Planet in Crisis Midterm 2

Eutrophication

The process of nutrient enrichment, increased production of organic matter, and subsequent ecosystem degradation.

What is the main effect of eutrophication?

Excessive plant and algal growth (organic matter increase), due to the increased availability of one or more limiting growth factors needed for photosynthesis

Cultural eutrophication

AKA anthropogenic eutrophication

Increases in plant and algal growth due to anthropogenic nutrient inputs.

Sources of cultural eutrophication

Sewage, fertilizer runoffs, phosphorous containing detergent (pre 70s)

Oligotrophic

Aquatic ecosystem with low nutrients, high clarity, high oxygen, and low productivity

Mesotrophic

Aquatic ecosystem with moderate nutrients, intermediate clarity, and moderate productivity

Eutrophic

Aquatic ecosystem with high nutrients, low clarity, low bottom oxygen, and high productivity

Principle of limiting factors

Certain ecological functions are controlled by whichever environmental factor is present in the least supply relative to demand (barrel with unequal staves/planks analogy. plant growth is limited by the element in the shortest supply)

Examples of limiting factors

• Water

• Light

• Nutrients

• CO2

What is the main limiting nutrient in terrestrial ecosystems?

Nitrogen

What is the main limiting nutrient in freshwater ecosystems?

Phosphorous

Explain the relationship between sediments and phosphorous

Sediments can act as a long term sink storing phosphorous, or a source releasing phosphorous back into water

What is so significant about phosphorous retention in sediments?

It is a key process controlling water quality, plant growth, and eutrophication in freshwater

Nutrient excess

Occurs when a specific element or compound is present in amounts higher than required for normal metabolic functioning

What is a limiting nutrient in the oceans?

Iron

What are the potential benefits and risks of fertilizing the oceans with Fe

Benefits:

• Capture atmospheric CO2 and store it

• temporary boost of phytoplankton growth (supporting marine food web)

Risks:

• May trigger toxic algae blooms

• Increasing ocean pollution with little effect on atmospheric CO2

What happened to Lake Erie in the 60s-70s?

Industrial waste, untreated sewage, and agricultural runoff had overloaded the lake with nutrients (cultural eutrophication occured), resulting in cyanobacteria blooms. When the blooms died off, bacterial decomp dissolved most of the oxygen in the water leading to hypoxic conditions and decimation of the ecosystem.

What was the importance of the Experimental Lakes Area (ELA)?

It established by the Canadian government specifically to resolve freshwater crises like Lake Erie's

What was the significance of Lake 226 of the ELA?

They divided the lake using a curtain, one half infused with nitrogen and carbon (it remained clear), the other with nitrogen, carbon and phosphorous (resulted in algal bloom). This provided proof that phosphorous was the limiting nutrient driving eutrophication

What is happening to the Gulf of Mexico and why?

The input of freshwater, nitrogen, and phosphorous from runoff that enters the Mississippi river exits into the Gulf of Mexico, causing eutrophication which forms a massive hypoxic dead zone

How are hypoxic dead zones formed?

• Stratification: lighter nutrient rich freshwater sits on top of denser saltwater creating a barrier that prevents O2 from mixing down into deeper water (Ex. Gulf of Mexico)

• Algal bloom die-off: when algae die they sink and are decomposed by bacteria. Bacteria consume a lot of dissolved O2 during decomp, bringing O2 levels down, killing marine life.

What are primary producers? (aka autotrophs)

Organisms that can make their own organic food molecules from inorganic materials

How are primary producers controlled? (Top down? Bottom up? Both?)

Top down via herbivory, bottom up via nutrients, water, and light availability

How does adding a trophic level impact eutrophication?

Adding a trophic level, such as introducing a top predator (ex., a pike), suppresses intermediate consumers (ex., minnow), triggering a top down trophic cascade. When pike are introduced, they feed on and reduce the population of planktivores like minnows, that eat zooplankton. This results in increased numbers of zooplankton, which keep phytoplankton in check, preventing eutrophication.

How does removing a trophic level impact eutrophication?

Removing a trophic level, such as a top predator, releases intermediate consumers from predation pressures. When pike are removed, minnows grow in number and eat more zooplankton. Less zooplankton allows the phytoplankton population to grow unchecked, resulting in eutrophication.

