In 4°C, Ruhl and Craig acknowledge that the Earth’s climate is changing at an increasingly rapid rate, outside the range to which society has adapted in the past. Realistically, achieving the goal set in the 2015 Paris Agreement of limiting global warming to 1.5°C will be almost unattainable without drastic actions to reduce greenhouse gas emissions. Ruhl and Craig acknowledge these trends and highlight the critical importance of concurrent governance efforts to both mitigate emissions of greenhouse gases to limit the rate of warming and anticipatorily adapt for inevitable impacts. But they go a step further, arguing that barring rapid global political, social, and technological transformations, we will be fortunate to limit temperature rise to 2.0°C and the possibility of reaching 4°C cannot be ignored. Whether or not one believes a 4°C world is likely, this Comment asserts that investments in anticipatory adaptation are critically important now.