Future challenges of representing land-processes in studies on land-atmosphere interactions

[摘要] Over recent years, it has become increasingly apparentthat climate change and air pollution need to be considered jointly forimproved attribution and projections of human-caused changes in the Earthsystem. Exchange processes at the land surface come into play in thiscontext, because many compounds that either act as greenhouse gases, aspollutant precursors, or both, have not only anthropogenic but alsoterrestrial sources and sinks. And since the fluxes of multiple gases andparticulate matter between the terrestrial biota and the atmosphere aredirectly or indirectly coupled to vegetation and soil carbon, nutrient andwater balances, quantification of their geographic patterns or changes overtime requires due consideration of the underlying biological processes. Inthis review we highlight a number of critical aspects and recent progress inthis respect, identifying in particular a number of areas where studies haveshown that accounting for ecological process understanding can alter globalmodel projections of land-atmosphere interactions substantially.Specifically, this concerns the improved quantification of uncertainties anddynamic system responses, including acclimation, and the incorporation ofexchange processes that so far have been missing from global models eventhough they are proposed to be of relevance for our understanding ofterrestrial biota-climate feedbacks. Progress has also been made regardingstudies on the impacts of land use/land cover change on climate change, butthe absence of a mechanistically based representation of humanresponse-processes in ecosystem models that are coupled to climate modelslimits our ability to analyse how climate change or air pollution in turnmight affect human land use. A more integrated perspective is necessary andshould become an active area of research that bridges the socio-economic andbiophysical communities.

[学科分类] 地球化学与岩石