Enviornment Science Final

Environmental science as a field

A multidisciplinary science incorporating biology, chemistry, physics, and non‑science fields.

Oceanography

Study of the ocean.

Limnology

Study of rivers and lakes.

Meteorology

Study of weather and atmospheric conditions.

Climatology

Scientific study of Earth’s climate.

Ecology

Study of organisms and their relationship to their surroundings.

Zoology

Study of animals.

Ichthyology

Study of fish.

Ornithology

Study of birds.

Herpetology

Study of reptiles and amphibians.

Taxonomy

Practice of classifying living things.

Evolutionary biology

Study of life history on Earth.

Conservation biology

Study of how to protect and maintain biodiversity.

Agriculture (discipline)

Scientific practice of cultivating soil, producing crops, and raising livestock.

Hydrology

Study of distribution, movement, and management of water.

Toxicology (discipline)

Study of effects of chemicals on living systems.

Geophysics

Science concerning physical properties and processes in/around Earth.

Four major nonrenewable resources

coal, oil (petroleum), natural gas, and nuclear energy (uranium)

Environmental & health effects of mining

habitat destruction, pollution, and exposure to harmful substances.

Products made from crude oil

include gasoline, diesel, jet fuel, asphalt, and various petrochemicals.

Using nonrenewables for energy

refers to the consumption of fossil fuels and nuclear materials to generate electricity and power

Energy → electricity conversion

is the process of transforming energy from various sources, such as fossil fuels, nuclear, or renewable materials, into electrical power for use in homes, industries, and other applications

Load following

the ability of a power plant to adjust its electricity output to match changes in electricity demand over time

Downsides of each nonrenewable

• coal: higher air pollution, health impacts, & environmental damage from mining

• oil: GG emissions, risk of spills/leaks, & limited supply and geopolitical issues

• natural gas: methane leaks, water and land impacts, & still nonrenewable

• nuclear energy: radioactive waste, accident risk, & high cost

Calculating remaining nonrenewable supply

remaining supply = total known reserves / annual rate of use

How renewable energy generates electricity

sunlight through solar panels, wind, and water to either spin turbines connected to generators or directly convert energy via photovoltaic cells

Solar energy

• converts sunlight into electricity through mainly solar panels, photovoltaic (PV) cells

• limitations: intermittent supply, energy storage is expensive, space requirements, and efficiency limits, upfront cost

Wind energy

• wind energy works by converting kinetic energy of moving air in electricity

• limitations: intermittent and unpredictable, location dependent, noise and visual impact, wildlife impact, and high upfront cost

Hydropower

• generates electricity by using the energy of moving water

• limitations: environmental impact, location dependent, high upfront cost, and dependence on water availability.

Geothermal

• energy created through heat from inside the earth

• limitations: location dependent, high upfront cost, environmental concerns, and limited scalability

Why use renewable energy

cleaner, safer, sustainable, healthier, and more reliable for the future

Solar thermal vs solar electric

• solar thermal (water/heating): DO collects heat but DO NOT generate energy

• concentrate solar power (CSP): DO collect heat and DO generate energy

• PV panels: DO NOT collect heat but DO generate electricity

Three biomass energy methods

• direct combustion

• converting it into biogas

• turning it into liquid biofuels

Energy storage

balance supply and demand and maintain reliable power, but it comes with cost, environmental, efficiency, and capacity limitations.

What is soil?

natural mixture of weathered rock (minerals), organic matter, water, air, and living organisms

Crop rotations

• Farmers grow different crops in the same field each season.

• Prevents nutrient depletion and reduces pest and disease buildup.

Intercropping

multiple crops are grown together to improve soil health, increase yields, reduce pests, and protect the environment, making farming more resilient and sustainable

Shelter belts

uses trees and shrubs to reduce wind, protect soil and crops, conserve moisture, and improve farm resilience, making agriculture more productive and environmentally friendly.

