One of the biggest challenges confronting society is understanding and predicting natural and anthropogenic climate and environmental change on time scales from seasons to decades. Apart from computer- based forecast models, improved global observing systems are required to achieve these goals. Of particular importance for climate change are Earth’s oceans and polar regions, since they play a major role in medium and long-term climate variations.

• Sea ice and ice sheets
• Sea level changes
• Ocean dynamics and primary productivity
• Coastal zones
• Atmospheric variability in polar regions

Sea ice and ice sheets affect Earth’s surface energy balance. Changes in the volume of ice on the continents modify the sea level, with severe consequences for people living in coastal areas. The oceans represent the largest heat reservoir on Earth and they determine the climate of our planet by transporting heat from the equatorial regions to high latitudes by means of their vast current system. They are home to a rich diversity of life and are an important food source. They regulate the concentration of atmospheric carbon dioxide – and thus the greenhouse effect – through their physical and biological carbon pumps.

Coastal zones deserve special attention as the most densely populated areas on Earth, representing diverse and competing interests from settlements, port facilities, aquaculture, wind parks, tourism and nature reserves. Understanding all the processes involved and predicting their future development is one of the keys to a stable future for our society.