Climate adaptation risks, vulnerabilities and main targets were identified in 2018. Adaptation work is part of the Covenant of Mayors 2030 Energy and Climate Action Plan (SECAP) that will be ready in 2019. SECAP is a continuation of SEAP2020, in which Lahti has 44 actions to mitigate climate change. Now, adaptation is also a part of the strategical action plan. Assessment of vulnerability indicators, and prioritizing the most important coping capasities will be done in autumn 2018.
These are the key areas for the success of the adaptation work. Lahti's values are Openly, Responsibly, Together. These values have been concretely embedded in all actions. Vulnerabilities have been discussed with the citizens at five ‘My Lahti’ participation events 2018. As part of the Resin (EU Horizon2020) project Resilient Cities and Infrastructures, a cross-sectoral adaptation working group has had so far six meetings in 2018. The working group coordinates the Climate Change Risks and Vulnerabilities Assessment. A stakeholders’ workshop was held in summer 2018. Fifty people, presenting different stakeholders and departments, gathered together for a Lahti Adapts workshop, where the main impacts, risks and vulnerabilities as well as coping capacities were identified and listed in IVAVIA tables (Fig.A1). After the workshop, the results were published on Lahti website and also sent to an iteration round for a wide range of stakeholders. Further on it will go to the Lahti Executive Committee and the Mayor to prioritaze the actions during autumn 2018. The Environmental Development Unit, which is under the City Group Administration, is responsible for the adaptation work.
Figure A1. The IVAVIA tool, developed in the Resin project, was used at the Lahti Adapt stakeholders’ workshop in 2018
Increasing precipitation (+5–36%, depending on scenario and month) and increasing temperatures (+2.9–8.2 degrees C, depending on scenario and month) were the two phenomenas recognized as the most threatening at the stakeholders’ workshop. Other hazards that Lahti will have to adapt to are heavy rains, heat waves and storm winds. Exposured sectors are 1) land-use planning and construction, 2) infrastructure, 3) biodiversity and urban green and blue spaces, 4) social and healthcare, 5) water and wastewater management and 6) rescue management. There is a variety of specific challenges identified for Lahti, i.e. stormwater management and ageing people. Area of Lahti was laserscanned in summer 2017 and a new spatial model is being constructed. Urban flood risk map will be finalized in autumn 2018. It can be layered with other maps, such as elderly population and ecosystem service hot spots.
Stormwater management is increasing its importance in land-use planning and special flood conveyance routes are being planned in every new urban plan. Stormwater detention quotas for every city block (mm per rain event) will be implemented in the master planning process in 2018. A Climate-Proof City – The Planner’s Workbook at ilmastotyokalut.fi database, is in use. Many ongoing actions are presented in Table A2.
Finding the best solutions to treat urban storm water is currently high on priority on the city’s agenda, as the city is implementing a large-scale investment project called “Hybrid Solutions for Urban Stormwater Management”. This improves the 1) climate resiliency of Lahti City and 2) water quality of nearby Lake Vesijärvi. The project received a Finnish Government Programme Key Pilot Project status and funding for 2017-2018. The idea is to create both large and small-scale solutions for treating urban stormwaters and to combine them into two urban development areas in Lahti (Fig. A5).
In 2012, PACT was produced by project consultant Alexander Ballard Ltd. to assess the organizational capacity of Lahti to respond to climate change effects. The results were as shown in Figure B1.
Lahti participated in a project called Adaption Strategies for European Cities (EU Cities Adapt) during 2012-2013. The project surveyed municipalities’ adaptive actions and the overall ‘adaptive capacity’ of individual cities, and created a base for adaptation programme planning. Together with specialists, key climate change risks were identified. A working group was established for adaption planning within the consortium.
An impact and risk assessment was performed during the EU Cities Adapt project. Ongoing actions (Table A2) have been chosen on the basis of the analysis. After the EU Cities Adapt, Lahti continued working with climate change adaptation within the ERDF funded national ILKKA project (2012-2014). At that time, Lahti started to draft a climate change adaption programme focusing on areas described in Section 2A. The ILKKA project provided a large number of planning tools, such as the Green ratio calculator for climate change adaptation, which are currently in use in the urban planning of many cities in Finland, including Lahti. A database, the Climate-Proof City – The Planner’s Workbook (ilmastotyokalut.fi) was created in the project. Also, the first carbon storage and carbon sink maps about the municipal area were created.
Since early 2000, the City of Lahti has coupled city development work with university research. Department of Environmental Sciences (UH-DES) of the University of Helsinki is mainly located in Lahti and receives strategic funding from the city. The aim of this co-operation is to increase city resiliency. The department has a strong focus on urban ecology and climate change research questions.
Increasing precipitation that causes, i.e. urban and river flooding, is expected to be one of the most problematic climate change impacts in Northern Europe. The City of Lahti has built and studied stormwater structures in new residential areas (Fig. B2) during 2008-2018, using scientific knowledge from UH-DES (Fig. A5). According to the research results from these study sites, stormwater systems reduce the speed of water flow from retention area to the water body, and diminish the leaching of nutrients and heavy metals.
Cities can greatly benefit from and create a more adaptable infrastructure by utilising ecosystem ecology research results. The University of Helsinki has studied green roofs and their impacts on nutrient leaching loss in northern climates, proving that these are important structures for balancing urban hydrology.
Forestry adaptation questions are highly relevant throughout Finland, including Lahti, as the city owns roughly 7 000 hectares of forest. A large part, circa 60%, of the forest consists of approximately 80-year-old spruce, which makes it prone to, e.g. mass colonization by certain damaging insects, such as Ips typographus, which additionally benefits from climate change induced warmer summers and increased wind damage. These threats are considered in the new forest management practices of Lahti.
As in the Southern Latitudes, climate change poses risks to human health in Northern Europe, although the effects occurring may not be that severe or sudden. Some preliminary actions are described in Table B3, but further analysis and attention is needed.
Lahti is aiming at becoming a climate-resilient city by 2030 by cutting the majority of our CO2 emissions (-70% from 1990 level by 2030) and building a society able to cope with the changes. We are currently designing a new SECAP for 2030 with even more ambitious CO2 reduction targets: by 2021 -70 % from 1990 level and carbon-neutrality by 2030 at the latest.
In Northern Europe the expected temperature rise is much higher than the global average: there will be a decrease in snow coverage, an increase in river flows and storm water, a northward movement of species and an increase in crop yields. The majority of climate change effects pose serious threats to ecosystems and risks to building infrastructure and human health. One positive impact may be the decrease in the need for energy in heating. The Forests and Green Areas Master Plan and Biodiversity Master Plan are under development. These strategical programmes will provide a strong adaptation basis. The more green areas and biodiversity Lahti has, the better the coping capacity is. The mapping of Lahti carbon storages started in 2012 and will be updated in 2018. Adaptation measures are included in the Lahti Environmental Programme that was accepted 2018. These will be revised in 2021 and 2030. Adaptation measures will be followed up also in SECAP 2030. Nature conservation actions will be made in order to protect and increase carbon sinks (Fig. C1). A compensation programme will be established before 2021.
Although the SECAP of Lahti City is as yet under preparation, we are implementing several climate change adaptation measures with a future perspective (Table C2).
Table C2. Current and future adaptation measures of Lahti City.