The study looked at CO2 emissions from tundra over 6 years using different methods. They found that the tundra released more CO2 than it absorbed each year. The difference between the methods decreased over time, with the tundra being a stronger source of CO2 initially. The thickness of the active layer in the soil affected how much carbon the tundra exchanged with the atmosphere. The tundra was a consistent source of CO2 in the summer, but emitted CO2 in the non-summer months, balancing out the uptake. Root damage from the measurement setup may have initially reduced the tundra's ability to absorb carbon, but it recovered over time.