Environment Science -Section 1

What is environmental science?

The study of the impacts of human activities on environmental systems

What does human activities include?

Large scale actions such as mining, fishing, clearing land, and emissions, but also everyday choices such as turning on the light, choosing to drive, and choosing to use plastic or paper or reusable bags

What is the environment?

The sum total of conditions, living and nonliving factors around an organism

What can an environment include?

Others of its kind, prey, predators, weather, landscape, etc.

What is a local environment?

The area immediately around the organism.

An environment can be as small as what and as large as what?

Small as a pond and as large as a mountain range or ocean.

What is the global environment/

Sum of all aspects of the Earth

What disciplines are included in Environmental science?

1. Bio

2. Chem

3. Physics

4. Earth and Atmospheric sciences,

5. Biological and Natural resources,

6. Population Dynamics

What does it mean that environment science is science-based?

It relies on the scientific method

What is one way of studying the environment?

Studying its different systems and how they interact.

What is a system?

A set of living and non-living components that are connected so that changes in a part affects other parts.

Can be isolated and studied apart from other systems

Examples of a system

Earth, ant colony, lake, farm

What is important to understanding the environment?

Systems

What is an example of an environmental indicator we can use to diagnose a forest?

Amount of growth on trees

Why are envionmental indicators potentially not accurate?

The same indicator can tell different stories depending on teh time/place

EG. for growth, in summer it would be less and it would be less in the poles than in the tropics, for example

What is important in measuring environmental indicators?

Rates of change

6 Environmental Indicators

1. Diversity

2. Human population growht

3. Food Production

4. Resource Consumption

5. Temperatures and gases

6. Pollution

What is a species?

A distinct group (morphology, physiological or biochemical) of organisms that can reproduce with each other

How many of species do we know?

1.8 million

How many times from teh known speices are the actual number of species?

10 times

How much have we accelerated from background extinction rate?

About 100x

What is the backgound extinction rate?

2 mammals perr 10,000 species per 100 years.

How did we determine the backgound extinction rate?

By using quiet periods of the geologic recod (no environmental or biological upheaval)

What is considered to most contribute to extinction?

The loss and degradation of habitats.

What is an estimation of current extinction rate and how did we get that?

40,000 species per year, by relating to area of land altered by human activity

What does current extinction rate rival?

Mass extinction events

Gains had been made in saving what species?

1. American bison

2. Peregrine falcon

3. Bald eagle

4. Californian condor

Especially the ones that catch peoples attention

What animals are endangered?

1. Bengal tiger

2. Snow leopard

3. West Indian Manatee

The loss of what species can cause cascading extinction?

Keystone

Rate of extinction can be used not only as indicator of biological diversity but also as an indicator of

environmental quality

According to the UN, how many people are in the world?

8 billion people in Nov 2022

How many infants and deaths each day?

378 and 148 (thousand) or a million people every 4 days.

Until when was the human population experiencing exponential growth?

1960s

How long more will the human population grow?

50-100 years

When does the UN project human population will level off?

2150, between 8 billion and 12 billiobn

What provides more than half of the calories consumed everyday?

Food grains such as wheat, corn, and rice

What is food production affected by?

1. Quality of soils,

2. Climate

3. Land area

4. Human labor

5. Energy

6. Water

What is intensity in agriculture?

How many crops are grown in a given area

What type of farming is usually high intensity?

Monoculture, polyculture is usually low intensity

What indicates the intensity and quality of the land?

Yield

What does high-intensity agriculture do?

It leads to

1. Soil erosion

2. Fertilizer and waste runoff

3. Buildup of pesticides.

What is sustainable use?

Present day consumption allows an adequate supply to remain for future generations

20% of people who live in developed countries eat

45% of meat and fish,

58% of energy,

84% of paper

87% of automobiles

The pooerst 20% of people in the world use

5% or less of each resouce

What influences temperature?

1. Solar radiation

2. Absorbed solar heat from the Earth

3. Surface area of icecaps and oceans

4. Concentration of gases that surround the Earth

What are 2 examples of greenhouse gases?

CO2 and Methane

What does anthropogenic mean?

The result of human activity

What is the primary activity that produces CO2?

Combustion of fosssil fuels

Since when did temperatures start to rise?

130 years ago (along with CO2 levels)

Over the past _______, temperatures and CO2 concentration have fluctuated frequently

160000

Annual layers of snow/ice can reach up to

thousands of meters in thickness

What is removed from the ice for scientists to analyze?

An ice core, so that the scientists can assign dates.

Then slices to analyse CO2 level

How is temperature inferred from the ice?

Ratios of oxygen of different masses (isotopes)

What is the symbol for lead?

Pb

Why is Pb useful?

Soft, malleable, resistant to corrosion.

Why is lead bad?

Neurotoxin, bad for developing brains , it is also toxic to most plants and animals

Since when had mining of lead increased?

