EGU2024: Highlights from the PARIS Consortium’s Contributions

The European Geosciences Union (EGU) General Assembly 2024 was a significant event for scientific exchange, and the PARIS consortium made a notable impact with over ten contributions. Despite being only running for a bit more than a year, PARIS showcased rapid progress and collaborative efforts in improving greenhouse gas (GHG) and aerosol emissions data to support the Paris Agreement. 

Annadate et al. presented their results about the emissions of HFC-134a, a common refrigerant with significant global warming potential. Observations indicated a decrease in HFC-134a emissions over the past decade, but a recent resurgence was noted, particularly in Italy. This study emphasized the importance of real-time validated observations to track and verify national emissions inventories effectively. Another innovative approach presented by van der Woude et al. was integrating biomass data with atmospheric CO₂ measurements to better understand biosphere carbon fluxes, initially focusing on Europe. This method aims to provide more accurate estimates of carbon sinks and sources, offering valuable insights for climate action. Additionally, Lei et al. presented a detailed analysis of submicron aerosol composition in Ireland, revealing significant improvements in air quality since the 1990s due to regulations like the smoky coal ban.

The PARIS project also expanded high-resolution methane isotope measurements to Cluj-Napoca, Romania, to better understand methane sources in the region (van Es et al.). Preliminary results suggest a mix of leakages from the gas network and microbial sources, with significant contributions from urban areas. Also a new tower station, equipped with a novel, optimised and compact gas handling system in Hungary was introduced (Molnar et al.).

Researchers assessed nitrous oxide (N₂O) emissions in the UK and Switzerland, finding discrepancies between atmospheric data and national inventory reports, emphasizing the importance of independent verification methods (Saboya et al). Despite reported declines in SF6 emissions, observations indicated ongoing emissions in southern Germany, highlighting the need for continuous monitoring (Meixner et al).

The conference also featured advancements in mid-IR absorption spectroscopy for measuring methane and ethane, helping differentiate between thermogenic and biogenic methane sources (Mohn et al.), and a detailed protocol for post-processing N2O isotope data from cavity ring-down spectroscopy (CRDS) analyzers to standardize data quality (Havsteen et al.). Overall, the EGU2024 showcased the PARIS consortium’s significant contributions to advancing our understanding of GHG emissions and improving the tools and methods used for climate action.

A dedicated splinter meeting to facilitate face-to-face interactions was organised ((https://meetingorganizer.copernicus.org/EGU24/session/50668), highlighting the collaboration between PARIS and its two Horizon Europe sister projects AVENGERS and EYE-CLIMA. The projects focus on reconciling national emissions estimates and enhancing national greenhouse gas inventories (NGHGIs) through observation-based methods combined with inverse modelling. This collaboration involves engaging with stakeholders, including policymakers, government entities, NGOs, and other relevant parties. The session was intended to meet in person, discuss joint activities and build networks. Key discussions focused on terminology, practices, and collaboration among projects. Particularly sector definitions across projects, intercomparisons EU practices across countries and the need for mandatory data sharing protocols and formats, the use of an ensemble of transport models, and exploring differences in meteorological inputs was discussed. Outreach efforts highlighted the importance of joint webinars, targeted communication on methodologies, and progress reports. Topic-focused seminars were suggested and the importance of clear messaging regarding targets and additional reduction measures was highlighted.

A joint poster on the collaboration between our three sister projects was prepared by PARIS and presented by Nalini Krishnankutty from EYE-CLIMA.

Looking forward to the next EGU!