Mount Pinatubo erupted in 1991 and injected about 20 million metric tons of sulfur dioxide into the stratosphere. Over the next two years, what happened to global average surface temperature?

A small eruption sends ash and gas only into the troposphere, where rain washes the particles out within a few weeks. What is the most likely effect on global average temperature?

An eruption releases both sulfate particles and carbon dioxide. The particles settle out after about two years, but the carbon dioxide stays far longer. What does this predict about temperature once the particles are gone?

A large meteor strikes Earth and lofts fine rock dust around the world, dimming sunlight for several years. What should global average temperature do while that dust stays in the air?

Two eruptions release similar amounts of sulfur. One plume reaches the stratosphere; the other stays low in the troposphere. Which eruption cools the planet more, and why?

True or False: volcanoes release carbon dioxide, but all the world's volcanoes together release far less of it each year than human activities do.

Ice cores from Greenland contain thin layers with sudden spikes of sulfate, a sulfur compound. Which past events do scientists use these layers to identify?

Ash from an eruption settles across a snowfield, darkening the white surface. What does the darkened snow do to the sunlight it reflects, and to local temperature?

Rock dust thrown up by a large meteor impact dims sunlight worldwide for several years. Which chain through Earth's systems best explains the loss of plant-eating animals afterward?

Sulfur dioxide from an eruption mixes with water in the atmosphere and falls as rain downwind. What does this rain do to the lakes and soils it lands on?

Thick ash from an eruption buries a forest, and over many years that ash breaks down through weathering. What happens to the buried land, and why?

An eruption happens beneath a glacier, and heat from the erupting rock melts the overlying ice quickly. What change in the hydrosphere should scientists expect downstream?

True or False: a meteor impact can change the atmosphere, the hydrosphere and the biosphere, not only the ground it strikes.

A meteor strikes the deep ocean far from land. Which effect on Earth's systems is most likely within hours of that impact?

Sediment cores from a normally dry Peruvian coast contain layers of flood debris in certain years. Those same years show unusually warm surface water offshore. What do these records indicate?

Along one coast, cool water normally rises from below and carries nutrients up to the surface. In one year that rising water stops. What should the fishery records for that year show?

In one year the equatorial Pacific winds blow unusually strongly, piling warm water in the west and pulling more deep water up in the east. What weather record fits the western Pacific that year?

A coral skeleton records the temperature of the water it grew in. A core drilled from Pacific coral shows bands of unusually warm water repeating every few years. What ocean change do these bands most likely record?

The Gulf Stream carries warm surface water northeast across the Atlantic toward Europe. If that flow slowed sharply, what would climate records for northwestern Europe most likely show?

Fishing logs show tuna caught far north of their usual range in years when a warm current pushed poleward. What do these records show about ocean currents and living things?