5000 years ago

What led to lead emissions:

1. lead mining and refining

2. Coal and oil burning

3. Gasoline for a better engine

4. Paint in houses before 1960 (Over 50%)

5. Water from lead pipes that corrode if the water is acidic

When was legislation passed for no lead gasolation

1975

How is reporting done?

Through peer-reviewed written publications or formal presentations of the results at conferences and meetings

When may preliminary, individual results be reported to the general public before other scientists get to it?

When the issue is of great popular interest or concern policy

What limitations limit environmental science

1. The One Earth Problem

2. Inconsistent Units for Energy

3. Subjectivity

4. Unpredictable Consequences of Preferences and Policies

Where can PCBs be found?

Fatty tissue of penguins and species carried by ship to tropical islands from other parts of the world

Where can lead be found historically?

Roman Empire, in the Greenland ice sheet

What is gasoline, electricity, AC energy measured in?

1. Gasoline: gallons

2. Electricity: Kilowatt-hours

3. AC: Watts, Celsius, Thermal units per hour

What is used to make plastic and paper bags

Benzene and chlorine respectively

What is the harm done by paper bags and plastic?

Paper chlorine may harm stream fishes but Benzene plastic may harm humans more.

Since 1975, car efficiency

from 13 miles per gallon to 30 in 2021

But not linear: In the 1990s, efficiency down because sport cars, light trucks and minivans.

Smaller SUVs and electric and hybrid vehicles reveresed this trend.

What paraphrase exemplifies interactions between systems?

A butterfly stirring the air in Beijing can affect weather patterns in NY a month later

In practice, what are systems defined by?

The person looking at them.

What is system dynamics?

The interactions between systems and system components

Environmental systems exchagne what?

Matter and energy

What are most important materials to flow through systems?

1. Water

2. Fuels

3. Chemicals and gases

What is flux? What is analysing flux also called?

input-output, mass balance analysis

What is steady state?

When the flux is zero

What is flux rate

Flux over a period of time.

What is the balance of a system called?

A pool

Many pools in the natural world are in______

steady state

Water in the atmosphere is in steady state because

evaporation and precipitation are almost the same

The oceans are steady state because

rivers flowing in and evaporation are same

How old is Mono Lake?

One of America's oldest lakes, between 1 million and 3 million years ago

Where is Mono Lake?

300 miles NE of LA, between Great Basin Desert and Sierra Nevada Mountain Range

Where does the water input into Mono Lake come from?

Sierra Nevada Mountain Range

What type of lake is Mono Lake?

Terminal Lake

What are the 4 systems of Mono Lake?

1. Natural Water System

2. Salt Balance System

3. Ecological System

4. Water Use System

Describe the Ecological system of Lake Mono

Algae who do photosynthesis are eaten by shrimps and flies, which are eaten by gulls.

Gulls, shrimps and flies's decayed bodies are taken in by algae for nitrogen, etc, for photosynthesis

Describe the Water-Use system of Lake Mono

Beginningg in 1941, began extracting 80.4 million gallons a day from the non-salty tributaries of the Lake, made the level drop 40 ft in 40 years

What wasa the effect of the Water Use system on the Ecological ystem of Lake Mono?

1. Exposure of tufa towers led to more predation of shrimp and flies which led to decline for both them and the seagulls.

2. Exposed alkaline dust which affected the bird population as well as other wildlife.

What did increased salinity do for Mono Lake?

1. wildlife can't adapt

2. increased salinity inhibits nitrogen intake for algae

By when wa Lake Mono and its inhabitant "dying"?

By the early 1980s

Who tried to save Lake Mono when?

In the 1980s, ecologists and environmental scientists infomed advocates and lawyers to bring lawsuits and legislative proposals, and also a campaign emphasizing Mono's beauty and fragility. Their efforts failed but in 1983, the California Supreme Court ruled that the Californian government has to protect Mono Lake, and reduced water extraction.

When did snowmelt from Sierra Nevada help Mono Lake?

In 2023

When a pool is in steady state, we can calculate the

MRT (mean residence time)

Fomula forr Mean residence time

pool / flux in or out

In the case of air pollutants what is MRT called?

Atmospherice lifetime

Atmospheric lifetime of different greenhouse gases.

CO2 = 100 years

Nitrous oxides = 109 yeras

CFC = 100 years

Hydrofluorocarbons = 222 years

Methane = 11.8 years

Why is the atmospheric lifetime of CO2 estimated?

Because of the carbon cycle, the rate of which varies from a few years to thousands of years

How to calculate Accumulation and Depletion?

Change in Flux/ time

What is one positive feedback loop and negative feedback loop of "great importance to environmental scientists"?

Warmer temperatures lead to more evaporation: more water vapor to act as a greenhouse gas.

But more vapor also creates more clouds, which reflect the sun's rays

A negative feedback look sends a system to _________ while a positive feedback loop pulls it away

set point