The past, present and future of the sea level in the Basque Country

4 p.The sea level has significantly changed throughout the Earth's history. -120,000 years ago, during the earlier interglacial period, the sea level was 4.5 m higher than the current mean level in Bilbao. -The sea level rose by 2mm per year in the Basque coast during the twentieth century, 4 times faster than over the previous 7,000 years. -The mean global sea level could reach 53-98 cm by the end of the century in the worst case scenario (RCP8.5). -In the Basque coast, the latest regionalised forecasts show values of 41-57 cm (for RCP4.5 and 8.5 forecasts, respectively)

Environmental and economic impacts of sea-level rise on the Basque Coast

257 p

Bridging Science and Policy to Mitigate and Adapt Cities to Climate Change: Challenges and Opportunities in the Context of the Basque Declaration

4 p.A reduction in emissions and the adaptation of cities to climate change is a key point in the Basque Declaration-The potential of science making a valuable contribution to urban climate objectives-Possible divergence of interests in terms of science and urban policy-The occasional difficulty in attaining applicability and scientific soundness-The challenge and opportunity of reaching understandable and applicable scientific results

Climate change impacts on the water services in Costa Rica: a production function for the hydroenergy sector

23 p.The case study presented in this section aims to estimate the economic value of the water services used for hydropower in tropical forests in Costa Rica, and to assess the expected economic impact due to climate change. The model developed allows estimating the economic impacts of climate change on the hydroelectric sector, using the association between bio-physical data, technical data related to the plants and economic inputs. A production function is used for this purpose which relates the quantity of water available (runoff) with the energy generated by the selected plants, based on a sample of 40 plants. Results show a significant reduction in the hydropower production in all future scenarios, estimated between 41 and 43% for Costa Rica. This translates in a considerable reduction in the expected revenues of the hydroelectric sector in Costa Rica under all climate change scenarios considered, but with lower reductions in the B1 scenario, which incorporates sustainability criteria. Taking into account future technological changes, the model shows that it would be necessary to double the installed capacity of all plants to get an increase in annual revenue that ranges from 3-18%. With an increase in the installed capacity of about 50%, economic losses would be reduced by 12% in all the scenarios

The costs of sea-level rise: coastal adaptation investments vs. inaction in Iberian coastal cities

Iberian coastal cities are subject to significant risks in the next decades due to climate change-induced sea-level rise. These risks are quite uncertain depending on several factors. In this article, we estimate potential economic damage in 62 Iberian coastal cities from 2020 to 2100 using regional relative sea-level rise data under three representative concentration pathways (RCP 8.5, RCP 4.5 and RCP 2.6). We analyze the expected accumulated damage costs if no adaptation actions take place and compare this scenario to the investment cost of some adaptation strategies being implemented. The results show that some adaptation strategies are less costly than the potential damage under inaction. In other words, it is economically rational to invest in adaptation even in a context of high uncertainty. These calculations are very relevant to inform climate change adaptation decisions and to better manage the risk posed by sea-level rise. Moreover, our findings show the importance of a good understanding of the shape of the sea-level rise and damage cost distributions to calculate the expected damage. We show that using the 50th percentile for these calculations is not adequate as it leads to a serious underestimation of expected damage and coastal risk

Climate Risk Assessment under Uncertainty: An Application to Main European Coastal Cities

This paper analyses the risk of extreme coastal events in major European coastal cities using a stochastic diffusion model that is calibrated with the worst case emission scenario from the Intergovernmental Panel for Climate Change (IPCC), i.e., the representative concentration pathway (RCP) 8.5. The model incorporates uncertainty in the sea-level rise (SLR) distribution. Expected mean annual losses are calculated for 19 European coastal cities, together with two risk measures: the Value at Risk (VaR) and the Expected Shortfall (ES). Both measures are well-known in financial economics and enable us to calculate the impact of the worst SLR paths under uncertainty. The results presented here can serve as valuable inputs for cities in deciding how much risk they are willing to accept, and consequently how much adaptation they need depending on the risk aversion of their decision-makers.The authors gratefully acknowledge funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement No. 603906 (Project: ECONADAPT). LMA and IG are grateful for financial support received from the Basque Government via project GIC12/177-IT-399-13. This work has also received funding from the European Union's Horizon 2020 Research and Innovation Programme under grant agreement No. H2020-DRS-9-2014 (Project: RESIN). LMA thanks the financial support from the Spanish Ministry of Science and Innovation (ECO2015-68023)

