Alf H. Hoel – författare

A Sea Change in a Changing Sea The oceans, seas and coastal areas encompass over 70% of the earth’s surface. They are a critical driver of the earth’s hydrologic cycle and climate system, important for c- merce, transport, and tourism, a source of economically important living marine resources, minerals such as hydrocarbons, as well as new pharmaceutical compounds. The marine environment provides essential habitats for thousands of marine living 1 2 resources, which in turn contribute significantly to global food security, employment, 3 and trade. Overall, the sea’s contribution to human welfare, in terms of market and non-market resources and environmental services, has been estimated at US$21 trillion/year (Costanza, 2000). However, despite the importance of the ocean realm to humans, there is a growing sense that human impacts are destabilizing this system. Some experts believe that current fishing levels are approaching or exceeding the total 4 productivity of the ocean ecosystem (National Research Council, 1999).

This book addresses the significant environmental changes experienced by high latitude and high altitude ecosystems at the beginning of the 21st c- tury. Increased temperatures and precipitation, reduction in sea ice and glacier ice, the increased levels of UV-radiation and the long-range tra- ported contaminants in arctic and alpine regions are stress factors that challenge terrestrial and aquatic ecosystems. The large natural variation in the physical parameters of these extreme environments is a key factor in structuring the biodiversity and biotic productivity, and the effect of the new stress factors can be critical for the population structures and the - teraction between species. These changes may also have socio-economic effects if the changes affect the bio-production, which form the basis for the marine and terrestrial food chains. The book is uniquely multidisciplinary and provides examples of va- ous aspects of contemporary environmental change in arctic and alpine - gions. The 21 chapters of the book are organised under the fields of •Climate change and ecosystem response, •Long range transport of poll- ants and ecological impacts, and •UV radiation and biological effects, each also including aspects of the •Socio-economic effects of environmental change. The introductory chapter presents and explains the internal c- nection and integration of all chapters. The added value of these reviews and review-like manuscripts from different disciplines hopefully yields new information about the integrated aspects of environmental change.

This book addresses the significant environmental changes experienced by high latitude and high altitude ecosystems at the beginning of the 21st c- tury. Increased temperatures and precipitation, reduction in sea ice and glacier ice, the increased levels of UV-radiation and the long-range tra- ported contaminants in arctic and alpine regions are stress factors that challenge terrestrial and aquatic ecosystems. The large natural variation in the physical parameters of these extreme environments is a key factor in structuring the biodiversity and biotic productivity, and the effect of the new stress factors can be critical for the population structures and the - teraction between species. These changes may also have socio-economic effects if the changes affect the bio-production, which form the basis for the marine and terrestrial food chains. The book is uniquely multidisciplinary and provides examples of va- ous aspects of contemporary environmental change in arctic and alpine - gions. The 21 chapters of the book are organised under the fields of •Climate change and ecosystem response, •Long range transport of poll- ants and ecological impacts, and •UV radiation and biological effects, each also including aspects of the •Socio-economic effects of environmental change. The introductory chapter presents and explains the internal c- nection and integration of all chapters. The added value of these reviews and review-like manuscripts from different disciplines hopefully yields new information about the integrated aspects of environmental change.