According to a study led by NASA, using data from the Arctic Boreal Vulnerability Experiment shows that carbon in Alaska’s North Slope tundra ecosystems spends about 13 percent less in frozen soil compared to what it did 40 years ago. The carbon cycle is close to the levels of American boreal forest.
Studies using Landsat and MODIS satellite imagery with field measurements over the past decades have observed a northward migration of trees and shrubs.
However, more important is the fact that the Arctic carbon cycle is being disturbed. It is a delicate balance of carbon being released into the atmosphere and carbon being removed from the atmosphere. It will affect territories even far away from the Arctic.
More specifically, warmer temperatures will thaw the uppermost layers of permafrost and it will allow microbes to break down organic matter that was previously frozen. This releases additional carbon dioxide into the atmosphere. On the other hand, during the same period plant growth increases, and causes removing carbon dioxide from the atmosphere through photosynthesis. With the temperature’s increases, the amount of time left for storing the carbon in the Arctic soil decreases.
This disrupts the balance between these two dynamics and scientist are analyzing whether Arctic ecosystems will ultimately remove or add atmospheric carbon in the future climate. Current results show that the latter is more likely. Researchers believe that the residence time of Arctic carbon will lead to faster and pronounced seasonal and long-term changes in global atmospheric carbon dioxide.
First of all, they saw an increase in the speed of the carbon cycle, using combined data from more than 40 years of carbon dioxide surface measurements from NOAA’s Barrow, Alaska Observatory with a standard ecosystem carbon balance model. However, when they have added a long-term satellite, airborne and surface data to the equation, they saw that the increase was underestimated and significant.
The study, titled “Accelerating Rates of Arctic Carbon Cycling Revealed by Long-Term Atmospheric CO2 Measurements” was recently published in the journal Science Advances.