The Arctic Tundra - Earth's Life Support Systems

• The Arctic Tundra occupies some 8 million km2 in Northern Canada, Alaska and Siberia.
• In the Arctic Tundra, the ground is permanently frozen with only the top metre or so thawing during the Arctic Summer.
• Low annual precipitation of 50 - 350 mm a year, with most of it falling as snow.
• Limited transpiration because of the sparseness of the vegetation cover and the short growing season.
• Temperatures can plunge below -40 degrees in the winter when the sun remains below the horizon for several weeks.
• Permafrost is a barrier to infiltration and percolation.
• Globally the tundra is estimated to contain 1600 GT of Carbon.
• Plants grow rapidly in the short summer.
• Net Primary Productivity (NPP) is less than 200 grams/m2/year.
• Oil and gas were discovered at Prudhoe Bay in 1968.
• Oil and Gas companies have caused localised melting of the permafrost. Melting is associated with:

  • Construction and operation of oil and gas installations.
  • Dust deposition along roadsides creates darkened snow surfaces, thus increasing absorption of sunlight.
  • Removal of the vegetation which insulates the permafrost.
• On the North Slope, estimated CO2 losses from the permafrost vary from 7 to 40 million/tonnes/year. Gas flaring and oil spillages also input CO2 to the atmosphere.
• Strategies to reduce the impact of development on the water and carbon cycles:

  • Insulated ice and gravel pads.
  • Buildings and pipelines elevated on piles.
  • Drilling laterally beyond drilling platforms.
  • More powerful computers can detect oil and gas-bearing geological structures remotely.
  • Refrigerated supports.