; range is not great

Protecting ocean biodiversity

· Strong laws and enforcement to reduce pollution in rivers flowing to oceans

· Collective action to reduce plastic pollution

· Strong laws and enforcement to regulate fishing

Key challenges of protecting ocean biodiversity

· Countries have legal jurisdiction over their coastal waters

· The open ocean belongs to no one and there are very few rules

Properties of freshwater

1. Water is at its densest when the temperature is 4 degrees Celsius

• Means that water freezes from the surface downwards

• Even in dead of winter, there is cold, oxygen-rich water for fish & other animals below the ice

2. Cold water contains more dissolved oxygen than warm water

• If human activity causes water to get warmer, oxygen levels drop, causing animals to die off

Dissolved Oxygen

· Air can hold more than 200,000 parts per million of oxygen

· Water holds ~10 parts per million of dissolved oxygen at 15 degrees Celsius

· Actual DO level depends on temperature

· Fish, shellfish species tend to die off if DO levels fall by more than half

Impacts on freshwater systems

· Damming, diverting watercourses

· Draining wetlands and ephemeral ponds

· Changing the shore environment

· Chemical and nutrient pollution from industry, farming

· Waste water from homes, residences

Impacts of Dams

· Alters water levels, flows above and below

· Changes water chemistry, temperature, turbidity

· Prevents migratory species from moving up/down river

Alteration of Streams, Ponds, Rivers

· Increases flow of water into, through channels

· Removes habitat for insects, waterfowl, amphibians, reptiles, fish

Draining Wetlands

· Wetlands collect surface drainage, slow its movement into streams, rivers

· In Ontario, vast majority of wetlands have been drained for farms, urban/suburban construction

· Draining wetlands increases flood risks, reduces habitat for aquatic animals and waterfowl, migratory birds

Nutrient Pollution of Freshwater

· People add nitrogen, phosphorus fertilizers to farmland, gardens

· Some of it gets washed into waterways where it fertilizes the growth of algae

· Water becomes less clear, temperatures rises

· Oxygen levels fall, changes in aquatic biodiversity occur

Global Access to Safe Drinking Water

· 2 billion people globally drink water that may be contaminated with feces

· 844 million people have no access to treated drinking water at all

· 144 million drink raw surface water

500,000 people annually die from

water-related illnesses

Dealing with Water Pollution

1. Reduce the production of pollution at the source

2. Collect polluted water and treat it

Key challenges:

Key Challenge

· Trying to prevent and capture "non-point source" pollution

· Point source: St. John's harbor

· Non-point source: run-off from streets, roads, parking lots, lawns

Ontario Clean Water Act

· Requires planning at the watershed level to protect water quality

· Watershed is a large area that drains to a single point

· We have strict laws today because of the Walkerton Crisis

In May 2000, manure got into the town's water supply and seven people died, 2,300 people became sick after E.coli bacteria entered the town's drinking water supply wells

3 categories of forests

• Primary forest: Have not been logged

• Production forests: Have been logged or are being logged

• Plantation forests: Trees have been cut, and trees are being replanted

Pinchot's 3 principle of conservation

1. Natural resources should be used for the benefit of people who love here noe

2. Do not waste natural resources;effecient use is critical

3. Natural resources must be developed for the benefit of all people, just not a few

What sustainability looks like in terms of forest management:

1. Protecting forests with unique ecological characteristics (e.g. redwoods, sequoias, ancient trees, etc) PLUS Setting aside areas of untouched primary (“old growth”) forests to preserve and maintain biodiversity

2. Careful management of production forests to provide livelihoods, economic opportunities AND preserve biodiversity

3. Avoiding forestry practices that damage soil, water and prevent forest from regenerating

First law of thermodynamics:

• New energy can not be spontaneously created

  • We can take existing forms of energy

Second law of thermodynamics:

• When energy changes from one form to another, there is a load of efficiency

  • We can never gain additional energy when we change it from one form to another

Coal

Used primarily as fuel to generate electricity

Conventional oil reserves

• Oil has variety of uses

• Most common use= Transportation

• Also used as a feedstock for

  • Plastics

  • Polyster

Conventional natural gas:

• Natural gas is burned to heat homes, heat water, cook foods

• Also used in thermal generating stations to produce electricity

Environmental impacts of fossil fuels:

• Extraction

• Transportation

• Consumption

Pathway to a greener energy future:

• We need to use a lot more electricity, and generate it without creating

  • Greenhouse gas emissions

  • Air pollution

  • Other environmental problems

Our electricity distribution model in Ontario:

• Consumers use less electricity at night than in daytime

• Consumer use less electricity on weekends than on working days

• Consumers use more electricity on a hot summer day than any other time of year

How humans have fed themselves over time:

• Hunting, gathering & scavenging

  • Tool-making hominids first appeared 3m years ago

  • Humans were opportunistic hunters/gatherers/scavengers until only 12,000

• Subsistence agriculture( Domestication of plants & animals)

Subsistence farming systems

• Typically conducted on small parcels of land with modest technology; highly adapted to local conditions

• Sometimes done communally, other times by families

Commercial agriculture

• Farmers no longer produce food simply for themselves, but for a global food marketplace

• Became possible because of technological developments in food production, storage, transportation and processing

Monoculture cropping

• Use of chemical herbicides, pesticides allows farms to specialize and produce large volumes of a single crop

• Increases efficiency, yields

Experimentation with crop varieties

• Selective breeding & hybridization of high-producing plant varieties

• Develops more drought-tolerant, pest-resistant varieties

Driver of deforestation

• In North America, Europe & much of Asia:

• Wildfires + commercial forestry are main drivers

• In Africa, deforestation is driven by small-scale, subsistence agriculture

• For survival

• In Latin America and Southeast Asia, forests are cleared to make way for commercial agriculture (i.e. “commodity-based” deforestation)

• Soybean

• Coffee

What sustainability looks like in terms of forest management:

What sustainability looks like in terms of forest management...

1. Protecting forests with unique ecological characteristics (e.g. redwoods, sequoias, ancient trees, etc) PLUS Setting aside areas of untouched primary (“old growth”) forests to preserve and maintain biodiversity

2. Careful management of production forests to provide livelihoods, economic opportunities AND preserve biodiversity

3. Avoiding forestry practices that damage soil, water and prevent forest from regenerating

Pathway to a greener energy future:

• We need to use a lot more electricity, and generate it without creating

  • Greenhouse gas emissions

  • Air pollution

  • Other environmental problems

Our electricity distribution model in Ontario:

1. Consumers use less electricity at night than in daytime

2. Consumer use less electricity on weekends than on working days

3. Consumers use more electricity on a hot summer day than any other time of year

James Bay Project

A series of 8 massive hydroelectric dams built in northern Quebec in the 1970s and 1980s

Traditional farming methods: learning by doing

• Over thousands of years, through trial and error, farmers developed considerable environmental knowledge

• Traditional farmers are very knowledgeable about nutrient cycling, water conservation, soil protection

• Farming was often combined with hunting, fishing, forestry and other subsistence activities to ensure a stable subsistence livelihoods

Subsistence farming systems

• Typically conducted on small parcels of land with modest technology; highly adapted to local conditions

• Sometimes done communally, other times by families

• Farmers hope to be self-sufficient in food and have some left over to sell or exchange for things they cannot themselves produce

• This system leads to a high rural population density in areas with good soils

Commercial agriculture

• Farmers no longer produce food simply for themselves, but for a global food marketplace

• Became possible because of technological developments in food production, storage, transportation and processing

Developments in animal husbandry, veterinary science:

• Through selective breeding, artificial insemination we create animal breeds that yield more protein per animal

• Antibiotics, vaccines allow animals to be kept in larger concentrations without disease outbreaks, increasing the number of animals we can raise for food

Formula:

CO2 + 12 H2O + energy→lC6H12O6 + 6 O2 + 6 H2O

Soil Layers:

• O Horizon: Humus (plant litter, other decomposing organic material)

• A Horizon: Topsoil (mix of humus and leached mineral soil

• B Horizon: Subsoil (accumulation of leached minerals e.g. iron & aluminium oxides

• C Horizon: Weathered parent material (partly broken down)

• R Horizon: Parent material (rock)

Characteristics of good agricultural soil

• A mixture of organic material + inorganic particles of various sizes

• Ability to hold water (but not too much!)

• Porosity that allows air movement, root penetration

• Availability of nutrients, minerals

• pH near neutral (i.e. neither especially acid nor alkaline)

• Minimal amount of salt

Key nutrients/minerals for plant growth

• Plants require nitrogen (N), phosphorus (P) and potassium (K) to grow

• Historically farmers would apply animal manure to the soil because it contains these nutrients

• Today, farmers often use fertilisers instead

Pathways to sustainable agricultural systems

• Better land management to avoid soil erosion

• Fewer monoculture farms, more polyculture farms

• More use of technology (precision agriculture)

• Better water, nutrient management on farms

• Perennialization of grain crops

• Reduce use of chemicals, return to more organic production

• Change consumer preferences in high-income countries

• Renewed focus on production of local foods for local consumers

• More urban food production

• Reduce food wastage

Energy balance:

Amount of solar energy coming into the atmosphere must be equal to the amount leaving the earth

Incoming solar radiation averages 342 W/m^2

Milankovitch variations

• Earth’s orbit is not perfectly round, but elliptical

• The shape of the ellipse varies slowly

• When the Earth is farther from the sun, it receives less

radiation (and vice versa)

• Cycle takes ~ 100,000 years