Natural Agents of Climate Change

Flashcards on natural agents of climate change based on lecture notes.

What is the definition of climate change?

A change in the typical weather for a region over a long period.

What are some effects of global warming?

Hotter temperatures, more severe storms, flooding, increased drought, wildfires, warming ocean, and sea level rise.

Where does most of the energy affecting Earth’s climate originate?

The Sun.

What is the solar cycle?

The slight variation in solar output (by close to 0.1%) in an 11-year cycle.

What happens when the Sun has more sunspots?

The Sun gives off more energy, warming the planet.

What is the Maunder Minimum?

A period of near-zero sunspot activity from 1645 to 1715, during which the Little Ice Age occurred.

What are the Milankovitch Cycles?

Cyclical movements related to the Earth's orbit around the Sun (eccentricity, obliquity, and precession).

What is eccentricity in relation to Milankovitch cycles?

The shape of Earth’s orbital path around the Sun changes from more circular to more elliptical, completing a cycle about every 100,000 years.

What is obliquity in relation to Milankovitch cycles?

The tilt of Earth’s axis, which moves back and forth between 22.1 and 24.5 degrees over a cycle of about 41,000 years.

What is axial precession (wobble) in relation to Milankovitch cycles?

A wobble around Earth’s axis that takes nearly 26,000 years, affecting the timing of seasons.

What is the role of greenhouse gases in climate change?

Trap solar radiation in Earth’s atmosphere, making the climate warmer. Examples include carbon dioxide (CO2), methane (CH4), and water vapor (H2O).

How do ocean currents affect climate?

Carry heat around Earth, and changes in their direction can affect temperatures in different areas.

What are gyres?

Large systems of rotating ocean currents.

What happens when oceans absorb more heat?

Sea surface temperature increases, potentially increasing atmospheric water vapor and reducing the ocean's ability to absorb CO2.

What is El Niño?

A condition that sometimes occurs in the Pacific Ocean, affecting weather all over the world.

How do mountain ranges affect climate?

Influence the circulation of air around the globe, deflecting warm air to cooler regions.

What is the impact of landmasses concentrated in middle and high latitudes?

Continental glaciers are more likely to form, increasing reflection of sunlight and lowering air temperature.

How do volcanic eruptions affect climate in the short term?

Cool Earth by producing ash and aerosols that block incoming solar radiation.

How do volcanic eruptions affect climate in the long term?

Warm Earth by releasing greenhouse gases such as water vapor and carbon dioxide, with enough intense volcanism.

What is albedo?

How much light a surface reflects rather than absorbs.

How does vegetation cover affect albedo?

Land covered with dark-colored vegetation has a low albedo and will absorb most incoming solar radiation. A decrease in vegetation cover tends to increase local albedo.

How does desertification amplify global warming?

Through the release of CO2 because of the decrease in vegetation cover.

What is the ice-albedo feedback?

Ice reflects most sunlight back to space. Seawater and land surfaces reflect less sunlight and thus, the planet warms, melting more ice.

How do asteroid impacts affect climate in the short term?

Cause global cooling due to dust and aerosols blocking sunlight.

How do asteroid impacts affect climate in the long term?

Cause global warming due to greenhouse gases released from the impact.