Environmental Science Midterm Study Guide

What is sustainable development?

It is meeting the needs of the present without compromising the ability of future generation to meet their own needs.

What is tragedy of the commons?

It is a shared resource that gets overused and depleted when individuals act out of self-interest.

What is an example of tragedy of the commons?

The Maine lobster fishery where there was a risk of overfishing in the 1980s-1990s. Trap limits and other regulatory actions solved this problem.

What is longevity in sustainability?

Ensures systems can continue in the future.

What is holistic in sustainability?

Considers environmental, social, and economic factors together.

What is resilience in sustainability?

The capacity to adapt and recover from change such as climate events.

What are the three balancing pillars for sustainability?

Environment, Economy, and Society.

What is the provisioning ecosystem service?

Food from oceans such as fisheries.

What is the regulating ecosystem service?

Wetlands which provide storm protection by absorbing flood waters.

What is the cultural ecosystem service?

National parks which boost tourism and mental health.

What is the supporting ecosystem service?

Pollinators and insects pollinate crops.

Which isotope of oxygen evaporates easily from the ocean?

O-16 because it is lighter.

Which oxygen isotope is more likely to fall first?

O-18

As cooling continues which isotope of oxygen does precipitation contain more of?

It contains more O-16 and less O-18 which means the ratio of O-16 to O-18 in snow and ice depends on temperature.

What does it mean if there is more O-18 in snow and ice?

Nonglacial (interglacial) period which means there were warmer conditions.

What does it mean if there is more O-16 in snow and ice?

Glacial period which means there were colder conditions.

What are organic compounds?

They contain carbon that is bonded to hydrogen. They are usually found in living things or products of line. (plants, animals, fossil fuels.)

What are inorganic compounds?

They usually don’t have C-H bonds. They are found in minerals, rocks, water, and the atmosphere.

Is water a polar molecule?

Yes, it is 2 Hydrogen atoms boned to an Oxygen.

What is the cohesion and adhesion property of water?

Water sticks to itself and to other surfaces. (Plants can pull water up through their stems)

What does it mean that water has a high specific heat?

Water has a high specific heat as it takes a lot of energy to heat water, which stabilizes climates especially near the coast.

Why does ice float?

Ice floats because it is less dense than liquid water.

Why is water a universal solvent?

Water dissolves more substances than anything which makes it essential for nutrient transport in ecoystems.

What is the difference between an acid and a base?

A substance that donates hydrogen ions in water and usually has a pH below 7. (Ex: Lemon juice) A Base is a substance that accepts hydrogen ions or produces OH^- ions. It usually has a pH above 7 (Ex: Baking soda)

What happens when rainwater is acidic?

It has a pH below 5 which aquatic organisms are sensitive and organisms like fish eggs die below Ph 5.

What causes acid rain?

Sulfur Dioxide and nitrogen oxides from coal-burning plants.

What is kinetic enegry?

Energy in moving objects.

What is potential energy?

Stored energy.

What is chemical energy?

Energy stored in food or fossil fuels.

How does the sun deliver energy?

It is delivered as shortwave radiation.

What is the Hydrologic Cycle?

It is the path of water through the environment.

What is a state variable?

It is a measurable quantity in a system such as population size, temperature, or CO2 levels. They can change over time.

What is a positive feedback loop?

Something that amplifies a change.

What is a negative feedback loop?

Something that suppresses a change by stabilizing the system.

What is a disturbance in the stability of systems?

It is a periodic destructive event that destabilizes or changes the system.

What is resilience in the stability of systems?

It is the ability of a system to recover from a disturbance.

What is a state shift in the stability of systems?

It is a sever disturbance in a system where the system does not return back to normal but instead results in significant changes in some of its state variables.

What is the carbon cycle?

It is the path carbon takes through the environment.

What is the dual purpose carbon serves?

It serves a structural role (a building block of organic molecules like sugars, proteins, and DNA.) It serves as energy storage (its chemical bonds hold energy that cells release when needed).

How is carbon released during Photosynthesis?

it is released by respiration.

How can carbon be locked away?

It can get locked away for millions of years in coal and oil released only when we burn them or in calcium carbonate (fossil shell deposits of limestone).

What is nitrogen needed for?

It is needed to make proteins and nucleic acids such as DNA.

What type of nitrogen do plants take up?

They take up inorganic nitrogen from the environment and build protein consumers.

What do nitrogen-fixing bacteria do?

They change nitrogen to a more useful form by combining it with hydrogen to make ammonia. Other bacteria convert ammonia to nitrites and nitrates which can be taken up by plants to make proteins.

What type of factor is Nitrogen?

Nitrogen is a limiting factor that regulates the rate of primary production.

How does nitrogen re-enter the environment?

It re-enters the environment through the death of organisms and excretion and urinary wastes.

What are the four key nitrogen transformations?

Nitrogen fixation: Atmospheric N2 is converted into ammonia and naturally fixed by bacteria and lightning.

Ammonification: Organic nitrogen released by the decomposition of dead animals and plants and is converted into ammonia.

