How oceans are changing

INTRODUCTION

The ocean plays a crucial role in sustaining life on Earth and is a key element in climate change. But, says Dr Gunnar Kullenberg, Executive Secretary of UNESCO's Intergovernmental Oceanographic Commission (IOC), "Ocean issues are not receiving the attention they ought to be given." The ocean is a resource that is less well known than some distant planets and undoubtedly contains a resource potential that remains partly untapped. But this resource is limited, both in capacity and in its ability to absorb effects of reckless development and pollution. Signs of stress are already visible, especially in low-lying coastal areas and small islands. The picture of the ocean that is emerging from shared observations all over the world is not very comforting. The catalogue of symptoms of disease include: pollution, exhausted fishing stocks, disappearing coastlines, rising sea level, increasing surface temperatures that threaten the deep ocean currents, more frequent storms, melting ice caps... When we understand the ocean system better, we will be able to predict some of the changes expected in the next century and, hopefully, offset them through intelligent, co-operative action. In the shorter term, better and more systematic observations of the ocean will enable us to forecast imminent disasters from storms, floods and drought and mitigate their effects, by warning the populations at risk.
Text courtesy of UNESCO

Flooding of the Bering Land Bridge, A Geospatial Animation

During the Last Glacial Maximum, about 21,000 years ago, global sea level was approximately 120 m (400 ft) lower than today. The Bering Land Bridge existed as a vast tundra plain connecting Asia and North America. As the world's glaciers and ice sheets melted over the following millenia, rising sea level flooded the land bridge - blocking migration routes for animals and humans.

Full-resolution QuickTime movies are available for analysis, education, and outreach at The Institute of Arctic and Alpine Research (INSTAAR).
Text provided courtesy of INSTAAR.

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