What are hypoxic dead zones?

Hypoxic areas in aquatic ecosystems, typically a consequence of pollution, eutrophication, and high decomposition rates, that are essentially devoid of life.

How do hypoxic dead zones form?

Excess nutrients enter lake from inland rivers and streams, nutrients cause algal blooms, algae die and sink to bottom of water column, bacteria decompose the algae consuming oxygen in the process, depleting oxygen from the body of water.

What are harmful algal blooms?

Colonies of algae—or bacteria-like organisms such as cyanobacteria (blue-green algae)—growing out of control in bodies of water that may produce excess biomass or toxins.

What are some toxins produced by harmful algal blooms?

Neurotoxins, hepatotoxins, dermatotoxins

What is neoclassical economics?

• A theory of economics that explains market prices in terms of consumer preferences for units of particular commodities.

• Buyers desire the lowest possible price, whereas sellers desire the highest possible price

• Conflict between buyers and sellers results in a compromise-price and the “right” quantities of commodities being bought and sold

What are the assumptions of the neoclassical economics theory? How are each assumption flawed?

• Resources are infinite or substitutable - Earth is a closed system. even renewable resources can be exploited and used up faster than they can be replenished

• Long-term effects should be discounted - what about future generations?

• Costs and benefits are internal - everyone and everything is connected! transactions involve other people than the buyer or seller

• Growth is good - overconsumption and overproduction leads to negative impacts

What is the Tragedy of the Commons?

An analogy that shows how individuals driven by self interest can end up destroying the resource upon which they all depend. A few benefit for a while but everybody loses in the end.

What is the single bottom line system?

Concentrates strictly on economic returns and financial viability. ie., generating profit

What is the triple bottom line system?

Profit (economic), People (social equity and labor), and Planet (environmental stewardship). In the middle is sustainability.

Ecosystem goods and services

The benefits humans derive, directly or indirectly, from ecosystem functions

Ecosystem functions

The capacity of natural processes and components to provide goods and services that satisfy human needs, either directly or indirectly.

4 types of ecosystem services

• Provisioning: the delivery of products that we directly use like food, water, and biochemicals

• Regulating: services provided (by the ecosystem) that regulate our environment, like forests, oceans, and wetlands regulating carbon and climate.

• Cultural: non-material benefits that enrich the human experience

• Supporting: the provision of ecosystem processes need to support life and all other ecosystem services, like primary production and nutrient cycling

Ecosystem valuation

the assignment of economic value to an ecosystem or ecosystem services. Often represent:

• The monetary cost of replacing the ecosystem service

• The monetary value of the capital gained from the resource

Types of capital under neoclassical economics

• Social capital: the value of relationships between people

• Natural capital: the summation of all ecosystem services on Earth, available to us for free

• Normal capital: goods and services of economic value; resources that can be used to produce goods

Types of capital under ecological economics

• Natural capital: resources and services provided by the Earth’s natural processes

• Human capital: peoples physical and mental talents; includes social capital from neoclassical economics

• Manufactured capital: tools and materials

What is the difference between neoclassical economists and ecological economists?

• Neoclassical economists believe that Earth’s natural capital is part of the human economic system

• Ecological economists believe that human economic systems are subsystems of the biosphere, and that conventional economic growth will become unsustainable

Difference between full cost pricing and market pricing of goods and services.

• Full cost pricing: implemented by eco-economics, the inclusion of the harmful environmental and health costs of producing goods and services in their market prices (taxing pollution and waste instead of wages and profit)

• Market pricing: implemented by neoclassical economics, does not include indirect, external, or hidden environmental and health costs

Do intact functioning ecosystems have a lot to offer us?

YES

Main principle of neoclassical economics

Grow, compete, and use resources fast

Main principles of ecological economics

• Use just enough and no more

• Take only what you need and leave your competitor enough to live

• When parts wear out, don’t discard, recycle

• Give to the future

What is biodiversity?

The variability among living organisms, from plants to animals, and the terrestrial, marine, and freshwater ecosystems they inhabit. Biodiversity includes diversity within the same species (genetic diversity), between different species, and between ecosystems.

Why does biodiversity matter?

• Many rely on animal and plant-based resources like medicine and food.

What is the biodiversity crisis?

