Most global carbon-budgeting efforts assume a linear flow of water from the land to the sea, which ignores the complex interplay between streams, rivers, lakes, groundwater, estuaries, mangroves and more. A study co-led by climate scientist Laure Resplandy, an assistant professor of geosciences and the High Meadows Environmental Institute (HMEI) at Princeton University, details how carbon is stored and transported through the intricacy of inland and coastal waterways. Published in the current issue of the journal Nature, the work has significant implications for enforcing the carbon calculations that are part of international climate accords.

Terrestrial and marine ecosystems have a powerful influence on climate by regulating the level of atmospheric carbon dioxide (CO2). These ecosystems, however, are often viewed as disconnected from each other, which ignores the transfer of carbon from land to the open ocean through a complex network of water bodies — the continuum of streams, rivers, estuaries and other bodies carrying water from land to the sea.

In a detailed analysis, the team of researchers from Belgium, the United States and France discovered that this land-to-ocean aquatic continuum (LOAC) carries a substantial amount of carbon of anthropogenic (e.g., fossil-fuel) origin. Thus, the carbon removed from the atmosphere by terrestrial ecosystems is not all stored locally, as is commonly assumed, which has implications for global agreements that require countries to report their carbon inventories. The researchers also found that the land-to-ocean carbon transfer of natural origin was larger than previously thought, with far-reaching implications for the assessment of the anthropogenic CO2 uptake by the ocean and the land.

Read more at Princeton University

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