Vulnerabilities

Roads and railways

Higher groundwater levels associated with extreme precipitation will mean an increased risk of landslides on excavation slopes. There is a risk that the bearing capacity of bridge and tunnel foundations, supporting walls and sheet pilings will be reduced by increased groundwater levels. This can be a great problem, especially for foundations on sand. For railways, higher groundwater levels mean an increased risk of erosion of track cuttings and embankments (1).

Buildings

The changing climate has the potential regionally to increase premature deterioration and weathering impacts on the built environment, exacerbating vulnerabilities to climate extremes and disasters and negatively impacting the expected and useful life spans of structures (6).  

There is a lack of knowledge of how many existing buildings would be damaged as a result of increased storm activity, the types of damage and the cost of prevention (1).

Infrastructure

Small increases in climate extremes above thresholds or regional infrastructure ‘tipping points’ have the potential to result in large increases in damages to all forms of existing infrastructure nationally and to increase disaster risks (7). Since infrastructure systems, such as buildings, water supply, flood control, and transportation networks often function as a whole or not at all, an extreme event that exceeds an infrastructure design or ‘tipping point’ can sometimes result in widespread failure and a potential disaster (8).

Sewerage systems

Sewers have a lifetime of 50–100 years. More and heavier extreme rainstorms will cause increasing flooding of land and cellars. In addition, more and heavier precipitation means a lowering of water quality in waterways and lakes and a lowering of bathing water quality from rain-provoked discharges from treatment plants and sewer system overflows.

This may also mean a risk that the objectives of the EU Water Framework Directive and the Bathing Water Directive will not be met. Recommendations in the Waste Water Committee's Report no. 27: "In common sewerage areas surface flooding may occur no more often than every ten years. In areas with separate sewerage, flooding may occur no more often than every five years."  During heavy precipitation events municipalities must issue warnings and information concerning deterioration of bathing water quality.

Benefits of climate change

Greenland: Projections of Arctic marine access

Since the 1980s, the extent of older, thicker multiyear ice has decreased by ca 15% per decade, driven especially by reductions in March (declining from ca 75% to 45 %) and September (ca 60 % to ca 15 %) (10). A short period of ice-free conditions in summer has been projected as early as 2030 (14) and as late as 2100 (11).

Projections have been made of 21st-century Arctic marine access for the early (2011–2030), mid-(2046–2065), and late-21st century (2080–2099); assuming Polar Class 3 (PC3), Polar Class 6 (PC6), and open-water vessels (OW) with high, medium, and no ice-breaking capability, respectively (12). These projections are based on sea ice simulations for three climatic forcing scenarios (4.5, 6.0, and 8.5 W/m2; defined in IPCC Fifth Assessment Report); these scenarios are roughly correlative to the IPCC SRES scenarios B1, A1B, and A2, respectively (13). The projections are compared with the baseline period 1980–1999. Results suggest substantial areas of the Arctic will become newly accessible to Polar Class 3, Polar Class 6, and open-water vessels, rising from ca 54%, 36%, and 23%, respectively of the circumpolar International Maritime Organization Guidelines Boundary area in the late 20th century to ca 95%, 78%, and 49%, respectively by the late 21st century. Of the five Arctic Ocean coastal states, Russia experiences the greatest percentage access increases to its exclusive economic zone, followed by Greenland/Denmark, Norway, Canada and the U.S (12).

The impact on three potential shipping routes was assessed: Northwest Passage, Northern Sea Route, and Trans-Polar Route. Along the Northern Sea Route, July-October navigation season length averages ca 120, 113, and 103 days for PC3, PC6, and OW vessels, respectively by late-century, with shorter seasons but substantial increases along the Northwest Passage and Trans-Polar Route (12).

Trans-Arctic navigation is likely to remain a summertime phenomenon. The Arctic marine environment is likely to be fully or partially ice-covered 6–8 months each year for the first half of the century, and no climate model projects an ice-free Arctic in winter by 2100 (9).

Adaptation strategies

Roads and railways

Road regulations and rail standards must be harmonised with the expected climate changes, just as extension and renovation of roads and railways must be adapted to expected climate changes (1).

During the 1970s, a possible sea-level rise of about 30 cm within the next 200 years (corresponding to the projected value without climate changes) was taken into account in the planning of the dike system of southern Jutland. In future planning of flood risks, a expected 50 cm sea level rise is now included (4). In the planning of the Copenhagen Metro and the new town district “Ørestad” on Amager, a most likely total sea level rise of 52 cm in 2100 is assumed (5).

Buildings

It is estimated that there is no need, in the short term, to change the laws pertaining to building safety under extreme weather conditions. The risk of collapsed roofs from snow calls for reconsideration of snow-load standards (1).

Sewerage systems

Danish sewerage systems and waste water treatment plants have so far generally been planned without taking a climate induced sea-level rise into account. Now the possibility is recognised, but it is assumed that potential problems can be solved with pumping systems (3).

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 Denmark.

1. Danish Government (2008)
2. Fenger et al. (2008)
3. Andersen (2000), in: Fenger et al. (2008)
4. Møller (2000), in: Fenger et al. (2008)
5. Frisk (2000), in: Fenger et al. (2008)
6. Auld (2008b); Larsen et al. (2008); Stewart et al. (2011), all in: IPCC (2012)
7. Coleman (2002); Munich Re (2005); Auld (2008b); Larsen et al. (2008); Kwadijk et al. (2010); Mastrandrea et al. (2010), all in: IPCC (2012)
8. Ruth and Coelho (2007); Haasnoot et al. (2009), both in: IPCC (2012)
9. ACIA (2004a); Stroeve et al. (2012a), both in: Stephenson et al. (2013)
10. Maslanik et al. (2011); Comiso (2012); Polyakov et al. (2012), all in: Stephenson et al. (2013)
11. Boe et al. (2009), in: Stephenson et al. (2013)
12. Stephenson et al. (2013)
13. Van Vuuren et al. (2011); Vavrus et al. (2012), both in: Stephenson et al. (2013)
14. Wang and Overland (2009), in: Stephenson et al. (2013)