Global Bio Exam 3

Good ozone

located in the stratosphere and absorbs harmful uv radiation, which protects life on earth

Bad ozone

located in the troposphere (ground level), pollutant that acts as a respiratory irritant and GHG

Components needed to form an ozone hole over antartica?

1. CFCs - provide chlorine that destroys O3

2. polar stratospheric clouds (PSCs) - provide surface for chemical rxns to occur

3. spring sunlight - triggers release of chlorine atoms from reservoir species

Montreal protocol (1987)

International treaty designed to phase out the production of ozone-depleting substances (like CFCs). Considered the most successful environmental treaty as the ozone layer has been slowly recovering.

Foundation Species

A species that define the physical structure of a community on which the entire ecosystem depends. Example: eastern hemlock tree, cools shaded microclimates and regulates stream flow/temp.

How does the hemlock wooly adelgid (HWA) kill hemlock trees?

It is a aphid-like insect that feeds on the trees phloem (nutrients) and injects a toxic saliva. The tree typically dies in 4-15 years, shifting forest from hemlock dominated to deciduous (birch//oak/maple)

What is the "Benthic-Pelagic Shunt" caused by Zebra and Quagga Mussels?

Mussels filter-feed so efficiently that they "shunt" (move) energy and nutrients from the open water (pelagic) to the bottom of the lake (benthic/littoral). This causes phytoplankton/zooplankton to decline and benthic algae/weeds to increase.

The two primary aims of ecological restoration?

Functionality (restoring ecosystem services) and pre-settlement condition (returning the community to its state before industrialized civilization)

In the "Leaky Pipe" model of the Nitrogen Cycle, which process is the only one that permanently removes nitrogen from the water?

It converts Nitrate (NO3-) into Nitrogen gas (N2), which then leaves the aquatic system and enters the atmosphere.

What are the 5 core principles of Natural Climate Solutions (NCS)?

Nature-based, Sustainable, Additional, Measurable, and Equitable

NCS: nature-based

stewardship of natural/working lands

NCS: Sustainable

must sustain biodiversity and food/wood production

NCS: additional

mitigation that would’t happen without the project

NCS: measurable

quantified in terms of radiative forcing

NCS: equitable

respects human and indigenous rights

In the context of NCS, what does "Additionality" mean?

It means the carbon sequestration or emission reduction is a direct result of the human intervention and would not have happened naturally on its own. It also means the project isn't just used to "excuse" emissions that could have been easily reduced elsewhere.

Two main drivers of sea level rise

1. thermal expansion

2. melting of grounded ice

Driver of sea level rise: thermal expansion

As water warms, its molecules move more and take up more space.

Driver of sea level rise: melting of grounded ice

glaciers and land-based ice sheets (greenland/antartica) adding new water to the ocean

Does sea ice melt contribute to sea level rise

NO, it does not. B/c that ice is already in the ocean

Chemistry of ocean acidification

when CO2 dissolves in seawater, it reacts to form carbonic acid , which releases hydrogen ions (H+). this lowers the pH (making it more acidic) and reduces the availability of carbonate ions, which marine organisms need o build shells and skeletons.

Why is the ocean becoming "less alkaline" even though it is still above a pH of 7?

The ocean is currently slightly basic (pH ~8.1). "Acidification" refers to the pH moving downward on the scale toward the acidic side, even if it hasn't crossed the neutral point (7.0) yet.