Here’s how sea ice algae could show past and future climate change

Here’s how sea ice algae could show past and future climate change

As sea ice concentration ebbs and flows, so do the algae associated with it, as well as the molecules they leave behind.

This can help scientists determine past temperatures - and understand climate change now.



A previously problematic molecule turns out to be a reliable proxy for reconstructing sea ice, a new study shows.

The research could help understand human-induced climate change happening now.

In the study in Nature Communications, the researchers show that an organic molecule often found in high-latitude ocean sediments, known as tetra-unsaturated alkenone (C37:4), is produced by one or more previously unknown species of ice-dwelling algae. As sea ice concentration ebbs and flows, so do the algae associated with it, as well as the molecules they leave behind.

"We've shown that this molecule is a strong proxy for sea ice concentration,“ says Karen Wang, a PhD student at Brown University and lead author of the research. "Looking at the concentration of this molecule in sediments of different ages could allow us to reconstruct sea ice concentration through time.“



Researchers have used other types of alkenone molecules for years as proxies for sea surface temperature. At different temperatures, algae that live on the sea surface make differing