Q 01/05

Where was carbon, the fourth most abundant element in the Universe, first forged before any of it reached Earth?

A) In the Big Bang

B) In black holes

C) Inside stars

D) In comet tails

Answer · why

C) Inside stars

Inside stars, helium nuclei fuse into carbon through the triple-alpha process, which runs only in giant and supergiant stars. NASA calls carbon the ba...

Q 02/05

Which British Isles landmark is built from the skeletons of tiny algae that locked carbon away in an ancient sea?

A) White Cliffs of Dover

B) Fingal's Cave on Staffa

C) The Giant's Causeway

D) The Cliffs of Moher

Answer · why

A) White Cliffs of Dover

The White Cliffs of Dover are chalk, laid down as white mud on a Late Cretaceous sea floor at about half a millimetre a year. They now stand up to 110...

Q 03/05

Which planet's carbon dioxide atmosphere traps so much heat that the surface is hot enough to melt lead?

A) Mars

B) Venus

C) Mercury

D) Jupiter

Answer · why

B) Venus

Venus has an atmosphere that is 96.5% carbon dioxide, which holds its surface near 467 °C, hotter even than Mercury. On Earth the carbon cycle keeps m...

Q 04/05

Which fuel, cut from bogs and dried in rural Ireland, holds more carbon worldwide than all forests combined?

A) Kelp

B) Gorse

C) Reeds

D) Peat

Answer · why

D) Peat

Peat stores up to 550 billion tonnes of carbon while covering just 3% of the land surface. It builds up where waterlogged ground stops dead plants fro...

Q 05/05

Which thawing Arctic layer holds about twice as much carbon as the entire atmosphere, locked in plant remains?

A) Permafrost

B) Sea ice

C) Bedrock

D) Glacier ice

Answer · why

A) Permafrost

Permafrost in the far north holds an estimated 1,400 to 1,650 billion tonnes of carbon, built up over thousands of years. As it thaws, microbes turn p...