## 2 Literature Review
### Climate Change Structural Characteristics of Greek Agriculture  
Greek agriculture appears particularly vulnerable to climate change, which is reflected by its productivity, diversity, and resilience. Moreover, the agricultural sector is expected to be more affected than any other economic sectors in Greece. In detail, the effects of climate change on the most important high-productivity agricultural areas of the country, including Central and Eastern Macedonia, Thessaly, and Western Peloponnese, are reflected to the significant moisture deficit and the reduction of water reserves in the medium-to-long term, and are expected to affect both key crops (by varying their yield) as well as the nurturing zones, depending on the evolving climate conditions in the future [37]. Even though GHG emissions from agriculture have decreased by 24% in the period 1990-2019, the agricultural sector remains a significant source of emissions to date, being responsible for around 12% of total emissions in the EU, while in Greece the corresponding percentage amounts to 8.5% [38]. The GHG emissions directly related to Greek agriculture are mainly methane (CH4) and nitrogen oxide (N2O), both of which are showing a steadily decreasing trend over time. Agriculture and forest ecosystems can simultaneously contribute to GHGs' sequestration, considering that cultivated land and pastures act as important \"carbon sinks\". Greek agriculture exerts significant pressure on natural resources, with the greatest risks from climate change being observed in the quantity and the quality of irrigation water and soil erosion. The main air pollutant from agriculture is ammonia, with a share of total emissions in Greece up to 91.47% in 2018, but with a decreasing trend over the period of 1995-2018--in contrast to the average increasing trend observed in the EU since 2013 [39]. It should be also noted that until recently the utilization of renewable sources in Greek agriculture for energy production is at a low level, compared to that of the EU, with significant margins for increase considering the particularly high and dispersed energy potential of Greece in renewable energy sources (RES). In addition, Greece's agriculture and animal industries produce a significant amount of waste that is not currently being used for biomass-related power generation. According to estimates [40], Greece's agricultural and animal industries generate over 57,983,751 tn/y of waste each year, with 53% of them generated by the agricultural industry and 47% by the animal industry. From an economic perspective, agriculture in Greece is an important and dynamic sector of economic activity. Agricultural land in Greece covers 46% of its total area [41], employing 12% of the workforce and contributing 3.6% of GDP, higher than the EU average, where 4% is employed in agriculture and the sector's participation in EU GDP is 1.5%. Consequently, the primary sector offers income and employment to a significant part of the population of the Greek countryside, contributing substantially to the regional development and social cohesion of the country's rural areas, while at the same time showing strong sectoral linkages with other sectors of economic activity, such as arts and crafts, manufacturing, and of course accommodation and tourism. Regarding the structural characteristics of Greek agriculture, it is worth mentioning the large number of small farms with an average size about half that of the European market, with all the challenges this entails for their competitiveness and sustainability, also considering the small degree of organization of producers in collective schemes in relation to the EU. Cooperation could help improve their position in the agri-supply value chain and make them easier to adapt to new conditions and challenges, by increasing productivity and the added value of their production, by creating economies of scale and making appropriate investments, including those to address the effects of climate change.