27.11.2022 URBAN CLIMATOLOGY X. Adaptation and mitigation Paper to read |Jj ADAPT UK SAN HEAT iSLAf 05 Climate Change and Urban Heat Islands Adaptation Measures for Urban Planning https://is.muni.cz/auth/el/sci/podzim2022/ZX601/um/67875456/10 ADAPT UHI Brochure EvaluationMeasures.pdf 1 Summary of expected climate changes in Central Europe • Rising temperatures and higher intensity of Urban Heat Island • Higher frequency and longer duration of heat waves • Changes in precipitation distribution during a year • More frequent occurrence of high precipitation totals of short duration, higher probability of local floods • Higher frequency of drought periods without precipitation I Negative effects prevail Heat load is increasing Survive New York's Heot Woves Stoy cool during your trip to New York (http://www.frenzytours.com) Adaptation and mitigation in urban climatology • Besides „physical controls" urban climatology has also „human / social controls" https://jpi-urbaneurope.eu • In cities climate change is strongly intertwined with other socioeconomic changes: demographic trends, higher proportion of older people, urbanization, competing demand for water, etc. • These socio-economic changes increase the vulnerability of people, property and ecosystems under current climate conditions as long as no adaptation measures are taken. • Negative impacts of climate change in cities require various actions, strategies, technologies that help inhabitants to adapt or mitigate. Human controls — the elderly are considered to be a group more sensitive to various climatic siress factors than people of a working age (Urban adaptation to climate change in Europe, EEA Report 2012) Vulnerable people — the elderly are considered to be a group mare sensitive to various climatic stress factors than people of a working age Proportion of aged population > 65 in dties/countries, 2004 ^ --- 14 14-15 I 115-17 ^ 17-20 > 20 ^ No data Outside data coverage Total population in cities, 2004 O < 100 000 O 100 000-250 000 O 250 000-500 000 O 500 000^1 000 000 Q > 1 000 000 Human controls - Percentage of population aged > 65 — share of cities per class per country r 0 r 20 ' 40 Germany Belgium Italy Slovenia Austrl a Estonia Sweden Spain Czech Republic Portugal Latvia United Kingdom Greece Hungary hrdrtt Finland Netherlands Bulgaria Poland Cyprus Denmark Ireland Lithuania Luxembourg Romania Slovakia Percentage or cities in the c luntry per das 100 % Share of population age ^ 6b of" total city papulation ■ >20% □ 13-20% □ 16-17% [314-15% ■ <- 14 % (Urban adaptation to climate change in Furooe FFA Report 2012 Human and geographical controls - Low share of green and blue urban areas and high population densities can contribute to the urban heat island effect in Cities (Urban adaptation to climate change in Europe, EEA Report 2012) — both a low share of green and blue urban areas and high population densities contribute potentiaIly to the urban heat island in cities Greeryblue areas per city tUMZ), 2006 (%) 0.. ?*• 40 © 3Q-39 O 20-29 Population density per city (UMZ), 200.4 [inh./km1) O * 3 000 O 3 000-4 000 O 40 00 - 5 000 O 5 000-10 000 Q > 10000 Number of combined tropical night? 20 °C) and hot da/5 O 35 °C), 2070-2100 ■....... 34 3B A2 5D Human and geographical controls - Percentage of green and blue urban areas — share of cities per class per country ***^+j^****mtw*m Cyprus Estonia Luxembourg Slovakia France United Kingdom Germany [taly Czech Republic Netherlands Denmark Latvia li-/: M on Share of green and blue areas of the city area (Urban adaptation to climate change in Furooe FFA Report 2Q12\ Adaptation and mitigation - terminology Adaptation to climate change is the adjustment in urban areas in response to actual or expected effects of adverse climate. It moderates harm or exploits beneficial opportunities of climate change. Mitigation of climate change is an anthropogenic intervention to reduce the anthropogenic forcing of the climate system. It includes strategies to reduce greenhouse gas sources and emissions and enhancing greenhouse gas sinks. Vulnerability is the degree to which a system is susceptible to, and unable to cope with, adverse effects of climate change, including climate variability and extremes. Resilience is the ability of a social or ecological system to absorb disturbances while retaining the same basic structure and ways of functioning, the capacity for self-organization and the capacity to adapt to stress and change. Adaptation strategies (approaches) 1. 'Srey' infrastructure approaches - physical interventions or construction measures and using engineering services to make buildings and infrastructure essential for the social and economic well-being of society more capable of withstanding extreme events. 2. 'Green' infrastructure approaches - contribute to the increase of ecosystems resilience and can halt biodiversity loss, degradation of ecosystem and restore water cycles. At the same time, green infrastructure uses the functions and services provided by the ecosystems to achieve a more cost effective and sometimes more feasible adaptation solution than grey infrastructure. 3. 