Considered by some to be the 6th mass extinction, caused by humans. 75% of land and 66% of marine environments have been significantly altered by humans, with the majority devoted to farming.

What are some things that impact biodiversity?

• Climate change - increases the number of at risk species

• Natural disturbances - wildfire, pests, disease

• Industrial (anthropogenic) disturbances - roads, oil and gas exploration and development, pipelines, infrastructure, forestry, pollution

What is an indicator species and give an example.

An indicator species are species that are sensitive to disturbances in an ecosystem. An example includes the Woodland Caribou in mature forests and wetlands.

What would the decline of an indicator species, such as Caribous, indicate?

That something is wrong in the environment.

When an indicator species is in decline, what is the cause?

• Anthropogenic activities such as:

  • forestry

  • oil and gas exploration and development

  • mining and mineral exploration and development

  • hydro-electric development

  • tourism

  • and more

• These activities affect indicator species through a combination of direct and functional habitat loss, decreased habitat quality, and development of linear features, causing fragmentation.

What effect do human-induced habitat alterations have on predator prey relationships?

Habitat alterations via anthropogenic activity cause an imbalance in predator prey relationships, resulting either in unnaturally high predation rates, or prey overpopulation.

What percentage of undisturbed habitat does a range need to have a likely outcome of population stability? Is this a bare minimum threshold?

65%. Yes it is a bare minimum threshold. It correlates to a 60% chance of becoming self-sustaining.

What is disturbed habitat?

An environment where the natural state has been disrupted or damaged, changing the vegetation, physical structure, and types of wildlife that can live there

What are conservation areas?

Areas reserved for undisturbed habitat.

What are the 6 parts of creating a nature strategy?

• Comprehensive land use planning

• Parks and protected areas

• Biodiversity conservation

• Sustainable economic opportunities

• Indigenous-led conservation

• Nature-based solutions

What is a protected area?

A clearly defined geographic space, recognized, dedicated, and managed through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values.

We can’t make everything a protected park. So how do we manage the spaces in between?

Land use planning is key. We need to consider all activities on the landscape

Climate change

Long term variations of the average weather conditions experienced in a particular region (ex., Edmonton has milder winters than 30 years ago)

Global warming

Increase over time in the average temperature across the entire planet

What are the main drivers of climate change?

• Human Activities:

  • Burning fossil fuels - GHG’s and carbon emissions

  • Deforestation and land use change - carbon emissions and reduced capacity to store CO2

  • Agriculture and livestock farming - ruminant livestock produce methane, cultivation releases emissions

  • Industrial processes - materials like steel, cement, and plastic release process related carbon emissions and chemical byproduct

  • Nitrogen fertilizers

  • Transportation and more

• Natural factors:

  • volcanic eruptions

  • solar variations

  • Earth’s orbital cycles

  • Meteor and asteroid impacts

  • glacial and interglacial periods

Variations in solar output

The amount of solar radiation we receive from the sun varies on a daily to millennial basis.

What causes changes in total solar irradiance?

Changes in total solar irradiance (TSI) are caused mostly by changes in activity of sunspots (dark spots on surface with strong magnetic forces) and faculae (bright spots that put out more radiation than normal). Sunspots and faculae increase and decrease in concert. More sunspots = more faculae = increased TSI

What are the 3 processes that contribute to variations in earths orbit?

• Eccentricity: orbit cycles between circular and elliptical every 100,000 years

• Obliquity: tilt of the Earth changes, cycling between 24.5 and 22.1 degrees every 40,000 years (higher angle = more extreme seasons, lower angle = less extreme seasons + formation of ice sheets)

• Precession: changes in the orientation of the Earth’s axis, cycles every 25,000 years

What are Milankovitch cycles?

Regular cycling of the eccentricity, obliquity, and precession of Earth’s orbit drives glacial and interglacial periods

How do volcanic events contribute to climate change?

• Eruptions produce:

  • Sulfuric gas (aerosols)

  • Volcanic ash (particulates of rock and glass)

• These compounds can cause cooling via scattering incoming solar radiation

• Volcanoes can cause warming as well:

  • Increase water vapor

  • Increase CO2

• These compound are GHG’s and can aid heat retention in the atmosphere

How do meteorite events cause climate change?

