He has worked extensively with stakeholders in participatory research projects and led large interdisciplinary research teams. He has published about 200 peer-reviewed research articles on topics such as climate change adaptation and mitigation, participatory modelling, management of ecosystems services, land use change and governance. His research has been supported by national agencies in Austria, the Czech Republic, China, Japan, Spain, the UK, and the U.S. and international institutions such as the European Commission, the Interamerican Development Bank and the World Bank.

Klaus is currently also a visiting professor in geographical sciences at the University of Maryland, College Park and affiliated with the International Institute for Applied Systems Analysis (IIASA), Austria. Previously he worked or held visiting positions at the University of Leeds, UK; the Chinese Academy of Sciences, Beijing Normal University, China; Shandong University, China; the University of Cambridge, UK. Klaus has been recently involved in building an integrated climate assessment model funded by Horizon 2020 and on forecasting carbon emissions funded by NASA. He is recognized as a highly cited researcher with multiple papers in the top 1% by citations. Klaus was a lead author of the most recent 6th assessment report of the UN’s Intergovernmental Panel on Climate Change (IPCC).