Air

Troposphere

The lowest layer of Earth's atmosphere, where the air is densest and contains 75% of the atmosphere's mass.

Ozone Layer

A region of the stratosphere that absorbs most of the sun's harmful ultraviolet radiation.

Cyanobacteria

Single-celled organisms that produce oxygen, playing a significant role in the development of Earth's atmosphere.

Stratosphere

The second layer of the atmosphere, ranging from about 11 km to 50 km above sea level, characterized by a temperature increase with altitude.

Carbon Cycle

The process by which carbon is exchanged among the atmosphere, land, water, and living organisms.

Albedo Effect

The measure of how much sunlight is reflected by the Earth's surface, influencing climate and temperature.

Montreal Protocol

An international treaty designed to phase out substances that deplete the ozone layer, particularly chlorofluorocarbons (CFCs).

Greenhouse Effect

The warming of Earth's surface caused by greenhouse gases trapping heat in the atmosphere.

Heavy Metal Extraction

The process of obtaining metal ores, often leading to environmental contamination and health risks.

Emerging Contaminants

New or newly recognized pollutants that are not commonly monitored in the environment, such as PFAS.

Stromatolites

Fossilized remains of microbial mats that enriched the atmosphere, leading to the development of plants.

Scale Trees

Trees that converted carbon dioxide into oxygen, significantly contributing to the ice age at the end of the Carboniferous period.

Acid Rain

Precipitation that contains harmful amounts of sulfuric and nitric acids, damaging plant life and infrastructure.

Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)

Synthetic chemicals resistant to heat, grease, water, and oil, often referred to as 'forever chemicals' due to their persistence in the environment.

Chernobyl

A nuclear disaster in 1986 that resulted in significant radioactive fallout, leading to the establishment of exclusion zones.

Biomagnification

The process by which the concentration of toxic substances increases in organisms at each successive level of the food chain.

Mercury Sources

Artisanal and small-scale gold mining, along with historical events like WW2 manufacturing, contributing significantly to global mercury pollution.

Greenhouse Gas Emissions

Gases released into the atmosphere from human activities that contribute to the greenhouse effect and climate change.

Ozone-depleting Substances (ODS)

Chemicals, including chlorofluorocarbons (CFCs), that harm the ozone layer and are targeted by the Montreal Protocol.

Ruddiman Hypothesis

Proposes that human activities, particularly agriculture and deforestation, have significantly impacted atmospheric CO2 levels, preventing a new ice age.

Atmospheric Circulation

The large-scale movement of air that distributes heat and moisture around the Earth, influencing climate and weather patterns.

Photosynthesis

The process by which green plants, algae, and some bacteria convert light energy into chemical energy stored in glucose, using carbon dioxide and water.

Eutrophication

The process of nutrient enrichment in water bodies, often leading to excessive growth of algae and decline of oxygen levels, impacting aquatic life.

Climate Change

Long-term alterations in temperature, precipitation, wind patterns, and other elements of the Earth's climate system, primarily driven by human activity.

Carbon Footprint

The total amount of greenhouse gases emitted directly or indirectly by an individual, organization, event, or product, typically measured in carbon dioxide equivalents.

Biodiversity Loss

The reduction in the variety and variability of life forms, often resulting from habitat destruction, pollution, climate change, and overexploitation of resources.

Renewable Energy Sources

Energy sources that are replenished naturally, such as solar, wind, hydroelectric, and biomass, contributing to the reduction of greenhouse gas emissions.

Soil Degradation

The decline in soil quality and productivity caused by factors like erosion, compaction, pollution, and overuse of chemicals.

Invasive Species

Non-native species that, when introduced to a new environment, can disrupt local ecosystems and outcompete native species.

Sustainable Development

Development that meets current needs without compromising the ability of future generations to meet their own needs, balancing economic, social, and environmental factors.

Historical Perspective on Climate Change

Understanding climate change through historical events helps clarify its scope and scale, emphasizing that human civilization developed in a temperate climate.

Medieval Warm Period

A time when temperatures were elevated, leading to agricultural expansion and population growth in Europe, including Viking explorations to Greenland.

The Little Ice Age

A climatic phase characterized by cooler temperatures, economic hardship, and notable events like frozen canals in the Netherlands and frost fairs in London.

Columbian Exchange

The widespread transfer of diseases, crops, and populations following the arrival of Europeans in the Americas, resulting in significant demographic impacts.

Carbon Dioxide Reduction (1610)

Post-colonization reforestation in the Americas led to a significant drop in atmospheric CO2 levels due to reduced agricultural land.

Anthropocene Epoch

A proposed geological epoch marked by significant human impact on Earth's geology and ecosystems, primarily starting with industrialization.

Coalification

The process where peat is transformed into coal under heat and pressure, reflecting millions of years of energy storage.

Sociogenic Global Warming

Refers to the warming caused by industrial activities beginning in Britain during the late 18th century, driven by coal use for steam power.

The Great Acceleration

Post-1945 period marked by rapid economic growth, population increase, and significant impacts on Earth's ecosystems.

Guy Callendar

The first person to quantitatively associate CO2 emissions with atmospheric warming, initially viewing global warming as beneficial.

Keeling Curve

A graph representing atmospheric CO2 concentration measurements from the Mauna Loa Observatory since 1958, illustrating seasonal fluctuations.

Clean Air Act

US legislation from the 1950s and 60s aimed at improving air quality by reducing outdoor pollutants, cutting toxic emissions, and phasing out ozone-depleting substances. It regulates six key pollutants: sulfur dioxide, nitrogen dioxide, carbon monoxide, particulate matter 2.5, ground-level ozone, and lead.

Major sources of emissions in the US

Industrial processes, stationary fuel combustion, non-road mobile sources, and highway vehicles.

Disparities in Air Pollution Exposure

Black and Hispanic communities contribute less to air pollution yet face higher exposure compared to white populations.

Montreal Protocol's Success

Resulted in significant recovery of the ozone layer, with the Antarctic ozone hole becoming the 7th smallest since recovery began in 2024.

Bush Era Climate Action

Included calls for mandatory GHG emissions reductions and the notion of maintaining doubt about climate change.

Massachusetts vs. EPA (2006)

Supreme Court decision that greenhouse gases are covered under the Clean Air Act's definition of 'air pollutant'.

EPA Endangerment Finding (2009)

Determined that six greenhouse gases are harmful to public health and welfare, leading to regulatory actions.

Clean Power Plan (2014)

Aimed at reducing CO2 emissions from power plants by 32% by 2030.

What is the Denial Machine in climate change?

A network of beliefs and doubts about climate change, heavily influencing political agendas.

Inflation Reduction Act and Infrastructure Investment and Jobs Act

Legislation targeting lower costs for families, fair tax code, and addressing the climate crisis through incentives.

Kyoto Protocol (1997)

An international agreement setting legally binding CO2 emission reduction targets.

How does the Clean Air Act impact climate change?

It allows for the regulation of greenhouse gases, contributing to efforts aimed at reducing climate change effects.

Copenhagen Protocol

An international agreement stemming from the 2009 Copenhagen climate conference, aimed at addressing climate change by recognizing the need for deep cuts in greenhouse gas emissions and setting goals for emissions limitations for countries, although it lacks binding commitments.