Regional climate model simulations for Europe at 6 and 0.2 k BP: sensitivity to changes in anthropogenic deforestation

Abstract

Abstract. This study aims to evaluate the direct effects of anthropogenic deforestation on simulated climate at two contrasting periods in the Holocene, ∼ 6 and ∼ 0.2 k BP in Europe. We apply We apply the Rossby Centre regional climate model RCA3, a regional climate model with 50 km spatial resolution, for both time periods, considering three G. Strandberg et al.: Sensitivity to changes in anthropogenic deforestationfrom the KK10 scenario (V + KK10). The climate model results show that the simulated effects of deforestation depend on both local/regional climate and vegetation characteristics. At ∼ 6 k BP the extent of simulated deforestation in Europe is generally small, but there are areas where deforestation is large enough to produce significant differences in summer temperatures of 0.5-1 • C. At ∼ 0.2 k BP, extensive deforestation, particularly according to the KK10 model, leads to significant temperature differences in large parts of Europe in both winter and summer. In winter, deforestation leads to lower temperatures because of the differences in albedo between forested and unforested areas, particularly in the snow-covered regions. In summer, deforestation leads to higher temperatures in central and eastern Europe because evapotranspiration from unforested areas is lower than from forests. Summer evaporation is already limited in the southernmost parts of Europe under potential vegetation conditions and, therefore, cannot become much lower. Accordingly, the albedo effect dominates in southern Europe also in summer, which implies that deforestation causes a decrease in temperatures. Differences in summer temperature due to deforestation range from −1 • C in south-western Europe to +1 • C in eastern Europe. The choice of anthropogenic landcover scenario has a significant influence on the simulated climate, but uncertainties in palaeoclimate proxy data for the two time periods do not allow for a definitive discrimination among climate model results.

Are pollen records from small sites appropriate for REVEALS model-based quantitative reconstructions of past regional vegetation? An empirical test in southern Sweden

“…Climate models generally use descriptions of land vegetation including few large units with comparable plant functional types, such as the LCTs used here (e.g. Strandberg et al 2014). Pollen-based reconstructions over large areas for climate modelling will unavoidably require that small sites are used because there are too few pollen records from large lakes.…”

“…Nielsen and Odgaard 2010;Cui et al 2013Cui et al , 2014Mazier et al 2015;Hultberg et al 2015), (ii) the study of regional spatio-temporal land-cover/landscape dynamics over the past millennia (e.g. Marquer et al 2014;Fyfe et al 2013;Nielsen et al 2012;Trondman 2014), (iii) the evaluation of anthropogenic land-cover change scenarios (ALCCs) (Gaillard et al 2010) and (iv) the study of land cover-climate interactions in the past (Strandberg et al 2014). Recently, Pirzamanbein et al (2014) developed a set of statistical models to create spatially continuous maps of past land cover by combining (i) pollen-based REVEALS ''point estimates'' of past land cover and (ii) spatially continuous estimates of past land cover, obtained by merging simulated potential vegetation (using the LPJ-GUESS model; Smith et al 2001) with an anthropogenic land-cover change scenario (KK10; Kaplan et al 2009).…”

The PMIP4 contribution to CMIP6 – Part 3: The last millennium, scientific objective, and experimental design for the PMIP4 <i>past1000</i> simulations

“…In parts of the world where ALCC led to quasi-permanent deforestation and where climate is tightly coupled to land surface conditions, we might expect regional climate to have been strongly influenced by biogeophysical feedbacks (e.g. Cook et al, 2012;Dermody et al, 2012;Pongratz et al, 2009;Strandberg et al, 2014). Additionally, permanent deforestation and loss of soil carbon as a result of cultivation (e.g.…”

Constraining the Deforestation History of Europe: Evaluation of Historical Land Use Scenarios with Pollen-Based Land Cover Reconstructions

“…ALCC scenarios have been used to estimate the impact of humans on the carbon cycle [26], regional and global climate [20,27,28], freshwater and marine ecosystems [29], geomorphology and landscape dynamics [23,30] and biodiversity [31,32], among others. Despite their utility, the evaluation of ALCC models and their scenarios has received relatively little attention [33].…”