Reading the cited article in Nature, specifically re. methane, it states that "Arctic wetlands are effective methane emitters, yet dry and moist arctic tundra s

Reading the cited article in Nature, specifically re. methane, it states that "Arctic wetlands are effective methane emitters, yet dry and moist arctic tundra soils in north east Greenland have been measured to draw down methane", suggesting that the issue is the balance between the two.