From the 2030 Agenda of the Metropolitan City of Milan to Municipal Urban Planning Documents (DUP) through shared climate change adaptation indicators and targets.
Glossary
A
ADAPTATION
Anticipate the adverse effects of climate change and take appropriate measures to prevent or minimize the damage they may cause or exploit the opportunities that may arise.
Examples of adaptation measures include large-scale infrastructure changes, such as building sea-level rise defenses, and behavioral changes, such as individuals reducing food waste. In essence, adaptation can be understood as the process of adjusting to the current and future impacts of climate change.
Source: EEA
C
CLIMATE CHANGE
A change in the state of climate that persists for an extended period of time (usually decades or more), and is identifiable (for example, through the use of statistical tests) by changes in the mean and/or variability of its properties.
It may be due to internal natural processes, or to external forcings, such as modulations of solar cycles, volcanic eruptions, and repeated anthropogenic changes in the composition of the atmosphere or land use.
Note that the United Nations Framework Convention on Climate Change (UNFCCC), in its Article 1, defines climate change as: "a change in climate, attributable directly or indirectly to human activity, that alters the composition of the global atmosphere and that is in addition to natural climate variability observed over comparable periods of time". Therefore, the UNFCCC makes a distinction between climate change attributable to human activities that alter the composition of the atmosphere, and climate variability attributable to natural causes.
Source: IPCC AR5 Fifth Assessment Report on Climate Change IPCC MINIMUM GLOSSARY , 2014
CER - Renewable Energy Community
A group of citizens, small and medium-sized businesses, territorial entities and local authorities, including municipal administrations, cooperatives, research institutions, religious entities, third sector entities and environmental protection entities, who share the renewable electrical energy produced by plants available to one or more entities associated with the community. In a CER , renewable electrical energy can be shared between the various producers and consumers , located within the same geographical perimeter, thanks to the use of the national electricity distribution network, which makes the virtual sharing of such energy possible.
The primary objective of a CER is to provide environmental, economic and social benefits to its members or associates and the local areas in which it operates, through the self-consumption of renewable energy.
Source: MASE
CLIMATE
Average of weather conditions at a given location over a long period of time, which can range from months to thousands or millions of years. The WMO uses a 30-year period (CLINO) to determine the average climate. There are five main components of the Earth system:
- the atmosphere;
- the hydrosphere (oceans, lakes and rivers);
- the cryosphere (ice and snow);
- the lithosphere (earth's surface);
- the biosphere (living organisms).
The complex interactions and influences between these components, such as the exchange of energy, water and carbon dioxide, determine our climate patterns and their variability.
By observing and monitoring components of the climate system such as temperature, precipitation, atmospheric pressure, ice cover, and carbon cycles over long periods of time, we can better understand the climate and the causes of its changes, as well as build climate models to predict our future climate.
Source: WMO
URBAN CLIMATE
Specific atmospheric conditions in urban areas , which significantly modify the radiative, thermal, humidity and aerodynamic properties of the surface due to factors such as high building density, poor heat reflection from dark-coloured materials and reduced availability of vegetation and water.
This change alters the flows and balances of heat, mass and momentum, producing a phenomenon called 'urban heat island'.
Source: American Meteorological Society
CLINO - Climatological Normal
Statistical processing of meteorological parameters on the ground over a thirty-year period, which allows to describe the typical climatic conditions of a location, as well as, by comparing them with current data, highlight any climatic anomalies. The averages referred to the climatic period according to the WMO criteria are called “normal values” or “climatic values”.
Source: WMO
D
DNSH - Do No Significant Harm
Not support or carry out economic activities that cause significant harm to the environmental objective , pursuant to, where relevant, Article 17 of Regulation (EU) 2020/852.
Principle to combine economic growth and ecosystem protection, ensuring that investments are made without compromising environmental resources.
An economic activity is considered to cause significant damage if its activity impacts on:
- climate change mitigation,
- adaptation to climate change,
- the sustainable use and protection of water and marine resources,
- the circular economy,
- the prevention and reduction of pollution,
- the protection and restoration of biodiversity and ecosystems.
Source: REGULATION (EU) 2021/241 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL, 2021; MASE , 2023
DUP - Unified Planning Document
Tool that allows the strategic and operational guidance of local authorities and allows them to address environmental and organizational discontinuities in a permanent, systemic and unitary way.
