Enviornmental Science Midterm 1

Independent and Dependent Variable

Independent Variable is the factor that is changed or controlled to test its effects on the Dependent Variable, which is typically plotted on the Y axis. The Dependent Variable is what is measured in the experiment and is affected by changes in the Independent Variable, which is usually displayed on the X axis.

Control Variable

A variable that is kept constant throughout an experiment to ensure that any changes in the Dependent Variable are solely due to the Independent Variable.

Types of Visualizations for Data Sets

Line Graph:

Data over periods of time

Choropleth:

Data from place to place

Pie Chart:

Data as A Percentage

1st step of scientific method

Observation

2nd step of scientific method

Question

3rd step of scientific method

Research

4th step of scientific method

Hypothesis (educated guess)

5th step of scientific method

Experimentation (testing the hypothesis)

6th step of scientific method

Data Analysis (Degenerate/ Noisy Relationships)

7th step of scientific method

Conclusion

Hydrograph

Apply the Scientific method to generate a hypothesis about enviornmental and human factors that influence flooding

Degenerate Relationship

Multiple processes lead to one result

Noisy Relationship

One process lead to multiple results

Use data to evaluate support for multiple hypothesis

Pattern Recognizition (what is different in two graphs, etc)

Factors that lead to the dead zone in the Gulf of Mexico every summer

Pollution: River carrying agricultural run off into the gulf of mexico. (Lighter freshwater floats on top)

Eutrophication: Increased nutrients in water leading to algae bloom (Murky Water)

Light Deprivation, causing the death of Cyanobacteria

Bacteria that decompose algae consumes oxygen in the process

Hypoxia: Areas with low oxygen

Dead Zone Formation: Hypoxic regions unsuitable for survival, marine animals fled or dead.

Stratospheric change between 1979 and 2019

1979-1987:

Ozone cocentration decreased from 225 to 125DU

Ozone hole increased from 0 to 20 millionKm²

1988-2019:

Ozone cocentration stop decreasing at such a fast rate(early 1990s)

Why is ozone depletion most prevalent over Antartica in Southern Hemisphere Spring

CFC +UV RADIATION + COLD TEMPERATURE + SURFACE = Ozone Depletion

Impact of the Montreal Protocol on Ozone layer, and why it will take time before ozone concentration will return to pre CFC levels

Montreal Protocol slows Ozone depletion by banning CFCs

Graphical data related to Atmospheric CO2 Concentrations and average surface temperature trends

Evaluate evidence for long term and recent changes in Earth’s climate

Draw conclusions about trends in average surface temperature and their relationship to atmospheric CO2 concentrations

Keeling Graph

Increase CO2 = Increase Average Surface temperature

Long term: ~125ppm over 50,000 years

Recent: ~110 ppm over 70 years

albedo: ability of surfaces to reflect sunlight

Aerosols

Tiny solid and liquid particles suspended in the atmosphere

Highest aerosol concentration is in Central Africa and Arabian Peninsula in 2025 Jan.

aerosols have adverse effects on human health at a regional and global scale

Direct Effect of Aerosols

Scatters and reflect sunlight(high albedo)

Indirect effects of Aerosols

Influence cloud formation and properties

MODIS

Moderate Resolution Imaging Spectroradiometer

Measures the thickness and size distribution of atmospheric particulate matter to determine the amount of aerosols

Use Satellite imagery to visualize spatial and temporal patterns in Atmospheric aerosols

Describe the relationship between atmospheric CO and Aerosol concentration

Investigate possible sources of CO and aerosols

Flooding Events

When water overwhelms a landscape because more water is supplied than can be contained within a stream channel, or than can be removed by infiltration into the ground

Planetary Boundary

a "safe operating space" for humanity, beyond which abrupt or irreversible changes to the Earth system could occur

Crossing these boundaries creates the risk of destabilizing the Earth system.

Anthropocene

the time during which humans have had a substantial impact on our planet

the nine planetary boundaries

Climate change

Biodiversity loss

Biogeochemical flows

Land-system change

Freshwater use

Ocean acidification

Stratospheric ozone depletion

Atmospheric aerosol loading

Release of novel chemicals

Quadruple Squeeze

• Population and development: The number of people and their affluence 

• Climate change: The concentration of greenhouse gases and the inability of the Earth to buffer their effects 

• Ecosystem crisis: The risk of tipping points in the Earth system 

• Surprise: The unpredictability of how systems can tip over rapidly and irreversibly 

resilience

the ability of a system to maintain key functions and processes in the face of stresses or pressures, by resisting and then adapting to change.

tipping points

thresholds beyond which they cannot recover

% of Earth’s water that is freshwater, and the % of freshwater that is easily accessible for human use.

