Greenhouse Gases
What is the difference between greenhouse gas emissions and atmospheric concentrations?
Emissions = amount released; concentrations = amount present in the atmosphere.
How has the U.S. average temperature changed since 1901?
Overall warming, accelerating since the 1970s.
Name two causes of sea level rise.
Melting land ice, thermal expansion of water.
What is glacier mass balance?
The net gain/loss of ice over time.
How can climate change affect timing of natural events?
Earlier blooms or migrations.
Why do scientists convert gases into CO₂ equivalents?
To compare their warming effects on the same scale.
What does “unusually hot days” mean?
Hotter than 90% of historical baseline days.
What is ocean acidification?
CO₂ absorbed by ocean forms acid, lowering pH.
How has snowmelt timing changed?
Occurs earlier, affecting runoff and ecosystems.
Why do warmer waters affect aquatic life?
Low oxygen, stress on species.
Name two human activities that contribute to greenhouse gas emissions.
Energy, transportation, agriculture, industry, waste.
Why is night warming faster than day significant?
Affects health, ecosystems, and energy use.
Why isn’t sea level rise the same everywhere?
Land movement, currents, gravity differences.
Why is Arctic sea ice minimum important?
Reflects sunlight; loss accelerates warming.
How might wildfires respond to climate change?
More frequent and intense.
Why is current CO₂ concentration considered unprecedented?
Highest in at least 800,000 years.
Name one U.S. region that has warmed more and one that has warmed less.
Southwest/Alaska more; Southeast less.
How does ocean warming affect marine life?
Coral bleaching, less oxygen, habitat shifts.
What is permafrost thawing?
Frozen ground melts, damaging structures, releasing methane.
Why are wildfires part of climate feedbacks?
Release carbon, increasing warming.
Which gas traps the most heat per molecule?
Nitrous oxide.
How does climate differ from weather?
Climate = long-term patterns; weather = short-term changes.
What % of Earth’s excess heat is absorbed by oceans?
About 90%.
How does snow/ice loss accelerate warming?
Darker surfaces absorb more heat (positive feedback).
Example of vulnerable species/process?
Coral reefs (heat), salmon (temp), polar bears (ice loss).