Viruses may help phytoplankton make clouds — by tearing the algae apart

Emiliania huxleyi rapidly shed their covering of tiny calcium carbonate plates when infected

Emiliania huxleyi phytoplankton

OCEAN SPHERE  Phytoplankton called Emiliania huxleyi (one shown) are covered in tiny calcium carbonate platelets. When infected with a virus, the algae lose the platelets quickly.

The Natural History Museum, London/Science Source

When tiny sea algae get sick, they may sneeze the seeds of clouds.