The DUP constitutes, in compliance with the principle of coordination and coherence of budget documents, the necessary prerequisite for all other programming documents.
It is composed of two sections: the Strategic Section (SeS) and the Operational Section (SeO).
Source: DL 267/2000, art.170
E
EXTREME WEATHER EVENT
An extreme weather event is one that is rare in a particular place and time of year, with unusual characteristics in terms of magnitude, location, timing, or extent. The characteristics of what is defined as an extreme weather event can vary from place to place in an absolute sense.
Source: WMO
G
GG - Winter Degree-Day
The difference between a standard reference indoor temperature (typically set at 20°C) and the daily average outdoor temperature. Only positive differences count toward the total – in other words, if the outdoor temperature averages higher than the reference point, the degree-day value automatically defaults to zero.
Source: D. P. R. n. 412/1993
GGE - Cooling Degree-Day
This index serves to quantify the energy demand required for summer cooling in buildings. It's defined as the difference between the daily average outdoor "feels-like" temperature (what people actually perceive as hot or cold, as measured by the Humidex index) and the indoor set-point temperature fixed at 25°C (according to UNI 10339 and 10349 standards). Similar to winter degree-days, only positive differences are counted - meaning we only consider instances when the outdoor temperature exceeds this indoor reference point.
H
HUMIDEX INDEX
This biometeorological index helps assess human thermal comfort by accounting for both air temperature and relative humidity, effectively describing the discomfort experienced during hot, humid days.
The Humidex index is based on an empirical relationship that incorporates air temperature and vapor pressure. Originally developed in Canada in 1965 and later refined by Masterson & Richardson in 1979, its calculation formula identifies varying levels of heat stress.
The resulting values are categorized into different tiers of thermal discomfort, helping to quantify how oppressive summer conditions truly feel to the human body.
H = T + ( 0.5555 * ( e – 10 ) )
T [°C] = air temperature
e [hPa] = vapor pressure
A Humidex reading above 40°C indicates dangerous conditions. When temperatures reach this threshold, all non-essential activities should be suspended. Readings between 30-35°C signal significant thermal discomfort - during these conditions, people should reduce strenuous physical activity and exercise caution.
I
INDICATOR
An indicator is a measurable parameter that provides insight into a specific concept. When multiple indicators are combined, they form what we call an index - essentially a composite variable that incorporates various statistical values or qualitative classifications depending on temporal or spatial circumstances. Most indicators derive their values or classifications from processed raw data through analytical methods.
Within the IndicaMi project framework, we work with two distinct types:
-
Context Indicators
These describe existing pressures (P) and baseline conditions (S). Examples include: frequency of extreme weather events and hectares of flood-prone territory.
-
Performance Indicators
These track impacts (I) and response effectiveness (R), such as: actual hectares affected by flooding and annual increase in urban green spaces.
IPE - Energy Performance Index
Also referred to as the Consumption Index, this architectural parameter quantifies the total primary energy consumption for climate control systems (operating continuously, 24 hours) per unit of usable floor area (expressed in kWh/m²/year) or gross volume for non-residential buildings (kWh/m³/year).
The EPI indicates how much energy is required to maintain optimal comfort conditions in a building or property unit, including: winter heating, domestic hot water production, summer cooling, artificial lighting.
Source: Decreto Ministeriale 26/6/2009 – Ministero dello Sviluppo Economico "Linee guida nazionali per la certificazione energetica degli edifici"
URBAN HEAT ISLAND (UHI)
This distinctive microclimatic phenomenon occurs in metropolitan areas, where urban zones experience significantly higher temperatures compared to suburban and surrounding rural regions. The effect becomes particularly pronounced during evening and nighttime hours, primarily under specific weather conditions - typically high-pressure systems with clear skies and minimal wind.
Source: CMCC; WMO
L
LCZ - Local Climate Zone
This system categorizes urban areas based on key morphological and surface characteristics, including surface structure properties (building height, tree coverage), sky View Factor (SVF), built-up area ratio, surface albedo.
The classification helps identify distinct microclimates within cities, particularly for heat island analysis and mitigation planning.
Source: Città Metropolitana di Milano
LST - Land Surface Temperature
This refers to the radiative skin temperature of the ground (distinct from air temperature), derived from spaceborne thermal infrared remote sensing measurements.This refers to the radiative skin temperature of the ground (distinct from air temperature), derived from spaceborne thermal infrared remote sensing measurements.
