Human Impact of Climate Change
What gas is released when people burn fossil fuels and contributes to warming the planet?
Carbon dioxide (CO2)
What is erosion?
Erosion = movement of rock particles and soil from one place to another.
Which era is known as "the era of dinosaurs"?
Mesozoic.
Give one example of a gradual change to Earth's surface.
Example: weathering, soil formation, continental drift.
What principle says the youngest sediment layer is usually on top?
Law of Superposition.
Name one human activity that causes deforestation.
Examples: cutting down trees for farms, logging, clearing land for cattle or crops.
What is deposition?
Deposition = when eroded material is dropped in a new place.
Name the three eras of the Phanerozoic Eon from oldest to youngest (short list).
Paleozoic, Mesozoic, Cenozoic.
Give one example of a rapid change (an event that can happen quickly).
Example: earthquake, volcanic eruption, landslide, tsunami.
What is radiometric dating used to find?
To find a numerical age (e.g., years since formation) using radioactive decay.
Give two actions individuals can take to reduce their carbon footprint.
Examples: reduce car trips, use public transit, recycle, eat less meat, use energy-efficient appliances.
Define the geologic time scale in one sentence.
Geologic time scale = a system scientists use to divide Earth’s long history into named time units based on major events.
What period ended about 66 million years ago with a mass extinction?
Cretaceous (Cretaceous–Paleogene extinction ~66 mya).
Name and briefly describe the three processes grouped under gradual change in the unit (one word each + short note).
Weathering (breaking down), erosion (movement), deposition (dropping).
Briefly explain what a cross-cutting relationship can tell you about the age of a feature.
If Layer A cuts through Layer B, then A is younger than B.
How does planting trees help slow climate change? (one clear sentence)
Trees absorb CO2 from the air (they act as carbon sinks), storing carbon in wood and soil.
What does "superposition" tell us about sedimentary layers?
Superposition = in undisturbed layers, oldest at bottom, youngest at top.
What is an epoch? Give one example from the Cenozoic.
An epoch is a smaller division of geologic time within a period; example: Pleistocene.
Compare and contrast how erosion and an earthquake can both change landforms — include one similarity and one difference.
Similarity: both can reshape landforms; Difference: erosion is slow and continuous, earthquakes are sudden and instant.
Explain why scientists use multiple types of physical records (e.g., tree rings, ice cores, sediment) instead of just one. (two sentences)
Multiple records cross-check each other, fill gaps, and give a more complete, reliable picture than a single source.
Describe one way industry or agriculture can reduce greenhouse gas emissions (include a short explanation).
Examples: switch to renewable energy (solar/wind), improve fertilizer use to reduce nitrous oxide, capture methane from waste — these lower emissions from those sectors.
Explain the difference between relative dating and absolute dating (two short sentences).
Relative dating orders events without numbers; absolute dating gives a numerical age (e.g., radiometric years).
On a timeline, which came first: the Cambrian Period or the Permian Period? Explain briefly.
Cambrian came before Permian — Cambrian is early Paleozoic (~541 mya), Permian is later Paleozoic (~298 mya).
Why might glaciers (glacial movement) be considered both gradual and capable of faster change? (two sentences)
Glaciers move slowly over long time but can surge or cause rapid melt and flooding; therefore mostly gradual but can produce faster change under some conditions.
How can fossils in sediment layers give clues about past climates? (one or two sentences)
Certain plant or animal fossils indicate the climate they lived in (e.g., tropical plants mean warmer past climates).