Integrated Regional Changes in Arctic Climate Feedbacks: Implications for the Global Climate System

A. David McGuire, F.S. Chapin, John E. Walsh, Christian Wirth
2006 Annual Review Environment and Resources  
■ Abstract The Arctic is a key part of the global climate system because the net positive energy input to the tropics must ultimately be resolved through substantial energy losses in high-latitude regions. The Arctic influences the global climate system through both positive and negative feedbacks that involve physical, ecological, and human systems of the Arctic. The balance of evidence suggests that positive feedbacks to global warming will likely dominate in the Arctic during the next 50 to
more » ... ing the next 50 to 100 years. However, the negative feedbacks associated with changing the freshwater balance of the Arctic Ocean might abruptly launch the planet into another glacial period on longer timescales. In light of uncertainties and the vulnerabilities of the climate system to responses in the Arctic, it is important that we improve our understanding of how integrated regional changes in the Arctic will likely influence the evolution of the global climate system. The Arctic is a key part of the global climate system because the net positive energy input to the tropics must ultimately be resolved through substantial energy losses at high latitudes. There are several avenues through which the Arctic influences the energy balance of the global climate system. These avenues include the transfer of energy and moisture between the Arctic and the other parts of the global climate system as well as the effects of the Arctic on greenhouse gas concentrations in the atmosphere. In this review, we consider five Arctic components of the climate system that may influence these exchanges with other parts of the climate system: the atmosphere, the oceans, snow and glaciers, ecosystems, and people. We first discuss alternative defintions of the Arctic. We next focus our discussion on the atmosphere of the Arctic, which is central to the climate of the Arctic and of the globe, in the context of polar amplification and recent climate changes. In the remainder of the review, we turn our attention to the role of the oceans, snow and glaciers, ecosystems, and people of the Arctic in affecting the climate system. Annu. Rev. Environ. Resourc. 2006.31:61-91. Downloaded from arjournals.annualreviews.org by University of Alaska -Fairbanks on 10/14/06. For personal use only.
doi:10.1146/annurev.energy.31.020105.100253 fatcat:j4giswhphvh77gcvvv6gqbsphm