Global changes alter the amount and composition of land carbon deliveries to European rivers and seas

Lateral carbon transfer along the land-ocean continuum is a key component of global carbon cycle, yet its response to global change is poorly quantified. Here, we use a land-surface model to simulate vertical (soil-plant-atmosphere) and lateral (land-river-ocean) carbon exchanges in Europe between 1901–2014 and investigate the effect of atmospheric carbon dioxide, climate and land use changes on lateral carbon transfer. We find that global change during 1901–2014 led to a significant increase in the total terrestrial carbon delivery to European rivers (33% increase) and to the sea (20% increase). Carbon delivery increased in the dissolved phase and decreased in the particulate phase. Climate change, increased atmospheric carbon dioxide, and land-use change explain 62%, 36% and 2% of the temporal change in European lateral carbon transfer during the study period, respectively. Our findings suggest that redistribution of soil carbon due to lateral carbon transfer induced a 5% reduction in the net land carbon sink in Europe.