The climate of the Earth is changing. It gets warmer. Over the last 100 years, the temperature of the Earth has risen by an average of about 0.6 °C. It may not sound as much, but in many places you can already see the results of the warmer climate – trees bloom earlier than usual, winters are milder, glaciers retreat and species of animals and plants that usually live further south are pushed north.
Intensification of the greenhouse effect is the main reason for the temperature rise. This intensification happens as a result of the formation of so-called greenhouse gases (carbon dioxide, CO2, from energy production and methane and nitrous oxide from agricultural production) resulting from human activities. The greenhouse gases rise up into the atmosphere where they form a layer around the Earth.
Part of Earth's heat is lost to the atmosphere and further into space in the form of so-called heat rays. The greenhouse gases reflect the heat rays and direct them back to Earth. As the layer of greenhouse gases becomes denser, it reflects a larger part of the heat rays that previously passed through the atmosphere and into space. As a result, the Earth can no longer get rid of as much heat as before. That is why the Earth's temperature rises. Especially in the past 50 years, the formation of greenhouse gases due to human activities has increased strongly, augmenting the greenhouse effect.
Climate researchers use models to predict how the Earth's climate will develop. The climate models are based on information about factors that affect the climate, such as the atmosphere, the oceans, ocean currents, ice and snow as well as land surfaces. The models are constantly becoming more complex, and the analysis of the future climate requires large computer systems.
The researchers obtain realistic projections of the future climate by feeding the climate models with different predictions about how the Earth’s population, energy consumption, technology, production etc. develop. The most advanced climate models predict an average temperature increase between 1.4 and 5.8 °C over the next approx. 100 years depending on how society evolves. Some of the consequences are that the large ice masses of the Arctic and Antarctica will begin to melt, the air and ocean currents will change, the water levels in the oceans will rise, more precipitation will occur in some areas and draught in others, and the weather will be more extreme.
At Aarhus University we strive to constantly increase our knowledge about the impact of climate change on the Arctic ecosystem and the vegetation and wildlife in Greenland.
The Department is via the DCE – Danish Centre for Environment and Energy – the driving force behind the BioBasis biological monitoring programme at Zackenberg in high Arctic North-east Greenland. BioBasis is one of the most comprehensive terrestrial (on-land) studies of the biological effects of climate change in the Arctic.
We also participate in the GeoBasis programme, which monitors the physical environment of Zackenberg in high Arctic North-east Greenland and at Nuuk in low Arctic West Greenland. All information collected through BioBasis and GeoBasis at Zackenberg is publicly available and can be found on the website www.zackenberg.dk.
We study and monitor the structure and function of Arctic marine ecosystems, especially in order to assess the effects of climate change. The department participates, among others, in the marine monitoring programme, MarinBasis, at Zackenberg in North-east Greenland. The department also investigates the ecology of Arctic lakes, especially with the purpose to assess the effects of climate change.
The Department of Environmental Sciences conducts surveys and monitoring of transported air pollution to and deposition (precipitation) in the Arctic environment as well as investigates and monitors the levels of environmental pollutants in various Arctic media (soil, water, ice) and organisms.
The Department participates in the interdisciplinary nature conservation and research programme at Zackenberg in North-east Greenland and in the Nuuk/Kobbefjord area in South Greenland. The purpose of the research programme is to investigate and monitor the effects of climate change on high Arctic terrestrial and marine ecosystems.