It turns out that land ecosystems like forests and grasslands store and cycle large quantities of greenhouse gases, including all three we’ve mentioned here: carbon dioxide, methane, and nitrous oxide. Human uses of natural ecosystems can change the land’s capacity to store and emit these gases. For example, deforestation releases carbon stored in trees and soils into the atmosphere as carbon dioxide, and adding nitrogen fertilizer to growing crops releases nitrous oxide: both processes contribute to the increasing concentrations of greenhouse gases in the atmosphere. Careful land management can reduce these emissions, even reverse them, by favoring natural processes that consume greenhouse gases. Because plants grow by taking carbon dioxide out of the atmosphere and turning it into leaves, roots, and wood, planting trees can help reduce carbon dioxide concentrations in the atmosphere, helping slow global warming. Our project is examining NAU’s land management around campus (tree planting, fertilizer use) as well as NAU’s Centennial Forest, which could serve as either a large source or a large sink for greenhouse gases. We’re also assessing how managing this land could influence NAU’s footprint. Of all the sectors in constructing greenhouse gas inventories, land management has the largest margin of error, so we’re still crunching the numbers to try to pin this down.