Inland Water’s Contribution to the Carbon Cycle: Now It’s Known

November 20, 2013

Yale School of Forestry and Environmental Sciences’ Professor Peter Raymond was lead author on “Global Carbon Dioxide Emissions from Inland Waters”, published in Nature.  An ecosystem ecologist,” Raymond tracks carbon, the element most closely associated with life, as it makes its way between living and non-living realms.  Today’s provides the first global maps of inland water that account for their total CO2 emissions.

You only need three things to calculate that value, says Raymond.   The surface area of the world’s lakes and streams, the amount of dissolved CO2 in their water, and the gas transfer velocity, which looks at the physics of exchange. Until recently, none of them had been mapped globally.

Raymond et al, determined that annual efflux of Carbon from inland waters was 2.1 pentagrams, more than double that of previous estimates.  Streams and tropical lakes are described as hot spots for CO2 exchange, with 70% of the efflux coming from 20% of the streams, and lakes in the tropics contributing approximately 1/3 of the world’s total lake-derived CO2 despite representing just 2.4% of its lakes.  By demonstrating how much more CO2 was transported from the system by inland waters, Raymond’s group challenged standard assumptions about terrestrial Carbon’s pathway.

To force that redetermination Raymond’s group had to determine how the worlds’ wetted perimeters expand and shrink as time goes on. 

A continued effort is needed to map inland waters and understand how they impact global processes such as the carbon budget, species habitat, and production of clean drinking water.”

“If you’re going to plan for the future, you’ve got to know where the water is,” says Raymond.  Colleagues at the Yale Climate and Energy Institute are investigating how to incorporate his estimations of changing stream, river and lake areas into their current efforts to develop developed a high-resolution model to estimate how global warming will effect Yale and the New England area.

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