Siberia has experienced a steady temperature rise during the last half century (Frey and Smith, 2003) and as a consequence the Arctic lakes are facing widespread decline in areal extent. During the last three decades, 11% of the lakes have disappeared or shrunk in size. Thawing and breaching of permafrost due to climate warming is causing lake water to be drained into the subsurface (Smith et al. 2005). If climate warming continues, the Arctic region will face dramatic changes in regional hydrology and ecosystem processes in the near future.
Arctic Lakes of Siberia
A study by Smith et al. (2005) using satellite imagery across 515,000 km2 of Siberia for the early 1970s and 1997 - 2004 over 10,000 large lakes showed a decline in lake abundance and area is going on at alarming rate, despite notable precipitation increase (Frey and Smith, 2003).
The study also found that between 1973 and 1997-98, the total number of large lakes (those which are greater than 40 ha) had decreased from 10,882 to 9,712, representing a decline of 1,170 ha or around 11%.
Regional lake surface area declined by 93,000 ha (6%) between 1973 and 1998. Most of the large lakes did not disappear completely, but their size had shrunk to below 40 ha (Smith et al. 2005).
A total of 125 lakes vanished completely by 1973-1998 period, and now vegetation is taking over the lakes.The yearly observations for 2000-2004 confirm that none of these 125 lakes have refilled since 1997, which indicates permanent water loss (Smith et al. 2005).
Most of the lakes are lying on top of permanently frozen ground, a surface that prevents lake water from draining into the ground.The temperature of soil and air has risen by three decades due to climate change, which is responsible for thawing of frozen permafrost, draining water under the ground and causing the lakes to disappear (Smith et al. 2005).
Many lakes have already disappeared and many have shrunk in area.A six percent decrease in regional lake surface area between 1973 and 1998 indicates a rapid change in Arctic wetlands, which will continue as long as climate warms further (Smith et al. 2005). The lake shrinkage and disappearance is a clear measurable indication of the overall changes to hydrology in the Arctic.
This sudden draining of lakes can alter entire ecosystems, including the trees, birds and wildlife that depend on this unique environment (Live Science).
The region would potentially have less precipitation if lakes continue to decline because they are a source of evaporation (Smith et al. 2005).
The arctic lakes are expected to disappear further north of the current areas of lake loss due to temperature change (Live Science).
Climate models suggest that temperatures will continue to climb in the Arctic.Continued climate warming will cause high-latitude, permafrost-controlled lakes and wetlands to continue to disappear, which may impact the regional biodiversity and water availability.
Smith, L. C., Y. Sheng, G. M. MacDonald and L. D. Hinzman. 2005. Disappearing Arctic Lakes, Science, Vol. 308. no. 5727, p. 1429.
Frey, K. E. and Smith, L. C. 2003. Recent temperature and precipitation increases in West Siberia and their association with the Arctic Oscillation, Norwegian Polar Intitute, polar Environmental Center, N-9296, Tromso, Norway.
Live Science, http://www.livescience.com/environment/050603_lakes_gone.html (Last accessed 23 November 2009).