Set 3A — Warming climate / impacts / carbon cycle

Greenhouse gas effect

Greenhouse gases trap heat and warm Earth by absorbing outgoing infrared radiation. If a question asks what the greenhouse effect is, think heat-trapping gases warming the planet.

Why CO2 matters

CO2 acts like a heat-trapping blanket, and human activity is adding it quickly to the atmosphere. If the clue is modern warming plus fossil fuels, think CO2.

Human cause of warming

Climate models only match current warming when human activity is included. If the question asks whether humans are to blame, the class answer is yes.

Climate projection

If emissions stay high, Earth could warm much more by 2100, but even strong action does not stop all warming immediately. If the clue is business as usual versus drastic changes, think climate projections.

Business as usual

If emissions continue at current rates, Earth could warm about 4°C by 2100.

Best-case warming floor

Even with major changes, Earth is still expected to warm at least about 1°C by 2100.

Carbon cycle

The movement of carbon among the atmosphere, ocean, land, and living things. If the clue is carbon moving through Earth systems, think carbon cycle.

Human carbon cycle effect

Humans add carbon to the atmosphere so fast that natural sequestration cannot keep up. If the clue is current and future climate being shaped by people, think carbon cycle disruption.

Positive feedback loop

A positive feedback loop strengthens the original climate change.

Negative feedback loop

A negative feedback loop weakens the original climate change.

Current feedback scenario

Earth is currently in a warming feedback cycle, not a cold one.

Drought clue

Warming increases evaporation, reduces available water, and worsens drought. If the clue is wildfire risk plus water shortage, think drought.

Drought trap

Drought does not reduce the urban heat island effect. If that is the statement, it is false.

Heatwave clue

Heatwaves are tied to persistent high pressure, sinking air, compression, and dry hot conditions. If the clue is stagnant high pressure, think heatwave.

Urban heat island

Cities are hotter because of less vegetation, more waste heat, and low-albedo surfaces. If the question asks why heatwaves are worse in cities, think urban heat island.

Urban heat island trap

If a choice says cities are hotter because they have higher albedo, that is wrong.

Wildfire risk

Hot and dry conditions raise wildfire risk. If the clue is drought plus vegetation catching fire more easily, think wildfire risk.

Storm intensification

Warming oceans add moisture and energy, which can make storms stronger. If the clue is stronger storms in a warmer climate, think intensification.

Storm trap

Warming does not necessarily mean more hurricanes. It more clearly means stronger hurricanes.

Jet stream instability

More warming toward the poles can make the jet stream wavier and help weather patterns lock in place. If the clue is prolonged dry or wet periods, think unstable jet stream.

Growing season trend

A warming climate is increasing the length of the growing season in many places. If the clue is earlier spring and later frost, think longer growing season.

Ocean acidification

The ocean absorbs CO2, which lowers pH and harms marine life. If the clue is the ocean as a carbon sink with a harmful trade-off, think ocean acidification.

Coral bleaching

The primary cause of coral bleaching in this class is increased ocean temperatures. If the clue is corals whitening, think warming water.

Sea level rise

Sea level rises because melting ice adds water and warmer ocean water expands. If the clue is both melting ice and expansion, think both.

Sea level rise main causes

The two main causes are reduced global ice volume and warmer ocean temperatures.

Permafrost clue

As permafrost thaws, CH4 is released. If the question asks which gas is released, think methane.

Regional climate change clue

All regions are experiencing climate change, but not all in the same exact way. If a choice says some regions are not experiencing climate change, that is false.

Cloud mitigation

More clouds can reflect sunlight and slightly cool Earth, but they do not solve the warming problem. This is a negative feedback example.

Ozone layer

The ozone layer protects life by absorbing UV radiation. If the clue is environmental repair through human cooperation, think ozone recovery.