Background Climate change mitigation is a crucial objective of the Kyoto Convention, and is oriented towards reducing GHG emissions. By 2013, the EU reduced its greenhouse gas (GHG) emissions by 11%, a progress achieved through multidisciplinary strategic planning and applying measures in numerous EU policies. However, only forests’ capacity as carbon sinks were taken into consideration in the calculations, while agricultural land and farming practices were not acknowledged in GHG accounting for storing carbon in soil. This may have possibly resulted in incorrect estimations of the carbon dioxide balance in the atmosphere. Accurate monitoring and accounting of carbon stocks and fluxes is a serious challenge, which will result in an improved assessment of climate change and its impacts. The main indicator for measuring agricultural land and farming practices with regard to securing carbon stored in soil is the carbon dioxide balance with respect to CO2 capture and storage capacity through the application of land use, land use change and forestry. In the EU, the agricultural sector has been embedded in a consistent strategic framework in the form of common agricultural policy (CAP) since 1954. In its latest reform (2013), the CAP acknowledged the significance of agriculture for climate change policy. GHG emissions from stock breeding have been found to contribute significantly on a global level. On the other hand, agriculture is also a significant factor for carbon capture. The assessment of this capture and consequent storage of carbon in the form of plant tissues relates to the production of GHG during cultivation and to the annual life cycle of most crops. Objectives The ClimaTree project aims to contribute to the development of a new methodology and provide policy-makers with an innovative tool for the quantification of carbon storage in permanent tree-crops. The primary objectives are to: Improve and update the estimated carbon sink accounting within the EU by including the calculated tree-crop capacity; Estimate the socioeconomic benefit of tree crops for carbon storage and evaluate the economic dimensions in different climatic and economic scenarios; Improve the design and efficacy of EU environmental and climate policy and legislation; Act as a catalyst for, and promote, the integration and mainstreaming of carbon sink objectives into the agricultural sector; Provide a more accurate and increased baseline for carbon sink capacity and improve the knowledge base for the monitoring and evaluation of effective climate change mitigation actions and measures; and Improve agricultural and environmental policies at the micro-level and provide a tool for supporting the evaluation of investments related to tree crops. Expected results: The main expected results of ClimaTree are: Development of a new methodology for the accounting of carbon storage from permanent tree crops, contributing to a more accurate estimation of carbon sinks in EU; Demonstration of best tree-crop practices regarding the increase of carbon sink capacity and their related socioeconomic benefits; Development of a guide for the suggestion of climate change mitigation policies and their incorporation into the CAP; Estimation of carbon balance of tree-ecosystems for the following years; Development of a software application for the accounting of carbon sequestration by tree crops; and Evaluation of the economic benefits arising from tree crop sequestration.