Similar to volcanoes, they create dust on impact which can block solar radiation; they also create shock waves that can disrupt ecosystem structure

What is the most abundant GHG? Why?

Carbon dioxide, it lasts a long time in the atmosphere

What are some GHG’s?

• Carbon dioxide

• Water vapor

• Methane

• Nitrous oxide

• Ozone

• Chlorofluorocarbons

Where are GHG emissions coming from? By country and by sector

By country: mostly China, the USA, India, and Russia (then Japan, Germany, and South Korea)

By sector: oil and gas, transportation, buildings, heavy industry, agriculture, electricity, waste, coal production, construction and forest resources.

What are feedback loops (in the context of climate change)

Self-reinforcing processes that can either amplify (+) or dampen (-) the effects of climate change. They can have significant and sometimes unpredictable effects on global temperatures and environmental conditions

Examples of positive (amplifying) feedback loops

• Reduced albedo

• Carbon cycle

• More water vapor in atmosphere

• Melting of permafrost

• Deforestation

Examples of negative (dampening) feedback loops

• Increased albedo

• Clouds

• Biological uptake of CO2

• Ocean heat uptake

• Ocean carbon sequestration

Are the effects of climate change and global warming location specific?

YES

What are the current trends and predicted changes in surface temperatures due to climate change?

• Current trends

  • Hot extremes increased and cold extremes decreased since the 50s

• Predicted changes

  • Global temperatures are projected to exceed the 1.5 degree threshold in the next decade under current trajectories, with intensity scaling sharply.

• Impacts

  • High latitude and Arctic regions are warming the fastest

What are the current trends and predicted changes in precipitation due to climate change?

• Current trends

  • Global land precipitation has generally increased since the 50s. Water cycle has intensified as warmer air holds more moisture per degree of warming

• Predicted changes

  • Rainfall is to be increasingly concentrated in intense, infrequent downpours separated by longer dry periods

• Impacts

  • Floods and droughts

What are the current trends and predicted changes in soil moisture due to climate change?

• Current trends

  • Rising temps increase surface evaporation and plant water demand, worsening agricultural and ecological droughts; glaciers are shrinking cutting off meltwater supply

• Predicted changes

  • Drought conditions expected to worsen and expand in range

• Impacts

  • Drought and food scarcity

What are the current trends and predicted changes in oceans due to climate change?

• Current trends

  • Oceans have absorbed massive amounts of excess heat and carbon dioxide, and sea levels have risen 8-9 inches due to melting glaciers and thermal expansion

• Predicted changes

  • Ocean acidification expected to worsen, making it harder for calcium dependent organisms to survive, sea levels continue to rise

What are the current trends and predicted changes in food availability due to climate change?

• Current trends

  • Agricultural stress is apparent, crop failures, extreme heat, and shifting rainfall patterns disrupt traditional farming; leads to food insecurity

• Predicted changes

  • Food availability will face increased pressure from severe droughts, degrading soils, high temperatures, and changing pest and disease ranges

  • Malnutrition risks and climate related health impacts expected to climb

What are some predicted changes in ecosystems due to climate change?

• Increased pests and fires in boreal forests

• Thawing permafrost

• Species extinctions

• Increased drought and water scarcity

What are some predicted changes in humans due to climate change?

• Inability for energy production to keep up with demand

• Heat-related health problems

• Decreased work productivity due to heat

• Displacement and destruction due to extreme weather events

• Violence of deterioration of resource-based livelihoods

Why is dealing with climate change difficult?

• It is a global problem: requires unprecedented and prolonged international cooperation

• Long term political issue: most people who will suffer the most have not been born yet

• Impacts of climate change is not spread evenly worldwide

• Proposed solutions can be controversial

• Projected effects are uncertain

Role and importance of the Intergovernmental Panel on Climate Change (IPCC)

• Evaluates thousands of scientific studies to deliver comprehensive assessments of climate change, its risks, and adaptation options > in order to help policymaking decisions

• Reports must remain neutral on policies and do not suggest any particular political action

Role and importance of the Paris Agreement

• A global treaty signed by 195 parties to combat climate change.

• Set long term goals to guide all nations:

  • Reduce global GHG emissions to limit global temperature increase

  • Review countries commitments each year

  • Provide financing to developing countries to mitigate climate change and adapt to climate impacts

What are some solutions to slow climate change?

