clearThe Arctic Science Summit Week (ASSW) 2021 - The Arctic: Regional Changes, Global Impacts was organized from 19-26 March 2021online (Lisboa,Portugal) by the International Arctic Science Committee (IASC) and co-hosted by the Instituto Superior Técnico - the University of Lisbon, the Fundação para a Ciência e Tecnologia, and Ciência Viva. Due to COVID-19 pandemic, ASSW 2021 was held entirely online.