Greenhouse Gases and Global Climate Change

These flashcards cover key concepts related to greenhouse gases, climate change, and their impacts based on the lecture notes.

What are greenhouse gases?

Gases in the atmosphere that trap heat, including CO2, CH4, and N2O.

What is the enhanced greenhouse effect?

The increased warming of Earth's surface due to elevated levels of greenhouse gases from human activities.

What are natural sources of atmospheric CO2?

Plant and microbial respiration, ocean-atmosphere exchange, and volcanic eruptions.

What are anthropogenic sources of CO2 in the U.S.?

Mainly from fossil fuel combustion and land-use changes like deforestation.

What is the main consequence of increased CO2 concentrations in the atmosphere?

It leads to global warming and changes in climate patterns.

What is seasonal variability in climate?

Changes in climate due to seasonal patterns, such as summer versus winter conditions.

What triggers El Niño and La Niña events?

Changes in ocean temperature and currents in the Pacific Ocean that affect global climate.

How do Milankovitch cycles affect Earth's climate?

They cause cyclical changes in Earth's orbit, axial tilt, and precession leading to climate variations.

What is the typical period of glacial cycles?

Approximately every 100,000 years.

What is the significance of the Mauna Loa Observatory?

It provides critical long-term data on atmospheric CO2 concentrations.

What does the 'triple-dip' refer to in climate patterns?

A rare phenomenon where La Niña conditions persist for three consecutive years.

What is the typical range of Earth's axial tilt?

It varies between 22.1 and 24.5 degrees over a cycle of about 41,000 years.

How does CO2 influence the greenhouse effect?

CO2 absorbs infrared radiation, warming the atmosphere and contributing to climate change.

What evidence supports the rise of CO2 due to human activity?

The Suess Effect shows a decline in atmospheric 14C due to fossil fuel emissions.

What is the current concentration of atmospheric CO2?

Approximately 424 parts per million (ppm) as of the latest data.

Why is interannual variability in CO2 significant?

It relates to seasonal differences in respiration and photosynthesis in the Northern Hemisphere.

What is the relationship between temperature and CO2 over the last 150,000 years?

They are closely correlated, with temperature changes lagging behind CO2 changes by 600-1000 years.

What is the purpose of measuring atmospheric CO2 at Mauna Loa?

To determine global atmospheric CO2 levels unaffected by local pollution sources.

What is meant by anthropogenic global warming?

Global warming caused primarily by human activities such as burning fossil fuels.

What are potential outcomes of rising global temperatures?

More severe weather, rising sea levels, and disruptions in ecosystems.

How do plants act as a natural sink for CO2?

They absorb CO2 during photosynthesis, reducing atmospheric CO2 levels.

What is the impact of land-use change on CO2 emissions?

Deforestation and urbanization increase CO2 emissions by reducing carbon sinks.

What are the main components of the carbon cycle?

Photosynthesis, respiration, decomposition, and ocean uptake.

What role do oceans play in the carbon cycle?

Oceans absorb CO2 from the atmosphere and release it through various processes.

What evidence from ice cores shows historical CO2 levels?

Gas trapped in ice cores provides records of atmospheric CO2 over hundreds of thousands of years.

What is a potential global consequence of the enhanced greenhouse effect?

Rising temperatures leading to climate change and extreme weather events.

What cycles in Earth's movements are responsible for natural climate changes?

Milankovitch cycles which include eccentricity, axial tilt, and precession.

How does urbanization affect local climate?

Urban heat islands can cause temperatures to be higher compared to surrounding rural areas.

What is the predicted temperature increase by 2100 according to climate models?

Models predict an increase of 1.4° - 5.8°C.

Why do some experts refute the impact of CO2 on temperatures?

They argue that temperature changes lag behind CO2 levels and attribute warming to natural effects.

How does the heat island effect impact climate measurements?

It can cause localized warming but is considered a minor factor in global temperature assessments.

What is ocean acidification?

The ongoing decrease in the pH of Earth's oceans, caused by the uptake of atmospheric CO2.

What is a positive feedback loop in climate science?

A process that amplifies an initial change, such as melting ice reducing albedo and increasing warming.

What is albedo and its role in climate?

The reflectivity of a surface; high albedo surfaces (like ice) reflect more sunlight, influencing Earth's energy budget.

What is carbon sequestration?

The process of capturing and storing atmospheric carbon dioxide, typically involving natural processes like photosynthesis or technological methods.