• Changing the way we produce energy (using less fossil fuels and more renewable)

• Carbon pricing industry (taxing production of CO2, introducing a cap on total human generated CO2 and CH4 emissions by country or region)

• Eat less animal products to decrease demand, and decrease land use

• Capture atmospheric CH4 and turn it into less potent CO2

• Capture atmospheric CO2 via mass tree planting/forest and wetland restoration, or physically store it via injection deep underground

• Better policies and regulations, like eliminating subsidies to fossil fuel and promoting clean energy

How does carbon pricing work?

• Govt establishes a tax rate per unit of emissions that is applied to entities that emit carbon

• Those entities pay a fee based on amount of emissions produced

• Tax generates revenue managed by the govt

Objectives:

• reduce emissions

• promote innovation and investment in clean and low carbon tech

• govt encouraged to create sustainability funds

How does cap and trade work?

• Govt establishes overall cap on emissions and allocates a certain number of emission allowances to businesses and industries

• Annual evaluation of compliance, and penalties for companies that exceed their emissions

Objectives

• Reduce emissions

• Flexibility

• Economically efficient

• Promotes innovation and investment in clean and low carbon tech

Clean energy

Energy gained from sources that do not release air pollutants

Green energy

Energy derived from natural sources; it often comes from renewable energy sources

Renewable energy

Power generated from sources that are constantly being replenished

Carbon free energy

No CO2 or other GHGs are emitted. Most renewable energy is also carbon free, but not all. Not all carbon free energy is renewable either

Give an example of renewable energy that isn’t carbon free, and an example of carbon free energy that isn’t renewable.

Biofuels - renewable energy; burning plant matter releases CO2 (growing does absorb CO2 though)

Nuclear energy - carbon free; nuclear plants dont emit any ghg’s but they do use uranium we can’t get back

What are five types of renewable energy?

• Wind power

• Solar power

• Water power

• Geothermal power

• Biomass power

What is the source of wind power? How is energy produced with the source? Pros and cons?

• Source of wind power is wind currents (need to be between 13 and 90 km/h)

• Energy is produced using wind to turn a set of blades that powers a generator creating electricity

• Pros: operates continuously, 1 hour of activity can power a home for over a month

• Cons: expensive, wind is inconsistent, wildlife impacts, ideal sites are in remote locations

What is the source of solar power? How is energy produced with the source? Pros and cons?

• Solar power uses solar radiation to generate electricity

• Electricity is generated via photovoltaic cells

• Pros: lots of energy hits Earth’s surface in a short amount of time, constant source of energy

• Cons: night, expensive initially, weather dependent, storage expensive, requires lots of space, production involves toxic and hazardous materials and products

What is the source of water power? How is energy produced with the source? Pros and cons?

• Source is fast moving water in rivers or from waterfalls to generate electricity

• Flow of water from rivers, waves, tides, or waterfalls spin a turbine connected to a generator that generates electricity

• Pros: generates the most electricity out of all renewable sources

• Cons: major environmental impacts, habitat alteration/destruction, affects water quality and supply, can cause droughts or floods, construction is dangerous, concern for safety and maintenance over time

What is the source of geothermal power? How is energy produced with the source? Pros and cons?

• Geothermal power uses the heat trapped inside the Earth

• Geothermal plants use heat from inside Earth to heat water and generate steam which moves a turbine powering a generator and produces electricity

• Pros: can heat hot springs, pools, houses, has lots of uses.

• Cons: production limited to areas near tectonic plate boundaries, locations may cool down over time, drilling and exploration is expensive, potential to release harmful gases or toxic compounds, increased earthquake potential.

What is the source of biomass power? How is energy produced with the source? Pros and cons?

• Source is organic material from plants and animals, including crops, trees, and waste wood.

• Generates energy from biological or thermal conversion (anaerobic digestion or combustion) of biomass resources.

• Pros: biomass can be converted into liquid biofuels that can power vehicles, and is rich in hydrogen which can be extracted and used to generate power

• Cons: not pollution free, does generate some GHGs, less efficient than fossil fuels and other renewable energies, requires lots of space, expensive, unpleasant odors, concerns about pathogens, requires large amounts of water

What are some other types of clean energy?

• Hydrogen

• Nuclear