
A new study found discrepancies among four state-of-the-art emission inventories.
The review on methodologies for quantifying emissions from open vegetation fires and the data provided by the inventories has been published in the journal Science of the Total Environment and involves a research team from CNR-ISAC, in collaboration with the CNR Institute for Mediterranean Agricultural and Forestry Systems (CNR-ISAFOM), the Scuola Universitaria Superiore Pavia (IUSS) and the University of Urbino.
The study compared climate-altering gas emissions from open vegetation fires in the Mediterranean region between 2003 and 2020 for four inventories (GFAS, GFED, FINN and EDGAR). The focus was on emissions of carbon dioxide, methane, nitrous oxide and black carbon.
Although these inventories recorded the same emission peaks for particularly fire-affected years in the region (2007, 2012 and 2017), the comparison showed significant differences in quantifying GHG and black carbon emissions. ‘Discrepancies in emissions were attributed to differences in fire detection methods, spatial resolutions, and emission factor assumptions.’ - explains Rabia Ali Hundal, author of the study and PhD student at the Scuola Universitaria Superiore Pavia and the University of Urbino and associate at CNR-ISAC - ‘These discrepancies underscore the need for harmonised methodologies to improve the reliability of emission estimates.’
The researchers also noted that the years with peak emissions due to open vegetation fires in the Mediterranean were characterised by La Niña events, the cold counterpart of El Niño and which together constitute an oscillatory phenomenon (El Niño Southern Oscillation, ENSO) affecting the Pacific Ocean and atmosphere and capable of conditioning the global climate in the short term.
In this sense, ‘ENSO may have played a role in determining part of the observed inter-annual variability of GHG and BC emissions associated with open vegetation fires in the Mediterranean region,’ the study states. ‘However, due to the rather short period considered in our analysis work and the complex interactions of several factors influencing the occurrence of forest fires in the Mediterranean, further and more specific studies are needed to consolidate this possible relationship,’ Hundal continues.
This research underlines the importance of improving systems to quantify emissions and support research in this direction. Future studies could in fact develop consistent methodologies, integrating satellite and ground-based data and using systems already used in other emission sectors. ‘In particular, what we suggest is that top-down emission assessment techniques could also be attempted for open vegetation fires, i.e. based on the combined use of atmospheric concentration data of climate-altering substances collected from ground and satellite stations with simulations of atmospheric transport,’ - explains Paolo Cristofanelli of CNR-ISAC, author of the study - ‘This would allow independent estimates to be compared with the numbers provided by inventories such as those we analysed in our work.’
Improving emission inventories would therefore allow the development of evidence-based strategies for fire prevention and effective climate change mitigation, especially at the local and regional level.