The Earth's climate system has varied over geologic time. There have been continual fluctuations in the Earth's atmosphere and ocean currents, and most recently in the last 2-3 million years the Earth has cycled between glacial and interglacial periods. During the last glacial period, large land masses located at the mid and high latitudes were covered with ice; while the warmer climate during this current interglacial period is similar to past interglacial periods. On a large scale, climate change has affected the physical and the biological environment in a variety of ways that can have an impact on day-to-day life. Natural factors which have resulted in climate change have been shown to interact with human activity (anthropogenic causes).
The best archive of evidence for millions of years of climate change are deposited in the sediments on the ocean floor; however, ice cores from Greenland, and the sediments and rocks on land can also be studied. NGU continues to participate in several projects, both nationally and internationally, that aim to improve our understanding of the magnitude of the natural climate variations and how the climate system works. This will provide the knowledge base for understanding future changes in climate. Ongoing research activities at NGU focus on climate and environmental change in the Arctic and sub-Arctic areas in Norway, Russia, the Norwegian Sea and in the Barents Sea.