Environmental Impacts of Arctic Urbanization: The Anthropogenic Urban Heat Island Effect in Nuuk, Greenland
Using multiple weather observation stations, the magnitude of the urban heat island (UHI) effect in Greenland’s capital and largest city, Nuuk, was studied. The UHI effect describes the temperature difference between an urban area and its surrounding rural areas. Human activities in urban areas can increase local temperatures, developing an UHI. While most UHI studies focus on large, middle and lower latitude cities, high-latitude cities present a unique opportunity for studying local warming. UHIs in high-latitude cities have a strong seasonal component. Solar influences are practically negligible during the cold and dark winters, thereby, isolating anthropogenic contributions to the UHI. Winter energy demands are very high, and space heating is a major source of energy consumption. The energy used to heat buildings ultimately escapes into the atmosphere, contributing to localized warming. Since the 1970s, Nuuk has experienced significant growth and development becoming Greenland’s economic center. As the population doubled to over 16,000, mean annual temperatures also increased. This study demonstrates the existence an UHI with a strong positive relation to energy consumption for heating. In 2011, the urban area averaged 0.5°C warmer than surrounding areas. The UHI reached a maximum of 1.1°C in February. Since Greenland’s urbanization trend is projected to continue, identifying and understanding the environmental impacts is critical to pursuing more environmentally sustainable urban development.