Climate: Alarm for the Mediterranean, heat waves and new highs in CO2 (+15%) and methane (+9%)

02 February 2023 Last Updated: 02 February 2023

The Mediterranean is increasingly at risk due to an increase in emissions - particularly CO₂ and methane - and severe heat waves, as shown by ENEA data of its climate observatory of Lampedusa, an international point of reference on climate change. Data show that in the last quarter of a century CO₂ has increased from about 365 to about 420 parts per million (+15%), methane from about 1825 to 1985 parts per billion (+9%), while the average temperature by about 0.5°C, together with the frequency and intensity of heat waves.

“Before the industrial revolution, the atmospheric content of CO₂, one of the main human greenhouse-gas emissions that affect climate, was around 280 parts per million, while in 1992, when we started measuring carbon dioxide in Lampedusa , they were about 350 parts per million”, pointed out Alcide di Sarra of the ENEA Laboratory of Observations and Measurements for the Environment and Climate. “To date we have recorded 420 parts per million, with a sharp 15% increase in the last 25 years and an annual growth rate that has gone from 1.7 ppm/year to about 2.6 ppm/year. This increase, combined with the surging temperatures we are recording, would make the ocean and vegetation less efficient at absorbing excess CO₂”.

Lampedusa contributes to the main global and European observation networks by providing integrated marine, terrestrial and atmospheric information and by providing an overall picture of the carbon cycle in the Mediterranean, which is representative of what is happening on a global scale, where climate change impacts with amplified effects. The smaller size, the absence of reliefs, but also its position, far from the continents and anthropic emissions and vegetation, make it an ideal site also to verify and validate satellite observations.

The atmospheric observatory is also used to study water vapor, clouds, aerosols and other greenhouse gases like nitrous oxide (N2O), halogenated compounds, methane (CH4), responsible for more than 30% of anthropogenic climate warming, and their action on solar and infrared radiation and the water cycle.

"Methane is also closely monitored due to its very important role in achieving the objectives of the international climate protocols, considering that it has a heating capacity 30 to 80 times greater than CO2", said ENEA researcher Damiano Sferlazzo. “From pre-industrial times to 1997, the atmospheric concentration of methane has more than doubled, from 720 to about 1825 ppb (parts per billion) and has further increased by 8% in the last 20 years, with a growth rate which has become faster since 2010, reaching +15 ppb/year in 2021 and 1985 ppb today”. (Fig. 1 and 2)

The oceanographic observatory, a hi-tech buoy equipped with advanced sensor systems to study the chemical-physical properties of the water, validate satellite observations and provide meteorological, temperature, radiation, pressure, pH but also chlorophyll and dissolved organic matter at various depths, is located at 5 km from the coast.

This climate "sentinel" has also confirmed the over 1.5°C increase in the average temperature of the sea occurred in the last 100 years, much higher than the global average, more frequent severe heat waves and sea temperatures that reached 30°C in 2022, threatening biodiversity, modifying the habitats of various species and mainly affecting fishing, aquaculture, atmospheric conditions and evaporation.

“These data show the need to implement specific policies to reduce CO₂ and other human-made emissions like methane, in line with the European objectives of climate neutrality by 2050", pointed out ENEA researcher Tatiana Di Iorio. "This is a key challenge for the future of Europe and the planet, particularly of the Mediterranean, one of the regions most responsive to climate change where the impacts on the environment can be critical and which is incresingly at risk" .

Shortly, measurement of CO₂ exchanges between vegetation and the atmosphere will be added to the atmospheric and oceanographic ones in order to have an overall integrated picture of the exchanges and distribution of CO₂ and energy among the sea, land and atmosphere, which regulate the climate of the whole region.

The Lampedusa Climate Observatory was also at the center of the activities of the ES-PA project which aims at improving the skills of regional and local PAs on energy and sustainability issues. As part of the project, in collaboration with various Public Administrations, integrated territorial projects were implemented for sustainable development, efficient use of resources and sustainable tourism. In collaboration with the Marine Protected Area of the Pelagie Islands, several initiatives were also conducted, including citizen science workshops and events for the management of the marine ecosystem and sea-atmosphere interaction. Infrastructures and data for weather-marine monitoring were made available to the AMP.

The data collected in Lampedusa contribute to the main global observation networks crucial to understand climate and its mechanisms, including:
studies on the interaction, distribution and characteristics of atmospheric components such as clouds and aerosols (the latter of natural and anthropic origin), and their effects on the earth's radiation balance, also in the context of the European infrastructure ACTRIS (Aerosols, Clouds, and Trace Gases Research InfraStructure);
studies on the evolution of greenhouse gases and the role of the ocean and vegetation in the carbon cycle within the European research infrastructure ICOS (Integrated Carbon Observation System);
atmospheric measurements of greenhouse gas concentrations that contribute to the Global Atmosphere Watch(GAW) – the global network for the study of climate change comprising around 80 countries within the World Meteorological Organization (WMO);
monitoring of greenhouse gases within the Global Greenhouse Gas Reference Network of NOAA (National Oceanic and Atmospheric Administration, USA);
measurements for the characterization of aerosols in the atmospheric column within the NASA AERONET(AErosol RObotic NETwork);
studies on the properties of the water column, also within the national network of the European infrastructure EMSO (European Multidisciplinary Sea Floor and Water Column Observatory)
activities on pollution within the PULVIRUS project conducted by ENEA, ISS and SNPA;
collaborations with national and international institutions for the measurement of ozone concentration and the chemical-physical properties of atmospheric particulate matter (PM) and for ionospheric and seismic measurements.