Abstract
The scientific community has produced increasingly robust knowledge and evidence of the physical impacts of warming on time scales of tens of decades and longer. However, the social and humanitarian impacts of climate overshoot remain largely unknown. As we quickly approach the Paris Agreement's aspirational target of 1.5 °C of global mean temperature rise, new and dynamic climate and social realities of climate overshoot must be considered and managed. Here, we outline 5 factors influencing human and social climate overshoot impacts, describe potential post-peak behavior that would lead to varied impacts, and call for enhancing action to fill pressing knowledge, data, and policy gaps to understand the risks to human and social systems.