@article{KalkuhlSchwerhoffWaha2020,
  author    = {Kalkuhl, Matthias and Schwerhoff, Gregor and Waha, Katharina},
  title     = {Land tenure, climate and risk management},
  series = {Ecological economics},
  volume    = {171},
  journal   = {Ecological economics},
  publisher = {Elsevier Science},
  address   = {Amsterdam [u.a.]},
  issn      = {0921-8009},
  doi       = {10.1016/j.ecolecon.2019.106573},
  pages     = {16},
  year      = {2020},
  abstract  = {We analyze to what extent climate conditions affect the prevalence of sharecropping as a form of traditional land tenure. We investigate how sharecropping tenure is related to climate risk and how it interacts with fertilizer use and livestock ownership that both influence production risk. We first develop a stylized theoretical model to illustrate the role of climate for land tenure and production. Our empirical analysis is based on more than 9000 households with considerable heterogeneity in climate conditions across several African countries. We find that farmers in areas with low precipitation are more likely to be sharecroppers. We further find evidence for risk management interaction effects as sharecropping farmers are less likely to own livestock and more likely to use fertilizer. In economies where formal kinds of insurance are unavailable, sharecropping thus functions as a form of insurance and reduces the need for potentially costly risk management strategies.},
  language  = {en}
}
@article{WahaZipfKurukulasuriyaetal.2016,
  author    = {Waha, Katharina and Zipf, Birgit and Kurukulasuriya, Pradeep and Hassan, Rashid M.},
  title     = {An agricultural survey for more than 9,500 African households},
  series = {Scientific Data},
  volume    = {3},
  journal   = {Scientific Data},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2052-4463},
  doi       = {10.1038/sdata.2016.20},
  pages     = {8},
  year      = {2016},
  abstract  = {Surveys for more than 9,500 households were conducted in the growing seasons 2002/2003 or 2003/2004 in eleven African countries: Burkina Faso, Cameroon, Ghana, Niger and Senegal in western Africa; Egypt in northern Africa; Ethiopia and Kenya in eastern Africa; South Africa, Zambia and Zimbabwe in southern Africa. Households were chosen randomly in districts that are representative for key agro-climatic zones and farming systems. The data set specifies farming systems characteristics that can help inform about the importance of each system for a country's agricultural production and its ability to cope with short- and long-term climate changes or extreme weather events. Further it informs about the location of smallholders and vulnerable systems and permits benchmarking agricultural systems characteristics.},
  language  = {en}
}
@article{KarpTallisSachseetal.2015,
  author    = {Karp, Daniel S. and Tallis, Heather and Sachse, Rene and Halpern, Ben and Thonicke, Kirsten and Cramer, Wolfgang and Mooney, Harold and Polasky, Stephen and Tietjen, Britta and Waha, Katharina and Walt, Ariane and Wolny, Stacie},
  title     = {National indicators for observing ecosystem service change},
  series = {Global environmental change : human and policy dimensions},
  volume    = {35},
  journal   = {Global environmental change : human and policy dimensions},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0959-3780},
  doi       = {10.1016/j.gloenvcha.2015.07.014},
  pages     = {12 -- 21},
  year      = {2015},
  abstract  = {Earth's life-support systems are in rapid decline, yet we have few metrics or indicators with which to track these changes. The world's governments are calling for biodiversity and ecosystem-service monitoring to guide and evaluate international conservation policy as well as to incorporate natural capital into their national accounts. The Group on Earth Observations Biodiversity Observation Network (GEO BON) has been tasked with setting up this monitoring system. Here we explore the immediate feasibility of creating a global ecosystem-service monitoring platform under the GEO BON framework through combining data from national statistics, global vegetation models, and production function models. We found that nine ecosystem services could be annually reported at a national scale in the short term: carbon sequestration, water supply for hydropower, and non-fisheries marine products, crop, livestock, game meat, fisheries, mariculture, and timber production. Reported changes in service delivery over time reflected ecological shocks (e.g., droughts and disease outbreaks), highlighting the immediate utility of this monitoring system. Our work also identified three opportunities for creating a more comprehensive monitoring system. First, investing in input data for ecological process models (e.g., global land-use maps) would allow many more regulating services to be monitored. Currently, only 1 of 9 services that can be reported is a regulating service. Second, household surveys and censuses could help evaluate how nature affects people and provides non-monetary benefits. Finally, to forecast the sustainability of service delivery, research efforts could focus on calculating the total remaining biophysical stocks of provisioning services. Regardless, we demonstrated that a preliminary ecosystem-service monitoring platform is immediately feasible. With sufficient international investment, the platform could evolve further into a much-needed system to track changes in our planet's life-support systems. (C) 2015 Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@phdthesis{Waha2012,
  author    = {Waha, Katharina},
  title     = {Climate change impacts on agricultural vegetation in sub-saharan africa},
  address   = {Potsdam},
  pages     = {156 S.},
  year      = {2012},
  language  = {en}
}
@phdthesis{Waha2012,
  author    = {Waha, Katharina},
  title     = {Climate change impacts on agricultural vegetation in sub-Saharan Africa},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64717},
  school      = {Universit{\"a}t Potsdam},
  year      = {2012},
  abstract  = {Agriculture is one of the most important human activities providing food and more agricultural goods for seven billion people around the world and is of special importance in sub-Saharan Africa. The majority of people depends on the agricultural sector for their livelihoods and will suffer from negative climate change impacts on agriculture until the middle and end of the 21st century, even more if weak governments, economic crises or violent conflicts endanger the countries' food security. The impact of temperature increases and changing precipitation patterns on agricultural vegetation motivated this thesis in the first place. Analyzing the potentials of reducing negative climate change impacts by adapting crop management to changing climate is a second objective of the thesis. As a precondition for simulating climate change impacts on agricultural crops with a global crop model first the timing of sowing in the tropics was improved and validated as this is an important factor determining the length and timing of the crops´ development phases, the occurrence of water stress and final crop yield. Crop yields are projected to decline in most regions which is evident from the results of this thesis, but the uncertainties that exist in climate projections and in the efficiency of adaptation options because of political, economical or institutional obstacles have to be considered. The effect of temperature increases and changing precipitation patterns on crop yields can be analyzed separately and varies in space across the continent. Southern Africa is clearly the region most susceptible to climate change, especially to precipitation changes. The Sahel north of 13° N and parts of Eastern Africa with short growing seasons below 120 days and limited wet season precipitation of less than 500 mm are also vulnerable to precipitation changes while in most other part of East and Central Africa, in contrast, the effect of temperature increase on crops overbalances the precipitation effect and is most pronounced in a band stretching from Angola to Ethiopia in the 2060s. The results of this thesis confirm the findings from previous studies on the magnitude of climate change impact on crops in sub-Saharan Africa but beyond that helps to understand the drivers of these changes and the potential of certain management strategies for adaptation in more detail. Crop yield changes depend on the initial growing conditions, on the magnitude of climate change, and on the crop, cropping system and adaptive capacity of African farmers which is only now evident from this comprehensive study for sub-Saharan Africa. Furthermore this study improves the representation of tropical cropping systems in a global crop model and considers the major food crops cultivated in sub-Saharan Africa and climate change impacts throughout the continent.},
  language  = {en}
}