The main focus of this book is the study of environmental dynamics in the Arctic, coupled with ecosystem dynamics. Particular emphasis is placed on problems of the composition of the Arctic atmosphere, including minor gases, aerosols and clouds, as well as changes in the composition due to impacts of human activity. Analysis of observational data and numerical modelling results, which characterize the Arctic basin pollution dynamics, and its impact on ecosystems is also provided. Other topics covered include problems of general circulation in the atmosphere and oceans - beginning with the 1930s when the Arctic was regarded as the kitchen of global weather and climate and concluding with the situation today when modern observational data and numerical modelling make for a more balanced view.