27.11.2024 • Presentation of Your LCZ mapping exercise will start on Monday, December 4th at 1:00 PM, Z7 lecture room • To save time and avoid technical problems, please upload your presentation before the date indicated to IS: Study materials - Homework vaults - LCZ_mapping_exercise • Or you can send me your presentation via e-mail URBAN CLIMATOLOGY X. Adaptation and mitigation l Paper to read 'M ADAPT Climate Change and Urban Heat Islands Adaptation Measures for Urban Planning https://is.muni.cz/auth/el/sci/podzim2024/ZA311/um/67875456/10_ADAPT_UHI_Brochure. EvaluationMeasures.pdf Some expected climate changes in cities 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 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) From understanding to some action lysical processes well understooc Main drivers of negative impacts are known We know that we can either adapt or mitigate Jumerous solutions already exisi. 4 izations are not adequate in many cases) What are the main reasons/problems? Is there any analogy with the global climate change? 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 stress factors than people of a working age (Urban adaptation to climate change in Europe, EEA Report 2012) O Vulnerable people — the elderly □re considered to be a group more sensitive to various climatic stress factors than people of □ working age PrOp&rtiOn Of aged population > 65 in dties/cauntries, 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 > l ooo ooo Human controls - Percentage of population aged > 65 — share of cities per class per country Germany Belgium Italy Slovenia Austria Estonia Sweden Spain Czech Republic Portugal Latvia United Kingdom Greece Hungary France Finland Netherlands Bulgaria Poland Cyprus Denmark Ireland Lithuania Luxembourg Romania Slovakia :entage of cities in the country per class 80 100 % Share of population age > of total city population H>20% □13-20% L|lS-l?% □ 14-15% ■ < 14 « tUrban 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) Heat waves — bath a low share of green and blue urban areas and high population densities contribute potentially to the urban heat island! in cities Green/blue areas per city (UMZ), 2006 Pfa) 0 30-39 O 20-:? Population density per city (UMZ), 2004 [inn./km*) C < 3 000 O 3CO0-4Q0G O 4 0 00 - 5 000 O 5 000-10 000 Number of combined tropical nights [> 20 CC) and hot days (> 35 aC)t 2070-2100 l ID IB if, 34 30 4i 50 Human and geographical controls - Percentage of green and blue urban areas — share o f cities per class per country ^^^u^^^^^^ } 20 40 60 SO 100 % Hungary ™ -' Cyprus Estonia Luxembourg Slovakia_ Fra™_ Unite: Kin; :;.'P' Germany Italy Czech Republic _ P . - Bulgana_ Rorriania_ Netherlands Belgium"1 Malta Portugal Finland Sweden Share of green and blue areas of the city area 1*20% 0 20-29 % 030-39% ■ > = 40 % (Urban adaatatian to cMmat.p. c.hannp. in Furonp. FFA Rp.nort. P01P 27.11.2024 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. Causes of urban warming and mitigation strategies (Grimmond, 2007) Urban heal island causes Mitigation strategy Increased surface area Large vertical faces Reduced sky view factor Increased absorption of shortwave (solar) radiation Decreased longwave I terrestrial) radiation loss Decreased total turbulent heat transport Rodlicod wind speeds High reflection building and road materials, high reflection paints for vehicles Spacing of buildings Variability of building heights Surface materials Thermal characteristics Higher heat capacities Higher conductivities Increased surface heat storage Reduce surface temperatures ichanging albedo and emissivity) Improved roof insulation Moisture characteristics Urban areas have larger areas that are impervious Shed water more rapidly -- changes the hydrograpli Increased runoff with a more rapid peak Decreased evapolranspiration (latent heat flux, Porous pavement Neighbourhood detention ponds and wetlands which colled slormwalcr Increase greenspace fraction Greenroofs., greonwalls Additional supply of energy - anthropogenic heat flux - QT blectricity and combustion of fossil fuels: heating and cooling systems, machinery, vehicles. 3-D geometry of buildings - canyon geometry Reduced solar loading internally, reduce need lor 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 Air Dollution 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') District heating and cooling systems Combined heat and power or regeneration systems 6 Adaptation measures (approaches) in cities 1. 