Climate Change Flashcards
What is climate?
The broad composite average of the conditions of the region, measured in terms of temperature, precipitation
What does Earth’s temperature depend on?
The balance between energy entering and leaving the planet’s system.
What happens if incoming energy from the sun is absorbed?
Earth get’s warmer
What happens if absorbed energy is released back into space?
Earth get’s cooler
What are four ways to change the climate?
1.) Change how heat moves around the planet.
2.) Vary in the sun’s energy reaching earth
3.) Changes in the reflectivity of Earth’s atmosphere and surface.
4.)Changes in the greenhouse effect, affect the amount of heat retained by Earth’s atmosphere.
Where does ocean circulation change?
heat is moved/stored in the planet
What drives ocean circulation ?
plate tectonics
How does ocean circulation effect climate?
Slows changes in climate
What are plate tectonics?
Slow changes, imperceptible at human time scale. Large magnitude over geologic time.
What is eccentricity?
How ovicalar the rotation of the earth is around the sun. The shape of the earth’s orbit.
What is obliquity?
The tilt of the earth’s axis
What is precession?
The wooble of the earths axis
How does tilt change seasons?
It changes the pattern of solar radiation making one hemisphere warmer and the other colder.
What does precession do at solstices?
Changes the distance from earth and sun at solstices.
When does the Milankovitch cycle change?
It changes seasonally, specifically the length and intensity of seasons.
How do we measure past climate?
Climate proxies
What are climate proxies?
Preserved physical characteristics that enable scientists to reconstruct the climate conditions over a longer fraction of Earth’s history.
What are the climate proxies that are used?
Ice cores
Pollen
Tree rings
Coral Reefs
Sediment cores
How is an ice core used as a climate proxy?
Changes is 016 and 018 ratio is a proxie for temperature.
How is pollen used as a climate proxy?
Plants and trees have distinct ranges of ‘tolerance’ based on climatic conditions: Changes to this change the vegetation.
How are tree rings used as a climate proxy?
Thickness controlled by climatic growing conditions: also records fires
How are coral reefs used as a climate proxy?
As they grow, coral records info about the temperature and composition of the water.
How are sediment cores used as a climate proxy?
Sediment layers can indicate changes in deposition throughout time.
What are some issues with climate proxies?
temporal resolution (time)
spatial distribution issues