Source: ESA
M
MITIGATION
This involves reducing the severity of climate impacts by preventing or decreasing greenhouse gas (GHG) emissions. Mitigation strategies work through two primary approaches: (1) cutting emission sources (like boosting renewable energy shares or creating cleaner transport systems), and (2) enhancing carbon storage (such as expanding forested areas).
In essence, mitigation represents deliberate human actions to either shrink GHG emission sources or amplify natural carbon sinks.
Source: EEA
CLIMATE MODEL
A numerical representation of the climate system based on the physical, chemical, and biological properties of its components, their interactions, and feedback processes, incorporating known characteristics of these elements.
The climate system can be modeled at varying complexity levels - each component or combination of components exists along a modeling spectrum. These models differ in key aspects like:
-
Spatial dimensions employed
-
How explicitly they represent physical/chemical/biological processes
-
Their reliance on empirical parameterizations
State-of-the-Art Modeling
Coupled Atmosphere-Ocean General Circulation Models (AOGCMs) represent the most comprehensive end of current modeling capabilities. The field is evolving toward even more sophisticated models incorporating interactive chemistry and biology. Climate models serve dual purposes:
-
Research tools for studying climate dynamics
-
Operational systems for monthly, seasonal, and interannual climate forecasting
Source: IPCC AR5 Quinto Rapporto di Valutazione sui Cambiamenti Climatici GLOSSARIO MINIMO dell’IPCC, 2014
DPSIR MODEL
The DPSIR (Drivers, Pressures, State, Impacts, Responses) model is a widely accepted analytical framework used across EU countries and beyond. It classifies environmental actors into five categories, serving as a key tool for properly framing questions and presenting solutions to environmental issues.
D – Drivers
These represent the "indirect causes" (often interconnected) of adverse environmental effects. Depending on the phenomena studied, they may include:
-
Population density and lifestyles
-
Agricultural and industrial production methods
-
Urbanization patterns
-
Natural factors (topography, hydrology, regional climate, ocean currents, etc.)
Note: For the IndicaMi project methodology, Drivers were not considered.
P – Pressures
Anthropogenic and natural factors directly influencing the climate system and territory. Examples:
-
Increased frequency of heatwaves
-
Extreme precipitation events
-
Soil sealing
-
Deforestation
S – State
The environmental condition, characterized by specific measurable indicators. Examples:
-
Extent of flood-prone areas
-
Current gas and energy consumption under existing demand
-
Vulnerable populations
-
Green space coverage
I – Impacts
Significant changes in environmental conditions, manifested as disruptions to ecosystems, their ability to sustain life, human health, and society. Example indicators:
-
Health problems
-
Flooding events
-
Water damage
-
Increased cooling energy demand
R – Responses
Governance actions implemented to protect the environment. Responses may target:
-
Any DPSIR element (including correcting prior responses)
-
Take forms such as policy objectives, funding programs, direct interventions.
Example indicators:
-
Improved public services
-
Energy efficiency upgrades in public/private buildings
-
Awareness campaigns
-
Expansion of green areas
Source: EEA
MRV - MONITORING
A continuous process - initiated from the planning phase - involving systematic collection of qualitative and quantitative data on specific indicators. This function provides policymakers with clear evidence about:
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Progress magnitude
-
Target achievement levels
-
Appropriate use of allocated funds
within ongoing climate adaptation processes. Crucially, it enables measurable tracking of advancements toward the goals established in the monitored action plan.
Source: UNFCCC, 2014
MRV - REPORTING
A structured process for documenting and communicating progress on climate-related activities against predetermined targets. This reporting framework serves three core purposes:
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Ensuring transparency in implementation
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Maintaining accountability for results
-
Enabling data comparability (both qualitative and quantitative metrics)
By standardizing progress tracking, it facilitates collective monitoring of advancements toward global climate goals.