IPCC WGII Fifth Assessment Report (AR5): Expanding the solution space for adaptation

6 p.The IPCC Report shows increasing confidence of current impacts of anthropogenic climate change, including migration of species in oceans and diminishing crop yields. *Adaptation is widely occurring and has become the central focus for dealing with climate change. If done in an effective way, taking account of the wide range of options and opportunities it offers a positive prospect to addressing the climate challenge. *The scope for adaptation can be significantly widened by emphasising the important contributions of exposure and vulnerability as opposed to focusing on hazards when facing climate risks. *Mainstreaming adaptation into other domains of public action such as sustainable development or poverty alleviation while identifying synergistic low-regret options leads to an even larger solution space. *As there are limits to adaptation stronger mitigation efforts are required to prevent the occurrence of irreversible impacts and the crossing of tipping points

Understanding risks in the light of uncertainty: low-probability, high-impact coastal events in cities

A quantification of present and future mean annual losses due to extreme coastal events can be crucial for adequate decision making on adaptation to climate change in coastal areas around the globe. However, this approach is limited when uncertainty needs to be accounted for. In this paper, we assess coastal flood risk from sea-level rise and extreme events in 120 major cities around the world using an alternative stochastic approach that accounts for uncertainty. Probability distributions of future relative (local) sea-level rise have been used for each city, under three IPPC emission scenarios, RCP 2.6, 4.5 and 8.5. The approach allows a continuous stochastic function to be built to assess yearly evolution of damages from 2030 to 2100. Additionally, we present two risk measures that put low-probability, high-damage events in the spotlight: the Value at Risk (VaR) and the Expected Shortfall (ES), which enable the damages to be estimated when a certain risk level is exceeded. This level of acceptable risk can be defined involving different stakeholders to guide progressive adaptation strategies. The method presented here is new in the field of economics of adaptation and offers a much broader picture of the challenges related to dealing with climate impacts. Furthermore, it can be applied to assess not only adaptation needs but also to put adaptation into a timeframe in each city.The authors acknowledge funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 603906, Project: ECONADAPT and Horizon 2020 Project RESIN (grant agreement no. H2020-DRS-9-2014). LMA and IG are grateful for the financial support received from the Basque Government for support via project GIC12/177-IT-399-13. LMA also thanks financial support from the Spanish Ministry of Science and Innovation (ECO2015-68023)

Addendum to Understanding risks in the light of uncertainty: low-probability, high-impact coastal events in cities

This addendum adds to the analysis presented in Understanding risks in the light of uncertainty: low-probability, high-impact coastal events in cities Abadie et al (2017 Environ. Res. Lett . 12 [https://doi.org/10.1088/1748-9326/aa5254] 014017 ). We propose to use the framework developed earlier to enhance communication and understanding of risks, with the aim of bridging the gap between highly technical risk management discussion to the public risk aversion debate. We also propose that the framework could be used for stress-testing resilience.European Union’s Horizon 2020 research and innovation programme under grant agreement no. 653522 (RESIN−Climate Resilient Cities and Infrastructures project). E Sainz de Murieta acknowledges funding from the Basque Government (grant no. POS_2016_1_0089)

klima aldaketa sozioekonomiaren ikuspegitik

Ekarpen honek, azken urteotan hainbesteko garrantzia bereganatu duen klima-aldaketaren arazoa ikuspegi sozioekonomikotik aztertzea du helburu. Artikuluan, klima-aldaketaren eragin fisiko eta ekonomikoei aurre egiteko beharrezkoak izango diren ekidite eta egokitze politikak aztertuko dira, bai ikuspegi orokorretik bai eskualdeen ikuspegitik ere. Horren harira, kontuan hartuko dugu Euskal Herria bezalako lurraldeek bere gain har dezaketen zeregina. Horretarako, norabide horretan egon litezkeen zailtasun eta kostuak laburbilduko dira, ekonomiaren ikuspegitik klima-aldaketaren arazoa merkatuaren akats bat bezala uler daitekeela kontuan hartuz eta ekimen publikoak konponbidean duen garrantzia azpimarratuz. Azkenik, nazioarteko elkarrizketei gainbegirada bat emango zaie, Kioto osteko prozesuak etorkizunean jasan dezakeen bilakaera aztertuz