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Peter K. Snyder

surface temperature that can drive changes in atmospheric heating and deep convection, may affect the tropical circulation regime and their communication to the extratropics (e.g., Hoskins and Karoly 1981 ; Trenberth et al. 1998 ). Interestingly, tropical land-use change may initiate heating anomalies and an atmospheric response that are similar to that generated during an El Niño–Southern Oscillation (ENSO) event. The analogy between tropical deforestation (a relatively slow process, occurring over

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Paulo Nobre, Marta Malagutti, Domingos F. Urbano, Roberto A. F. de Almeida, and Emanuel Giarolla

1. Introduction Several studies have investigated the effects of Amazon deforestation on regional climate variability and change (e.g., Henderson-Sellers and Gornitz 1984 ; Nobre et al. 1991 ; Zeng et al. 1996 ; Werth and Avissar 2002 ; Voldoire and Royer 2005 ; Schneider et al. 2006 ). Although the conclusions of such studies are dependent on a number of parameterized processes [e.g., convection schemes on atmospheric general circulation models (AGCMs)], there is a general agreement that

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Xuefeng Cui, Hans-F. Graf, Baerbel Langmann, Wen Chen, and Ronghui Huang

1. Introduction Large-scale land cover changes in general can result in dramatic climate changes (e.g., Charney 1975 ) through biogeophysical effects ( Brovkin et al. 2004 ) or via biogeochemical feedbacks ( Sitch et al. 2005 ), for example, affecting hydrological cycle intensity (e.g., Avissar and Werth 2005 ) or atmospheric chemistry (e.g., Ganzeveld and Lelieveld 2004 ). During the last two decades, tropical deforestation (e.g., Henderson-Sellers and Gornitz 1984 ), such as in the Amazon

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Douglas C. Morton, Ruth S. DeFries, Yosio E. Shimabukuro, Liana O. Anderson, Fernando Del Bon Espírito-Santo, Matthew Hansen, and Mark Carroll

1. Introduction Deforestation in the humid Tropics is a conspicuous change in land use with myriad impacts on global carbon (e.g., Houghton et al. 2000 ) and climate (e.g., Salati and Nobre 1991 ; Werth and Avissar 2002 ). Deforestation rates in tropical Africa, Southeast Asia, and South America have remained constant or increased over the past two decades ( DeFries et al. 2002 ), elevating the need for frequent and accurate assessment of forest loss. In Brazil, the continued expansion of

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Natalia Hasler, David Werth, and Roni Avissar

1. Introduction Numerous simulations of tropical deforestation suggest that replacing rain forests with grassland would decrease precipitation and evaporation and increase surface temperature over the deforested area (see Henderson-Sellers et al. 1993 for a review). Typically conducted over Amazonia ( Henderson-Sellers and Gornitz 1984 ; Dickinson and Henderson-Sellers 1988 ; Eltahir and Bras 1993 ; Lean and Rowntree 1993 ; da Rocha et al. 1996 ; Costa and Foley 2000 ; Gedney and Valdes

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Nilson Clementino Ferreira, Laerte Guimarães Ferreira, and Fausto Miziara

since the early 1970s ( Skole et al. 1994 ). Interestingly, even after the boom of such initiatives and the adoption of environmental policies concerning the conservation of the natural resources in the 1990s, the pace of forest conversion did not decrease. In fact, clearcutting rates are continuously increasing, currently approaching nearly 2 Mha (million hectares) yr −1 (INPE 2000, unpublished manuscript). Although these deforestations have been closely monitored since 1978 with the help of

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Edouard L. Davin and Nathalie de Noblet-Ducoudré

forest cover has been converted to pasture or cropland ( Goldewijk 2001 ). Historically, the largest part of this conversion affected temperate forests in Eurasia and North America ( Ramankutty and Foley 1999 ; Goldewijk 2001 ). Over the last decades, however, the rate of deforestation strongly accelerated in tropical regions and it is projected that a large part of the tropical forest will be lost by the end of the twenty-first century ( Alcamo et al. 1994 ). Yet the biogeophysical effect of these

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C. Kendra Gotangco Castillo and Kevin Robert Gurney

1. Introduction Deforestation and forest degradation continue to be a significant contributors to total anthropogenic carbon dioxide (CO 2 ) emissions, with Intergovernmental Panel on Climate Change (IPCC) estimates at 20% between 1989 and 1998 ( Robledo and Blaser 2008 ; Nabuurs et al. 2007 ), updated to 12% by Van der Werf et al. ( Van der Werf et al. 2009 ). Tropical deforestation, in particular, is projected to remain high, particularly in Africa and South America, until 2050 ( Nabuurs et

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Tom Akkermans, Wim Thiery, and Nicole P. M. Van Lipzig

.0 × 10 4 m 2 ) of vast primary forest ( Mayaux and Malingreau 2001 ). The principal driver of deforestation in this region is forest clearing for agriculture ( Norris et al. 2010 ), mainly in the form of shifting cultivation ( Russell et al. 2011 ). Because of increasing human population growth rates, the demand for agricultural land in the Congo basin may increase by 100% the next 20 years ( Zhang et al. 2006 ), which is a reason for concern since the farmers lack any incentive for production

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David Medvigy, Robert L. Walko, Martin J. Otte, and Roni Avissar

1. Introduction Many numerical models have predicted that Amazon deforestation would lead to local increases in surface temperature and decreases in precipitation ( Henderson-Sellers et al. 1993 ; Lean and Rowntree 1993 ; Gash and Nobre 1997 ; Hahmann and Dickinson 1997 ; Costa and Foley 2000 ; Gedney and Valdes 2000 ; Werth and Avissar 2002 ; Avissar and Werth 2005 ; Findell et al. 2006 ; Sampaio et al. 2007 ; Hasler et al. 2009 ; Medvigy et al. 2011 ). Using numerical models, some

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