Environmental Science- Section 4 Part 2

What are "potentially" renewable resources?

biofuels like wood if they are managed properly with regrowing and such.

Almost all energy from earth comes from where, except for what?

The Sun, except for nuclear, geothermal and tidal energy

What is the solar potential and the solar constant

The solar constant is the 1370 watts per square meter that hits top of the atmosphere and the solar potential is the 200 watts per m2 when it reaches us. (50-300)

In the US, which area has the greatest solar potential?

The Southwest (90% of the time, solar is available)

How do we get the most sun in the northern hemisphere?

By building a south facing wall with a lot of windows

What is thermal inertia.?

The property that resist temperature changes.

What materials have thermal inertia and what materials do not have thermal inertia?

Stone and concrete have thermal inertia, wood and glass do not.

What are active and passive solar systems?

Systems that utilize pumps, blowers and fans to utilize the solar energy are active while systems that do not utilize those are passive (no intermediate technology)

What 2 applications is active solar energy used for?

Energy generation and heating of water

Solar water heater?

A small electric pump pumps water onto the roof in copper tubing painted black and sometimes behind glass to absorb the Sun's energy and heat the water.

Solar Electricity Generation?

Current in Photovoltaic solar cell: very thin, clean layers of SiO2, combined with arsenic or antimony to increase the voltage

How much energy does a single solar cell usually create?

1 or 2 watts

How many solar cells are usually joined together?

24 or more

How tall are wind turbines and how big are the blades?

100 m tall and 40-75 m long

How much energy do wind turbines crerate?

843000kWh per month, can power 940 homes

Where are wind turbines most rapidly growing?

Offshore wihtin a few miles of the coastline.

How many wind farms in Europe and US/

40, with over 2000 turbines in Northern Europe and 2 in US

What land use are wind turbines compatible with?

Agriculture, farming, grazing

Cape Cod and wind turbines

In 2003, a proposal to install wind turbines off the coast of Cape Cod in Nantucket

Opponents: wind is a public good, aesthetic degradation, wealthy celebrities

Proponents: accuse of NIMBY, the wind turbines can look good.

Disadvantages of wind turbines and solar energy?

1. Need for batteries since not reliable: mining and production of lithium, cobalt and other dangerous materials

2. Aesthetic

3. 10000-40000 birds get hit and die. (but millions die from buildings )

4. Migratory and endangered whales off New England coast's

What are the 2 renewable energy reasources widely used in the US?

Biomass and hydropower

How much of the US's energy and renewable energy does hyddropower provide?

28.7% and 6.2%``

What does the amount of electricity generated by a hydroelectric turbine depend on?

Flow rate (how fast and how much) and vertical distance

2 main ways of hydropoer

run of the river and impoundment

What is bad about run-of-the-river

1. It is not reliable, especially during the summer.

2. It disturbs the migratory fish moving upstream, even though fish ladders are made, these are eyed by prey and can be hard to utilize.

3. It is dangerous to work in run-of-the-river plants

How much can a peak run-of-the-river plant produce?

1 MW, 1000 homes

Negatives of impoundment

1. Flooding of rivers and areas: loss of ecologies, etc.

2. People are displaced: Cree from James Bay, 1.3 million people from Three Gorges Dam in China

3. Mercury to methylmercury: bacteria.

4. Blockage of flow leads to destroyed migratory cycles

Where does methylmercury accumulate?

In the fatty tissue

What fish have migrartory cycles?

Salmon, steelhead trout, freshwater clams and mussels.

What plant relies on natural flooding?

The cottonwood tree depends on sand bars created by natural flooding to carry out reproductive cycles.

Where is municipal solid waste used?

Waste-to-energy facilities

How much of US RENEWABLE energy does biomass provide?

37%

What is the difference between modern carbon and fossil carbon

Modern carbon is carbon from plants and animals that just get replaced, but fossil carbon is carbon from millennia ago

Portions of biomass used in the US

2/3 frrom wood, 1/4 from MSW, methane from landfills: 5%

What type of forest removes very little carbon from the atmosphere?

Older forests, because their primary prooductivity is not much different from their respiration.

What is the most common biofuel

Ethanol

What is fermentation?

Decomposition of sugars and starches by yeats, bacteria and molds

What ratio is Ethanol mixed with gasoline?

1:10

How much ethanol is made and used in teh US annually?

1.8 billion gallons, 92% is from corn

How much of ethanol is from corn?

92%

Benefits and non-benefits of using ethanol

Benefits: oxygenates gasoline (by boosting its octane) and makes it cleaner by boosting its octane

Non-benefits: 2-3% less efficient, using agricultural land and fossil fuels just to make ethanol???

Ethanol prevents gasoline from

Freezing, absorbs moisture

What is geothermal energy?

Heat from the radioactive decay of elements deep within the Earth.

Where is geothermal energy active?

Iceland, lots of volcanoes

Describe Iceland's energy distribution

100% renewable energy

]73% hydrodam, 27% geothermal,

Where are tidal plants operating rn?

Maine, Washington state, Brittany, France, Nova Scotia, Canada,

Why is tidal energy no good?

The difference between low tides and high tides is not enough to produce a lot of electricity, and it has aesthetic degeneration

What is conservation?