'Soft' approaches - include policies, plans, programs, procedures, information dissemination and economic incentives to reduce vulnerability, encourage adaptive behavior. They are related to behavioral changes, emergency systems and the adequate provision of information to vulnerable groups. Adaptation approaches and measures Overview on grey, green and soft adaptation measures to heatwaves (Urban adaptation to climate change in Europe, EEA Report 2012) Grey measures Green measures Soft measures 1 Building insulation to keep the inside cool 1 Blinds to provide shade ' Passive cooling of buildings 1 Urban designs providing siiade ■ Ventilation of urban space by intelligent urban design 1 Emission reduction of air pollutants ' Boosting green infrastructure, such as green urban areas, trees, green walls and roofs where possible, but ensuring sustainable watering 1 Ensuring that fresh air from green areas outskle the city can flow in • General awareness raising and ensuring broad participation • Mapping of urban heat island as well as cool places • Identification of vulnerable groups and their distribution as basis for targeted action • Warning systems • Heat action plans including appropriate institutional structures • Preparedness of health and social care system • Information on adapting behaviour during heatwaves in particular to the vulnerable • Adapting building codes to include insulation and shadowing to cope with heatwaves • Consider reducing heatwave impacts through urban renewal projects and urban planning • Transport management to reduce air pollutants Adaptation strategies (approaches) Resilient cities Further possibilities: • Energy saving and passive houses • Warning systems and disaster risk management programs • Urban adaptation relies on action beyond cities' borders (flooding due to inappropriate land use and flood management in upstream regions) and incudes reducing cities' dependency on external services 27.11.2022 Causes of urban warming and mitigation strategies (Grimmond, 2007) Urban heat island causes Mitigation strategy Increased surface area ^T^^^HT^iHaces^™ Reduced sky view factor Increased absorption of shortwave (soiar) radiation Decreased longwave (terrestrial) radiation loss Decreased total turbulent heat transport Reduced wind speeds Surface materials_ Therms! characteristics Higher heal capacities Higher conductivities Increased surface heat storage Moisture chaw.tei titles Urban areas have larger areas that are impervious Shed water more rapidly - changes the hydrograpli Increased runoff with a more rapid peak Decreased evapotranspiration (latent heat flux, Qe) Additional supply of energy - anthropogenic heat flux - QT HeHnHTy^rT^omTusnori of fossil fuels: heating and cooling systems, machinery, vehicles. 3-D geometry of buildings - canyon geometry Air^ollutioi^ Human activities lead to ejection of pollutants and dust into the atmosphere Increased longwave radiation from the sky Greater absorption and re-emission ('greenhouse effect') High reflection building and road materials, high reflection paints for vehicles Spacing of buildings Variability of building heights Reduce surface temperatures (changing albedo and emissivily) improved roof insulation Porous pavement Neighbourhood detention ponds and wetlands which collect stormwater increase greenspace fraction Green roots, greenwalls Reduced solar loading internally, reduce need for active cooling (shades on windows, change materials) District heating and cooling systems Combined heat and power systems High reflection paint on vehicles to reduce temperature District heating and cooling systems Combined heat and power or cogene ration systems Examples of adaptation measures Shading effect, evaporation of water into Green tram tracks (Mulhouse, France) the atmosphere and its storage in soil Grey measure - shading of a public Soft measure - change in our mind square in Benicassim, Spain (© urbadis) (© projectADAPT-UHI(KR17AC0K13693) 7 Urban climate analysis map for the city of Arnhem, the Netherlands (Urban adaptation to climate change in Europe, EEA Report 2012) Urban climatic analysis map of Arnhem city UMC classification ^| Fresh air area Cool air area Mixed climate Overheating | Overheating 2 | Overheating 3 Background winds Climate planning strategy, Stuttgart (Germany) (Urban adaptation to climate change in Europe, EEA Report 2012) An excellent example of urban heat island management. The city of Stuttgart has been designed to not only respect and protect nature, but to exploit how natural wind patterns and dense vegetation can actively help the city to reduce its problems of overheating and air pollution. At night cool air sweeps down from the surrounding hills and runs through a series of 'ventilation-corridors' which have been kept open as wide, tree-flanked arteries within the city's street infrastructure. Klimaanalysekarte Stuttgart Planungshinweiskarte Stuttgart http://www.stadtklima-stuttgart.de Effectiveness of adaptation strategies Oswald et al. 2020 - Klagenf urt (Austria) Two adaptation strategies: (i) White city - an increase in the albedo values of sealed areas (i.e., roofs, walls and streets) (ii) Green city - an increase in green surfaces (i.e., lawns on streets and at roof level) and high vegetated areas (i.e., trees). PI P2 PJ Evaluation of the different climate adaptation measures for the urban area of Klagenf urt. difference in the average number of summer days per year ( SD y 1) compared to the reference simulation for the time period 1981-2010. • Some climate adaptation measures show higher potential in mitigating hot days than others, varying between reductions of 2.3 to 11.0%. • An overall combination of adaptation measures leads to a maximum reduction of up to 44.0% 27.11.2022 Analog scenarios Model simulations with different land use / land cover parameters „what - if" scenarios 2010s Land cover maps of Brno in 1870s, 1940s and at present Final remarks and questions Mills (2006) - the sustainable city is the new urban Utopia 1. How to persuade politicians (local authorities) that some adaptations/mitigations are needed? 2. What is the role of geographers in the adaptation process of cities to climate change? 10