Source: UNFCCC, 2014
MRV - EVALUATION
A systematic and objective assessment of an ongoing or completed adaptation policy, strategy, or action – including its implementation and outcomes. This process determines:
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The relevance and achievement of project objectives
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Operational efficiency
-
Implementation effectiveness
-
Measurable impact
-
Long-term sustainability
Source: UNFCCC, 2014
N
NBS - Nature Based Solutions
Actions to protect, sustainably manage, and restore both natural and modified ecosystems that effectively address societal challenges. These solutions deliver simultaneous benefits for human well-being and biodiversity, while tackling critical issues including:
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Climate change mitigation and adaptation
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Disaster risk reduction
-
Food and water security
-
Biodiversity conservation
-
Public health improvement
Recognized as essential for sustainable development, NbS integrate ecological principles with human needs through adaptive, cost-effective approaches.
Source: IUCN, Unione Mondiale per la Conservazione della Natura;
NDVI – Normalized Difference Vegetation Index
This index assesses how "green" an area is by measuring the amount of healthy, active vegetation present. Using satellite imagery, it compares how plants absorb and reflect light to calculate vegetation vigor.
How to Interpret NDVI Values:
-
High values (close to +1): Indicate dense, healthy vegetation (parks, thriving trees, lush lawns)
-
Low values (near 0 or negative): Reveal built-up areas, bare soil, or dry/stressed plants
Source: NASA
O
HEATWAVES
Prolonged periods of extreme heat that pose significant health risks – particularly cardiovascular stress – especially for elderly and vulnerable populations. These high-temperature events are becoming increasingly frequent during summer months.
Urban areas face heightened impacts due to the urban heat island effect, where cities retain substantially more heat than surrounding rural zones, particularly during evening and nighttime hours. This phenomenon intensifies both the duration and severity of heatwave conditions.
Source: ISPRA
P
CLIMATE PREDICTION
The outcome of attempting to estimate the actual evolution of future climate conditions – whether seasonal, interannual, or decadal – based on a specific starting state of the climate system. Because the climate system's future trajectory can be highly sensitive to initial conditions, such projections are typically probabilistic in nature.
Source: IPCC AR5 Quinto Rapporto di Valutazione sui Cambiamenti Climatici GLOSSARIO MINIMO dell’IPCC, 2014
CLIMATE PROJECTION
A simulated response of the climate system to future greenhouse gas/aerosol emission or concentration scenarios, typically generated using climate models. Crucially, projections differ from climate predictions because they inherently depend on:
-
Selected emission/concentration/radiative forcing scenarios
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Underlying assumptions about potential socioeconomic and technological developments
These scenario-driven simulations reveal how climate could evolve under different human activity pathways rather than forecasting how it will evolve from current conditions.
Source: IPCC AR5 Quinto Rapporto di Valutazione sui Cambiamenti Climatici GLOSSARIO MINIMO dell’IPCC, 2014
R
RESILIENCE
The ability of a system and its components to anticipate, absorb, adapt to, and recover from the effects of a hazardous event in a timely and efficient manner, while ensuring the preservation, restoration, or enhancement of its essential structures and functions.
Source: IPCC
RUNOFF
The portion of rainfall that, unable to infiltrate the ground due to either:
-
Soil saturation (maximum water retention capacity reached), or
-
Reduced infiltration capacity (e.g., from compaction or impervious surfaces),
flows overland until reaching the hydrographic network, generating measurable surface runoff.
Source: ISPRA
S
SUDS - Sustainable Urban Drainage System
Stormwater management solutions designed in line with sustainable development policies to address environmental risks from urban runoff while enhancing ecological quality. This approach follows a triple-objective framework:
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Water Quality Improvement – Treating polluted runoff
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Water Quantity Control – Regulating flow rates and volumes
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Biodiversity & Amenity Enhancement – Maximizing ecological and social benefits
SUDS mimic natural site hydrology as closely as possible, replicating pre-development drainage patterns through nature-based techniques like bioswales, permeable pavements, and retention ponds.
Source: Commissione Europea
U
UGAI – Urban Green Area Index
Green-to-built ratio
A metric that quantifies the amount of green space (parks, trees, gardens) relative to artificial surfaces (buildings, roads, pavements) in urban areas.
Why It Matters for Cities:
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Evaluates urban sustainability: Reveals whether green spaces are sufficient compared to urbanization.
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Guides planning decisions: Helps prioritize environmental interventions (e.g., new parks, tree-planting).
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Improves livability: More green space = better air quality, reduced heat islands, and enhanced well-being.
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Controls land use: Encourages sustainable urban expansion by balancing development with nature.
Source: European Data