The Boundless Carbon Cycle Reflection
The Boundless Carbon Cycle (Battin et al 2009) provides an argument for why inland waters are important in the carbon cycle, as well as covering some carbon cycle basics. The article points out that only about 1% of Earth’s surface is covered by inland waters (streams, rivers, ponds), but 1% is still a lot and can have a big impact (Battin et al 2009). Remember that around 1% of Earth’s water is drinkable (non-saline, nor frozen), and that 1% is pretty important to us!
Inland waters are important because they transport carbon that goes from land to sea. They also mineralize and bury that carbon, being a helpful sink. But as the climate changes, will inland waters take in more carbon? More carbon will be transported to these waters through erosion, and will be stored in sediments and transported to the ocean, but some of it will just be fed back into the atmosphere (Quillen 2007). And carbon dioxide back into the atmosphere just propagates climate change.
We still need to know more about the amount of carbon they sequester. The top down approach starts in the atmosphere, and lets you better find sinks. The bottom up approach starts at the ground level, where there are both sinks and sources like soils and vegetation. It seems like both of these methods do not account for inland waters, and they can be lumped with terrestrial sinks or overlooked in considering the movement of carbon from land to sea.
I chose Feng’s article because she discusses different accounting methods. I thought I would find a better way of quantifying carbon transitions. Annual carbon, annualized carbon, and ton/year methods are all looked at. Feng states that if carbon transport is linear, that is if all carbon is moving at the same rate, then each of these methods used would produce the same answer for a system (Feng 2005). But, we know that carbon movement is non-linear. So, there are many factors that can affect results. But, as Battin et al describes, quantifying carbon is critical for predicting climate change. It seems like we need better ways to estimate carbon fluxes, and pay more attention to inland waters.
The USGS is doing a project called LandCarbon, the National Assessment of Ecosystem Carbon Sequestration and Greenhouse Gas Fluxes. The project includes aquatic ecosystems, so hopefully they will find out more about the processes. I included the image they used to show the carbon reservoirs they will look at. Here’s their site: http://www.usgs.gov/climate_landuse/land_carbon/default.asp
Battin, Tom J., Sebastian Luyssaert, Louis A. Kaplan, Anthony K. Aufdenkampe, Adreas Richter, Lars J. Tranvik. 2009. The Boundless Carbon Cycle. Nature Geoscience. Vol (2): 598-600.
Feng, Hongli. 2005. The Dynamics of Carbon Sequestration and Alternative Carbon Accounting, with an Application to the Upper Mississippi River Basin. Ecological Economics [Internet]. Vol. (54) 23-35.
Quillen, Lori. 2007. The Global Carbon Budget – Proper Accounting Means Paying Attention to Inland Waters. Available from: http://www.eurekalert.org/pub_releases/2007-04/ioes-tgc040307.php