Monitoring Atmospheric CO₂ in the Mediterranean: A Strategic Infrastructure for Climate Action and Latitudinal Impact Assessment

The presence of CO₂ in the atmosphere facilitates the maintenance of adequate levels of heat, which is essential for the establishment and sustenance of life on Earth. Although its concentration has varied dramatically throughout the planet's history, recent levels of atmospheric CO₂ are the result from a delicate balance among processes such as volcanism, weathering, photosynthesis, respiration and combustion. However, extensive use of fossil fuels has altered this balance causing atmospheric CO₂ concentrations to rise, thereby intensifying global warming and accelerating climate change

While relatively few countries in the intertropical region release substantial amounts of CO₂, nations in the northern hemisphere have been the primary contributors to CO₂ emissions over the past centuries, largely due to industrialization. Since the Industrial Revolution, urban development has concentrated several people around heavily industrialized cities, which have become central drivers of climate change. Global atmospheric circulation facilitates the rapid dispersion of CO₂ emissions originating from tropical latitudes throughout the troposphere. In contrast, emissions from mid- to high-latitude regions persist longer on a regional scale. Consequently, the latitude of CO₂ emissions significantly influences their climatic effects, with high-latitude emissions remaining in the atmosphere for longer time.  On the other hand, growing urban areas in the transitional mid-latitude regions are particularly vulnerable to the impacts of climate change, with Mediterranean cities being especially susceptible to extreme events. These include more frequent heatwaves, rising sea levels, droughts, and intense rainfall, all of which pose significant threats to infrastructure, public health, and urban ecosystems. Moreover, rising temperatures enhance social and economic inequalities, underscoring the urgent need for resilient and sustainable adaptation strategies. 

This study addresses the rationale for and development of a research infrastructure aimed at monitoring atmospheric CO₂ and its latitudinal variation within the Mediterranean region. The objective is to assess the impacts of actions taken to reduce anthropogenic CO₂ emissions as outlined in the European Green Deal. 

The proposed infrastructure is designed to collect and disseminate data for a comprehensive examination of the causes of latitudinal and temporal variations in atmospheric CO₂ across a north-south transect from the Alpine glaciers in Valle d’Aosta to the island of Lampedusa, both located in Italy. This system includes 12 automatic monitoring stations equipped to measure the concentration and isotopic composition of carbon and oxygen in atmospheric CO₂. Extensive research highlights the importance of monitoring carbon isotopes (e.g., ¹³C, ¹²C) to identify emission sources, as well as triple oxygen isotope ratios (¹⁶O, ¹⁸O, and ¹⁷O) to trace the fate of CO₂ within the interconnected carbon and water biogeochemical cycles.

The network’s high-frequency acquisition capability (minute intervals) enables near real-time evaluation, facilitating the identification and characterization of diverse CO₂ sources and the apportionment of their emissions.