Background Climate Change

Global climate change is one of the greatest ecological challenges facing humanity in this century. A solid scientific understanding of the reasons behind and the shifts and feedbacks caused by climate change is essential to manage it within acceptable limits.

The increase of atmospheric greenhouse gas (GHG) concentrations is considered to be the primary reason for climate change. It is caused by direct anthropogenic emissions from the combustion of fossil fuels and land use changes. In addition, there may be potentially strong feedback mechanisms between the climate and natural greenhouse gas sources and sinks; however, understanding of these mechanisms is limited, and their representation within global climate models may not be adequate. 

Get more information on GHG and climate change at the Climate Navigator

 ICOS is a research infrastructure for the oberservation of greenhouse gases

Long-term, precise and internationally comparable measurements are a essential tools for improving the knowledge of complex interactions between the climate on the one hand and biosphere, hydrosphere and atmosphere on the other hand. They are the best investment to avoid surprises and to reduce uncertainty about the future.

The „Integrated Carbon Observation System“ (ICOS) is a European research infrastructure which provides long-term continuous and high-quality standardized observations within an adequate observation network which allows


  • to identify systematic GHG emission changes despite a high internal variability
  • to reduce uncertainties in corresponding model predictions
  • to warn against adverse impacts at an early stage and
  • to initiate early adaptation measures and to evaluate the success of climate protection measures

The main objective of ICOS-D, the German contribution to this European infrastructure, is the long-term consolidation of the world’s leading observation networks of atmospheric GHG concentrations and their exchange with terrestrial and marine ecosystems. Europe plays a leading role in the combination of atmospheric, marine and terrestrial observations, which allows for the evaluation of the influence of land-use changes, climatic variabilities, and changes within the marine system on the GHG balance. ICOS was thus recognized as an important research infrastructure and added to the roadmap of the European Strategy Forum on Research Infrastructures (ESFRI) in the year 2006. In 2015, ICOS achieved the official status of a “European Research Infrastructure Consortium” (ERIC). From 2016 ICOS is registered on the list of the ESFRI Landmarks, which includes projects defined as “pillars of scientific excellence and competitiveness within the European research area.”

ICOS is of great importance for basic research in Earth Sciences, as only research projects planned on a long-term basis enable us to analyse and break down slow processes and trends in the earth system, and to differentiate them from the background natural variability. The infrastructure is designed in such a way that it allows for additional or specialized temporary studies and thereby guarantees that in-depth questions can be taken up at any time.

ICOS consists of three observation networks (atmosphere, ecosystem, and ocean) and a number of different central institutions, which receive basic funding by their host countries and may be co-financed by partner countries. Due to special expertise, Germany is considered to be the ideal location for central laboratories for high-precise analysis of trace gases, for providing calibration standards for monitoring networks, and for the analysis of the radioactive carbon isotope 14C in air samples. Further central European institutions are the so-called thematic centres for the three monitoring networks, one central data portal in Lund, as well as a European office in Helsinki. Throughout the long-term operation of ICOS, the Thünen Institute of Climate-Smart Agriculture is appointed for managing the coordination of the national network in Germany. Its tasks include the integration of data as well as reports and knowledge transfer to research, politics and public.

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