Alex de Vries is a researcher at the School of Business and Economics at the Vrije Universiteit Amsterdam. In 2014 he founded digiconomist.net, which is best known for featuring the Bitcoin Energy Consumption Index since late 2016 and has played a major role in the global discussion regarding the sustainability of cryptocurrencies and blockchain technology. Ulrich Gallersdörfer is a research associate in the Department of Informatics at the Technical University of Munich. His research focuses on the intersection of blockchain technology and adjacent fields. He is a co-founder of CCRI, a company providing GHG emissions estimates for investments in cryptocurrencies, blockchain, and other technologies. Lena Klaaßen is a PhD student in the Climate Finance and Policy group at ETH Zurich. Her research focuses on energy finance for the low-carbon transition as well as the environmental impact of companies and technologies. She also co-founded CCRI, a company providing GHG emissions estimates for investments in cryptocurrencies, blockchain, and other technologies. Christian Stoll is a research affiliate at the Center for Energy and Environmental Policy Research at the Massachusetts Institute of Technology and at the Center for Energy Markets of the Technical University of Munich. His research focuses on the implications of climate change from an economic point of view.