Rob Spencer, FSU – Permafrost

Thawing carbon in the arctic is presenting some potential problems.

Rob Spencer, an oceanographer at FSU, is studying permafrost.

Rob Spencer is an  assistant professor of oceanography at Florida State. Research in his laboratory is focused on understanding the chemical composition of Earth’s major carbon reservoirs (soils, sediments and dissolved organic matter (DOM) in marine and terrestrial ecosystems), and how this controls movement between these reservoirs and the atmosphere. These major reservoirs can vary between carbon dioxide source or sink with respect to the atmosphere in a changing climate and due to anthropogenic impacts. His team works across a range of scales from global to molecular level and a wide variety of environments from the Arctic to the tropics. Application and development of a range of analytical techniques is undertaken in the laboratory and field centered on organic geochemistry, but encompassing methodology from oceanography, hydrology, microbiology and soil science.

Permafrost

Between 2012 and 2014, I had the unique opportunity to visit Siberia several times to study perma-frost, and the effect thawing perma-frost was having on the environment. Particularly, receiving aquatic ecosystems like streams, rivers, and ultimately the ocean.

Permafrost in the arctic is a thick, thick, sub-surface layer of frozen soil that stores vast amounts of carbon. Often, this carbon has been locked inside these frozen soils for tens of thousands of years. It’s almost like storing food in a freezer, but for a very long time.

So what happens when this permafrost starts to thaw?

Terrestrial scientists have compelling evidence that permafrost is thawing and releasing this long-stored carbon, but aquatic scientists, examining what gets exported from the mouths of major arctic rivers, found no evidence of this ancient carbon in their samples.

So my team and I set out to find out why.

Where was the carbon going? And, what was driving this disconnect.

The answer turned out to be relatively straightforward and tied to simple life-forms.

Microbes are single-cell organisms that are all around us but invisible to the human eye.

It turns out that this ancient permafrost derived carbon is an incredibly attractive food source for microbes. Our research showed that microbes were rapidly consuming it as permafrost thaws, then releasing it back into the atmosphere as carbon dioxide.

More thaw equals more food for the microbes and this additional carbon dioxide, so the whole thing has potential to get into a runaway effect.

I live in Florida, one of the greatest states at risk from sea-level rise caused by climate change.

More carbon dioxide in the atmosphere will lead to more warming at high latitude, more permafrost thaw, as well as more melting of the ice sheets.

That all adds up to sea-level rise with well described impacts on our coastal communities.

Read More: FSU 24/7: Thawing permafrost feeds climate change