Earth Day is widely recognised as the largest secular observance in the world, marked by more than a billion people every year as a day of action to change human behaviour and provoke policy changes. This day recognises and celebrates the Earth and its ecosystems as our home and highlights the need to protect earth to enhance people’s livelihoods, counteract climate change, and stop the collapse of biodiversity. To raise awareness of Earth Day 2021, Elsevier presents a curated list of free access journal articles and book chapters in support of this year's theme - Restore our Earth.