97.2% ocean water, 2.8% fresh water

Metro Vancouver Water Supply

Capilano, Seymour, and Coquitlam watersheds

flows or fluxes

Water moves between stores through various processes

hydrologic cycle

Freshwater: Groundwater

Water beneath Earth’s surface, stored in aquifers: geologic formations that contain pore spaces in soil and fractures in bedrock. Only accessible by drilling/pumping from a well.

Freshwater: Surface Water

snow and land ice (glaciers, ice sheets, ice caps) lakes, ponds, wetlands, rivers, streams

Watershed

an area of land where all the water that falls into it and drains off of it goes to a common outlet

Global Freshwater Resources: Why is there a Planetary Boundary

Freshwater is being consumed by human activities at a pace that is faster than it can be replenished

Ways Humans Cause Water to Stop Flowing (Partly or Completely)

Earth System Functions of Water

Hydroclimatic Regulation – Water flows regulate the Earth's climate system

2. Hydroecological Regulation – Water enables and connects life on land and in aquatic ecosystems, and creates and sustains the ecosystems that human societies and Earth system stability depend on

3. Storage – Freshwater storage in groundwater, lakes, wetlands, reservoirs, and frozen water interacts with the Earth system as a control over sea level

4. Transport – Water fluxes are fundamental for moving, displacing, and diluting sediment and dissolved nutrients on the surface or within soils

the Nitrogen cycle

Fixation

Storage

Accumulation

Recycling

Phosphorus Cycle

Phosphates move slowly through the soil and ocean; one of the slowest biogeochemical cycles

How does the biosphere function? Through which two fundamental processes

Energy flow and Nutrient/ Biogeochemical cycling

Atmosphere Structure

We live in the troposphere, which starts at the surface of the Earth and can extend up to 20 km.

The next layer is the stratosphere, which is the section found between 20 km and 50 km above the Earth’s surface.

Where is the Ozone Layer?

Approximately 90% of the ozone in the atmosphere is found in the stratosphere. The peak ozone concentration occurs between 30 and 35 kilometers above the Earth’s surface

How is Ozone (O3 ) created?

Ozone is formed when high energy ultraviolet radiation from the sun breaks apart molecular oxygen

An oxygen atom then combines with an oxygen molecule producing a new molecule with three atoms of oxygen: ozone.

Role of Ozone in the Atmosphere

When the ozone layer is intact, it absorbs 50% of the UV-A radiation, 90% of the UV-B radiation, and all of the UV-C radiation coming from the sun.

Why is ozone disappearing?

CFCS, when the normally stable CFC’s hit the lower temperatures and higher amounts of UV radiation in the stratosphere could break them down – and that once they were broken down, they could attack and destroy ozone molecules.

Canada and CFCs

Canada banned CFCs in most aerosol products in the late 1970s.

WEATHER vs. CLIMATE

Weather describes short-term atmospheric conditions

Climate is the long-term average of weather conditions in a region, over time

The Global Carbon Cycle

Biosphere • Carbon is found in the form of organic compounds trapped in living organisms.

• Lithosphere • Carbon is held in the soil, in carbonate rocks, and other materials like coal.

• Hydrosphere • Carbon dissolves in the water to form carbonic acid

• Atmosphere • Carbon is mostly in the form of CO2 (carbon dioxide) and CH4 (methane)

• Cryosphere • Carbon is stored in permafrost (frozen soil), and as CO2 and in CH4 gasin bubbles in ice

1 Pg

10^15 grams

Greenhouse effect

Warms Earth’s surface

What do greenhouse gases do?

GHGs are molecules that absorb and emit radiation at wavelengths that overlap with some of the wavelengths of radiation emitted by Earth

Evidence for a changing climate

• Warming air temperatures

Warming ocean temperatures

• Shrinking glaciers and sea ice

• And subsequent rises in sea level

• Changes in the biosphere

How can we reduce greenhouse gas emissions

Conservation: Use less energy (e.g., fly less, drive less, eat less red meat, etc.) Efficiency: Use technologies that get the most from an energy source (e.g., Energy Star appliances, LED bulbs) VOTE!: Use the ballot box and your dollars to let politicians and corporations know reducing GHG matters to you and to push for systemic change – the only real solution Systemic Change: Energy Sources: Convert our energy sources to non-fossil fuel burning solutions – simply put, the only solution to this problem is that we have to reduce GHGs now

3 ways nitrogen can be fixed

Atmospheric

Biological

Industrial

Fossil fuels

Slow carbon

AOD

Aerosol optical thickness

Effects of Aerosols on human health

Lung cancer, cardiopulmonary disease, respirator infections, etc