'Grey' 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 ' Building insulation to keep the inside cool 1 Blinds to provide shade 1 Passive cooling of buildings • Urban designs providing shade • Ventilation of urban space by intelligent urban design 1 Emission reduction of air pollutants ' Boosting gieen 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 outside 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 ■;■ ami rig • Transport management to reduce air pollutants Adaptation measures (approaches) Resilient cities "green" city "blue" city "white" city 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 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) 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 Climate sensitive design (resilient cities) Cities are efficient in their use of resources Cities are designed to improve local climate and microclimate Inhabitants and infrastructure are well protected from extreme weather events Air Quality control The simplest means of Improving air reduce omissions. Poorer street leve n poorly ventilated st-ccta v. Wider : Solar control Street geometry regulates access to Sun. Trees and arcades can provide additional shade outdoors Solar gain to buildings can be managed with trees and awnings. Where solar gain is desirable, overshadowing should be minimized. Rooftops provide ideal location for solar gain if not overshadowed. r p:intl ■ ... Awning X—- Runoff control Runoff can be managed by increasing the capacity to detain rainwater, adding vegetation and enhancing the permeability of street facets. Green roofs can provide insulation for buildings and some evaporative control but may require that roofs are strengthened to cope with additional weight. "■.'■Rapid runoff Irom "mpervious Examples of poor and good practices in street design (Oke et al. 2017) Temperature control Daytime surface turuui :iu. j cir be nanaged through shading of facets and controlling reflectivity. Fountains can be employed when needed to provide evaporative cooling. Green facets will reduce surface temperature and rrees can provide both shade and Wind control Wind shelter within the urban canopy is controlled by ambient wind velocity and street design. When airflow is perpendicular to the street axis, tall buildings will draw faster moving air to ground level while closely spaced buildings of even height provide shelter. Dark roof pooi n>u:;tlioi Fountain Green wall \ X Trees retard airflow 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 pi 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% Weather extremes and the effectiveness of soft measures An example from extreme flood events in CR Soft measures • General awareness raising and ensuring broad participation • Identification of vulnerable groups and their distribution as basis for targeted action • Warning systems • Preparedness of health and social care system • Information on adapting behaviour in particular to the vulnerable The weather forecast called for 400 mm of rainfall over three days. Moravia and Silesia in July 1997 CT 52 victims material damage 63 billions of Czech crowns _ Bohemia in August 2002 ^ 19 victims material damage 73 billions of Czech crowns Moravia and Silesia in September 2024 CT 13 victims material damage 10s billions of Czech crowns Urban climate and recent global warming A paper by McKitrick <& Michaels (2004) concluded that half of the global warming trend from 1980 to 2002 was caused by Urban Heat Island - not proved UHI and recent global warming Urban and rural regions show the same warming trend. R jral stations - old (Jones et al.) Rural stations - new (Li et al.) urban Actions - old [Jones et el.} - urtian stations - new (Li et al.) ■1.0 . ■ _ Anomaly (°C) time series relative to the 1961 to 1990 mean of the full US Historical Climatology Network (USHCN) data (red), the USHCN data without the 16% of the stations with populations of over 30,000 within 6 km in the year 2000 (blue), and the 16% of the stations with populations over 30,000 (green). The full USHCN set minus the set without the urban stations is shown in magenta. Source IPCC 2007 Parker (2004, 2006) noted that warming trends in night minimum temperatures over the 1950-2000 period were not enhanced on calm nights, which would be the time most likely to be affected by urban warming. UHI and recent global warming GISTEMP v4 Annual Trend 1979-2019 Temperature change