Climate warming is resulting from disruption of the global carbon (C) cycle. The Arctic is already warming significantly and the region governs some critical feedbacks in global change, including release of huge C stores from high-latitude soils, shift in albedo due to changes in vegetation and snow cover, and potential effects on the thermohaline circulation as a result of alterations in river discharge to the Arctic Ocean. However, the links between climate, the C cycle, energy balance, and hydrology are complex and our understanding of them – and their impact on Arctic ecosystems – is poor. ABACUS aims to provide answers to these critical questions.

The polar environments are rapidly changing and leaving a lasting impact on the freshwater and terrestrial ecosystems within them. However the region is so vast and diverse that the knowledge of what drives these changes is limited. This project will assess how terrestrial and freshwater ecosystems and environments have changed in the past and record their current status and biodiversity. IPY provides a timely opportunity for passing on knowledge to new generations of researchers and forming a new and authoritative baseline of environmental characteristics with which to examine future changes. Among the sites to be studied are some first examined during the ICSU-sponsored International Biological Programme, which will allow some assessment of changes over recent decades.

There is increasing recognition that multiple environmental changes are occurring in the northern regions of Europe. Some of these environmental changes, for example climate warming, levels of UV-B radiation, and habitat fragmentation, are projected to continue leading to impacts on the lands of the Nordic countries unprecedented since deglaciation some 10,000 year ago. Three ENVISNAR projects studying these processes are profiled below:

The International Tundra Experiment is a network of researchers examining the impacts of climate change on tundra vegetation throughout the Arctic, Antarctic and Alpine regions of the world. The goals of the networks are to document, understand and forecast changes in the tundra biome. Most members of the network do research at sites established in the early 1990s using standardized measurement protocols and a common warming experiment. The power of the network allows researchers to pool their data and make statements about the fate of the tundra biome as a whole. The four main areas of activity as part of the International Polar Year are: 1 vegetation change; 2 changes in the timing of key biological events (phenology); 3 changes in nutrient cycling; and 4 changes in carbon balance. Each of these areas is described below with a photograph and caption.

The goal of ELOKA is to facilitate the collection, preservation, exchange, and use of local observations and knowledge of the Arctic by providing data management and user support, and to foster collaboration between local and international researchers. Over the last decade, Arctic residents and indigenous peoples have been increasingly involved in, and taking control of, research. Through Local and Traditional Knowledge (LTK) research and community-based monitoring, Arctic communities have made, and continue to make, significant contributions to understanding recent environmental change.

POLENET will deploy an ambitious array of geophysical instruments across the polar regions in order to study the complex interplay between climate, ice sheets, geodynamics, and global sea level change. POLENET geodetic and seismic observations, paired with other types of geophysical measurements, will greatly improve our understanding of high latitude Earth systems. This international collaboration of 24 countries will involve scientists, students and educators at all levels, and will further advance our capability to deploy autonomous instruments in extreme environments

The proposed activity aims at establishing a bipolar network to obtain data needed to quantify properties of aerosols at high latitudes, including seasonal background concentrations by measurements of aerosol optical depth (AOD), spectral characterizations, and the evolutionary patterns of the natural and anthropogenic processes that perturb the aerosol cycles. An effort to quantify direct and indirect climate forcing by polar aerosols will be made through a set of closure experiments using observations in conjunction with model calculation and satellite data.