![The NASA CARVE and DOE NGEE-Arctic projects are combining airborne and ground-based campaigns to understand the importance of natural emissions from the Alaskan tundra. (Source: J. B. Curtis, LBNL [main photo and left inset]; S. Wullschleger, ORNL [right](https://www.globalchange.gov/sites/globalchange/files/styles/landing_feature_image/public/HL33_Arctic-quantifying-emissions-NASA-CARVE-DOE-NGEE.png?itok=vTJGy7to)
In addition to emissions from human activities, natural emissions of greenhouse gases such as carbon dioxide and methane can affect the climate system, and vice versa. Quantifying these natural fluxes, especially in Arctic ecosystems, is critical to understanding how they may interact with human-driven changes to affect future climate. Some research has shown increased emissions of greenhouse gases from tundra and boreal forests during warming in the spring, but little is known about what causes this or whether its occurrence is widespread enough to influence