How This Sea Shell Knows the Weather in Greenland

Forams, tiny single-celled marine organisms, build shells from calcium carbonate. These shells contain oxygen isotopes that reveal historical climate data. By analyzing the ratio of regular to heavy oxygen in foram shells, scientists can infer past global temperatures and ice volumes. Forams have been recording this data for millions of years, providing a continuous climate record through sediment cores.

What unique ability do forams have despite lacking eyes, brains, or limbs?

• They can fly.

• They can build houses from seawater ingredients.

• They can change color.

• They can communicate with other marine life.

How do forams help scientists understand past global temperatures?

• By counting the number of forams in a sample.

• By measuring the size of their shells.

• By analyzing the color of their shells.

• By examining the oxygen isotope ratio in their shells.

What happens to regular oxygen during colder global climates?

• It evaporates more quickly.

• It disappears from the ocean.

• It is stored in ice sheets.

• It becomes heavier.

Why are forams considered valuable for studying Earth's climate history?

• They have been recording data for millions of years.

• They are found in all ocean regions.

• They are immune to climate changes.

• They are easy to collect.

What method do scientists use to access the climate data stored by forams?

• By measuring ocean currents.

• By drilling and extracting sediment cores.

• By using satellite imagery.

• By observing them in their natural habitat.