This document discusses carbon dioxide removal as a means of addressing climate change. It notes that all pathways to limiting global warming to 1.5°C involve the use of carbon dioxide removal techniques to compensate for remaining emissions and achieve net negative emissions. Specifically, it will require removing 100-1000 gigatons of carbon dioxide from the atmosphere this century. However, large-scale deployment of carbon dioxide removal poses feasibility and sustainability challenges. Near-term emissions reductions can help limit required removal to a few hundred gigatons without relying heavily on bioenergy with carbon capture and storage. The document outlines natural carbon dioxide removal methods like afforestation as well as technological approaches.