Biodiversity in numbers

Greece has a total area of 131.957 km2 and occupies the southernmost extension of the Balkan Peninsula. The mainland accounts for 80% of the land area, with the remaining 20% divided among nearly 3000 islands. The Greek landscape, with its extensive coastline, exceeding 15,000 km in length, is closely linked with the sea, since only a small region in the northwest is further than 80 km from the sea. Approximately 25% of it is lowland, particularly the coastal plains along the seashore of the country (1).

The protected areas enacted through national law (National Forests, National Parks, Wild Life Refuges and Landscapes of Particular Aesthetic Value) cover only 2.5% of the Greek territory (1).

Vulnerabilities - Terrestrial biodiversity

The Paris Agreement of December 2015 aims to maintain the global average warming well below 2°C above the preindustrial level. Ecosystem variability during the past 10,000 years was reconstructed from pollen analysis. Only a 1.5°C warming scenario permits Mediterranean land ecosystems to remain within this Holocene variability. At or above 2°C of warming, climatic change will generate land ecosystem changes that are unmatched in the Holocene (12).

In fact, regional temperatures in the Mediterranean basin are now ~1.3°C higher than during 1880-1920, compared with an increase of ~0.85°C worldwide. Climate model projections indicate that the projected warming in the Mediterranean basin this century continues to exceed the global trend. Without ambitious mitigation policies anthropogenic climate change will likely alter ecosystems in the Mediterranean this century in a way that is without precedent during the past 10,000 years. The highly ambitious low-end scenario of climate change (the so-called RCP2.6 scenario) seems to be the only possible pathway toward more limited impacts. Under a high-end scenario of climate change (the RCP8.5 scenario), all of southern Spain turns into desert, deciduous forests invade most of the mountains, and Mediterranean vegetation replaces most of the deciduous forests in a large part of the Mediterranean basin (12).

In addition to climate change, other human impacts affect ecosystems, such as land-use change, urbanization, and soil degradation. Many of these effects are likely to become even stronger in the future because of the expanding human population and economic activity. Without ambitious climate targets, the potential for future managed or unmanaged ecosystems to host biodiversity or deliver services to society is likely to be greatly reduced by climate change and direct local effects (12). 

Various ecosystems in the Mediterranean are close to the environmental limits, for example with respect to their ability to cope with drought stress (2).

A 3.6°C global warming could lead to a loss of over 50% of plant species in the northern Mediterranean and the Mediterranean mountain region, while species loss is likely to exceed 80% in north central Spain and the Cevennes and Massif Central in France (3).

Vulnerabilities - Fresh water biodiversity

The Mediterranean ecohydrology is vulnerable to climate change, and can affect flora and fauna of the region. In arid and semi-arid parts of the region, the biggest danger facing the lakes is the expected decrease in water input resulting from increasing evapotranspiration with increasing temperature and decreasing precipitation. This process can lead to conversion of existing freshwater to saltwater (6).

Wetlands

Wetland systems are vulnerable to changes in the quantity and quality of water supply. Even small changes in fresh water input or output can affect the water balance of wetlands such that plant communities and habitat for animals are strongly affected (9). Wetlands in Greece, and the Mediterranean in general, face on-going climate impacts including 20% less rainfall in the course of the previous century (10). Further deteriorating of these wetlands due to climate change is expected. Projections were made for two Greek wetlands (11): Lake Cheimaditida and Lake Kerkini. Lake Cheimaditida is a natural lake that covers an area of 10 km2 at its maximum water level. Lake Kerkini is an artificial lake fed by a river that has developed into a unique wetland ecosystem covering an area of 73.2 km2. These projections are based on two scenarios of climate change (A1B for the period 2020 - 2050 and A1B and A2 for the period 2070 – 2100) that have been fed into a large number of European regional climate models. The influence of groundwater inflow and outflow on the lake’s water balance was not taken into account (11).

According to these projections, climate change will further disturb the water balance in both lakes by increasing evaporation, and by decreasing water input from precipitation and lake’s catchment run-off. Catchment run-off represents a considerable amount of the water inflow into the lakes. Projections indicate this run-off will reduce by one-fourth during the period 2020 - 2050 and by half during the period 2070 - 2100, compared with the reference period 1961 – 1990. In addition, lake water will be used for irrigation. Consequently, the surface area of Lake Cheimaditida may shrink by 20% during the period 2020 - 2050 and by 37% during the period 2070 - 2100; the water volume of the lake may decrease by 39 and 61%, respectively. Lake Kerkini’s surface area may shrink by 5% during the period 2020 - 2050 and by 14% during the period 2070 - 2100; the water volume of the lake may decrease by 18 and 38%, respectively. In fact, these percentages may be even higher due to a possible increase in irrigation demand in the future, in a warmer and drier climate (11). 

Vulnerabilities - Marine, estuarine and intertidal biodiversity

A key factor is the tidal range. In general, the smaller the tidal range, the greater the susceptibility to increasing sea level (4). The Mediterranean and Baltic coastal wetlands, which have low tidal ranges, are therefore considered to be more vulnerable than wetlands in the Atlantic and North Sea. … The largest losses in Europe have been projected for the wetlands along the Baltic and Mediterranean coasts. Estimates vary between 84–98% and 31–100%, respectively (5).

The eastern Mediterranean is an essentially land-locked basin with nutrient-poor surface waters (“marine desert”). In the past two decades rapid increases of the sea surface temperature have been observed, dominated by changes in summer. Modeling studies suggest that this tendency will continue in future, and the warming of surface and deep waters will result in salinization and water mass stabilization. The marine biodiversity can be affected, e.g. through reduced nutrient delivery to surface waters, “tropicalization” and the invasion of alien species through the Suez Canal (7).

From a number of model experiments and three climate change scenarios (B1, A2 and A1B, respectively optimistic, pessimistic and intermediate scenarios in terms of gases emissions) it was concluded that the mean Mediterranean sea surface temperature will increase with a range between +1.73 and +2.97 °C in 2070–2099 compared to 1961–1990. These experiments project mean Mediterranean sea surface salinity increase with a range between +0.48 and +0.89 for the period 2070–2099 compared to 1961–1990 (8). 

Adaptation strategies Greece

Adaptation strategies should focus on increasing the resilience of watershed systems to climatic change. Given the heterogeniety in watershed types, strategies need to incorporate local needs and issues with active participation of all stakeholders. The conservation and sustainability of watersheds in the Mediterranean region is an important issue to sustain local and regional economies and ecosystems. A localized strategy that incorporates watershed characteristics and information is vital to sustain the region. A long-term strategy is needed to involve resilience enhancing measures that will enable watersheds to withstand and transform to climatic change (6).

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Greece.

1. Hellenic Republic, Ministry for the Environment, Physical Planning and Public Works of Greece (2006)
2. European Environment Agency (EEA) (2005)
3. Thuiller et al. (2005), in: Giannakopoulos et al. (2005)
4. Kundzewicz et al.(2001), in: European Environment Agency (EEA) (2005)
5. Gitay et al.(2002); Kundzewicz et al.(2001), both in: European Environment Agency (EEA) (2005)
6. Erol and Randhir (2012)
7. Lelieveld et al. (2012)
8. Adloff et al. (2015)
9. Acreman et al. (2007), in: Doulgeris et al. (2016)
10. Climate Change Impacts Study Committee (2011), in: Doulgeris et al. (2016)
11. Doulgeris et al. (2016)
12. Guiot and Cramer (2016)