The tundra - a dark horse in planet Earth's greenhouse gas budget

Vast areas on the Northern Hemisphere are covered by tundra. Here, dwarf shrubs, sedges, mosses etc. thrive on top of permafrost in areas where only the uppermost soil layer thaws during the short Arctic summer.

Arctic wildfires threaten global climate

After 10,000 fire-free years, the Arctic tundra is again experiencing wildfires, and they're contributing significantly to the world's carbon dioxide levels.