标题：Biogeophysical impacts of forestation in Europe first results from the LUCAS (Land Use and Climate Across Scales) regional climate model intercomparison
摘要：The Land Use and Climate Across Scales Flagship PilotStudy (LUCAS FPS) is a coordinated community effort to improve theintegration of land use change (LUC) in regional climate models (RCMs) andto quantify the biogeophysical effects of LUC on local to regional climatein Europe. In the first phase of LUCAS, nine RCMs are used to explore thebiogeophysical impacts of re-/afforestation over Europe: twoidealized experiments representing respectively a non-forested and amaximally forested Europe are compared in order to quantify spatial andtemporal variations in the regional climate sensitivity to forestation. Wefind some robust features in the simulated response to forestation. Inparticular, all models indicate a year-round decrease in surface albedo,which is most pronounced in winter and spring at high latitudes. Thisresults in a winter warming effect, with values ranging from +0.2 to +1K on average over Scandinavia depending on models. However, there are also anumber of strongly diverging responses. For instance, there is no agreementon the sign of temperature changes in summer with some RCMs predicting awidespread cooling from forestation (well below −2 K in most regions), awidespread warming (around +2 K or above in most regions) or a mixedresponse. A large part of the inter-model spread is attributed to therepresentation of land processes. In particular, differences in thepartitioning of sensible and latent heat are identified as a key source ofuncertainty in summer. Atmospheric processes, such as changes in incomingradiation due to cloud cover feedbacks, also influence the simulatedresponse in most seasons. In conclusion, the multi-model approach we usehere has the potential to deliver more robust and reliable information tostakeholders involved in land use planning, as compared to results based onsingle models. However, given the contradictory responses identified, ourresults also show that there are still fundamental uncertainties that needto be tackled to better anticipate the possible intended or unintendedconsequences of LUC on regional climates.