A consumer based approach to conserving electricity such as not using as much lights.

Are small or large cars more energy efficient?

small cars

How did companies use to combat against peak demand?

By building new power plants.

What are usually peak demand hours?

8 AM to 8PM

How is peak and non-peak demand measured?

By having 2 electric meters for every location.

What AC is Energy Star Approved?

removes 10,000 Btus of heat per hour while using less than 1000 watts

20 Megawtts is _% of a power plant's output

4

What are forever chemicals?

PFAS: perfluoroalkyl and polyfluoroalkyl

Where does radon come fom?

It is a radioactive gas that leaks from the breakdown of uranium and occurs naturally in rock and soil.

How many people die each year from radon-induced lung cancer?

6500 and 31000 people, 2nd only to smoking

What is the estimation of radon cancer rates based on?

The rates of miners in uranium mines rather than the general public.

Who is rersponsible for assessing environmental risks?

the EPA

The EPA has the legal authority to regulate only radon in where? Why is this ironic?

Drinking water, because most radon-caused lung cancer is from airborne radon.

What does the EPA suggest people do to reduce radon levels?

Test thei homes and seal basements and improve netilation

EPA programs for radon?

$86 million for a recommended air reduction and required drinking water rection, would significantly decrease radon lung cancer.

But further improvement in water treatment plants would cost $400 million

How many deaths per year is caused by radon in drinking water?

Around 168 people

Forrmula for risk

Probability of exposure x Probability of harm

What carcinogen lives in peanut butter?

Aflatoxin fungus

We tend to downplay the risk of what?

The risk of activities that may result in cultural, political, or economic advantages to ourselves.A

What 3 things can environmental hazards include?1

1. human activities

2. substances

3. natural catastrophes

Environmental Risk Assessment is qualitative or quantitative?

Quantitative.

What are the 3 parts of risk analysis?

1. Assessment

2. Acceptance

3. Management

What 4 risks does the EPA want to assess?

1. Cancer

2. Non-Cancer health

3. Damage to public welfare

4. Ecological risks

what does ecological risk assessment focus on?

The harm done to ecosystems and communities of the enviornment, and biodiversity

A statistical risk assessment determines the

probability of harm

What is the dose response?

The harm caused by varying amounts of a hazard

What is the EPA's 4 step assesssment process?

1. Hazard identification

2. Dose Response Assessment

3. Exposure Assessment

4. Risk Characterization

Workers in PCB industry have higher rates of

cancer

Why is PCB used in industry?

Beucase they are inflammable, chemically stable, and have insulating properties.

When did the EPA carry out a dose response study of PCBs?

In 1996

Dose rresponse study of PCBS by te EPA

1. Epidemiological studies of PCB effects on human

2. Dose response studies of PCBS on rats

3. Comparative studies of how different pathways will affect PCB exposure

4. Math models that combine the first 4 to estimate tthe rate of cancer

What are the findings of the EPA on PCB?

Exposure is low, eating contaminated food is worse than water or breathing. This is however, an extrapolation

What research is being done on PCBS?

Its effects on the immune system, dementia, and cardiovascular diseases, new sources like e-waste recycling sites and how the movement of materials through trophic levels affect exposure levels.

PCB bioaccumulation and biomagnification can lead to

reduced fertility in one generation and harm to reproductive organs of offspring.

What factorrs do our acceptance of risk include?

1. Amount of harm

2. Importance of the activity

3. Confidence in dealing with the isk

What risk is the EPA acceptable fo?

1 in a million for environmental hazards

What 2 philosophies in risk management?

Precautionary principle or the innocent unitl proven guilty principle

What principle of rsik management is used where?

Precautionary in EU and the 2nd thing in the US

What is risk management?

Balancing of risks and acceptance of risks with the benefits

What institution prepares reviews of the state of the current knowledge on climate change?

The IPCC, founded by the UNEP and WMO in 1988

IPCC ( Intergovernmental Panel on Climate Change)

UNEP (United Nationals Environment Programme)

WMO (World Meterological Organization)

When did the IPCC publish what?

In 2021-2023, they published their 6th volume of their assessments.

How much has CO2 in the atmosphere over the laste how many years?

180 ppm to 280 ppm over the last 800000 years

What is globalc change?

Change that occurs in teh chemistry, biology and physical properties of worldwisde systems

What is the CO2 concentrations today?

400-420 ppm

What are some biogeochemical changes that aer occuring over the last 50 years?

1. increrase in CO2

2. Increase in nitrogen and sulfur

3. Increase in mercury

What does "climate change" refer to?

variation in average weather and temperature and conditions over years and decades

What radiation is often emitted by objects that absorb solar radiation

Infrared radiation, which is trapped by greenhouse gases.

What temperature is the Earth?

15C

Without GHGs, what would the temperature of the Earth be?

-18 C or 0 F

What are the inputs and outputs of the Sun_Earth Heating System:

input: teh Sun

output: reflection of the atmosphere

output: radiation fom objects

What are sunspots

areas of gas on the sun's surface that are cooler than the gases around them

What is the major GHG?

water vapor

What are the GHGs emitted by humans?

1. methane

2. carbon dioxide

3. nitrous oxide

4. chlorofluorocarbons