Environmental sustainability indicators
By environmental sustainability indicators or, more simply, environmental indicators means data, statistical values and parameters useful for the qualitative or quantitative assessment of the environmental and socio-economic conditions of a system under examination.
– environmental indicators are detectable parameters that show the conditions of an environmental system;
– the sustainability indicators are particular environmental indicators that help to understand if the environmental conditions fall within certain expectations and satisfy the objectives of sustainable development.
Environmental indicators can be seen both as indicators of the state (quality) of the environment and as indicators of stress (or pressure) imposed on the environment. Next to them are other indicators that provide additional “speculative” information. These are indicators that measure phenomena whose connection with the environmental theme considered is not uniquely interpreted by the scientific world. An example is that of the environmental issue “climate change”: the stress indicator used is the emission of greenhouse gases, that of state the radiant force, and finally the speculative information is given by the average terrestrial temperature and the volume of ice in the Barent Sea.
Based on the pressure-state-response model proposed at national level by the OECD (Organization for Economic Cooperation and Development), we can identify three types of environmental indicators:
Status indicators: refer to the quality of the environment in all its components and highlight situations in fact at a specific time; when they measure the reactivity or the level of exposure to alterations or degradation factors of the environmental and settlement system, they are also called quality / degradation / exposure indicators.
Pressure indicators: they measure the pressure exerted by human activities on the environment and are expressed in terms of emissions or consumption of resources (material flows).
Response indicators: they are necessary to prevent or mitigate the negative impacts of human activity and summarize the capacity and efficiency of the actions undertaken for environmental rehabilitation, for the conservation of resources and for the achievement of the objectives assumed.
To these we can add those indicators that are limited to the characterization of aspects useful to the description of the reference context: Scenario indicators.
At the international level, although there is a list of indicators established by the EU (“Towards Environmental Pressure Indicators for the EU” – “TEPI” published by Eurostat), the need to leave individual communities the autonomy to select indicators has now been understood better suited to the local situation to better represent their environmental specificity. While maintaining the model described above valid and regularly used, there is also a new concept model that best identifies the concept of sustainability: the DPSIR model.
The DPSIR model is an extension of the PSR model (Pressure-State-Response) and is the most widely accepted indicator structure; this scheme is based on a structure of causal relations that link the following elements together:
This model highlights the existence, “upstream” of the pressures, of driving forces or determinants, which in essence can be identified with the anthropic activities and processes that cause the pressures (transport, industrial production, consumption).
Pressure indicators describe the variables that directly cause environmental problems (toxic CO2 emissions, noise, etc.)
Instead, the “state” of pressures is the state of nature that changes at all levels following human stresses (global average temperature, noise levels, etc.).
The change in the state of nature implies Impacts on the anthropic system (health, ecosystems, economic damage); these impacts are mostly negative, since the change in the state of nature generally coincides with its departure from the initially existing conditions, favorable to human prosperity. Society and the economy, in the face of this negative feedback, react by providing answers (environmental and sectoral policies, legislative initiatives and planning) based on the awareness of the mechanisms that determine it. The answers are directed both to the immediate causes of the impacts (changes of the state) and to their deeper causes, going back up to the pressures themselves and to the factors that generate them (determinants).