Descrizione del progetto
Ripercussioni delle emissioni di gas serra provenienti dai fiumi sui cambiamenti climatici
Gli scienziati non sono ancora in grado di quantificare in che modo le emissioni fluviali di CO2 e CH4 influiranno sul futuro riscaldamento del clima. Il progetto RIV-ESCAPE, finanziato dall’UE, combinerà quindi il flusso fluviale di CO2 e CH4, le dinamiche di flusso dei fiumi e la fornitura di carbonio con una risoluzione da minuti a ore su scale temporali stagionali. I ricercatori si concentreranno sui fiumi artici, che sono soggetti a un forte riscaldamento e che conservano grandi riserve di carbonio antico nei suoli. RIV-ESCAPE applicherà inoltre la geochimica isotopica ai gas, alle acque e ai sedimenti dei fiumi per quantificare i controlli sull’età e sulla fonte di CO2 e CH4 nei fiumi di tutto il mondo. I risultati contribuiranno a determinare la sensibilità delle emissioni fluviali di CO2 e CH4 al riscaldamento futuro.
Obiettivo
Rivers around the world release large quantities of greenhouse gas, with an estimated 1.8 ± 0.3 PgC yr-1 released as carbon dioxide (CO2), and ~20-25 TgC yr-1 as methane (CH4). These fluxes are equivalent to half of the annual increase in CO2 and CH4 concentrations in the atmosphere due to human activities. However, we cannot yet quantify how river CO2 and CH4 emissions will change, nor assess their potential to amplify future climate warming. There are two main challenges: i) the main drivers of CO2 and CH4 release from rivers (supply of carbon and the dynamics of river flow) change simultaneously, and their relative importance is obscured in existing data, limiting our ability to build and test predictive models; ii) the age of river CO2 and CH4 is poorly constrained, meaning that we cannot determine whether this is anthropogenic carbon that is leaking out from prior storage on land, or whether it derives from ancient carbon stores in the landscape.
RIV-ESCAPE will transform our understanding by recognising the need for direct measurements that combine river CO2 and CH4 flux, river flow dynamics and C supply at high temporal resolution (minutes to hours) over seasonal timescales, across nested scales in river catchments. Such novel field installations could be used anywhere to improve our understanding: we will focus on Arctic rivers that are experiencing pronounced warming and hold large stores of ancient carbon in soils. In parallel, we will use cutting-edge isotope geochemistry methods for river gases, waters and sediments to quantify the controls on the age and source of CO2 and CH4 in rivers around the world. The new empirical data will combine with physical and numerical experiments to provide a step-change in our knowledge of how changes in temperature and precipitation set river greenhouse gas source and the rate of release, allowing us to assess for the first time the sensitivity of river CO2 and CH4 emissions to future warming.
Campo scientifico
Parole chiave
Programma(i)
Argomento(i)
Meccanismo di finanziamento
ERC-COG - Consolidator GrantIstituzione ospitante
OX1 2JD Oxford
Regno Unito