Nitrification: Bacteria in the soil convert ammonia into nitrites and nitrates, forms plants can take up.

Denitrification: Bacteria in the soil convert nitrates back into atmospheric N2 completing the cycle.

What is Phosphorus needed for?

Phosphorous is needed to make DNA, ATP, and other important biomolecules.

How does the Phosphorous cycle work?

Phosphorous compounds are leached from rocks and minerals and usually transported in liquid form.

It is taken in and incorporated by producers.

Passed on to consumers then returned to the environment by decomposition.

The cycle takes a long time as deep ocean sediments are significant sinks.

What is the hydrologic cycle?

It is the path of water through the environment.

How does the hydrologic cycle work?

Solar energy evaporates water continually and distributes the water vapor around the globe.

The water vapor condenses over land surfaces supporting all terrestrial systems; responsible for cellular metabolism, nutrient flow in ecosystems, and global distribution of heat and energy.

When is ozone good and bad?

Ozone is good when it is in the stratosphere where it absorbs harmful UV-8 radiation, protects the skin and eyes, and shields phytoplankton and crops.

Ozone is bad when it is in the troposphere. It forms a secondary pollutant from NOx plus sunlight. It irritates lungs, contributes to smog, and harms crops and outdoor exercise days.

What is Photochemical Smog (smoke fog)?

Sunlight turns car and factory exhaust into a gas that’s hard to breath. Exhaust goes into the air, UV rays hit that exhaust which triggers a chemical reaction, then that reaction creates a ground-level ozone (smog) that is hard to breath.

What is weather?

It is the state of the atmosphere. A “snapshot.”

What is climate?

The long-term average of weather.

What is insolation?

The amount of solar radiation reaching a given area.

What is the equinox?

It is when the sun sits directly above the equator. Day and night are equal length are equal everywhere.

What is solstice?

It is when one pole tilts closest to the sun.

June solstice: The sun is directly above the Tropic of Cancer.

December solstice: The sun is directly above the Tropic of Capricorn.

Does latitude or the curve of the Earth change how concentrated the sunlight is once it arrives?

The Earth’s curve changes how concentrated that sunlight is once it arrives. Example: On December 21st, the North Pole gets 24 hours of darkness while the South Pole gets 24 hours of daylight.

Would a penguin in Antarctica on December 21st be in 24 hours of sunlight or 24 hours of darkness?

It would be in 24 hours of sunlight. In the southern hemisphere it is summer December. Antarctica is tilted toward the sun. The arctic is in 24 hours of darkness at this time.

What is atmospheric circulation?

The large-scale movement of air that spread heat around the globe.

Why do we have prevailing winds, deserts, and jet stream?

It is from atmospheric circulation which is driven by differential heating: different parts of the Earth receive different amounts of heat.

How does wind blow?

Wind blows from areas of high pressure to areas of low pressure.

What is the Coriolis Effect?

The curving of the path of objects or fluids due to the Earth’s rotation.

The equator spins faster than the poles (it covers more ground each day)

The speed difference bends the path of moving air and water.

How do the trade winds blow?

They blow from the northeast in the Hadley cell. (Deflected by the Coriolis force)

How do the westerlies blow?

They blow from the southwest in the Ferrel Cell.

How do the polar easterlies blow?

They blow from the northeast near the poles.

How does the ocean circulation move?

It moves both horizontally and vertically. It is driven by wind, Earth’s rotation, and water density differences.

What is upwelling?

Wind pushes surface water away from the coast.

Cold nutrient rich deep water rises to replace it.

Fuels phytoplankton growth and supports productive ecosystems.

Found in high-productivity regions.

What is downwelling?

Wind or currents push surface water toward the coast.

Surface water sinks, carrying oxygen and heat to deeper layers.

Supports deep-ocean life but has low surface productivity.

Why does upwelling and downwelling matter?

It transfers nutrients, oxygen, and heat between ocean layers.

It helps regulate global circulation and Earth’s climate.

What is ENSO?

A periodic climate pattern involving changes in the temperature of central/eastern tropical Pacific Ocean waters and their interaction with the atmosphere.

What are normal ocean circulation conditions?

Strong trade winds push warm surface water westward→upwelling of cold, nutrient-rich water off South America.

What is El Nino?

Trade winds weaken or reverse.

Warm water shifts eastward→reduced upwelling.

Alters east-west circulation→changes in global rainfall and temperature.

What is La Nina?

Stronger-than-normal trade winds.

Enhanced upwelling and cooler eastern Pacific.

Intensified east-west Circulation.

What did El Nino do to Peru?

Warmer ocean and wetter conditions.

What did El Nino do to Australia?

Cooler western Pacific→drier conditions in Australia/Indonesia.

What is thermohaline circulation?

It is the deep ocean circulation driven by temperature and salinity which controls water density.

What are ocean currents?

Continuous movement of sea water generated by surfaces acting upon the surface of the water.

They tend to center around gyres.

How do currents affect land temperature?

Warm currents like the Gulf Stream heat nearby coast and cold currents like the Labrador cool them.

That is why London stays milder than Boston despite sitting father north.