Terracing & contour farming

reduce soil erosion, manage water runoff, and improve fertility on sloped land

No‑till / conservation till farming

reduces soil disturbance, prevents erosion, conserves water, and improves long‑term soil health, making agriculture more resilient and environmentally friendly.

fertilizers issues

water pollution, soil degradation, air pollution, health risks, and long‑term sustainability problems

pesticides issues

environmental damage, health risks, water pollution, loss of biodiversity, and pesticide‑resistant pests

irrigation issues

water shortages, soil damage, ecosystem disruption, pollution, health risks, and high costs

monocultures issues

• the agricultural practice of growing a single crop species—such as corn, wheat, or soy

loss of biodiversity, soil depletion, increased pest and disease risks, higher chemical use, and reduced long‑term sustainability

feedlots issues

• intensive animal feeding operations designed to efficiently fatten livestock

High waste production, potential animal welfare concerns due to confinement, and reliance on intensive resource consumption

Overnutrition & undernutrition

• undernutrition: poverty, food insecurity, poor healthcare and sanitation, lack of education, & inequitable food distribution

• over nutrition: easy access to processed foods, urbanization, food marketing, economic development, & lack of nutrition education

Where drinking water comes from

• Surface water (rivers, lakes, reservoirs) = largest U.S. source

• Groundwater (aquifers, wells) = critical, especially in rural areas

• All drinking water must be treated to meet safety standards

Overuse of groundwater

• Water tables drop

• Land can sink permanently

• Rivers and wetlands lose water

• Coastal areas face saltwater contamination

• Communities face higher costs and long‑term shortages

Overuse of surface water

• Rivers and lakes shrink

• Ecosystems are damaged

• Water quality worsens

• Power, agriculture, and communities suffer

• Long‑term water security is threatened

Louisiana drinking water situation

• Comes mainly from surface water (especially the Mississippi River)

• Is generally accessible but vulnerable to saltwater intrusion, pollution, aging infrastructure, and extreme weather

• Faces greater challenges in rural and low‑income areas

Waco water source

• Source: Lake Waco (Bosque River → Brazos River basin)

• Treatment: City of Waco water treatment plants

• Use: Homes, schools, businesses, industry

• After Use: Wastewater treatment plants

• Final Return: Brazos River and connected waterways

Reclaimed water

treated wastewater reused for beneficial purposes

DPR (Direct Potable Reuse)

Treating wastewater to drinking‑water quality & sending it directly back into the water supply

Why can desalination not be used everywhere?

• Too expensive

• Very energy‑intensive

• Environmentally risky

• Limited to coastal regions

Xeriscaping

landscaping that uses little water, lowers maintenance needs, saves money, and helps protect local water supplies while still creating attractive outdoor spaces

Point source pollution

can be found from a direct soure

Non‑point source pollution

multiple different sources

Household waste

Solid trash, Recyclables, Organic waste, Hazardous waste, Wastewater, Electronic waste

Recyclable items

• Clean paper & cardboard

• Plastic bottles/jugs (#1 & #2)

• Metal cans

• Glass bottles & jars

Plastic & recycling

• Many plastics are not recyclable

• Contamination is common

• Plastics degrade each time they’re recycled

• Recycling is often not economically viable

• Recycling systems are inconsistent

Waste stream steps

Generation → Collection → Sorting/Processing → Recovery → Treatment → Disposal

Cradle‑to‑cradle

approach where products are designed from the start so that nothing becomes waste—everything can be reused, recycled, or safely returned to nature, supporting a sustainable and circular economy

Cradle‑to‑grave

traditional product life cycle where materials are taken from the Earth, used once, and then discarded as waste, often contributing to pollution and resource depletion

Good vs bad landfills

• Good landfills are engineered systems designed to protect people and the environment.

• Bad landfills pollute air, water, and soil, creating long‑term health and environmental risks.

Pros of incineration

• Reduces waste volume

• Produces energy

• Decreases landfill use

• Eliminates pathogens

• Saves land

Hazardous waste definition

considered hazardous when it poses a risk to human health or the environment

What happens to hazardous waste

1. Identified and labeled

2. Safely transported

3. Treated to reduce danger

4. Disposed of in secure facilities (or recycled)

Household hazardous waste

includes items that are toxic, flammable, corrosive, or reactive

Toxicology definition

substances that are poisonous, how they affect the body, and at what doses they become harmful.

Exposure routes

• ingestion

• inhalation

• dermal absorption

• injection

ADME

Absorption, distribution, metabolism, excretion.

Risk in toxicology

likelihood that a substance will cause harm, based on both how toxic it is and how much exposure occurs

High risk vs high hazard

• High hazard: Very dangerous substance, but little or no exposure

• High risk: Mildly dangerous substance, but frequent or high exposure

Dose‑response curve

illustrates how increasing exposure to a substance changes its effect on an organism, helping determine toxicity, thresholds, and safe exposure levels

LD50

standard measure in toxicology that represents the amount of a substance required to kill 50% of a test population (usually laboratory animals) after a single exposure

Chemical interactions

• Additive → effects simply add up

• Synergistic → effects multiply beyond expectation

• Antagonistic → one reduces another’s effect

• Potentiating → harmless substance boosts harm of another